Re:Days of denial are over.
on
Baked Alaska
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· Score: 1
Much of the data is indeed flawed. It is riddled with assumptions and inconsistencies. It depends on long chains of assumptions. For example, sea temperature data has been inferred from characteristics of coral growth. And yet just in the last month a paper was published (Science) showing that the coral growth is significantly affected by other factors, blowing away that assumption. Tree rings are used as a substitute for temperature or precipitation data, but have been shown to be unreliable in many cases. Other data is significantly contaminated - I am using one such data set right now.
Indeed... not only that, but let's also not forget that even with recent data, there are problems with the methodologies.
How many of these weather stations that we're using for data collection are now surrounded by urban heat islands where they weren't 50 years ago? It's known as a fact that urban heat islands do exist and have local effects on temperature and humidity.
Now, let's see here... increased urbanization raises the temperature of 25% of the recording stations by 1 degree Celsuis, just as a local effect... that produces a 0.25 degree Celsius "average" increase in "global temperatures", even though urban areas take up a very insignificant amount of the area of the globe.
Is this "rise" real? Possibly... but the data is contaminated in more ways than one. Urban/local effects, improvements in equipment (I can link to multiple stories about the error bars on old equipment, but don't feel like digging those up), changes in equipment (see the May 2002 issue of the Bulletin of the American Meteorological Society, "When Was the Hottest Summer?", particularly the "Mysterious Climate Change?" sidebar), and many other factors affect the data we use to make these conjectures and forecasts. This is something that climatologists are struggling with... and I should know since I only help a few of them pretty often.
{begin rant}
The point is that even the conjecture of "global warming" can be brought into question. The real PROBLEM here is the media garbling the messages the climatologists really want to give out. The media (and public) assumes science is "cut and dry"; that there's one right answer and no uncertainty. In truth, though, very little is as black and white as an arithmetic test. That's why the National Weather Service recently started getting a little more wordy in their forecasts, calling for temperature ranges and precipitation chances rather than a specific temperature and time/type of precipitation. Hopefully, the media (and public) realize that much of what goes on in our world isn't as simple as the media makes it sound.
{end rant}
... way back in '94-96. We had a small cluster of 386-33's in the library that were used for research. There wasn't any internet access on those at the time, but they were networked via Novell to a small server that had all the library researching programs.
I was the resident computer nerd at the time and had gotten addicted to TradeWars on a local BBS. So, with some sweet-talking of the librarian in charge of the server and a promise to help out even more than I already was (I was the only one around that whole district at the time who could even remotely fix any of the Macs that were in some of the labs), I had TW set up on the system. For the two hours after school, a small group of us would play that. It was fun setting up the universe and all that and it got us talking and enjoying those dull hours between the end of school and dinner. (Except the nights some of us had to work on the school newspaper...)
We tried a bit of Doom and some of the other BBS network games, but the afternoons of TW will always stick in my memory.:) Ahhh... the joys of having 5000 turns a day, alliances and backstabbings, maxed ships.:)
We did that and also used the printer-networked Mac Classics to play Bolo... LOTS of Bolo.:) Bolo was a big drawing point to our little group. One of us would make a new map every month or so and we'd all play on it. Dang it, you're bringing back all these fond memories.
So, yeah, keep the games nights. Make sure to enforce fair play and decently long breaks for socialization. And keep the gore to a minimum. There's plenty of fun games out there. And also don't be afraid to do contests with single-player games... for example, we'd have Sim City races... first one to 10,000 population and $5000 wins. The Sim games can be good for those. Just be creative and don't fall into the same game every time. That keeps the minds fresh and the options interesting.
Well, somewhat. I did the ACM for three years in undergrad. I was (and still am) a little code hacker in the sense of being able to digest simple coding problems and get code out to work out those problems quite quickly. I am not a programmer, per se, since I actually kind of suck at doing large extended projects. *sheepish grin.* But at least I still got my minor in CS.
The contests weren't very helpful in and of themselves. But studying for them... that was helpful, at least for me. In studying for them, you get exposed to lots of interesting algorithms and different ways of attacking problems. Learning to "problem-solve" on your feet (or actually your tush) is not only lots of fun, but it's also one of those talents that it never hurts to develop.
Then, of course, there's the whole fun of time-managing. In the ACM, you have three people, one computer, and six hours. First time you do it, you realize that you're going to have to code on paper... and debug on paper... and figure out I/O on paper. (And anyone who has done one of these contests knows that I/O is the single nastiest part of the whole experience.) With the limited time and resources, you quickly find yourself having to visualize code and running it in your head or on paper in order to do well. And these talents are useful once again only because they are generally useful in programming. And all these can be worked on in practice, not just in the competition.
So, yes, the competition really just comes down to enjoying yourself and having fun. You get an idea to see how good of a quick programmer you are and how you stack up against the rest of the region/nation/world. It can be both a humbling and an exhilirating experience. The ACM, at six quick hours, is loads of fun, especially if your programming partners are a blast to be around. (Let's just say that that last hour, if you've either finished or given up on the remaining problems, can be filled with some very screwy things...;) )
The important things to get out of these competitions come from the practices and such beforehand. Learning the algorithms, learning to think about problems clearly and quickly, learning to put ideas together on your feet. Those talents are just generally useful in programming, and life in general.
First of all, my biggest pet peeve: the difference between weather and climate. Yes, believe it or not, climate and weather are two very different terms. They should not be used interchangably, thankyouverymuch. Three days does not a climate make.
Now, to continue on that thought, it's interesting to think about the consequences of this "study". (The quotation marks are supposed to be there.) I cannot say what I really think of this "study" since I haven't read their results, but I cannot be that easily convinced that three days worth of data compared to years worth of data has any possible statistical significance, especially in something like diurnal ranges, which are 15-30 degrees C anyways. Show me three months and I might be convinced of a trend. I can name at least 10 different three-day weather features that could cause such a blip and that's just off the top of my head.
Next, IF this is true, then it only highlights something which has bothered me about climate modeling from the frickin' beginning: the role of clouds and how terribly they are handled in these (and all) models. Of course, this isn't the only problem I have with these modeling studies, but we won't enter that debate right now.
The type of cloud present has an effect on the net change in radiative flux. Deep, thick clouds (like cumulus) have a net positive change while thin clouds (like cirrus) have a net negative change. The thing, though, is that in balance calculations like these, there tend to be two effects, which are approximately equal and opposite in sign. So, you end up wondering how much of it is really real. (For example, the two terms might be 220 and -218, leading to 2 change... but if you're off by a little bit, those numbers might actually be 219 and -220, leading to a -1.) This is further compounded by the way models handle clouds, which is often routinely terrible (with respect to resolution, the actual physics involved in the cloud which can affect all the results, and many other factors).
To further put all this in perspective, let's assume the albedo (the amount of solar radiation reflected back to space by the earth which is largely a function of the cloudiness) of the earth increases by 1%. (It's currently around 30% in a climatological sense... even that number has an error bar of measurement around +/- 3%.) On average, that would mean that the earth would get 3.4 W/m^2 less radiation. (Daily and spacial average of solar radiation is about 340 W/m^2, again largish errors on this measurement.) This number is comparable to the change by doubling CO2 (about 4 W/m^2) and, as you can notice, opposite in sign. Of course, there's a huge extra batch of physics here that isn't even being considered like the change of the absorption of IR radiation from the earth by the clouds or the release of latent heat by the clouds or the feedback between warmer surface temperatures and clouds (which is barely understood since it's almost as complex a problem as the original)... Kind of makes your head spin to think about all these effects, doesn't it? And all of them are about the same order of magnitude by itself, i.e. about 0.5-5 W/m^2, both positive and negative. Let's also not forget that local effects, like all those new urban heat islands that have popped up around all our temperature recording stations that could very well explain that temperature rise in the last century or whatever, and that these effects are not put into these models...
Complex problem? You bet. Possible to understand? Eventually, I don't see why not. But, we can't sit back and keep using these antiquated ideas in these state-of-the-art models. As the old saying goes, "Garbage in, Garbage out." The effects of these contrails may be important, yes. I cannot debate that. However, to claim that off of whatever insignificant sample this is, or using any of the ideas we currently have, is ludicrous at best. Any imbecile with a computer nowadays can run a correlation analysis on data. But, to interpret it and explain WHY things are happening that way... that's the vital connection between statistical tomfoolery and real science. Then, to explain the dynamics and theory behind it all... that's the step to making a full fledged theory.
... and a very poorly understood one, at that. Urban areas do tend to create what one might consider shallow, localized fronts.
It's well known that any atmospheric boundary can have effects on a storm, both in motion and intensity. It's also well-known that urban areas do have localized differences compared to their environment.
But it's not well-known what the overall effects might be. Severe thunderstorms are creatures that require moisture and the energy condensing it provides. In an urban heat island situation, the temperature is often higher, but the amount of moisture is only marginally higher. This actually tends to reduce the CAPE (Convective Available Potential Energy) of the urban area compared to its immediate environment. Also, the boundary of the urban heat island may act as a sort of "guide" for the storm to propogate on, much like fronts and outflow boundaries (cold, moist air from previous thunderstorms) often act.
But, the storm is also affected by the upper air steering flow. There's a certain slaving between the upper and lower levels that is beneficial to storm development and intensification. An urban heat island may modify this enough to make a difference... that much is possible.
However, in the case of your storm switching direction, that's actually a pretty common feature of tornadic storms, i.e. to change direction and move to the right of their previous movement vector. The dynamics of right-moving supercells (as they are called) are fairly well understood and widely accepted. So, to say that the storm turned strictly because of the city, in this case, is a little hard to believe. But, it's something that bears watching.
And I have noticed that "effect" of cities before. It does seem to be relatively common, as a sort of informal survey... but I'm not aware of any study that's fully addressed it yet.
Just looking at the loops there, especially the radial velocity loop (all of the loops were well-annotated, I must admit), I would be surprised if SPC and the local NWS office there didn't forecast this thing pretty well. I'm too lazy currently to go and do my own little search on all that, but does anyone have some of that information?
Now, if only I could see one of these on my scheduled chase coming up next week.;) Of course, I would heavily prefer it going through a nice empty field or forest in the middle of nowhere, with a road running parallel to its path, keeping me a mile or so south/southeast of the mesocyclone at any one time.;) Of course, we all have to have dreams.
There is a certain bit of predictability to tornado prediction. It is well-documented that the vast majority of tornadoes come out of features in storms called "mesocyclones". However, beyond this, tornadogenesis is somewhat poorly understood. The NWS has been using their Doppler (NEXRAD) radars to find these mesocyclone signatures (which actually show up quite well frequently) and issuing tornado warnings from these. While not every mesocyclone will produce a tornado and not every tornado forms in a mesocyclone, it's still a useful way of trying to find them.
The problem with tornado prediction is that it appears to be a fully three-dimensional and nonlinear process. And anyone who has worked with the equations of fluid flow in three dimensions working with nonlinearities will tell you that it's near impossible to get much information from it. (Nonlinearities, BTW, are things like the wind acting on itself.)
I must agree with you that hurricane path prediction is just as important, if not more so. Even weak hurricanes can do much more widespread damage than any tornado, or even outbreak of tornadoes. That's not to say that tornado forecasting should go out the window in favor of hurricane track forecasting. They are different processes, both of which should be studied. But hurricanes have the potential to do much more damage due to their larger size and longer lifetimes. An error on a track forecast at 72 hours of 100 km could affect whether or not you evacuate a large city or not, which, by itself, is a substantial amount of money and/or lives.
*enters soapbox mode.* Now, if those people in charge of funding research in atmospheric science would stop shooting money at the climate modelers and give some of us in the field who are doing some of the most basic and fundamental research a bit more funding, maybe they'd find their money better spent. But that would make sense... and gods forbid, a government doing something that makes sense. *exits soapbox mode.*
... the point I was making there (rather badly, unfortunately) was that if you believe that Jupiter is fully a gas giant, what does one consider the "ground" at which to call it a "low-pressure" system? Hurricanes are low-pressure systems in that, at the surface, their pressure is lower than their surroundings. But, one could also classify storms by their structure in the upper levels, in which case, hurricanes could be classified as high-pressure systems.
It's all a matter of reference frames. On Earth, it's common to use sea level or the surface as a reference state. But on Jupiter, what do you call the "surface"? So, that's why I expressed a bit of caution in calling the Jovian storms high or low pressure systems since no one has defined the reference state.
That brings me to a further point, in that the vertical structure of a vortex is also important, especially when you you can only "see" part of it. Just because a vortex is spinning one way where you can see it doesn't imply that it's spinning that way throughout its vertical structure. So, like I said, I'm not an expert in the Jovian systems (even though I'm nearly a Terran vortex expert... at least as much as one who studies them for his job can be, at least), so I can make no claims about their vertical structures or what kind of circulations occur in them.
Well, you have to be careful about what you mean by high and low pressure systems, though. Near the surface (on a constant z surface), hurricanes have a lower pressure than the surrounding atmosphere. But near the tropopause, hurricanes tend to have a higher pressure than the surrounding atmosphere. That's all due to the fact that hurricanes are warm-core systems. Take a look at this FAQ on terrestrial hurricanes...
As for the Jovian storms, I'm not aware of the dynamics involved. Not my specialty... but it definitely sounds QUITE interesting.
... for scientists like myself, this is a very nice thing. Not all of us in the sciences are tech-savvy... I'm probably the one in my 5-person research group who understands the most about *nix. For those of you who don't realize this, many research scientists have to work hard to get their grants and outside money.
So, what does all this mean to us? As an atmospheric scientist, having some serious number crunching power is mighty helpful. Weather modeling is quite the processor intensive task, and then interpreting the results can take years after all the computing is done, including further computations and visualization routines. To put it shortly, we can easily tax our computers.
So, now you know that we need computing power, but money is a premium for us in many cases, so why shouldn't we just get some cheap Intel boxes and *nix cluster them? Well, we could, but then we'd need to hire a systems admin. Someone who is tech-savvy enough to keep everything running decently well for us. That requires another person who REALLY understands what's going on in many cases, which is another salary on the payroll. For us, it all ends up balancing in the end. The $5-10K that we save in clustering our 8 Intel boxes over the Macs is eaten up in one year or less by the guy (or woman) who has to set up the whole thing. So, for us, the ease of setup and use is something that can translate into some good savings and we don't have to worry as much about having to rely on another person to save us if something goes wrong. That's the benefit of simplicity for us.
I agree that it is important to know, as one person said, "The nature of the beast", but that's something that takes time to do, and when you're not being paid to learn about how to cluster computers, but to figure out how the atmosphere works, then things like "The nature of the beast" are just further complications. I would rather have something that I can slap together, know that it works, and get back to my work, without the interference of others if I don't need it.
And that brings me to another rebuttal, about someone mentioning that if you buy the Macs, you're also going to pay for all the extra Superdrives and video cards and all that. I say to that, "Good." That way, if the cluster doesn't need to be used, then I don't have a bunch of mostly useless boxes sitting around... or if a collaborator comes around and needs a computer, I can just remove one of the computers from the cluster and let them use that for as long as they need. The point is that there are advantages and disadvantages to each setup. Now you've heard some advantages and why the scientific community might care about this. Remember, not everyone here can compile their own kernels and not everyone cares about being able to do that. Some of us, thank the deity of your choice, actually want to do something with this power and not care how it works in depth. To each their own.
... even though it's more of a data language than anything else, is IDL. (Forgot the company that produces it, though, sorry.)
It's fairly intuitive, has a lot of great functions and makes some of the greatest plots of any language I've ever seen. (Which is why it's perfect for data visualization...)
Truthfully, as a theoretical scientist, I've used FORTRAN, C++, Java, IDL, MatLab, Mathematica, Maple, and Pascal for varying projects. It all really depends on what you want to do. And since other have mentioned much of that, I'll leave it at that.
-Jellisky
Distributed computing approaches are fine for computing small chunks of independent information. That's why it can work for SETI@home... You don't need to know what's happening in the other data sets to do the calculations. Each data set just needs to be analyzed independent of the others.
The problem with weather/climate modeling is that, for each time step, a huge amount of data is needed to compute everything and that local changes end up not being as local as you might think. An action in one part of the atmosphere can affect the atmosphere elsewhere. In other words, the atmosphere is an internally coupled system. You can't pull it apart spatially, at least in any sort of reliable fashion. So, if you wanted to distribute the computing, you would have to give each client a buttload of previous data for it to do it's calculations, on the order of tens to hundreds of megabytes. Then the computing power required to divide up this data, retrieve it, and place it in its proper position would be comparable to the original task's power.
Essentially, the problem is too interconnected and complex for distributed computing, at this point, to be useful. It's not easily pulled apart into simple, discrete computations. These models are some of the most complex algorithms out there currently.
A couple of things about CO2 in the oceans.
First, in relative units, there are 70 units of CO2 in the atmosphere compared to 4000 units of CO2 in the oceans, dissolved. So, even if we were to pump all the CO2 in the atmosphere into the ocean (which would be a very bad idea), we would only change the amount in the oceans by around 2%. This is minute compared to the changes and gradients currently in the ocean that life seems to have adapted to.
Second, the vast majority (99.999+%) of the ocean is sub-saturated with respect to CO2. Also, the vast majority of the ocean is held at a nearly constant temperature (the deep water). It would take a more than major climatic shift to significantly warm or cool this water, and even then, the extra dissolved CO2 would most undoubtedly stay in sub-saturated waters.
Lastly, since the density of CO2 is greater than the main components of the atmosphere (N2 and O2), the gas, if released from the ocean at sea level, would only really affect places that are lower than sea level. And since the diffusive time scale of turbulence in the boundary layer is quite small, the gas would not be available for long in high enough concentrations in a significant enough area to do much damage, really.
Either way, I agree that it's a bad idea, for the reason that a better ideas, some of which have been mentioned here already, exist.
-Jellisky
As a mathematician who has done some research, I hated the question about "practical applications" because people would lose sight of the beauty in the math and the proof. While it's nice to have these practical applications in mind when you do work, it's not what's important in the mathematics. That's the true beauty of mathematics: it can live in its own world and still function; it is a true art. Mathematics, like art, doesn't have to be practical, but it never hurts if it is.
Fundamentally, science is carefully considered observations. Thus, anything that cannot be observed cannot be addressed by science.
You're somewhat right in this, and somewhat wrong. Much of science, especially biology and the non-mathematical ones, are based on observations. However, in some of the more mathematically based sciences, logic and equations dominate, up to the point that without mathematics, there would be no way to explain any of the observable and non-observable phenomena. As an atmospheric scientist myself, I know this first-hand. I'm doing research essentially on a mathematical construct which describes some very difficult to observe structures inside a hurricane. These structures have never truly been observed, and even their existence is in doubt, but the mathematics behind it is solid and shows that they have to exist. So, my point is that not all science deals with observation then theory. Sometimes, the theory outruns the observational techniques.
Any truly enlightened person will realize that life could only have occurred because of a Divine Touch, but I won't expect scientists to realize this.
While this opens a can of worms, the real problem comes down to semantics. You said it yourself, really, when you said, "...an event that remote.". Whether life occured due to random chance or divine intervention of your favorite deity is a fun debate, but you're totally right: it's such a remote event, and totally irreproducable, that neither side can truly support its claim without invoking something that runs contrary to someone's beliefs. Essentially, the basic axioms everyone takes for granted don't help us out here.
So, what to do about the question? Ignorance may be bliss, but it's not the best option. Best option is to keep all options open, no matter how warped or strange they may seem. Just don't say that any evidence is bad, because there is some truth in all "evidence".
Much of the sciences have come to a stand still because scientists refuse to realize that their tool is not the appropriate one for all problems. Perhaps it is an education problem, or maybe it's just one of ego. Regardless, science needs to focus on what it applies to, and leave the mysteries of the origin of life to those who can best understand them.
Again, there's some truth and half-truth in that first statement. Some areas of the sciences are standing still, and shouldn't be, IMO. But the general scientific method is an excellent tool for figuring out many problems. Yes, you're right that it's not appropiate for all problems, and yes, some scientists are not aware of that fact. But the problem is that it's one of the best tools we have for dealing with many problems, so it's only natural to use it for problems that it might not work on. If anything, it gives some interesting results that may or may not lead to the solution to the problem. Does this mean that science should stop poking its nose into these problems? No! Many important advances were accidentally figured out when a person looked into a problem, and figured out the answer to a mostly unrelated problem in the process. It's this accidental nature of the scientific method that is the main reason that science shouldn't stop poking it's nose into other groups' business, or as you say, "those who can best understand them".
I'd like to address that last sentence also. Knowledge is not only advanced by the experts in a field, but also by those only loosely associated and interested in it. The history of mathematics is a great example. Many of the important theories in mathematics were not figured out by lifetime mathematicians, but by people who were interested in other disciplines that used math and needed a solution to a problem. Much of differential equations was worked out by engineers and physicists, for example. To deny a person who's interested in a subject, no matter what their background or approach is, is just a bad idea. (I'm not claiming that science has been perfect in this respect either.) Knowledge is gained by all those interested in a subject contributing, discussing and critiquing. That's what many disciplines strive for, and why segregating disciplines is a bad idea all around. It's not an ego problem of science or of any other discipline or even an educational problem. There's little problem there at all.
So what if there ends up to be too little evidence to theorize about the origin question? If something is learned about any question, even if it wasn't initially strived for, it's a success in my book. But it's nice having a big goal to shoot for, right?
Yeah, I'm well aware that there has been no proof of that nature. However, my big point was that the more important current consideration for RSA security is the re-using of primes in the algorithms. Until this breakthru in computation or number theory comes along, this is the biggest problem we have to worry about with RSA.
I really needed something as funny as this to brighten my day.
Seriously, though, I don't recall all the specifics, but I do believe that, unless some brilliant advances in number theory or computational power happen soon, RSA encryption will be one of the best types around, at least mathematically speaking.
The thing we have to worry about most currently with RSA is whether or not we're all using the same keys over and over again. That's more of a threat than someone "breaking" RSA.
Well, actually, it wasn't meant to be a nitpick, but I suppose it was, in a way.:)
(My mind just couldn't comprehend the idea of a parabolic loop, and I'm one who works entirely in pseudo-abstract mathematics...)
Thanks also for the link... My mechanical physics was a bit rusty and I was having trouble figuring out the zero-g parts... Now, if we were to work in fluid dynamics, that I could handle better...:)
I'm confused by the whole concept of a parabolic loop...:) Just doesn't make sense to the mathematician in me... If I recall something similar that I had caught on TV about this, the path would be more like (excuse the ASCII art): /\/\/\/\/\/\/\
where each of the downs are the zero-g portions of the trip...
Does anyone else recall a TV program in the USA about something similar to this, because it sounds VERY familiar to me...
that most of the Netherlands and other countries have significant ocean-side property that should be flooded, because it's below sea-level. Isn't it amazing what a little bit of old technology, called a WALL can do to a potentially flooded city in this situation?
Darn media blitz of bad news with no thought behind it...
That's incredibly true. In fact, there's also other things that these models, while incredibly complex, are just not catching and are totally unknown. You also have the trouble with grid spacing and all the smaller scale features that the modelers have to parametrize. Microscale effects, like cloud droplets, dusts, aerosols, urban emmisions, clouds, etc. all have profound effects on climate due to the fact that they happen globally and continuously. And these models and theory is not able to work with these explicitly yet.
As you pointed out, there are HUGE gaps left in our understanding of the climate system, some of which are just as important as CO2 and all those other things.
While I disagree that anthropogenic climate change is statistically and empirically proven, I think that the societal effects are, for the most part, positive. We're finally starting to really explore non-internal combustion (IC) and non-fossil fuel methods of energy production seriously. People are becoming more aware that people do affect their environment, and awareness and knowledge are most often good things. Unfortunately, all this change is coming at the expense of possible mis-information, and the media's want for exploiting bad news. There are a decent number of atmospheric scientists (including myself, obviously) who really believe that the current anthropogenic climate warming theory has so many holes in it, that it's not even really sound to rely on it.
However, I would disagree with you that this is "junk" science. Many of the people working on this problem are making the assumptions that we currently know to be good, or at least decent, assumptions.
However, the real problem lies in the SET of assumptions made, in that the set is not nearly complete enough. It's like trying to make a theory on the real numbers with the following subset of the real numbers: {0.0, 1.0, 2.0}. You can figure out some things, but you're going to catch properties of the subset which are not properties of the real numbers and you're going to miss properties of the real numbers that you can't notice in the subset.
What the media and many other scientists don't realize is this whole scenario about the assumptions.
Well, that's my view from within the field.
How the heck are chemicals from the northern hemisphere getting shoved to the south pole without the help of trade winds?
Well, two main things here:
First, there are still enough poleward-directed winds set up by simple imbalances to give a significant transport, even across the equator. Storm systems can significantly change the basic state of the atmosphere and move materials poleward and equatorward even if the basic state would not allow them to.
Second, there's still diffusion going on. Granted diffusion is a slow process, but it's still important on longer time scales.
On average, it takes, on average, about one year for any parcel of air in the troposphere in one hemisphere to get to the other hemisphere. Also, in the stratosphere, diffusion is significantly more important than in the troposphere. So, these processes together will tend to mix the CFC's from the Northern Hemisphere to the entire globe.
...how can anyone make a prediction about an effect by only measuring the cause?
That's a good question, and one that brings up a good point about most of these arguments, especially with the ideas of correlation and causation.
As it might be obvious, the two are not the same. Just because two fields are correlated does not imply that there is a causation between the two. For example, one could correlate the rise in the Dow Jones Industrial Average with the rise in global average temperature, with probably a surprising high correlation. But if you were to say that the two are therefore intimately related, you'd be laughed at. Thus the phrase "Correlation is NOT causation!".
To make the correlation into a causation, you need to explain the mechanisms that explain the correlation. So, in this case, the explanations are the chemistry which happen between CFC's and ozone (more importantly, between halogen radicals and ozone). I'm going to refrain from actually giving out the chemistry here, but assume that it is good chemistry and that it really works that way. Then there is some argument for causation.
Also, when you look at the chemistry and take a few other things into account, the causation becomes a little more apparent, but not without taking into account many other things. This problem is not a direct causation, but it's pretty close.
If you're interested in a little more of a detailed explanation of the chemistry and dynamics of ozone depletion, I might be able to point you in a good direction or answer some questions. Feel free to e-mail me. Trust me, the media tends to really dumb down the science, which is fine, but people then should have the full science available, and explained to them if they really want it. The moral here is that the media is only giving the tip of the iceberg on almost every scientific problem. There's so much more there in every case.
Ozone is created by sunlight. Sunlight is abundant near the equator where light hits the atmosphere at higher angles and that's where most of the ozone is created. Ozone coverage above the pole depends on whether there are enough jet streams to get it from the equator to the poles. The ozone heretics claim that a well-known priodic weather phenomenon over the south pole creates a pocket of air that doesn't interact much with the rest of the atmosphere and that is the real reason for the hole. This pocket is occasionally broken up by atmospheric turbulence and fresh ozone gets to the pole.
This is mostly true. This is what's called the "polar vortex". It happens during the polar winter, and it's primary effect is partially that, but it also does more than that. What happens during the polar winter, is that being there is no sunlight here during that time, some other chemistry can occur. Essentially, there are a few ozone destroying compounds that normally react not only with ozone, but with each other. These compounds (including ClO, BrO, OH, NO2) combine with each other producing other, non-reactive compounds (for example, ClONO2) which require sunlight to break apart back into those reactive species. Thus, the addition of some more of these species may not affect fast ozone destruction, as it would make these "reservior" compounds.
During these polar vortex events, though, the winds around the poles tend to isolated the air over the poles. This gives the air inside a chance to become more homogenous, but more importantly, it allows the concentrations of those reservior species to increase without them being destroyed.
Also, because there is not much sunlight, the air temperatures become very cold, allowing for what little water vapor there is to form clouds. On these cloud particles, more chemistry occurs that helps convert some of the more unreactive reservior species (like ClONO2) into more reactive reservior species (like Cl2). The chemistry also tends to produce nitric acid on these particles which can then fall out of the stratosphere. This reduces your less reactive reservior species a bit more, and removes some of the possibly balancing NO2 from the system.
Thus, when the sun comes back up, there are plenty of these more reactive reservior species around, with little balancing NO2 to prevent these species' radicals from destroying ozone. Thus, there's a lot of ozone destruction during the beginning of the polar spring.
That's why most of the ozone hole plots from Antarctica you see are from October. It's the start of their spring then.
So, while the ozone movement is hindered by this vortex, the additional chemistry involved is also important.
Hope this helps your understanding. (BTW, I am an atmospheric science student who is just finishing up a grad course in atmospheric chemistry.:) )
Too many things to respond to, so a bulk response is in order. BTW, I'm currently studying stratospheric chemistry in my grad atmospheric chemistry class, so I'm fairly sure on what I'm talking about...
First, to a comment about methane being a bigger ozone destroyer than halogens... While it's possible, as OH radicals produced by the oxidation of methane are ozone destroying, only a small percentage of tropospheric methane makes it to the stratosphere, and most of that is converted to H2O, which photolyzes into OH radicals. Notice that this is a complicated process already, with many fairly slow reaction rates involved. So, methane can be important, but it's highly doubtful that it's truly as important. Also, there's the fact that the OH radicals tend to react very nicely with many other species, while the ClO and FO radicals are more strictly reactive with each other and ozone. The fact of the matter is that methane probably has significantly less effect than halogens on the ozone destruction.
My second comment is directed to all you global warming people. First of all, yes, global warming due to increasing CO2 is almost definitely true. HOWEVER, and I cannot stress this enough, the magnitude of such warming and it's consequences is VERY much in dispute. Truthfully, these global models are decent, but they're running off parameterizations, some of which are sub-optimal; often cannot take into account further feedbacks, like changes in plant growth, changes in cloud cover (and its friend, changes in albedo, or reflection of sunlight), and other natural feedbacks. The climate is so more significantly more complex than these models can take into account that believing the magnitudes and trying to figure out the ramifications of these predictions is truly like playing roulette with a wheel that has millions of spaces. Yes, the oceans will rise, but how much is another question. And even if it is 100m over the next 100 years, why can't humanity adapt to this small change? So, please, stop with your doomsday predictions. Doubling CO2 might cause some warming, but how much is tough to call. And the results might not be that bad. Remember that during the age of the dinosaurs, there were concentrations of CO2 that were about 5-10 times current levels, and life sure wasn't dead then.
Third, I would like to applaud those people who are making sense in other posts. Change really is the only constant in the atmosphere. Humans may change the atmosphere, but to what extent is a question that is hard to really tough to figure out. And even if we figure it out, can we really figure out all the intricacies? Trust me, there's little out there that's more difficult to predict than a fluid's behavior, especially when you add heterogenous chemistry, additional effects from outside it's internal system (oceans, solar, humans, etc.), the interactions of water in the system (clouds, storms, etc.), and God know what else. Let's also not forget that atmospheric science is a truly young science (first major advances in the 1920's...). Even some of these seemingly simple questions haven't even been extensively worked out. A large part of the field is still conjecture and hypothesis. (Let's also not forget that fluids are chaotic by simple nature.) And it'll probably stay that way until the chaos theorists and partial differential equation people give us some even more incredible tools than we currently have. It's amazing that some people take these climate models that predict on significantly worse resolutions and time frames as absolute truth while they don't necessarily believe a 5 day forecast off a model that's significantly better. Noodle that one a while before you pin your faith on models.
-Jellisky
It's actually truly amazing that you could get something sizable out of fog, but it actually makes some sense.
Here's some back of the envelope calculations that might be a bit convincing:
(Note: I'll be using standard scientific E notation. So, 6.4E+3 = 6400.)
The liquid water content of a dry fog is 5E-8 m^3(H2O)/m^3(air). This translates into 5E-4 L(H2O)/m^3(air).
Assume that we can collect a fog bank that's 10km x 10km x 10m (height). That would be 1E+9 m^3 of fog, or 5E+5 (or 500000) L of water in that region.
Even if we only could collect 1% of that, it's still 5000 L. Seriously, that's not too bad for that kind of area of land.
Problem is that evaproation would take back quite a bit of that if one isn't careful.
It's amazing how much water could be tapped from clouds of all sorts. Problem is, that those well-versed in the hydrological cycle will tell you that the water in the atmosphere is VERY small compared to that elsewhere in the world. (We're talking hundreths of percentages here.) Perhaps trying to figure out better ways of de-salinating ocean water should be a little more important.
Just my thoughts.
Slashdot Mirror
Much of the data is indeed flawed. It is riddled with assumptions and inconsistencies. It depends on long chains of assumptions. For example, sea temperature data has been inferred from characteristics of coral growth. And yet just in the last month a paper was published (Science) showing that the coral growth is significantly affected by other factors, blowing away that assumption. Tree rings are used as a substitute for temperature or precipitation data, but have been shown to be unreliable in many cases. Other data is significantly contaminated - I am using one such data set right now.
Indeed... not only that, but let's also not forget that even with recent data, there are problems with the methodologies.
How many of these weather stations that we're using for data collection are now surrounded by urban heat islands where they weren't 50 years ago? It's known as a fact that urban heat islands do exist and have local effects on temperature and humidity.
Now, let's see here... increased urbanization raises the temperature of 25% of the recording stations by 1 degree Celsuis, just as a local effect... that produces a 0.25 degree Celsius "average" increase in "global temperatures", even though urban areas take up a very insignificant amount of the area of the globe.
Is this "rise" real? Possibly... but the data is contaminated in more ways than one. Urban/local effects, improvements in equipment (I can link to multiple stories about the error bars on old equipment, but don't feel like digging those up), changes in equipment (see the May 2002 issue of the Bulletin of the American Meteorological Society, "When Was the Hottest Summer?", particularly the "Mysterious Climate Change?" sidebar), and many other factors affect the data we use to make these conjectures and forecasts. This is something that climatologists are struggling with... and I should know since I only help a few of them pretty often.
{begin rant}
The point is that even the conjecture of "global warming" can be brought into question. The real PROBLEM here is the media garbling the messages the climatologists really want to give out. The media (and public) assumes science is "cut and dry"; that there's one right answer and no uncertainty. In truth, though, very little is as black and white as an arithmetic test. That's why the National Weather Service recently started getting a little more wordy in their forecasts, calling for temperature ranges and precipitation chances rather than a specific temperature and time/type of precipitation. Hopefully, the media (and public) realize that much of what goes on in our world isn't as simple as the media makes it sound.
{end rant}
-Jellisky
... way back in '94-96. We had a small cluster of 386-33's in the library that were used for research. There wasn't any internet access on those at the time, but they were networked via Novell to a small server that had all the library researching programs.
:) Ahhh... the joys of having 5000 turns a day, alliances and backstabbings, maxed ships. :)
:) Bolo was a big drawing point to our little group. One of us would make a new map every month or so and we'd all play on it. Dang it, you're bringing back all these fond memories.
I was the resident computer nerd at the time and had gotten addicted to TradeWars on a local BBS. So, with some sweet-talking of the librarian in charge of the server and a promise to help out even more than I already was (I was the only one around that whole district at the time who could even remotely fix any of the Macs that were in some of the labs), I had TW set up on the system. For the two hours after school, a small group of us would play that. It was fun setting up the universe and all that and it got us talking and enjoying those dull hours between the end of school and dinner. (Except the nights some of us had to work on the school newspaper...)
We tried a bit of Doom and some of the other BBS network games, but the afternoons of TW will always stick in my memory.
We did that and also used the printer-networked Mac Classics to play Bolo... LOTS of Bolo.
So, yeah, keep the games nights. Make sure to enforce fair play and decently long breaks for socialization. And keep the gore to a minimum. There's plenty of fun games out there. And also don't be afraid to do contests with single-player games... for example, we'd have Sim City races... first one to 10,000 population and $5000 wins. The Sim games can be good for those. Just be creative and don't fall into the same game every time. That keeps the minds fresh and the options interesting.
-Jellisky
Well, somewhat. I did the ACM for three years in undergrad. I was (and still am) a little code hacker in the sense of being able to digest simple coding problems and get code out to work out those problems quite quickly. I am not a programmer, per se, since I actually kind of suck at doing large extended projects. *sheepish grin.* But at least I still got my minor in CS.
;) )
The contests weren't very helpful in and of themselves. But studying for them... that was helpful, at least for me. In studying for them, you get exposed to lots of interesting algorithms and different ways of attacking problems. Learning to "problem-solve" on your feet (or actually your tush) is not only lots of fun, but it's also one of those talents that it never hurts to develop.
Then, of course, there's the whole fun of time-managing. In the ACM, you have three people, one computer, and six hours. First time you do it, you realize that you're going to have to code on paper... and debug on paper... and figure out I/O on paper. (And anyone who has done one of these contests knows that I/O is the single nastiest part of the whole experience.) With the limited time and resources, you quickly find yourself having to visualize code and running it in your head or on paper in order to do well. And these talents are useful once again only because they are generally useful in programming. And all these can be worked on in practice, not just in the competition.
So, yes, the competition really just comes down to enjoying yourself and having fun. You get an idea to see how good of a quick programmer you are and how you stack up against the rest of the region/nation/world. It can be both a humbling and an exhilirating experience. The ACM, at six quick hours, is loads of fun, especially if your programming partners are a blast to be around. (Let's just say that that last hour, if you've either finished or given up on the remaining problems, can be filled with some very screwy things...
The important things to get out of these competitions come from the practices and such beforehand. Learning the algorithms, learning to think about problems clearly and quickly, learning to put ideas together on your feet. Those talents are just generally useful in programming, and life in general.
Good luck.
-Jellisky
First of all, my biggest pet peeve: the difference between weather and climate. Yes, believe it or not, climate and weather are two very different terms. They should not be used interchangably, thankyouverymuch. Three days does not a climate make.
Now, to continue on that thought, it's interesting to think about the consequences of this "study". (The quotation marks are supposed to be there.) I cannot say what I really think of this "study" since I haven't read their results, but I cannot be that easily convinced that three days worth of data compared to years worth of data has any possible statistical significance, especially in something like diurnal ranges, which are 15-30 degrees C anyways. Show me three months and I might be convinced of a trend. I can name at least 10 different three-day weather features that could cause such a blip and that's just off the top of my head.
Next, IF this is true, then it only highlights something which has bothered me about climate modeling from the frickin' beginning: the role of clouds and how terribly they are handled in these (and all) models. Of course, this isn't the only problem I have with these modeling studies, but we won't enter that debate right now.
The type of cloud present has an effect on the net change in radiative flux. Deep, thick clouds (like cumulus) have a net positive change while thin clouds (like cirrus) have a net negative change. The thing, though, is that in balance calculations like these, there tend to be two effects, which are approximately equal and opposite in sign. So, you end up wondering how much of it is really real. (For example, the two terms might be 220 and -218, leading to 2 change... but if you're off by a little bit, those numbers might actually be 219 and -220, leading to a -1.) This is further compounded by the way models handle clouds, which is often routinely terrible (with respect to resolution, the actual physics involved in the cloud which can affect all the results, and many other factors).
To further put all this in perspective, let's assume the albedo (the amount of solar radiation reflected back to space by the earth which is largely a function of the cloudiness) of the earth increases by 1%. (It's currently around 30% in a climatological sense... even that number has an error bar of measurement around +/- 3%.) On average, that would mean that the earth would get 3.4 W/m^2 less radiation. (Daily and spacial average of solar radiation is about 340 W/m^2, again largish errors on this measurement.) This number is comparable to the change by doubling CO2 (about 4 W/m^2) and, as you can notice, opposite in sign. Of course, there's a huge extra batch of physics here that isn't even being considered like the change of the absorption of IR radiation from the earth by the clouds or the release of latent heat by the clouds or the feedback between warmer surface temperatures and clouds (which is barely understood since it's almost as complex a problem as the original)... Kind of makes your head spin to think about all these effects, doesn't it? And all of them are about the same order of magnitude by itself, i.e. about 0.5-5 W/m^2, both positive and negative. Let's also not forget that local effects, like all those new urban heat islands that have popped up around all our temperature recording stations that could very well explain that temperature rise in the last century or whatever, and that these effects are not put into these models...
Complex problem? You bet. Possible to understand? Eventually, I don't see why not. But, we can't sit back and keep using these antiquated ideas in these state-of-the-art models. As the old saying goes, "Garbage in, Garbage out." The effects of these contrails may be important, yes. I cannot debate that. However, to claim that off of whatever insignificant sample this is, or using any of the ideas we currently have, is ludicrous at best. Any imbecile with a computer nowadays can run a correlation analysis on data. But, to interpret it and explain WHY things are happening that way... that's the vital connection between statistical tomfoolery and real science. Then, to explain the dynamics and theory behind it all... that's the step to making a full fledged theory.
-Jellisky
... and a very poorly understood one, at that. Urban areas do tend to create what one might consider shallow, localized fronts.
It's well known that any atmospheric boundary can have effects on a storm, both in motion and intensity. It's also well-known that urban areas do have localized differences compared to their environment.
But it's not well-known what the overall effects might be. Severe thunderstorms are creatures that require moisture and the energy condensing it provides. In an urban heat island situation, the temperature is often higher, but the amount of moisture is only marginally higher. This actually tends to reduce the CAPE (Convective Available Potential Energy) of the urban area compared to its immediate environment. Also, the boundary of the urban heat island may act as a sort of "guide" for the storm to propogate on, much like fronts and outflow boundaries (cold, moist air from previous thunderstorms) often act.
But, the storm is also affected by the upper air steering flow. There's a certain slaving between the upper and lower levels that is beneficial to storm development and intensification. An urban heat island may modify this enough to make a difference... that much is possible.
However, in the case of your storm switching direction, that's actually a pretty common feature of tornadic storms, i.e. to change direction and move to the right of their previous movement vector. The dynamics of right-moving supercells (as they are called) are fairly well understood and widely accepted. So, to say that the storm turned strictly because of the city, in this case, is a little hard to believe. But, it's something that bears watching.
And I have noticed that "effect" of cities before. It does seem to be relatively common, as a sort of informal survey... but I'm not aware of any study that's fully addressed it yet.
-Jellisky
Nice to see some good data from this case.
;) Of course, I would heavily prefer it going through a nice empty field or forest in the middle of nowhere, with a road running parallel to its path, keeping me a mile or so south/southeast of the mesocyclone at any one time. ;) Of course, we all have to have dreams.
Just looking at the loops there, especially the radial velocity loop (all of the loops were well-annotated, I must admit), I would be surprised if SPC and the local NWS office there didn't forecast this thing pretty well. I'm too lazy currently to go and do my own little search on all that, but does anyone have some of that information?
Now, if only I could see one of these on my scheduled chase coming up next week.
-Jellisky
There is a certain bit of predictability to tornado prediction. It is well-documented that the vast majority of tornadoes come out of features in storms called "mesocyclones". However, beyond this, tornadogenesis is somewhat poorly understood. The NWS has been using their Doppler (NEXRAD) radars to find these mesocyclone signatures (which actually show up quite well frequently) and issuing tornado warnings from these. While not every mesocyclone will produce a tornado and not every tornado forms in a mesocyclone, it's still a useful way of trying to find them.
The problem with tornado prediction is that it appears to be a fully three-dimensional and nonlinear process. And anyone who has worked with the equations of fluid flow in three dimensions working with nonlinearities will tell you that it's near impossible to get much information from it. (Nonlinearities, BTW, are things like the wind acting on itself.)
I must agree with you that hurricane path prediction is just as important, if not more so. Even weak hurricanes can do much more widespread damage than any tornado, or even outbreak of tornadoes. That's not to say that tornado forecasting should go out the window in favor of hurricane track forecasting. They are different processes, both of which should be studied. But hurricanes have the potential to do much more damage due to their larger size and longer lifetimes. An error on a track forecast at 72 hours of 100 km could affect whether or not you evacuate a large city or not, which, by itself, is a substantial amount of money and/or lives.
*enters soapbox mode.* Now, if those people in charge of funding research in atmospheric science would stop shooting money at the climate modelers and give some of us in the field who are doing some of the most basic and fundamental research a bit more funding, maybe they'd find their money better spent. But that would make sense... and gods forbid, a government doing something that makes sense. *exits soapbox mode.*
-Jellisky
... the point I was making there (rather badly, unfortunately) was that if you believe that Jupiter is fully a gas giant, what does one consider the "ground" at which to call it a "low-pressure" system? Hurricanes are low-pressure systems in that, at the surface, their pressure is lower than their surroundings. But, one could also classify storms by their structure in the upper levels, in which case, hurricanes could be classified as high-pressure systems.
It's all a matter of reference frames. On Earth, it's common to use sea level or the surface as a reference state. But on Jupiter, what do you call the "surface"? So, that's why I expressed a bit of caution in calling the Jovian storms high or low pressure systems since no one has defined the reference state.
That brings me to a further point, in that the vertical structure of a vortex is also important, especially when you you can only "see" part of it. Just because a vortex is spinning one way where you can see it doesn't imply that it's spinning that way throughout its vertical structure. So, like I said, I'm not an expert in the Jovian systems (even though I'm nearly a Terran vortex expert... at least as much as one who studies them for his job can be, at least), so I can make no claims about their vertical structures or what kind of circulations occur in them.
Hopefully that clarifies my point.
-Jellisky
Well, you have to be careful about what you mean by high and low pressure systems, though. Near the surface (on a constant z surface), hurricanes have a lower pressure than the surrounding atmosphere. But near the tropopause, hurricanes tend to have a higher pressure than the surrounding atmosphere. That's all due to the fact that hurricanes are warm-core systems. Take a look at this FAQ on terrestrial hurricanes...
As for the Jovian storms, I'm not aware of the dynamics involved. Not my specialty... but it definitely sounds QUITE interesting.
-Jellisky
... for scientists like myself, this is a very nice thing. Not all of us in the sciences are tech-savvy... I'm probably the one in my 5-person research group who understands the most about *nix. For those of you who don't realize this, many research scientists have to work hard to get their grants and outside money.
So, what does all this mean to us? As an atmospheric scientist, having some serious number crunching power is mighty helpful. Weather modeling is quite the processor intensive task, and then interpreting the results can take years after all the computing is done, including further computations and visualization routines. To put it shortly, we can easily tax our computers.
So, now you know that we need computing power, but money is a premium for us in many cases, so why shouldn't we just get some cheap Intel boxes and *nix cluster them? Well, we could, but then we'd need to hire a systems admin. Someone who is tech-savvy enough to keep everything running decently well for us. That requires another person who REALLY understands what's going on in many cases, which is another salary on the payroll. For us, it all ends up balancing in the end. The $5-10K that we save in clustering our 8 Intel boxes over the Macs is eaten up in one year or less by the guy (or woman) who has to set up the whole thing. So, for us, the ease of setup and use is something that can translate into some good savings and we don't have to worry as much about having to rely on another person to save us if something goes wrong. That's the benefit of simplicity for us.
I agree that it is important to know, as one person said, "The nature of the beast", but that's something that takes time to do, and when you're not being paid to learn about how to cluster computers, but to figure out how the atmosphere works, then things like "The nature of the beast" are just further complications. I would rather have something that I can slap together, know that it works, and get back to my work, without the interference of others if I don't need it.
And that brings me to another rebuttal, about someone mentioning that if you buy the Macs, you're also going to pay for all the extra Superdrives and video cards and all that. I say to that, "Good." That way, if the cluster doesn't need to be used, then I don't have a bunch of mostly useless boxes sitting around... or if a collaborator comes around and needs a computer, I can just remove one of the computers from the cluster and let them use that for as long as they need. The point is that there are advantages and disadvantages to each setup. Now you've heard some advantages and why the scientific community might care about this. Remember, not everyone here can compile their own kernels and not everyone cares about being able to do that. Some of us, thank the deity of your choice, actually want to do something with this power and not care how it works in depth. To each their own.
-Jellisky
... even though it's more of a data language than anything else, is IDL. (Forgot the company that produces it, though, sorry.) It's fairly intuitive, has a lot of great functions and makes some of the greatest plots of any language I've ever seen. (Which is why it's perfect for data visualization...) Truthfully, as a theoretical scientist, I've used FORTRAN, C++, Java, IDL, MatLab, Mathematica, Maple, and Pascal for varying projects. It all really depends on what you want to do. And since other have mentioned much of that, I'll leave it at that. -Jellisky
Distributed computing approaches are fine for computing small chunks of independent information. That's why it can work for SETI@home... You don't need to know what's happening in the other data sets to do the calculations. Each data set just needs to be analyzed independent of the others.
The problem with weather/climate modeling is that, for each time step, a huge amount of data is needed to compute everything and that local changes end up not being as local as you might think. An action in one part of the atmosphere can affect the atmosphere elsewhere. In other words, the atmosphere is an internally coupled system. You can't pull it apart spatially, at least in any sort of reliable fashion. So, if you wanted to distribute the computing, you would have to give each client a buttload of previous data for it to do it's calculations, on the order of tens to hundreds of megabytes. Then the computing power required to divide up this data, retrieve it, and place it in its proper position would be comparable to the original task's power.
Essentially, the problem is too interconnected and complex for distributed computing, at this point, to be useful. It's not easily pulled apart into simple, discrete computations. These models are some of the most complex algorithms out there currently.
-Jellisky
A couple of things about CO2 in the oceans.
First, in relative units, there are 70 units of CO2 in the atmosphere compared to 4000 units of CO2 in the oceans, dissolved. So, even if we were to pump all the CO2 in the atmosphere into the ocean (which would be a very bad idea), we would only change the amount in the oceans by around 2%. This is minute compared to the changes and gradients currently in the ocean that life seems to have adapted to.
Second, the vast majority (99.999+%) of the ocean is sub-saturated with respect to CO2. Also, the vast majority of the ocean is held at a nearly constant temperature (the deep water). It would take a more than major climatic shift to significantly warm or cool this water, and even then, the extra dissolved CO2 would most undoubtedly stay in sub-saturated waters.
Lastly, since the density of CO2 is greater than the main components of the atmosphere (N2 and O2), the gas, if released from the ocean at sea level, would only really affect places that are lower than sea level. And since the diffusive time scale of turbulence in the boundary layer is quite small, the gas would not be available for long in high enough concentrations in a significant enough area to do much damage, really.
Either way, I agree that it's a bad idea, for the reason that a better ideas, some of which have been mentioned here already, exist.
-Jellisky
As a mathematician who has done some research, I hated the question about "practical applications" because people would lose sight of the beauty in the math and the proof. While it's nice to have these practical applications in mind when you do work, it's not what's important in the mathematics. That's the true beauty of mathematics: it can live in its own world and still function; it is a true art. Mathematics, like art, doesn't have to be practical, but it never hurts if it is.
-Jellisky
Just a few things about your comment:
Fundamentally, science is carefully considered observations. Thus, anything that cannot be observed cannot be addressed by science.
You're somewhat right in this, and somewhat wrong. Much of science, especially biology and the non-mathematical ones, are based on observations. However, in some of the more mathematically based sciences, logic and equations dominate, up to the point that without mathematics, there would be no way to explain any of the observable and non-observable phenomena. As an atmospheric scientist myself, I know this first-hand. I'm doing research essentially on a mathematical construct which describes some very difficult to observe structures inside a hurricane. These structures have never truly been observed, and even their existence is in doubt, but the mathematics behind it is solid and shows that they have to exist. So, my point is that not all science deals with observation then theory. Sometimes, the theory outruns the observational techniques.
Any truly enlightened person will realize that life could only have occurred because of a Divine Touch, but I won't expect scientists to realize this.
While this opens a can of worms, the real problem comes down to semantics. You said it yourself, really, when you said, "...an event that remote.". Whether life occured due to random chance or divine intervention of your favorite deity is a fun debate, but you're totally right: it's such a remote event, and totally irreproducable, that neither side can truly support its claim without invoking something that runs contrary to someone's beliefs. Essentially, the basic axioms everyone takes for granted don't help us out here.
So, what to do about the question? Ignorance may be bliss, but it's not the best option. Best option is to keep all options open, no matter how warped or strange they may seem. Just don't say that any evidence is bad, because there is some truth in all "evidence".
Much of the sciences have come to a stand still because scientists refuse to realize that their tool is not the appropriate one for all problems. Perhaps it is an education problem, or maybe it's just one of ego. Regardless, science needs to focus on what it applies to, and leave the mysteries of the origin of life to those who can best understand them.
Again, there's some truth and half-truth in that first statement. Some areas of the sciences are standing still, and shouldn't be, IMO. But the general scientific method is an excellent tool for figuring out many problems. Yes, you're right that it's not appropiate for all problems, and yes, some scientists are not aware of that fact. But the problem is that it's one of the best tools we have for dealing with many problems, so it's only natural to use it for problems that it might not work on. If anything, it gives some interesting results that may or may not lead to the solution to the problem. Does this mean that science should stop poking its nose into these problems? No! Many important advances were accidentally figured out when a person looked into a problem, and figured out the answer to a mostly unrelated problem in the process. It's this accidental nature of the scientific method that is the main reason that science shouldn't stop poking it's nose into other groups' business, or as you say, "those who can best understand them".
I'd like to address that last sentence also. Knowledge is not only advanced by the experts in a field, but also by those only loosely associated and interested in it. The history of mathematics is a great example. Many of the important theories in mathematics were not figured out by lifetime mathematicians, but by people who were interested in other disciplines that used math and needed a solution to a problem. Much of differential equations was worked out by engineers and physicists, for example. To deny a person who's interested in a subject, no matter what their background or approach is, is just a bad idea. (I'm not claiming that science has been perfect in this respect either.) Knowledge is gained by all those interested in a subject contributing, discussing and critiquing. That's what many disciplines strive for, and why segregating disciplines is a bad idea all around. It's not an ego problem of science or of any other discipline or even an educational problem. There's little problem there at all.
So what if there ends up to be too little evidence to theorize about the origin question? If something is learned about any question, even if it wasn't initially strived for, it's a success in my book. But it's nice having a big goal to shoot for, right?
-Jellisky
Yeah, I'm well aware that there has been no proof of that nature. However, my big point was that the more important current consideration for RSA security is the re-using of primes in the algorithms. Until this breakthru in computation or number theory comes along, this is the biggest problem we have to worry about with RSA.
-Jellisky
I really needed something as funny as this to brighten my day.
Seriously, though, I don't recall all the specifics, but I do believe that, unless some brilliant advances in number theory or computational power happen soon, RSA encryption will be one of the best types around, at least mathematically speaking.
The thing we have to worry about most currently with RSA is whether or not we're all using the same keys over and over again. That's more of a threat than someone "breaking" RSA.
-Jellisky
Well, actually, it wasn't meant to be a nitpick, but I suppose it was, in a way. :)
:)
(My mind just couldn't comprehend the idea of a parabolic loop, and I'm one who works entirely in pseudo-abstract mathematics...)
Thanks also for the link... My mechanical physics was a bit rusty and I was having trouble figuring out the zero-g parts... Now, if we were to work in fluid dynamics, that I could handle better...
-Jellisky
I'm confused by the whole concept of a parabolic loop... :) Just doesn't make sense to the mathematician in me... If I recall something similar that I had caught on TV about this, the path would be more like (excuse the ASCII art):
/\/\/\/\/\/\/\
where each of the downs are the zero-g portions of the trip...
Does anyone else recall a TV program in the USA about something similar to this, because it sounds VERY familiar to me...
that most of the Netherlands and other countries have significant ocean-side property that should be flooded, because it's below sea-level. Isn't it amazing what a little bit of old technology, called a WALL can do to a potentially flooded city in this situation?
Darn media blitz of bad news with no thought behind it...
That's incredibly true. In fact, there's also other things that these models, while incredibly complex, are just not catching and are totally unknown. You also have the trouble with grid spacing and all the smaller scale features that the modelers have to parametrize. Microscale effects, like cloud droplets, dusts, aerosols, urban emmisions, clouds, etc. all have profound effects on climate due to the fact that they happen globally and continuously. And these models and theory is not able to work with these explicitly yet.
As you pointed out, there are HUGE gaps left in our understanding of the climate system, some of which are just as important as CO2 and all those other things.
While I disagree that anthropogenic climate change is statistically and empirically proven, I think that the societal effects are, for the most part, positive. We're finally starting to really explore non-internal combustion (IC) and non-fossil fuel methods of energy production seriously. People are becoming more aware that people do affect their environment, and awareness and knowledge are most often good things. Unfortunately, all this change is coming at the expense of possible mis-information, and the media's want for exploiting bad news. There are a decent number of atmospheric scientists (including myself, obviously) who really believe that the current anthropogenic climate warming theory has so many holes in it, that it's not even really sound to rely on it.
However, I would disagree with you that this is "junk" science. Many of the people working on this problem are making the assumptions that we currently know to be good, or at least decent, assumptions.
However, the real problem lies in the SET of assumptions made, in that the set is not nearly complete enough. It's like trying to make a theory on the real numbers with the following subset of the real numbers: {0.0, 1.0, 2.0}. You can figure out some things, but you're going to catch properties of the subset which are not properties of the real numbers and you're going to miss properties of the real numbers that you can't notice in the subset.
What the media and many other scientists don't realize is this whole scenario about the assumptions.
Well, that's my view from within the field.
How the heck are chemicals from the northern hemisphere getting shoved to the south pole without the help of trade winds?
...how can anyone make a prediction about an effect by only measuring the cause?
Well, two main things here:
First, there are still enough poleward-directed winds set up by simple imbalances to give a significant transport, even across the equator. Storm systems can significantly change the basic state of the atmosphere and move materials poleward and equatorward even if the basic state would not allow them to.
Second, there's still diffusion going on. Granted diffusion is a slow process, but it's still important on longer time scales.
On average, it takes, on average, about one year for any parcel of air in the troposphere in one hemisphere to get to the other hemisphere. Also, in the stratosphere, diffusion is significantly more important than in the troposphere. So, these processes together will tend to mix the CFC's from the Northern Hemisphere to the entire globe.
That's a good question, and one that brings up a good point about most of these arguments, especially with the ideas of correlation and causation.
As it might be obvious, the two are not the same. Just because two fields are correlated does not imply that there is a causation between the two. For example, one could correlate the rise in the Dow Jones Industrial Average with the rise in global average temperature, with probably a surprising high correlation. But if you were to say that the two are therefore intimately related, you'd be laughed at. Thus the phrase "Correlation is NOT causation!".
To make the correlation into a causation, you need to explain the mechanisms that explain the correlation. So, in this case, the explanations are the chemistry which happen between CFC's and ozone (more importantly, between halogen radicals and ozone). I'm going to refrain from actually giving out the chemistry here, but assume that it is good chemistry and that it really works that way. Then there is some argument for causation.
Also, when you look at the chemistry and take a few other things into account, the causation becomes a little more apparent, but not without taking into account many other things. This problem is not a direct causation, but it's pretty close.
If you're interested in a little more of a detailed explanation of the chemistry and dynamics of ozone depletion, I might be able to point you in a good direction or answer some questions. Feel free to e-mail me. Trust me, the media tends to really dumb down the science, which is fine, but people then should have the full science available, and explained to them if they really want it. The moral here is that the media is only giving the tip of the iceberg on almost every scientific problem. There's so much more there in every case.
Hope that helps,
-Jellisky
Ozone is created by sunlight. Sunlight is abundant near the equator where light hits the atmosphere at higher angles and that's where most of the ozone is created. Ozone coverage above the pole depends on whether there are enough jet streams to get it from the equator to the poles. The ozone heretics claim that a well-known priodic weather phenomenon over the south pole creates a pocket of air that doesn't interact much with the rest of the atmosphere and that is the real reason for the hole. This pocket is occasionally broken up by atmospheric turbulence and fresh ozone gets to the pole.
:) )
This is mostly true. This is what's called the "polar vortex". It happens during the polar winter, and it's primary effect is partially that, but it also does more than that. What happens during the polar winter, is that being there is no sunlight here during that time, some other chemistry can occur. Essentially, there are a few ozone destroying compounds that normally react not only with ozone, but with each other. These compounds (including ClO, BrO, OH, NO2) combine with each other producing other, non-reactive compounds (for example, ClONO2) which require sunlight to break apart back into those reactive species. Thus, the addition of some more of these species may not affect fast ozone destruction, as it would make these "reservior" compounds.
During these polar vortex events, though, the winds around the poles tend to isolated the air over the poles. This gives the air inside a chance to become more homogenous, but more importantly, it allows the concentrations of those reservior species to increase without them being destroyed.
Also, because there is not much sunlight, the air temperatures become very cold, allowing for what little water vapor there is to form clouds. On these cloud particles, more chemistry occurs that helps convert some of the more unreactive reservior species (like ClONO2) into more reactive reservior species (like Cl2). The chemistry also tends to produce nitric acid on these particles which can then fall out of the stratosphere. This reduces your less reactive reservior species a bit more, and removes some of the possibly balancing NO2 from the system.
Thus, when the sun comes back up, there are plenty of these more reactive reservior species around, with little balancing NO2 to prevent these species' radicals from destroying ozone. Thus, there's a lot of ozone destruction during the beginning of the polar spring.
That's why most of the ozone hole plots from Antarctica you see are from October. It's the start of their spring then.
So, while the ozone movement is hindered by this vortex, the additional chemistry involved is also important.
Hope this helps your understanding. (BTW, I am an atmospheric science student who is just finishing up a grad course in atmospheric chemistry.
Too many things to respond to, so a bulk response is in order. BTW, I'm currently studying stratospheric chemistry in my grad atmospheric chemistry class, so I'm fairly sure on what I'm talking about...
First, to a comment about methane being a bigger ozone destroyer than halogens... While it's possible, as OH radicals produced by the oxidation of methane are ozone destroying, only a small percentage of tropospheric methane makes it to the stratosphere, and most of that is converted to H2O, which photolyzes into OH radicals. Notice that this is a complicated process already, with many fairly slow reaction rates involved. So, methane can be important, but it's highly doubtful that it's truly as important. Also, there's the fact that the OH radicals tend to react very nicely with many other species, while the ClO and FO radicals are more strictly reactive with each other and ozone. The fact of the matter is that methane probably has significantly less effect than halogens on the ozone destruction.
My second comment is directed to all you global warming people. First of all, yes, global warming due to increasing CO2 is almost definitely true. HOWEVER, and I cannot stress this enough, the magnitude of such warming and it's consequences is VERY much in dispute. Truthfully, these global models are decent, but they're running off parameterizations, some of which are sub-optimal; often cannot take into account further feedbacks, like changes in plant growth, changes in cloud cover (and its friend, changes in albedo, or reflection of sunlight), and other natural feedbacks. The climate is so more significantly more complex than these models can take into account that believing the magnitudes and trying to figure out the ramifications of these predictions is truly like playing roulette with a wheel that has millions of spaces. Yes, the oceans will rise, but how much is another question. And even if it is 100m over the next 100 years, why can't humanity adapt to this small change? So, please, stop with your doomsday predictions. Doubling CO2 might cause some warming, but how much is tough to call. And the results might not be that bad. Remember that during the age of the dinosaurs, there were concentrations of CO2 that were about 5-10 times current levels, and life sure wasn't dead then.
Third, I would like to applaud those people who are making sense in other posts. Change really is the only constant in the atmosphere. Humans may change the atmosphere, but to what extent is a question that is hard to really tough to figure out. And even if we figure it out, can we really figure out all the intricacies? Trust me, there's little out there that's more difficult to predict than a fluid's behavior, especially when you add heterogenous chemistry, additional effects from outside it's internal system (oceans, solar, humans, etc.), the interactions of water in the system (clouds, storms, etc.), and God know what else. Let's also not forget that atmospheric science is a truly young science (first major advances in the 1920's...). Even some of these seemingly simple questions haven't even been extensively worked out. A large part of the field is still conjecture and hypothesis. (Let's also not forget that fluids are chaotic by simple nature.) And it'll probably stay that way until the chaos theorists and partial differential equation people give us some even more incredible tools than we currently have. It's amazing that some people take these climate models that predict on significantly worse resolutions and time frames as absolute truth while they don't necessarily believe a 5 day forecast off a model that's significantly better. Noodle that one a while before you pin your faith on models.
-Jellisky
It's actually truly amazing that you could get something sizable out of fog, but it actually makes some sense.
Here's some back of the envelope calculations that might be a bit convincing:
(Note: I'll be using standard scientific E notation. So, 6.4E+3 = 6400.)
The liquid water content of a dry fog is 5E-8 m^3(H2O)/m^3(air). This translates into 5E-4 L(H2O)/m^3(air).
Assume that we can collect a fog bank that's 10km x 10km x 10m (height). That would be 1E+9 m^3 of fog, or 5E+5 (or 500000) L of water in that region.
Even if we only could collect 1% of that, it's still 5000 L. Seriously, that's not too bad for that kind of area of land.
Problem is that evaproation would take back quite a bit of that if one isn't careful.
It's amazing how much water could be tapped from clouds of all sorts. Problem is, that those well-versed in the hydrological cycle will tell you that the water in the atmosphere is VERY small compared to that elsewhere in the world. (We're talking hundreths of percentages here.) Perhaps trying to figure out better ways of de-salinating ocean water should be a little more important.
Just my thoughts.