Slashdot Mirror

Maybe someone who really knows can tell us if it makes a difference that it is frozen fresh water floating on salt water.

There is a difference. Because freshwater is lighter then saltwater it floats on the ocean surface. The conveyorbelt Gulf Stream carries warm ocean water north which warms up Northern Europe. But as melting freshwater submerges the warm saltwater the British Isles along with the Scandinavian countries, France and Germany will become cooler. The Woods Hole Oceanographic Institute has a good webpage on what's right and wrong about the movie "The Day After Tomorrow" which is based on this.

Abrupt Climate Change

What's After the Day After Tomorrow?
A science perspective on the science fiction movie

http://www.whoi.edu/institutes/occi/currenttopics/ abruptclimate_joyce_keigwin.html

quote:
Are We on the Brink of a New Little Ice Age? ...
They are of a magnitude comparable to the Little Ice Age, which had profound effects on human settlements in Europe and North America during the 16th through 18th centuries.

end quote

http://www.whoi.edu/institutes/occi/currenttopics/ climatechange_wef_faq_en4.html
quote:
Abrupt Climate Change ...
The Little Ice Age --The Norse abandoned their Greenland settlements when the climate turned abruptly colder 700 years ago. Between 1300 and 1850, severe winters had profound agricultural, economic, and political impacts in Europe.
end quote

http://www.whoi.edu/institutes/occi/currenttopics/ abruptclimate_joyce_keigwin.html

quote:
Are We on the Brink of a New Little Ice Age? ...
They are of a magnitude comparable to the Little Ice Age, which had profound effects on human settlements in Europe and North America during the 16th through 18th centuries.

end quote

http://www.whoi.edu/institutes/occi/currenttopics/ climatechange_wef_faq_en4.html
quote:
Abrupt Climate Change ...
The Little Ice Age --The Norse abandoned their Greenland settlements when the climate turned abruptly colder 700 years ago. Between 1300 and 1850, severe winters had profound agricultural, economic, and political impacts in Europe.
end quote

Alas poor Slashdot, I knew thee... I long ago gave up hope that the slashdoters would detect a difference between right and wrong, class or crass, hot or not. But I had hoped that there would still be perception of correct or incorrect. An angry and excited mob does not prove the existance of global warming. It does not matter how angry or how large the mob might be. A proof would consist of accurate data, and reasoned theory. The data would be expected to be fairly questioned, and the theory fairly argued. Correct or incorrect is not a democratic process. The earth's climate and temperature is always changing. At one time Greenland was farmland, and not covered in snow. At one time, during the US Revolutionary War, cannons were rolled accross the frozen Delaware River, a freezing which has not occured in living memory. There was a "mini" ice age in Europe in (I think) the 1300's AD. Ocean and Climate Change Institute: http://www.whoi.edu/institutes/occi/currenttopics/ ct_abruptclimate.htm A quote from this refereshingly reasonable website: "While strong trends, such as those associated with global warming, can often be seen in the modern record, the record is too short to decipher other important changes that occur over decades or longer." No amount of excitement will substitute for reason in scientific learning. There is no reason that un-reason should be substituted. If one joins an angry mob, then one should sensibly expect an equal and opposite angry mob to occur. The eventual result of joining the angry are guilt and shame proportional to one's angry activities. If you can not reason, then why are you reading slashdot?

The ABE (Autonomous Benthic Explorer) vehicle has been around since 1995. http://www.whoi.edu/VideoGallery/abe.html. And there are many others.

You know what, you're right. I only took classes in mechanics, materials, design in concrete, design in reinforced concrete, design in steel, participated in a concrete canoe team and a steel bridge team, obtained both a bachelor's and master's degree in civil engineering, worked for 5 years in the field, and bothered to include actual figures in my reply.

How much did I make up?

Why didn't you google for the compressive strength of concrete? Why didn't you google for the compressive strength of steel? Why can't you explain the ten fold difference in those figures?

Oh, and then there's that obviously made up link to an obviously made up PDF about obviously fictional DSVs.

Why didn't you notice that Alvin has a rated depth of 4,500 meters, that it's replacement will have a rated depth of 6,500 meters, and that neither vehicle is made of concrete?

Oh, and in case you still doubt and are still too lazy to research this issue that you obviously care enough to post about, try this:

http://www.whoi.edu/marops/vehicles/alvin/alvin_hi story.html

The meat is in the third paragraph.

But Popular Mechanics says that any steel submersible will crush at 1,800 feet, so it must be true. [oral cursing omitted]

1. The existance of "biomarkers", organic molecules found within oil with clear biological precursors (e.g., pristane and phytane are derived from chlorophyll)
2. The fact that you can put kerogen in a tube in a lab, heat it, squeeze it, and get oil out
3. The utter, utter failure and wasted $$$ of fools who drill in non-organic rich areas

Sorry for the rant, but some statements are just stupid. More information can be found at Woods Hole Organic Geochemistry group ( http://dynatog.whoi.edu/ ), at the Newcastle U site ( http://nrg.ncl.ac.uk ) or on wikipedia ( http://en.wikipedia.org/wiki/Organic_geochemistry )

For more information also see our instrument information page.

Oh, now I get it. The tail of the robot isn't entirely made of rigid plastic, right? Or anyway, the bladder is partly exposed to the outside.

From the drawing I linked, I thought the bladder was enclosed in the tail, in which case it would have needed to load water from the outside, pretty much like a submarine tank, I guess.

The picture on the website from your sig are much clearer, although I can't quite make out the bladder on Spray's tail, yet... Is it the darker grey area on the tail, here?

• Position
• Position near Bermuda (sorry no legend.. light blue is the current, grey is the heading steered to compensate, red dot is current position.)
• Along Track Temp.
• Waterfall Temp Plots
• Along track gross biomass counts.

• Position
• Position near Bermuda (sorry no legend.. light blue is the current, grey is the heading steered to compensate, red dot is current position.)
• Along Track Temp.
• Waterfall Temp Plots
• Along track gross biomass counts.

• Position
• Position near Bermuda (sorry no legend.. light blue is the current, grey is the heading steered to compensate, red dot is current position.)
• Along Track Temp.
• Waterfall Temp Plots
• Along track gross biomass counts.

• Position
• Position near Bermuda (sorry no legend.. light blue is the current, grey is the heading steered to compensate, red dot is current position.)
• Along Track Temp.
• Waterfall Temp Plots
• Along track gross biomass counts.

• Position
• Position near Bermuda (sorry no legend.. light blue is the current, grey is the heading steered to compensate, red dot is current position.)
• Along Track Temp.
• Waterfall Temp Plots
• Along track gross biomass counts.

• Position
• Position near Bermuda (sorry no legend.. light blue is the current, grey is the heading steered to compensate, red dot is current position.)
• Along Track Temp.
• Waterfall Temp Plots
• Along track gross biomass counts.

• Position
• Position near Bermuda (sorry no legend.. light blue is the current, grey is the heading steered to compensate, red dot is current position.)
• Along Track Temp.
• Waterfall Temp Plots
• Along track gross biomass counts.

Crichton is right, global warming will not cause a rise in sea levels, but just the opposite.

If you looked at it from the perspective of lives lost, it will have little effect on the industrialized world, and maybe farmland in non-industrialized countries will slowly disappear.

...from which the 'industrialised world' is already a net importer of food...

Then again, frozen areas in the north may become more cultivable. I'm always amused when people worry that frozen waste land is being changed from global warming, as if that's such a bad thing that the land is now more useful for our own use.

This is based on a bit of profound misunderstanding about the shape of the planet.

Sunlight falling in the tropics meets the surface of the planet at near enough 90 degrees (indeed, the definition of the tropics is that at some point in the year sunlight falls there at exactly 90 degrees). So one square metre of sunlight is available for photosynthesis to the plants on one square metre of surface.

At 60 degrees north (or south) latitude the amount of sunlight (average throught the year) available to plants on one square metre of surface is cosine( 60), or one half, as much. So the maximum total productiveness per unit area is half as much.

Now, assume for a moment there are no oceans, and the planet is a smooth round billiard ball of potentially usable agricultural land. What happens when you increase the temperature of the atmosphere and thus shift the arable zone away from the equator? The total area of the arable zone gets smaller, is what. Because the planet isn't a cylinder, as the mercator projection maps we all look at suggests. The diameter of the earth at 60 north is half what it is at the equator, so there's half as much land at 60 north as at the equator.

And finally, the distribution of land masses on the planet isn't even. Between 40 degrees and 60 degrees south there's virtually no land at all. So if you shift the arable band away from the equator, you decrease the proportion of the arable band which is land as opposed to ocean. Which means you have even less food production.

And that's before you notice the fact (which should be obvious) that the effects of global warming aren't distributed evenly. If, as is suggested, the warm water circulation of the North Atlantic is changing, then the eastern seaboard of the United States and the whole of Western Europe - historically important agricultural and industrial areas - are going to get a lot less productive. If, as is suggested, the Mid West of the United States becomes desert, an enormous proportion of the food producing capacity of the temperate world is going to be lost.

So you need to get away from this idea that 'global warming isn't going to hurt us here'.

Do you honestly believe that "a fat American in a Humvee" is going to destroy the environment and kill millions people?

One fat American in one Humvee, no. But one fat American in one Humvee is burning far more fossil fuel than the same fat American would burn if he rode a bicycle (he'd also be less fat, which wouldn't benefit the planet but it might benefit him). And one fat American in a Humvee driving to work fifty miles from his home is burning far more fossil fuel than the same fat American sitting at his desk in his home telecommuting (although he'd still be just as fat).

The problem is that there isn't just one fat American in a Humvee. There are 293 million Americans, most of whom are fat, in 24 million SUVs. And the difference in energy usage between 24 million SUVs and 24 million bicycles is enough - more than enough - to make a difference.

Underwater Mines, for one.

But the Vehicle used by the NUWC people is a REMUS, from th Woods Hole Oceanographic Institution (WHOI), which does all sorts of oceanographic monitoring.

Underwater Mines, for one.

But the Vehicle used by the NUWC people is a REMUS, from th Woods Hole Oceanographic Institution (WHOI), which does all sorts of oceanographic monitoring.

• Running astrophysics experiments
  
• Whale tagging
  
• Logging for robots
  
• Programming a rocket camera controller
  
• Interfacing with LEGO RCX bricks
  

Not that UCSD was going anywhere, but...

East Coast Mirror @ WHOI

Another project I work on makes /.; go figure. Here are some better links.
The US Global Data Center for the Argo project.

The Woods Hole Oceanographic Inst. Argo page. This includes links to data profiles and other info.

WHOI's realtime data grapher allows you to see where the floats are, where they have been, find a float in any region WHOI monitors, etc.

Also check out the Argo Information Center and their Global Float Map. (The WHOI one tends to be faster if you are only interested in the Atlantic)

Another project I work on makes /.; go figure. Here are some better links.
The US Global Data Center for the Argo project.

The Woods Hole Oceanographic Inst. Argo page. This includes links to data profiles and other info.

WHOI's realtime data grapher allows you to see where the floats are, where they have been, find a float in any region WHOI monitors, etc.

Also check out the Argo Information Center and their Global Float Map. (The WHOI one tends to be faster if you are only interested in the Atlantic)

Another project I work on makes /.; go figure. Here are some better links.
The US Global Data Center for the Argo project.

The Woods Hole Oceanographic Inst. Argo page. This includes links to data profiles and other info.

WHOI's realtime data grapher allows you to see where the floats are, where they have been, find a float in any region WHOI monitors, etc.

Also check out the Argo Information Center and their Global Float Map. (The WHOI one tends to be faster if you are only interested in the Atlantic)

it varies it's roll through it's dive, by changing the orientation of one of the two battery packs; thus as you correctly guessed, creating "uneven" lift.

And you can see, in realtime, when it was last heard from at the status page the last seven records are when it was ship board and being brought back into harbor. This isn't exactly an exciting link until it is redployed, most likely early in the new year.

here are the actual maps of the course it took:
The Whole Trip notice where it got caught in the gulf stream.
Coming South to Bermuda
The Final approach to Bermuda

The Crazy trip through the Gulf Stream the blue vectors indicate the stream's velocity.

here are the actual maps of the course it took:
The Whole Trip notice where it got caught in the gulf stream.
Coming South to Bermuda
The Final approach to Bermuda

The Crazy trip through the Gulf Stream the blue vectors indicate the stream's velocity.

here are the actual maps of the course it took:
The Whole Trip notice where it got caught in the gulf stream.
Coming South to Bermuda
The Final approach to Bermuda

The Crazy trip through the Gulf Stream the blue vectors indicate the stream's velocity.

here are the actual maps of the course it took:
The Whole Trip notice where it got caught in the gulf stream.
Coming South to Bermuda
The Final approach to Bermuda

The Crazy trip through the Gulf Stream the blue vectors indicate the stream's velocity.

The glider Photo Gallery

There is actually an informative and readable press release about the glider in general and the mission it just finished.

This was actually our third attempt to make it from Nantucket to Bermuda, the first two launches unfortunately ran into technical problems very early into the mission.

You can see the data it sent back over the IRIDIUM phone network every seven hours at these pages:
WHOI Instument page about the SPRAY glider
Our real-time plots page

Make sure you check out the plot of velocities when it got caught in the gulf stream

Also particularly interesting are the Continuous Temperature plot
and the Continuous Salinity (salt content) profile.

And you can also view the path it took to Bermuda

We hope to launch it again early next year, possibly for a roundtrip around Bermuda.

This was actually our third attempt to make it from Nantucket to Bermuda, the first two launches unfortunately ran into technical problems very early into the mission.

You can see the data it sent back over the IRIDIUM phone network every seven hours at these pages:
WHOI Instument page about the SPRAY glider
Our real-time plots page

Make sure you check out the plot of velocities when it got caught in the gulf stream

Also particularly interesting are the Continuous Temperature plot
and the Continuous Salinity (salt content) profile.

And you can also view the path it took to Bermuda

We hope to launch it again early next year, possibly for a roundtrip around Bermuda.

This was actually our third attempt to make it from Nantucket to Bermuda, the first two launches unfortunately ran into technical problems very early into the mission.

You can see the data it sent back over the IRIDIUM phone network every seven hours at these pages:
WHOI Instument page about the SPRAY glider
Our real-time plots page

Make sure you check out the plot of velocities when it got caught in the gulf stream

Also particularly interesting are the Continuous Temperature plot
and the Continuous Salinity (salt content) profile.

And you can also view the path it took to Bermuda

We hope to launch it again early next year, possibly for a roundtrip around Bermuda.

This was actually our third attempt to make it from Nantucket to Bermuda, the first two launches unfortunately ran into technical problems very early into the mission.

You can see the data it sent back over the IRIDIUM phone network every seven hours at these pages:
WHOI Instument page about the SPRAY glider
Our real-time plots page

Make sure you check out the plot of velocities when it got caught in the gulf stream

Also particularly interesting are the Continuous Temperature plot
and the Continuous Salinity (salt content) profile.

And you can also view the path it took to Bermuda

We hope to launch it again early next year, possibly for a roundtrip around Bermuda.

This was actually our third attempt to make it from Nantucket to Bermuda, the first two launches unfortunately ran into technical problems very early into the mission.

You can see the data it sent back over the IRIDIUM phone network every seven hours at these pages:
WHOI Instument page about the SPRAY glider
Our real-time plots page

Make sure you check out the plot of velocities when it got caught in the gulf stream

Also particularly interesting are the Continuous Temperature plot
and the Continuous Salinity (salt content) profile.

And you can also view the path it took to Bermuda

We hope to launch it again early next year, possibly for a roundtrip around Bermuda.

This was actually our third attempt to make it from Nantucket to Bermuda, the first two launches unfortunately ran into technical problems very early into the mission.

You can see the data it sent back over the IRIDIUM phone network every seven hours at these pages:
WHOI Instument page about the SPRAY glider
Our real-time plots page

Make sure you check out the plot of velocities when it got caught in the gulf stream

Also particularly interesting are the Continuous Temperature plot
and the Continuous Salinity (salt content) profile.

And you can also view the path it took to Bermuda

We hope to launch it again early next year, possibly for a roundtrip around Bermuda.

Suprised no one has alinked to the actual WHOI announcement.

There was also a very good NPR Science Friday Discussion on this back in August.

Check out the history of Alvin at the Woods Hole site and you'll see that concerns about fatigue in a 40-year-old pressure hull are misplaced. Alvin has been repeatedly overhauled, with pressure hull and other components replaced. The vehicle has undergone recertification by the U.S. Navy every few years, most recently in 2002. In fact, Alvin has gone deeper in recent years; until 1994 the DSV was only certified to 4000m, not the present 4500m.

However, the next Alvin will be larger (27 more cubic feet in the pressure sphere, adding about the volume of a good-sized coffin!) and have greater range, both horizontally and vertically. As "Rosco" pointed out above, operating two DSV's at once would be much more expensive. And frankly, any lesser facility than Woods Hole that can afford to operate a DSV would probably prefer to build their own.

This was after the global cooling fad. The chicken littles were adopting their new global warming fad. Now, the new ice age fad is starting:

Thaw in Greenland Threatens New Ice Age" (this one is kind of funny, it combines global warming with global cooling).

Are We on the Brink of a New Little Ice Age?. From the Woods Hole institute. You will probably dismiss this as a right-wing think tank.

Ice Age Now!. Kind of nutty. Just like the global-warming kooks.

Here's one of the old ones The Cooling World (1975). The scientists quoted are from NOAA. True to the fad cycle, there are no NOAA scientists on the global warming bandwagon.

But flooding won't be the only likely effect of melting polar ice. Increasing fresh water input into the oceans at the poles, if continued, could easily disrupt the Great Ocean Conveyor, which circulates heat throughout the world via currents like the Gulf Stream. This would have drastic and far-reaching effects, like those seen in the Younger Dyas Cooling period, bringing on the next ice age and making England not entirely unlike Siberia -- the bits of England that are still above water, of course.

More information can be found here:

Abrupt Climate Change

One of the things which drives peoples' passion for manned spaceflight is that for many atheists it takes the same place that religion does for others - providing a reference point for the future. Many space enthusiasts believe passionately in "man's destiny in the stars" as a thing inherently good in and of itself, the kind of principle without dependence upon rationality that forms the basis of religious belief.

This is just plain common or garden lunacy, mainly influenced by reading too much cod scifi. Manned inter-system travel is just never going to happen. The human body was not designed to survive many years in low gravity. The complexity of keeping the crew alive and viable for the distance is just too high, and the benefits just too low. There are not a hoard of habitable planets out there waiting for us to just move in - or, to be precise, given the size of the Universe, there probably are, but they are unlikely to be discovered in finite time.

The only argument that manned spaceflight must be undertaken is that the Sun will eventually go nova and destroy the Earth; consequently, we had better think of a way off. Since we don't anticipate this happening within the next hundred years, however, and we do anticipate the continued advance of technology, why not ignore the question for a few hundred years and then start investigating manned spaceflight (at much less effort required)?

The Sun going nova is pretty much an irrelevence. Whatever happens, whether we remain on Earth or all migrate through a freak wormhole to the greater horseshoe nebula, the species homo sapiens will not last ten million years. The average lifespan of a species is much less than that, and human beings are far more destructive of the environment they depend on for survival than the average species.

What is more to the point is the rate at which we are destroying this planet, the rate at which we are poisoning the air we breathe, the land we farm, and the sea we fish. So long as we continue fantasise about some mythical escape route, whether it's the 0930 shuttle to Alpha Centauri Beta or the idea that Jesus is going to call us to an unpolluted heaven where we'll play happy harps among the skipping fluffy clouds for the rest of eternity - so long as we fantasise, we will treat the Earth as expendible.

Folks, it's not.

This is the liferaft. When we've used it up, there won't be another.

It's hard not to be reminded of the civilisation of the Easter Islanders, who cut down their last trees to raise bigger and bigger statues of themselves, and then more or less died out in the ecological catastrophe they'd created.

We're doing the same, just on a bigger scale. Are we really going to use the last barrel of fossil fuel to send a man to Mars? Is that going to stop the Atlantic Conveyor from failing? Is it going to be any comfort when our economy has collapsed, our climate has crashed, and our ability to produce food has been drastically reduced, to be able to say 'hey, but we put a man on Mars'?

My generation - people in their forties now - are not only materially the richest generation that have ever lived. We're also very probably the richest generation that will ever live. We've hoovered up the worlds wealth at a rate that can't be sustained, and dumped our toxic wastes without thought. This isn't something that may bite us in the far distant future; it's something that's beginning to bite now and which will bite harder with every generation that passes.

So if you really believe that the solution is to create an escape pod and drift peacefully away to some happy-clappy planet in the stars, you don't have 'a few hundred years' to wait for better tech to be developed. You'd

No - it's not a scam nor perpetual motion machine. A company has already built submarines on this principle that are being used as autonomous research drones. Here's announcment about the Slocum Glider. Here's a couple of action shots of it being deployed. My advice would be to talk a couple of college physics courses to undertand how BUOYANCY works.
Granted it's more complicated in air (larger because air is so dilute when compared with water) however with advances in composite materials, it is certainly doable.

When such a large change occurs then there are going to be consequences ... which probably wont be good for human beings. What kind of consequences ? OK here is an article describing fears based on a possible slowing / shutdown of the Gulf Stream and perhaps even of the whole conveyor, and here is the article that probably inspired it, and finally here is the Pentagon take on the real world dire consequences.

By the way, I think this change is so large that there is no way it can be stopped. It is just plain too late.

Enjoy.

We actually have access to many thousands of years worth of climactic data, thanks to extracted ice cores, data from the ocean floor, and an number of other sources. For starters, have a look at The Woods Hole Oceanographic Institute's website for more information on the subject.

Here you can read up on the Woods Hole Oceanographic Institute's research on the subject, if you are interested in the details.

Here you can read up on the Woods Hole Oceanographic Institute's research on the subject, if you are interested in the details.

The operative word in that story was "salinity".

Warm salt water floats. Cold salt water sinks. BUT... cold fresh water floats on warm salt water. And when it does, it displaces the warm salt water towards the south. And that, of course, pushes the "great conveyor" to the south.

What's that mean? Well, for an ice-age to happen in the past, it means there had to be one heck of a lot of fresh water disrupting the conveyor up north.

So, to the experts who scream, "See? Warming!" I might suggest that you consider that the fresh water doesn't just *go away* when it has melted. It has a definite impact, and it doesn't make things warmer, either.

Next time, learn a little before you open your mouth.

http://www.whoi.edu/institutes/occi/currenttopics/ climatechange_wef.html