Slashdot Mirror
Ocean-wide Sensor Array Provides New Look at Global Ocean Current (nature.com)
An anonymous reader shares a Nature article: The North Atlantic Ocean is a major driver of the global currents that regulate Earth's climate, mix the oceans and sequester carbon from the atmosphere -- but researchers haven't been able to get a good look at its inner workings until now. The first results from an array of sensors strung across this region reveal that things are much more complicated than scientists previously believed. Researchers with the Overturning in the Subpolar North Atlantic Program (OSNAP) presented their findings this week at an ocean science meeting in Portland, Oregon. With nearly two years of data from late 2014 to 2016, the team found that the strength of the Atlantic Meridional Overturning Circulation -- which pumps warm surface water north and returns colder water at depth -- varies with the winds and the seasons, transporting an average of roughly 15.3 million cubic metres of water per second. The measurements are similar in magnitude to those from another array called RAPID, which has been operating between Florida and the Canary Islands since 2004. But scientists say they were surprised by how much the currents measured by the OSNAP array varied over the course of two years.
They still haven't found the underground city of Atlantis!
Maybe because they keep looking in the ocean.
Post may contain irony: discontinue use if experiencing mood swings, nausea or elevated blood pressure.
things are much more complicated than scientists previously believed
No doubt. And that will continue to be the case for the foreseeable future.
for a system that will show in great detail how human activity is irrevocably changing the climate
of the planet for the worse.
Hate to break it to you, but it actually proves we don't have a thorough-enough understanding of planetary systems to be able to make reliable predictions 100 years or more in the future.
From TFA:
The first results from an array of sensors strung across this region reveal that things are much more complicated than scientists previously believed.
Ocean currents a huge major factor in global climate trends, and here we're still making major discoveries about things like ocean currents and magma plumes.
Only recently it was accidentally discovered by a NASA satellite that the accelerated Antarctic ice-melt rates that had been blamed on AGW were actually being caused by a monster-sized magma plume rivaling the Yellowstone magma plume underneath the ocean floor under the Antarctic.
Given that there is so much we are still learning and have yet to learn, it's patently absurd to insist we can reliably & accurately predict global average temperatures 100 years or more in the future.
Strat
Progressivism (aka US 'Liberalism'): Ideas so good they need a police/surveillance-state to enforce.
Scientists love to be surprised. It leads to new and interesting insights into the world we live in. Scientists question the results of other scientists all the time. Science is one of the most competitive areas of human activities. The problem for people like you is if you want to question scientific conclusions you need to bring some real science to the table with you.
This. Trashing science is easy. Doing science is hard.
If it weren't for deadlines, nothing would be late.
No, actually. What you're seeing is an objection to seeing the Autopay box ticked next to any "scientific consensus" that arises. The assumption that such "conclusions" must automatically be reflected in social/economic policies is obnoxious. That's a matter for the political sphere and people's ability and willingness to pay the freight, nothing else.
What alternative to the consensus theory has been proposed? That fairies did it?
Pointing out there is a consensus (when there is) is hardly a crime. There's a consensus. Get over it. Why did a consensus on the issue arise? Because the scientists who supported the theory produced evidence, and then further evidence, and not one person who supports the myriad of alternate (and conflicting) views can produce a shred of evidence in support of the alternatives.
If you want scientists to support your alternative view, stop whining and produce evidence.
You seem to have a faith based belief that scientists don't know nuthin'.
We already know that there is a greenhouse effect on Earth since the normal thermodynamic temperature of an object orbiting at Earth's distance from the sun is about 0 degrees Fahrenheit (-18 degrees Celsius). Earth's average surface temperature is about 58 F. The presence of greenhouse gases in the atmosphere explains that temperature difference nicely. It makes sense that increasing the level of greenhouse gases in the atmosphere would increase temperatures. So scientists may not be able to predict with precision exactly what temperatures will be in 100 years but they can pretty easily predict they will be warmer than they are now as long as greenhouse gas levels in the atmosphere continue to increase. It's difficult to predict exactly what will happen since there are no analogs in Earth's history to the current rapid increase in greenhouse gases. Uncertainty is not your friend because the effects could just as easily be worse than expected as they could be better than expected.
NASA says that Antarctica is gaining ice mass except for the area with the plumes, so...
That means mathematically for CO2 to increase the temperature by 1C degrees that a single molecule of CO2 must be capturing and radiating back 2500C degrees.
I'm afraid your math is missing two parts: one, the thermodynamics of the problem, the CO2 molecules aren't sitting there in a vacuum, they're rattling around in thermal equilibrium as part of the atmosphere; two, the direction of outgoing vs. incoming radiation. So, in order of what happens:
any given CO2 molecule happens to be really good at absorbing IR (much more so than the rest of the stuff you list) while being transparent in the visible. Yep, very true, just go into a lab and measure absorption spectra. Turns out some even less common items like methane are even better at it, but let's consider just CO2 for now.
Next, that CO2 molecule, with the extra eV or so of IR energy it picks up from that one IR photon coming from some warm parking lot, can get rid of the bonus energy in one of two ways. It can give up that energy in a collision with other air molecules, turning the energy into thermal energy: air warms up slightly.
Or, it can spit an IR photon back out in a random direction. If the IR is coming from ground warmed up by sunlight, it's headed up into the air. When the CO2 re-radiates, half the time it's still going up. Half the time it's shining back down. So, in this very simple view, half the energy stays trapped ... also warming things up slightly. Nowhere required a 2500K blackbody as you implied, two ways to get heat trapped.
Making sure all the details are accounted quantitatively for is a bigger job (what's the exact absorption for each atmosphere component? What fraction is re-emiited vs collided away?): but people have done it. Important test: does all that work it agree with reality? Yeah, pretty much. Average temperature of a bare rock in orbit at 1AU is below freezing. Average temperature of the Earth with a CO2-laced atmosphere: not below freezing. Even just comparatively the simple energy balance equation outlined above gets this part right. In fact, yay for the greenhouse effect, or we'd be closer to Mars-like climate than what we are. A large fraction of the cold nasty Mars weather is due to its lack of a decent thick atmosphere (even though what's there is mostly CO2, there's not enough to help out very much), more so than the "it's a bit farther from the sun 1/r^2" contribution. And vice-versa for Venus: it's huge column depth of CO2 makes it the lead-melting sweatbox that it is, much more so than being slightly closer to the sun.
So while we may have been having temperature increases since the end of the last ice age, it is hard to say for certainty if things are speeding up or not,
Turns out that it's not hard to say. That's not even a particularly tricky bit of data analysis.
but mathematically it just seems unreasonable that CO2 is the culprit. Perhaps the Earth itself is radiating more heat, we are seeing quite a bit more volcanic activity so maybe more magma is closer to the surface. Or perhaps it is just the heating from the Sun cycles and as we start to enter the coming minimum the cooler temperatures will prevail.
Geologists say no to the first, although volcanic activity can contribute to greenhouse gases. And it also goes the other way, by reflective aerosols that cool things (this is where some cool potential geo-engineering ideas were born). As an astronomer I can say with more certainty that solar cycles do not change the overall energy output of the sun enough to account for what we're seeing now. Why? We measure that solar radiation as seen at the earth really well, and have been doing so for quite a few solar cycles. Not enough delta-luminosity.
Or maybe it is just the natural cycle of heating after an ice age.
There are certainly larger cycles, and of all the things you said, this is the least bo