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NASA Study: Ocean Abyss Has Not Warmed
submitter bigwheel sends this excerpt from a NASA news release:
The cold waters of Earth's deep ocean have not warmed measurably since 2005, according to a new NASA study, leaving unsolved the mystery of why global warming appears to have slowed in recent years. Scientists at NASA's Jet Propulsion Laboratory (JPL) in Pasadena, California, analyzed satellite and direct ocean temperature data from 2005 to 2013 and found the ocean abyss below 1.24 miles (1,995 meters) has not warmed measurably. Study coauthor Josh Willis of JPL said these findings do not throw suspicion on climate change itself. "The sea level is still rising," Willis noted. "We're just trying to understand the nitty-gritty details."
Lots of Ice melting. Could be that all the energy is going into phase change right now.
No. Your statement is false. It could only be true if you stated that ice melting is severely underestimated. This stuff is not ignored, you know. It's hell of a lot of energy to change ice to water at 0C. That's why polar ice caps are called air conditioning of the world.
For comparison, it's almost easier to boil water than to melt it from 0C ice to 0C water.
* 334kJ/kg for water to melt it
* 418kJ/kg for water to raise from 0C to 100C
Basically the energy required to melt ice is the same as to raise the temperature of water from 0 to 80C.
It's hard to admit that you could've been wrong isn't it?
Especially after you've been gloating over your high horse position and have insulted everyone that disagreed.
Allow my naivete to shine: What's the temperature of all of the rock that water is in contact with, and what's its thermal capacity relative to the water? Could it be that it's slow to warm as you need to warm all the rock it's in contact with?
You are correct to label your question naive :-)
The average ocean depth is about 4000 m, so the depth being looked at here (just under 2000 m) isn't typically in contact with rock at all. That is, if you demarcated the 2000 m depth line it would intersect very little ocean floor, and that just off the edges of continental shelves. These are pretty much the "mid-depths" we are talking about.
Furthermore, rock is both a) insulating (compared to water) and b) of relatively low heat capacity (compared to water).
Water has a heat capacity of about 4 kJ/kg*K, which is to day it takes 4 kJ to raise 1 kg of water 1 K in temperature. A typical rock (granite, say, although most others are similar) has a heat capacity of 0.8 kJ/kg*K, so rock is both less able to transport heat and less able to absorb heat than water.
Oceans are far more important to the heat balance of the Earth than the air is. Consider the scales. Earth has 5E18 kg of air, and 1.4E21 kg water, and water has 4 times the heat capacity of air, so the thermal mass of the oceans is about 1000 times greater than that of the air (I'm actually surprised it's not more than that, but I've confirmed the numbers from a couple of different sources.)
Given that AGW is adding about 1.6 W/m**2 to the Earth's heat budget, consider a typical square metre of ocean surface, below which is a water column 4000 m deep with a mass of 4E6 kg. That 1.6E-3 kJ/s*m**2 has the capacity to raise the temperature of that water column by 1.6E-3/4*4E6 = 1E-9 K/s. Which doesn't sound like much until you realize there are 3.14E7 s/year, so ocean warming, all else being equal, could be as much as 0.03 K/year, or 0.3 K/decade, or 3 K/century.
These are pretty appreciable numbers, and give a sense of the utility of precise ocean measurements as a way of getting at AGW, because we should be able to see a characteristic depth profile of temperature developing over time that would allow us to infer the additional radiative forcing very directly.
Blasphemy is a human right. Blasphemophobia kills.
In the atmosphere there's a situation: The weather all happens down near the surface, in a region called the troposphere. Here the density/temperature gradients can result in instabilities, where a parcel of air that is, say, lighter than its sourroundings can become MORE ligher-than-its surroundings as it moves up (and vice-versa). Above that is another (set of) layer(s) called the "stratosphere", where everything is most stable right where it is. Nothing very exciting happens there except when something coming up REALLY fast from below coasts up a bit before it stabilizes and moves back down.
The oceans do something similar, but upside down:
Water has an interesting property: Like most materials it gets more dense as it gtss colder - but only up to a point. As it approaches freezing the molecules start hanging out in larger groups, working their way toward being ice crystals. The hydrogens on one molecule attract the oxygens on another, and because of the angle between the hydrogens bondended to the oxygen in each molecule, the complexes are somewhat LESS dense than liquid. As a result, with progressively lower temperatures the density reaches a maximum, then the water begins to expand again. When it actually freezes it is so much less dense than near-freezing liquid that the ice floats. With fresh water the maximum density happens about 4 degrees C. Salt disrupts the crystalization somewhat so the maximum density is a tad cooler (and varies a bit with salt concentration - and thus depth), but the behavior is similar.
The result is that, when you have a mix of cooler and hotter blobs of fresh water, the water closer to 4 degrees sinks and that farther from it rises. The result is that, absent a heat or impurity source below, the bottom (and much of the volume) of a deep lake tends to be stable, stratified, water at about 4 degrees year around, while all the deviations from it and "weather" activity is in no more than about the top 300 feet: Wave action, ice, hot and cold currents, etc. are all above the reasonably abrupt "thermocline" boundary. Below that things are very slow, driven mostly by things like volcanic heat. (Diffusion is REALLY slow in calm water. It takes decades for, say, dissolved impurities to move a couple inches.)
The ocean is much like that, too, but a little cooler and with some temperature ramps spreading out the thermocline due to variations in salt concentration.
So global warming/cooling/weather, whatever would NOT be expected to affect deep water temperatures. This would all be happening in the top few hundred feet. If, say, the ocean were heating up without the surface water temperature changing, this would take the form of the thermocline gradually lowering near the equator and/or rising near the poles, rather than the deep water becoming warmer.
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
You know.....
This story is a legitimate chance for anti-GWers to crow a little bit. (sort of). We have something here, by a reputable source (NASA) that has revealed a tough question. We thought the deep ocean was warming. It turns out it isn't. We were using that as a sink for the heat to explain the recent pause in the global warming. Shit... This makes us search for some answers.
This is science working. It's also NASA saying "hey, wait a minute", which You People always seem to say never happens. It's also STILL saying that the oceans are warming, just not the deep oceans. It also says the deep oceans are REALLY hard to measure, so perhaps it's wrong. We'll see.
So, yeah, Anti-GWers, this was your moment to shine. This was your moment to crow. Instead CppDeveloper decided to make an ignorant comment about CO2 being plant food. Yes. We knew that. Thanks. You're about 20 years behind on your Stupid Anti-GWing statements. We know CO2 is plant food. We know plants absorb it. That's kind of the point of oil. It's a nicely balanced system and we have been A. releasing millions of years of Stored In Plants CO2 inside 200 years and B. cutting down rain forest for beef farms at the same time. We've hashed out your stupid statement years ago. You need to update...
Grumble.....