From the NASA/GODDARD SPACE FLIGHT CENTER and the “30 year trends don’t mean much if we’ve never observed them before” department comes this interesting study.
A new NASA analysis of 30-years of satellite data suggests that a previously observed trend of high altitude clouds in the mid-latitudes shifting toward the poles is caused primarily by the expansion of the tropics.
Clouds are among the most important mediators of heat reaching Earth’s surface. Where clouds are absent, darker surfaces like the ocean or vegetated land absorb heat, but where clouds occur their white tops reflect incoming sunlight away, which can cause a cooling effect on Earth’s surface. Where and how the distribution of cloud patterns change strongly affects Earth’s climate. Understanding the underlying causes of cloud migration will allow researchers to better predict how they may affect Earth’s climate in the future.
George Tselioudis, a climate scientist at NASA’s Goddard Institute for Space Studies and Columbia University in New York City, was interested in which air currents were shifting clouds at high altitude – between about three and a half and six miles high – toward the poles.
The previous suggested reason was that climate change was shifting storms and the powerful air currents known as the jet streams – including the one that traverses the United States – toward the poles, which in turn were driving the movement of the clouds.
To see if that was the case, Tselioudis and his colleagues analyzed the International Satellite Cloud Climatology Project data set, which combines cloud data from operational weather satellites, including those run by the National Oceanic and Atmospheric Administration, to provide a 30-year record of detailed cloud observations. They combined the cloud data with a computer re-creation of Earth’s air currents for the same period driven by multiple surface observations and satellite data sets.
What they discovered was that the poleward shift of the clouds, which occurs in both the Northern and Southern Hemispheres, connected more strongly with the expansion of the tropics, defined by the general circulation Hadley cell, than with the movement of the jets.
The Hadley cell is one of the major ways air is moved around the planet. Existing in both hemispheres, it starts when air in the tropics, which is heated at the surface by intense sunlight, warms and rises. At high altitudes it is pushed away from the equator towards the mid-latitudes to the north and south, then it begins to sink back to Earth’s surface, closing the loop.
“What we find, and other people have found it as well, is that the sinking branch of the Hadley cell, as the climate warms, tends to be moving poleward,” said Tselioudis. “It’s like you’re making the tropical region bigger.” And that expansion causes the tropical air currents to blow into the high altitude clouds, pushing them toward the poles, he said. The results were published in Geophysical Research Letters, a journal of the American Geophysical Union.
Scientists are working to understand exactly why the tropics are expanding, which they believe is related to a warming climate.
The poleward shift of high altitude clouds affects how much sunlight reaches Earth’s surface because when they move, they reveal what’s below.
“It’s like pulling a curtain,” said Tselioudis. And what tends to be revealed depends on location – which in turn affects whether the surface below warms or not.
“Sometimes when that curtain is pulled, as in the case over the North Atlantic ocean in the winter months, this reduces the overall cloud cover” in the lower mid-latitudes, the temperate regions outside of the tropics, Tselioudis said. The high altitude clouds clear to reveal dark ocean below – which absorbs incoming sunlight and causes a warming effect.
However, in the Southern Ocean around Antarctica, the high altitude clouds usually clear out of the way to reveal lower altitude clouds below – which continue to reflect sunlight from their white tops, causing little effect on the solar radiation reaching the surface.
When the results are taken together, the bottom line is that the cloud interactions with atmospheric circulation and solar radiation are complicated, and the tropical circulation appears to play a dominant role, said Tselioudis.
That information is a new insight that will likely be used by the climate modeling community, including the scientists who contribute modeling expertise to the Intergovernmental Panel on Climate Change, said Lazaros Oreopoulos, a cloud and radiation budget researcher at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, who was not involved in the study. Climate modelers aim for their computer simulations to correspond as closely to reality as possible in order to reliably predict Earth’s future climate.
“If current behavior is not well simulated, then confidence in predicted future behavior will be lower,” Oreopoulos said. “I anticipate this study to be looked at carefully and affect thinking on these matters.”
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Read the paper at Geophysical Research Letters: http://onlinelibrary.wiley.com/doi/10.1002/2016GL068242/abstract
Biggest laugh of the day:
“Climate modelers aim for their computer simulations to correspond as closely to reality as possible in order to reliably predict Earth’s future climate.”
HA, week before last they discovered Hadley Cell movement, ….. to wit:
Excerpted from article:
DUH, does not the sinking branch (end) of the Hadley cell start moving poleward as the seasons per se migrate from “winter to summer” in their respective hemispheres?
I think they do, …. I think they do, ….. as is evidenced by the seasonal “poleward” migrations of the Jet Streams in their respective hemispheres.
I think the “other shoe” has yet to fall. In their next update they’ll likely claim that the shift is due to anthropogenic warming, a new “positive feedback” that they desperately need in order to sell their snake oil given Sherwood’s failed attempts to dismiss data from thousands of weather balloons. Our task is therefore very clear, to preempt that claim with another – that the shift is 99% the cause of late 20th century warming.
soòooo satellite data is now good data?
Different satellites, different data collection.
In this case the data is visible light pictures.
“When the results are taken together, the bottom line is that the cloud interactions with atmospheric circulation and solar radiation are complicated, and the tropical circulation appears to play a dominant role, said Tselioudis.”
Collector
“Climate modelers aim for their computer simulations to correspond as closely to reality as possible in order to reliably predict Earth’s future climate.”
Is it just me or is there a big void between that and this:
https://www.ipcc.ch/ipccreports/tar/wg1/501.htm
“The climate system is a coupled non-linear chaotic system, and therefore the long-term prediction of future climate states is not possible. “
You missed the phrase “as closely to reality as possible”, which exonerates any attempt to call their results inaccurate.
This widening of the tropical band is part of the greening of the planet, more greenery with less water needed. This should have a generally cooling effect with a wider band reflecting more sunlight and the Hadley cells delivering a bit cooler air masses poleward. The net effect may be no change at all going poleward of 60, even if the reach is farther. Another unfinished study completed by G.P.!!
Some of the most robust SW Monsoon outbreaks I can recall were when I was a kid (1970s). Oh wait … that’s 40+ years ago. Oh, and that was during a La Nina and Negative PDO, at the outset of the bad drought we had way back when.
Sorry if mentioned before, but the only way the tropics can expand is if the earth tilts further. Just read the actual definition of tropics. It’s not complicated.
Re: high clouds (i.e. cirrus, thunderstorm anvil) and warming. At 17 km altitude in the stratosphere, the ice crystals in thunderstorm anvil clouds are at 190-210 K, and so emit a lot less infrared (IR) black body radiation than clouds in the lower troposphere (e.g. at 277 K) since the Stefan-Boltzmann law varies as the 4th power of the absolute temperature. Therefore if the albedo of both types of clouds is assumed the same (which leads to global cooling in both cases), replacing lower troposphere clouds by stratospheric clouds means less emission to outer space. For energy balance, the emission from the clear areas of the Earth’s surface must then be greater, i.e. there will be a small amount of global warming. Of course, the percentage of the Earth’s surface covered by cirrus and thunderstorm anvil clouds is small compared to that covered by normal cumulus type clouds in the lower troposphere, so the effect of increased clouds overall is global cooling during the daytime. At nighttime, the IR lost to outer space from cooler cloud tops is going to be less than that from clear areas of warmer Earth surfaces, so low-lying clouds can moderate heat loss.
Re: flow of hot air and ocean currents from the Equator toward the poles. It seems everyone assumes these convection currents move according to the simple temperature gradient. IMO warm parcels of air and water at the Equator are less dense than cold air and water (above 4 Celsius), so there is a centrifuge effect due to the Earth’s rotation: the less dense warm stuff gets driven towards the Poles, and the Coriolis Effect deflects currents clockwise in the Northern Hemisphere, and counterclockwise in the Southern Hemisphere. Hence the warm Gulf Stream and the Japan Current. For mass balance, colder, denser fluids move toward the Equator by the centrifuge effect of the rotating Earth, and are deflected in the opposite direction by the Coriolis Effect. Hence Clockwise circulation of major ocean currents in the Northern Hemisphere, and Counterclockwise circulation in the Southern Hemisphere. The one major exception is the El Nino, when water piles up from the upwelling cold Humboldt Current moving North and counterclockwise, and then East-West toward New Zealand. When the pendulum has become high enough, the circulation of ocean water reverses, driving the warm winds West-East and we get the El Nino. Because the troposphere has air circulation in 3 dimensions, the Hadley cells extend only so far toward the poles, before the cool dry air sinks back down, warming due to adiabatic contraction, resulting in zones of deserts around the world at intermediate latitudes.
I forgot to add that the climate change literature is all wrong when it talks about [black body] emission from the atmosphere: the main gases in the troposphere, N2, O2 and Ar, that make up 99.9% of dry air are made up of non-polar molecules that cannot and do not emit any significant infrared (IR) radiation (the main mechanism of emission is that from changing electric dipoles, and this is zero for N2, O2 and Ar). CO2 is a non-polar molecule, since it is linear, O=C=O , but since each C=O bond is polar, bond-bending vibrations create a changing electric dipole moment perpendicular to the O=C=O axis. This accounts for the great amount of absorption/emission of IR photons by CO2 at 667 cm^-1 (667 wavelengths in one cm). But the amount of IR emission from CO2 at 220 K in the stratosphere amounts to only about 16 W/m^2, as calculated from the spectrum observed by satellite looking down on a 210 K thunderstorm anvil (the anvil is too cold to power the emission, which must be due to heating of the stratosphere by incoming Solar UV radiation absorbed by ozone). Emission from ozone in the stratosphere amounts to only about 3 W/m^2, so the total emission is 16+3 = 19 W/m^2, nowhere near enough for energy balance. “Emission from a 220 K black body layer at 10 km altitude” can produce only 133 W/m^2, nowhere near the 240 W/m^2 needed for energy balance. Therefore the literature makes up a temperature of a hypothetical black body that WOULD emit 240 W/m^2, which turns out to be 255 K (this was used by James Hansen to estimate the greenhouse effect as 288 – 255 = 33 degrees). Since the actual spectra obtained by satellites are NOT Planck black body spectra, the “explanations” and calculations are all wrong.
I always wondered if it is possible that at certain times, instead of one ITCZ, there becomes a situation where two form, one north and one to the south of the current position it occupies, and that sequesters a lot of heat in the tropics in the middle, shifting the deserts and bringing rain to the Sahara.
I wonder if something like this, or some such similar shift in the primary circulation of the Earth’s atmosphere could be a trigger for the ice ages to reestablish and the interglacial end
Leaving one strong band of descending air in between the two zones of rising air, and two weaker bands of desert conditions which would be shifted away from the equator.
Negative North Atlantic Oscillation has increased since the mid 1990’s, that doesn’t suggest a poleward movement of the jet stream in the Atlantic.
So global warming is causing polar cooling. I seem to have forgotten that model.
As there has been next to no warming over the last 2 decades, such effects cannot have been cased by warming, if that is in fact what they have been observing. What is the smell? Something is rotten at NASA ..
Ahh, the Arctic is cooling, – and it is our fault!
A simple experiment to show that high clouds back radiate.
In winter.
Place a thermocouple sensor on the ground and one in the air, say 4ft above ground. Plug to a temp readout device.
Choose a calm night when there is patchy Ci cloud.
You will find that in a clear window the ground temp will fall away faster than the Tair.
Note when a patch of Ci blows over (doesn’t even have to be that thick).
You will see the ground temp rise whilst the Tair varies little.
The Ci may be at (say) 6 miles up and a temp of -30C.
Yet it *warms* the ground.
The reason?
There is a heat flux in the ground acting from below to the surface and then to space. The DWLWIR from the CI cloud (in this case) SLOWS that and the heat-flux balance goes out of equilibrium.
The thermo on the surface registers a rise.
Until balance is again achieved.
It does NOT violate the 2nd LoT.
No NET heat is transferred from the cloud to the ground.
Radiative equilibrium experiments have shown that this effect (it happens 24/7/365) out-ways the TSI lost to space via reflection.
Additionally:
Go to a weather website and access the Sat pic page.
On a day with Ci cloud you will see that the IR channel shows the CI opaque.
The Vis channel will be clearer (as in seeing structures below the Ci).
High cloud warms overall.
Low cloud cools overall.
Sorry and all that.
” A simple experiment to show that high clouds back radiate.”
It’s far simpler to just get a ir thermometer and point it up.
The problem is all clouds are warmer than a clear sky, and under clear skies, a grass covered lawn will cool below air temps.
Meanwhile in the tropics and over the equatorial oceans water vapour is being lifted from the sea surface and hurled 15 kilometres up into the atmosphere where it cools to MINUS ˚70 C!!!
You stick with your pictures of radiative imbalances of a few watts.
I’ll stick with the giant heat pump that cools our atmosphere on an hourly basis!
(the truly gratifying thing is that you don’t even realise how ridiculous your claims are!)
I’ve finally put my finger on the major flaw at the heart of the Warmist position.
We ‘skeptics’ accept that CO2 is a ‘greenhouse’ gas, and that Water Vapour is a ‘greenhouse’ gas.
However, we ‘skeptics’ also accept that Water Vapour is also a major ‘cooling’ agent, due to clouds and enthalpy.
The physical transportation of heated water vapour to frigid low pressure levels of the upper atmosphere literally ‘dwarfs’ any radiative imbalances.
Warmist models fail because they refuse to accept the complex role of Water Vapour in the atmosphere!
As always I point directly to the most excellent satellite imagery of the University of Wisconsin which illustrates these principles immediately and effortlessly!
Well, that’s it. Earth is doomed!
There’s nothing we can do now but watch the Atheist Nothing-Cam and wait for nothing to become a new universe.
http://31.media.tumblr.com/cfa55f70bbc5ce545eed804fa61a9d26/tumblr_mfpmmdCdWA1s1r5leo1_500.gif
“…“Sometimes when that curtain is pulled, as in the case over the North Atlantic ocean in the winter months, this reduces the overall cloud cover” in the lower mid-latitudes, the temperate regions outside of the tropics, Tselioudis said. The high altitude clouds clear to reveal dark ocean below – which absorbs incoming sunlight and causes a warming effect…”
High altitude clouds clearing will reveal not only dark ocean, but will open a shutter to IR longwave from the ground surface–i.e. expose 305K surface in the subtropics to direct transport to deep space.
Does a thirty year observation span sound like only half of the sixty year cycles we’ve been hearing about? If a barely detectable temperature change can drive the Hadley cells that much, then it can’t be long under the alarmist scenarios before the Hadley cells expand past the poles…
Reply to posting by cba, May 7 at 3:00 pm:
Thank you for updating figures on albedo. I derived albedos from the left side of the updated Kiehl & Trenberth energy budget diagram available at https://chriscolose.wordpress.com/2008/12/10/an-update-to-kiehl-and-trenberth-1997 and from the MODTRAN spectrum at https://en.wikipedia.org/wiki/Radiative_forcing . I am willing to concede that your figures are better, but the conclusions are still the same: high clouds are warming. Here are updated calculations:
If the albedo of the surface waters is 0.04, and land is assumed to be 0.12 (similar to that of the Moon), and water covers 2/3 of the Earth’s surface, then the average surface albedo will be [2(0.04) + 0.12]/3 = 0.067 [note that you recalled it is around 0.08, close enough]. Since the overall albedo is given as 0.30 in the literature, if cloud albedo is x, and cloud cover is 62%, then
0.62x + 0.38(0.067) = 0.30
0.62x = 0.30 – 0.0255 = 0.27
x = 0.27/0.62 = 0.44
Then in my calculations, the difference in Bond albedo is 0.44-0.067 = 0.37, so replacing 1% of the surface which is cloudless by reflective cloud will decrease the incoming Solar radiation absorbed at the surface by
1(341.3)(0.37)/100 = 1.26 W/m^2 . This leads to COOLING.
For clouds overall, if the 228 W/m^2 escaping at the TOA (consistent with 240 W/m^2 overall for energy balance, and 260 W/m^2 escaping from a cloudless surface at 288.2 K) remains the same, then the decrease in outgoing TOA emission on replacing 1% of the Earth’s surface which is cloudless with clouds is still 1(260-228)/100 = 0.32 W/m^2, which would lead to WARMING.
The NET result of the two components is still COOLING, by 1.26-0.32 = 0.94 W/m^2.
However, the calculation for a 210 K Thunderstorm Anvil also stays the same, at 1(260-110)/100 = 1.50 W.m^2, and this would lead to WARMING. This time, the NET result is 1.50 – 1.26 = 0.24 W/m^2 WARMING. This result becomes even greater if the high clouds which emit Planck black body radiation are at even lower temperatures, like 190 K or 200 K .
However, as I wrote several times, the importance of high clouds is negligible, given the small percentage of such clouds. The argument has perhaps been used by the CAGW true believers to try to bolster their cause, which is fatally flawed in so many ways. And someone has posted Roy Spencer’s measurements showing warming leads to a decrease in these warming cirrus clouds, so the feedback is negative, not positive. I also agree with geo smith’s skepticism re the transparency of ice crystals in cirrus clouds: if I can see them reflecting white light, their albedo is not zero, so some of the incoming Solar visible radiation will be reflected back to outer space.
IMO the right side of Kiehl & Trenberth’s energy budget diagram is wrong to show back-radiation from greenhouse gases like CO2 and water vapour “warming the planet”. Infrared (IR) photons are emitted from vibrationally excited states, and these are formed (1) either by occasional high-energy collisions with the main air molecules (N2, O2, Ar), or (2) by absorption of IR photons at resonant frequencies. In either case, there must be an outside power source, or else the atmosphere would continually cool. That power source is not incoming Solar radiation, which is in the visible and near-infrared, because the air is mostly transparent at those frequencies. Rather, the mainly visible radiation reaches the Earth’s solid and liquid surface and is absorbed there (albedo 0.07). The energy does not disappear, but shows up as increased vibrations of the zillions of bonds in the surface molecules; i.e. as an increase in temperature. But almost all condensed materials at the Earth’s surface have emissivity close to 1, so emit IR (far-infrared) radiation according to the Planck radiation law for black bodies. At 288.2 K (15 Celsius), the peak emission is close to the central band frequencies for CO2 bond-bending vibrations. So within metres of the surface, almost all the emitted IR photons at 667 cm^-1 are absorbed by CO2 molecules, which are boosted from their ground vibrational state (vibrational quantum number v=0) to the first excited state (v=1). The literature then states that these molecules re-emit IR photons which are then absorbed by molecules higher up, and the process continues until the IR photons finally escape from the atmosphere to outer space. This last sentence is wrong. The literature has failed to understand that the excited state CO2 molecules can lose their extra energy during radiationless collisions with N2, O2, and Ar molecules which constitute 99.9% of dry air and outnumber CO2 by 2500:1. The energy does not disappear, but ends up in increased translational and rotational motions of all molecules departing from the collision zone. I.e. the troposphere has warmed up. This is the true, simple explanation for the atmospheric greenhouse effect. As I wrote previously, the non-polar N2, O2 and Ar molecules do not re-emit IR photons, because the main mechanism for radiation requires a changing electric dipole moment. Therefore talking about “emission from the atmosphere” cannot involve N2, O2 and Ar gas molecules, which do not act like Planck black bodies (spectrometers looking upward at night in the “window” at 900 cm^-1 observe zero emission from the atmosphere). And CO2 and water vapor absorb and emit only at certain frequencies, in bands, not across the entire far-infrared black body spectrum characteristic of the solid and liquid surface of the Earth, or of condensed states (liquid droplets or ice crystals) in clouds.
Is there any observable back-radiation from excited state CO2 and water vapor molecules? Sure there is.
But the energy for each photon in back-radiation initially had to come from a photon of the same frequency emitted from the warm solid and liquid surface of the Earth. Therefore one can consider a back-radiation photon as essentially a photon originally emitted from the Earth’s surface, and after a delay reflected back to Earth. You can see therefore that there is no net change in the energy/temperature of the Earth’s surface.
Back-radiation does slow the rate of cooling of the Earth’s surface at nighttime. This is most obvious on clear winter nights in the Arctic, where nighttime lasts for months. Without any clouds, IR photons emitted from the Earth’s surface at frequencies not absorbed/emitted by CO2 and water vapor just escape directly to outer space (which is at 3 K, the temperature of the cosmic microwave background). This rate of heat loss by radiation can be so great that a temperature inversion occurs (the temperature at several hundred metres altitude can be greater than the surface temperature). Then, heat stored in the troposphere during the daytime/summer can be radiated back to Earth at greenhouse gas frequencies. An excited state CO2 molecule which has lost its energy as an emitted photon lost to the Earth can be replenished by collisional activation with the main air molecules (at 273 K = 0 Celsius, about 3% of all CO2 molecules are in the v=1 excited state at equilibrium, in accord with the Boltzmann distribution). In this way, energy stored during the daytime/summer as enthalpy (heat content) can moderate the temperature drop of the surface. But this is not the same as actually increasing the temperature of the Earth’s surface (warming the surface). During the long nighttime/winter, the average temperature/heat content of the troposphere does decrease, along with the surface temperature.
Where did the non-physical “explanation” for the greenhouse effect, involving radiation exchange to the top of the atmosphere come from? IMO from a false analogy with processes inside stars, accurately modelled by simple linear computer models (spherical stars can be modelled radially, with a shell surface weighting factor of 4.pi.r^2). Heat from exothermic thermonuclear fusion reactions at the center of the Sun is transported via gamma ray photons until they are degraded to visible photons which finally escape from the photosphere. The analogy fails for two main reasons: (1) gamma ray photons lose energy via inelastic collisions with electrons, protons, etc. in the Sun’s interior (Compton scattering), but these free particles have a continuous energy spectrum, so the photons can change frequency at each collision. However, the vibrational energy levels of CO2 and water vapor molecules are quantized, so the energy of the photons cannot be degraded. Constant absorption and re-emission cannot by themselves warm the troposphere; what’s required is inelastic collisions with the main molecules of the atmosphere (N2, O2, Ar) which cannot and do not re-emit IR photons. (2) photons of visible radiation escape at the photosphere because that’s where the atoms (ions and electrons of a plasma) run out; the mean density of the Sun is about that of liquid water on the Earth. There is no similar sudden drop in density at the top of the troposphere which would allow IR photons to “suddenly escape to outer space”. The density at 10 km (equivalent to the top of Mt. Everest) is about 1/4 that at sea level. If CO2 is so powerful an absorber/emitter that photons are essentially completely absorbed within metres of the Earth’s surface, a factor of 4 decrease in density is highly unlikely to allow “escape to outer space”. And a 220 K black body surface at 10 km altitude would emit only 133 W/m^2, nowhere near the 240 W/m^2 needed for energy balance. The literature “explanation” for the greenhouse effect is wrong in so many ways….
As I’ve pointed out umpteenth thousand times, explain why the oceans are warming and you explain why the globe is warming. Fewer clouds blocking direct sunlight, allows more high intensity visible light to reach the oceans. That is how you warm the oceans, and it has nothing to do with CO2. The article even uses a similar quote to what I’ve used umpteen thousand times about a room being heated by lifting the shade has nothing to do with CO2.
Note, that above quote explains warming, but it also rules out CO2 and IR as the cause. Clouds block/reflect INCOMING RADIATION. The warming discussed above has everything to do with warming due to more incoming radiation reaching the earth, and absolutely nothing to do with CO2, absolutely nothing. These climate “scientists” wouldn’t wouldn’t know the truth if is punched them in the face. Talk about not seeing the forest through the trees. These climate scientists are simply only looking for CO2 as the cause, they aren’t seeking the truth.
No Duh!!! But didn’t these NASA “scientists” get the memo? This “science” is settled. What a complete joke NASA and the field of climate science has become.