The world has never seen such freezing heat
in [Design]
|
Prev: Class D audio driver with external mosfets
Next: NE162 mixer: input/output impedance in balanced mode?
From: Martin Brown on 23 Dec 2008 03:30 Whata Fool wrote: > don(a)manx.misty.com (Don Klipstein) wrote: > >> In <hj8kk4le5784bdo5pf3r64g5rda9h6mv7r(a)4ax.com>, Whata Fool said in part: >> > Sidewalks in NYC can get too hot to walk on barefoot, I suggest > the ocean surface and the ground on the banks of the Amazon is always > less than 100 F. Probably true for the oceans less clear for shallow pools and unlikely for some equatorial river banks. Plants make pretty good air conditioners in terms of shading the ground and transpiring water. >>> Doesn't the fact that water evaporation provide a lot of >>> cooling of the "surface" suggest that the surface would be warmer >>> without water or GHGs? >> The heat goes somewhere - it does not get destroyed. It becomes part of >> the burden of radiational cooling of the atmosphere by GHGs. > > You seem to be contradicting your (and the current thought) premise > that the atmosphere would be cooler (or even below freezing), by saying > that cooling the atmosphere is a burden. Parts of the surface in direct sunlight would be warmer without GHGs but the parts in darkness would also get much colder since outgoing long wave thermal radiation has a free path to escape. This means global average temperature is lower. > >> Keep in mind that a blackbody in Earth's orbit, with a GHG-free >> atmosphere or none at all, would be cooler than Earth is now. And since >> Earth has thermal IR emissivity being a higher percentage than its >> absorption of solar radiation, with GHGs removed and albedo unchanged it >> would be colder than a blackbody. >> >> - Don Klipstein (don(a)misty.com) > > > It isn't even rational to say "or none at all", when the sun is > shining on the east facing slopes of mountains, there would be a lot > of thermal transfer to nitrogen, with no way for the nitrogen to cool > at that rate. Oxygen would not be much different than nitrogen. He meant no atmosphere at all. We happen to have a large satellite moon that provides concrete evidence of the extreme temperature range and average temperature for an airless body at about the Earths orbit. We don't have a handy example of a pure N2 or H2 atmosphere although some calculations of atmospheric circulations for the solar system planets based on that simplifying assumption do exist in the literature. The biggest factor in determining the nature of the atmospheric circulation is distance from the sun, spin rate of the planet with orbital inclination and eccentricity taking third and fourth place. > > Frankly, I don't think you are able to focus on a hypothetical > situation without drifting back to the learned atmospheric physics. You are clueless. Don's patience is admirable, but misguided as there is no way to educate "What a Fool" - he is well named. > Eight hours or more of sun warming the surface to more than 120 F > and the nitrogen warming and convecting upward would moderate the surface > temperature almost as much as the present atmosphere, but would not be > cooled by radiation. But it would be cooled by mass air circulation to the cooler poles and the night side terminator and particularly across the dawn edge where the temperature gradient will be maximised. It is a heat engine with N2 as the working fluid. In the sun would get warm, but out of the sun would get colder. GHGs put simply reflect some of the escaping LW IR radiation that would otehrwise escape back down onto the ground. It is clearly beyond your ability to comprehend. Regards, Martin Brown ** Posted from http://www.teranews.com **
From: Bill Ward on 24 Dec 2008 13:37 On Wed, 24 Dec 2008 02:45:38 +0000, Don Klipstein wrote: > In article <pan.2008.12.22.16.51.13.543198(a)REMOVETHISix.netcom.com>, Bill > Ward wrote: >>On Mon, 22 Dec 2008 02:11:15 +0000, Don Klipstein wrote: >> >>> In article <pan.2008.12.15.07.25.04.110636(a)REMOVETHISix.netcom.com>, >>> Bill Ward wrote in part: >>> >>>>On Mon, 15 Dec 2008 03:49:54 +0000, Don Klipstein wrote: >>>> >>>>> In article <pan.2008.12.02.09.04.49.526817(a)REMOVETHISix.netcom.com>, >>>>> Bill Ward wrote: >>>>>>On Tue, 02 Dec 2008 05:55:11 +0000, Don Klipstein wrote: >>>>>> >>>>>>> In <pan.2008.11.26.21.17.23.310423(a)REMOVETHISix.netcom.com>, Bill >>>>>>> Ward wrote: >>>>>> >>>>>>Do you think that the "wet adiabatic" environmental lapse rate is >>>>>>related to latent heat, or is it simply less than the dry adiabatic >>>>>>lapse rate because it's not at equilibrium? >>>>> >>>>> It is less due to latent heat. >>>>> >>>>> The "1 size fits all figures" that I have heard are 3.5 degrees F >>>>> per >>>>> 1,000 feet for the wet one and 5.4 degrees F per 1,000 feet for the >>>>> dry one. >>>>> >>>>>>>> Is it primarily by radiative transfer, or convection? It seems >>>>>>>> to me >>>>>>>>it must be convective, simply because warm, wet air is less dense >>>>>>>>than cold, dry air, and quickly rises to maintain the lapse rate. >>>>>>> >>>>>>> Much of the time the answer is a significant factor other than >>>>>>> radiation and vertical convection. Much of the "global convection" >>>>>>> involves air movement within a degree of horizontal, and often >>>>>>> forming clouds when moving upwards. Sometimes the lapse rate there >>>>>>> is between the "dry adiabatic" and the "wet adiabatic" rates and >>>>>>> the clouds have billowy cumuliform tops or are cumuliform >>>>>>> throughout. Sometimes "warm advection" occurs more at cloud-top >>>>>>> level than at cloud-base level (from the windspeed being greater >>>>>>> higher up in the troposphere), causing the clouds to be stratiform. >>>>>> >>>>>>OK, that all sounds plausible, but I'm not sure how much effect the >>>>>>horizontal component would have, other than the obvious mixing. >>>>> >>>>> The horizontal component involves atmospheric heat transfer from >>>>> the >>>>> tropics to the poles. It is very significant. It leads to frontal >>>>> inversions, which cover significant area ahead of warm fronts >>>>> (including areas where the warm fronts fail to reach at the surface). >>>>> It leads to existence of stratosphere at middle and upper latitudes >>>>> at pressure levels below that of the tropical tropopause. >>>>> >>>>>>>>IR radiated from the surface would be quickly absorbed by WV, >>>>>>>>clouds, CO2, and other GHGs, and at 500W/m^2 would be overwhelmed >>>>>>>>by the 10's of kW/m^2 available from convection of latent heat. >>>>>>> >>>>>>> Half the Earth's surface has no clouds overhead at any altitude. >>>>>> >>>>>>Surely you mean "at any given time". Or are there really regions >>>>>>comprising half the Earth's surface that have never had a cloud in >>>>>>the sky? >>>>> >>>>> I did mean "at any given time", and "those given times" in "those >>>>> given locations" account for half the world lacking clouds at any >>>>> altitude. >>>> >>>>OK, I'll buy that as an average. But I'll bet the tropics are far more >>>>likely to be cloudy than the polar regions, and that's where most of >>>>the cooling occurs. >>>> >>>>>>> The surface manages to radiate *somewhat* to outer space at night >>>>>>> when the air overhead is clear - otherwise there would be no such >>>>>>> thing as nighttime frost when air 2 meters above the surface is at >>>>>>> +2 degrees C (a fairly common situation). Some of the outgoing >>>>>>> radiation can easily be absorbed and reradiated a couple or a few >>>>>>> times by GHGs, but net of that is upward (and upward net is reduced >>>>>>> by increase of GHGs). >>>>>> >>>>>>OK, no argument with that. I look at it as the surface radiating to >>>>>>a target warmer than 3K space, but it's the same math. >>>>>>> >>>>>>>>At night, convection stops, but cooling is not required at night. >>>>>>>>Convection kicks in during the day, when cooling is needed. >>>>>>> >>>>>>> Cooling still occurs at night by radiation. 5 AM temperature has >>>>>>> a >>>>>>> great rate of being less than 10 PM temperature. Upper level of >>>>>>> radiation by atmosphere at night has half of its radiation to outer >>>>>>> space. That heat comes from radiation from surface - even if >>>>>>> absorbed and reradiated a couple times along the way. >>>>>> >>>>>>Agreed. At night the flux is always outward. >>>>>> >>>>>>> The "upper radiation level" also varies greatly with wavelength. >>>>>> >>>>>>Do you mean the "effective radiating altitude", which is calculated, >>>>>>or some sort of integrated spectrum involving all the photons >>>>>>reaching a surface outside the atmosphere, like a satellite imager? >>>>>>Neither I, nor apparently Google, is familiar withe the term "upper >>>>>>radiation level". >>>>> >>>>> Looks like I did not choose wrds well - it should have been >>>>> "effective >>>>> radiating altitude". >>>>> >>>>> Keep in mind that the "effective radiating altitude" is very fuzzy, >>>>> since some wavelengths radiated by the surface have good atmospheric >>>>> transparency (and a fairly clear shot to space) as long as there are >>>>> no clouds, others have low chance of reaching the 500 mb level >>>>> without being absorbed, and some are in-between - with absorption and >>>>> reradiation varying directly with concentration of GHGs. >>>> >>>>That's my point. It's not well enough known to claim 1.5W/m^2 is going >>>>to make any difference at all. All it takes is a minor negative >>>>feedback loop to correct for that small an effect. >>> >>> The Ice Ages having temperature swinging 10-plus K from slight >>> periodic >>> changes in insolation show that we have a lot of positive feedback. >> >>Has that actually been shown, or just inferred? If there were >>significant positive feedback, it would have shown up in the ice core >>signal as an exponential runaway to the rail. For long term stability, >>you need negative feedback. > > You can have positive feedback without latchup. Example: Armstrong > regenerative receiver. Right. But as you'll soon notice if you build one, they require constant and very careful gain tweaking in use, or they break into rail to rail oscillation. The super-regenerative receiver solved that by using chaos theory (before it was identified as such) to eliminate that, as it periodically quenches with negative feedback to stay on the verge of instability. Of course the superhet obsoleted both until the advent of digital techniques. The point is that systems are not long term stable unless they involve net negative feedback. Relying on luck to keep the loop gain under +1 is not a successful strategy. The climate appears long term stable, so I doubt any net positive feedback. > The ice core data do indicate CO2 atmospheric concentration lagging > temperature by about 800 years. (But temperature lagged CO2 since > Industrial Revolution.) Generally, to cross-correlate signals, you need to detrend them, to reduce correlation to other unrelated variables which may be overall increasing or decreasing with time. When I look at the recent temperature and CO2 concentrations, they don't seem to correlate unless you include the fact that they both have been generally increasing. For the last decade or so, CO2 has been steadily increasing, while temperature has stopped increasing, and may be decreasing. The same holds true in the 1940-1975 period. You could probably get a better correlation between temperature and the total number of electronic memory bits produced than you can with CO2. >>>>>>>>I don't see how radiative cooling is even necessary below the >>>>>>>>cloud tops, since there's plenty of cooling capacity from >>>>>>>>convection. >>>>>>> >>>>>>> When frost or dew forms on the ground and on cars and trucks, >>>>>>> the heat >>>>>>> loss has a very impressive rate of by being by radiation. >>>>>> >>>>>>True, but radiation is peanuts compared to the available cooling >>>>>>capacity of latent heat during the day. If the surface radiation >>>>>>were blocked, convection could easily make it up. >>>>> >>>>> What about on days when there is no convection past the 750 mb or >>>>> so >>>>> level for even a minute? (I see plenty of those even with sky >>>>> half-clear and cumulus clouds present.) What about in Arctic and >>>>> upper-midlatitude areas where change in radiation balance during the >>>>> 18 or whatever hours per day with little convection has a >>>>> significicant effect on snow/ice cover, and that affects how much >>>>> solar radiation the surface absorbs? >>>> >>>>It's the total transferred power that counts. It doesn't take much >>>>latent heat convection to make up for a lot of radiation. The place >>>>to look for changes is where the cooling is greatest, not places which >>>>are already being warmed by the tropics. >>> >>> Cooling is significant in the polar areas. The global insolation >>> map in >>> the Wiki article on insolation shows the polar areas getting about 1/3 >>> as much insolation as the tropics do. Cooling is even more than 1/3 >>> that of the tropics, since global circulation transfers heat from the >>> tropics to the polar regions. >> >>Doesn't that mean the tropics still provide the majority of the cooling? > > Yes, that is true, but that does not negate the significance of > cooling > in the polar and near-regions - nor the significance of ease of changing > temperature of the surface and lower troposphere in the polar and > near-polar regions. How quantitatively do we know the significance of polar cooling? Is there any reason to believe it would somehow counteract increased cooling in the tropics? > >>> Where the surface can warm significantly before convection occurs is >>> probably where the world can warm more if GHGs increase. I would also >>> expect more warming in areas where warming reduces surface albedo. >> >>Aren't those areas already colder than average? > > I would say not - the world has upward anomaly in temperature of > surface > and surface-level atmosphere and lower troposphere overall, which is > greatest in the Arctic. I meant actual temperature, not anomaly. The poles are likely below 14C average temperature. >>>>>>>>Once the energy reaches the tropopause, as you imply, it's a >>>>>>>>pretty straight shot to 3K deep space, since there's not much >>>>>>>>atmosphere left to absorb IR. >>>>>>>> >>>>>>>>Perhaps it's easier to see if you look at the lapse rate as >>>>>>>>bounded at the top by the effective radiating temperature, and >>>>>>>>consider the surface temperatures as derived from that and the >>>>>>>>adiabatic lapse rate. >>>>>>> >>>>>>> That gets complicated by half the troposphere having lack of >>>>>>> clouds at >>>>>>> any altitude, and there are separate adiabatic lapse rates for >>>>>>> clear air and clouded air. The global atmospheric average is >>>>>>> close to the "wet" one, leaving upward mobility of lapse rate in >>>>>>> the clear half of the world and in clear layers of the atmosphere >>>>>>> in the clouded half of the world. >>>>>> >>>>>>At any given point, the applicable lapse rate should be obvious, >>>>>>depending on whether cloud is present. I'm not convinced the lower >>>>>>"average" environmental lapse rate has much to do with latent heat. >>>>>>It might just be off-equilibrium due to transport lags or the like. >>>>> >>>>> It just happens to be that the "average lapse rate below the >>>>> tropopause" is close to the wet adiabatic one. Close to the >>>>> equator, it is more than coincidental - global circulation (from >>>>> atmosphere below_tropical_tropopause_pressure_level as-a-whole) >>>>> being warmer towards the equator and cooler towards the poles has >>>>> air in the intertropical convergence zone rising. That largely >>>>> establishes the lapse rate in the ITCZ as being close to the wet >>>>> adiabatic one from the levels of the bases of the deep tall >>>>> tropical convective clouds to the tropical tropopauuse. Below >>>>> that cloud base level where those clouds form, the lapse rate is >>>>> close to the dry adiabatic one at hot times of the day, and less >>>>> at other times. >>>>> >>>>> Although it sounds like global circulation merely forces upward >>>>> air >>>>> movement in the ITCZ and that should cause clouds other than the >>>>> billowy cumulus of natural convection, those show up anyway (along >>>>> with a lot of clear air). Surface temperature in the ITCZ is not >>>>> uniform. For one thing, some parts of the ITCZ have daylight and >>>>> others have night. Also, ocean currents cool the ITCZ unevenly. So, >>>>> upward air movement in the ITCZ occurs in hotspots where natural >>>>> convection is sufficient to account for the upward global >>>>> atmospheric circulation in the ITCZ - and the clouds there are >>>>> billowy thunderheads, with many having anvil tops. >>>> >>>>I've often seen precipitation falling out of the anvil, many times >>>>never reaching the ground. The energy in a thunderstorm is >>>>staggering, and seems far more than IR could ever provide. Most of >>>>that energy had to have come from the surface, and there's really no >>>>way back down. It seems to me it has to radiate to space. >>> >>> Little of the surface is covered by thunderheads. >>> >>> And the atmosphere at the level of tropical anviltops is so cold, >>> that >>> it actually experiences slight warming from radiation. The air >>> eventually does cool by radiation where it descends. >>> >>>>Thermals are what got me started on this issue. I asked myself just >>>>how much IR it would take to lift a sailplane at a thousand >>>>feet/minute. I immediately had doubts that IR is significant. The >>>>energy is clearly mechanical energy of convection, and the cloud (if >>>>any)sitting on top of the thermal has to represent an order of >>>>magnitude more energy from latent heat. >>>> >>>>Thermals may not be all that common on the average, but when they do >>>>occur, they must carry orders of magnitude more energy than IR. >>>> >>>>When I look (longingly) at pictures of tropical islands, I see very >>>>familiar looking clouds. I have to assume the dynamics are similar, >>>>and that they are common in the tropics. So I need a lot of >>>>convincing evidence before I'll believe their heat transfer ability is >>>>somehow comparable to an already cold polar surface or similar >>>>situation. All it would take is a slight modulation of humidity or >>>>lapse rate to have large effects on the power transmitted, far greater >>>>than the 1.5W/m^2 CO2 forcing assumed in the climate models. >>> >>> I agree that tropical thunderstorms lift warm air accounting for >>> thermal power densities many times the solar constant. However, that >>> heat is mostly not radiated at the tropical tropopause - the anviltops >>> are at about the same temperature as the surrounding clear air at the >>> same altitude, and it is actually colder at that altitude in the >>> tropics than in the middle latitudes. >> >>I don't see why the actual region where it's radiated to space matters. >>Once the heat is lifted, there's no way it can be pumped back down to >>the warmer surface without radiating more energy to an even colder heat >>sink. >> >>Cooling is cooling, no matter where it happens. >> >>> Cooling of the tropics is ultimately mostly from radiation from >>> altitudes lower than the tropical tropopause and from global >>> circulation. >> >>That seems plausible. >> >>>>> Do keep in mind that there is global atmospheric circulation at >>>>> altitudes and pressure levels that are troposphere in the tropics >>>>> and stratosphere elsewhere. Air rising through the ITCZ to close to >>>>> the 100 mb level does not all go down there but some descends >>>>> elsewhere poleward. And a lot of that moves poleward at altitudes >>>>> where the is little hope of convection to such level from the >>>>> surface, due to surface being cooler than in the ITCZ. At some of >>>>> these extratropical-stratospheric altitudes and pressure levels, >>>>> atmosphere is even usually warmer than it is over the ITCZ because >>>>> over the ITCZ it is so cold (from cooling by uplifting) that local >>>>> radiation balance warms the air moving largely horizontally at/near >>>>> the tropical tropopause level. It cools by radiation in order to >>>>> descend elsewhere, with much of that done during the descent - >>>>> especially in the polar regions. >>>> >>>>That seems reasonable, but I don't see how it really affects the >>>>tropical convection cells. That's how the energy got up there in the >>>>first place. >>> >>> I don't think radiation does much to tropical convection cells. >>> >>> But if the polar regions warm with increase in reception of solar >>> radiation, then horizontal temperature gradient will decrease. That >>> will slow global circulation, which means slightly less cooling of the >>> tropics. >> >>Why? It seems to me it might provide even more effective global cooling >>by restricting the radiation to warmer areas, rather than letting the >>warm air escape to the cooler poles. Remember the 4th power term. > > For one thing, the tropics only radiate more to the extent they > actually warm (or 4th power thereof). We need to be careful to distinguish between temperature increases in the radiation layer and those at the surface. If the effective 255K radiation layer decreases in altitude, it could actually cool the surface. > I expect the tropics to warm only slightly > as a result of global circulation slowdown by increase of temperature of > more extreme latitudes. > > Also, if we have an increase in GHGs, then radiation directly to space > will be more restricted to coming from upper atmosphere. And if the > surface albedo decreases from warming of the polar regions, then > reception of sunlight increases. > > But if radiating ability of everywhere at all altitudes from surface > to upper stratosphere is unchanged and surface albedo is unchanged, then > changing evenness of surface temperature would not change > "root-mean-4th_power" temperature, which is what determines radiation > outgo. > (Actually that is an oversimplification - for one thing, changing > radiation distribution only leaves "root-mean-4th_power" temperature > unchanged if radiation burden is not shifted towards areas where there > is either more or less water vapor.) > > If "root-mean-4th_power" of temperature is unchanged and evenness of > temperature changes, making the temperature more even will raise the > average and making it less even will lower the average. > There so many "ifs" there I don't know how to make any judgment without knowing more details like actual measurements and mechanisms involved. >>> The tropics will warm slightly as a result, and the thunderstorms >>> would have to become a little more intense. >> >>Which would increase the latent heat component. > > Yes it would - limiting a few things: > > 1. Area covered by tropical thunderstorms - that could decrease in > response to warming - since their ability to move heat appears to me > likely to increase more than the amount of heat to be moved should the > tropics warm. > > I have noticed that when there is little net vertical velocity in the > air in my area (according to appropriate maps) and there are convective > clouds, there is usually less cloud cover and more clear air when it is > warmer - even though more precipitation falls from convective clouds > when it is warmer. > > 2. Along with that - warming of the tropics would be limited - for one > thing by making it easier to move the heat elsewhere. How does that jibe with "global circulation slowdown" above? > > - Don Klipstein (don(a)misty.com)
From: Bill Ward on 24 Dec 2008 13:57 On Wed, 24 Dec 2008 03:19:52 +0000, Don Klipstein wrote: > In article <pan.2008.12.22.17.42.33.380297(a)REMOVETHISix.netcom.com>, Bill > Ward wrote: >>On Mon, 22 Dec 2008 12:39:09 +0000, Don Klipstein wrote: >> >>> In article <pan.2008.12.09.17.36.37.607052(a)REMOVETHISix.netcom.com>, >>> Bill Ward wrote: (With snip of at least stuff already quoted more than >>> 3 times) >>>>On Tue, 09 Dec 2008 07:09:08 +0000, Don Klipstein wrote: >>>> >>>>> In <pan.2008.12.04.08.02.57.92862(a)REMOVETHISix.netcom.com>, B. Ward >>>>> wrote: >>>>>>On Thu, 04 Dec 2008 03:45:45 +0000, Don Klipstein wrote: >>> >>>>>>> But CO2 is close to blackbody within some range of wavelengths >>>>>>> where >>>>>>> emission is close to peak of a 218 K blackbody. And the range does >>>>>>> widen somewhat when there is more CO2 in the atmosphere. >>>>>> >>>>>>Look at this graph: >>>>>> >>>>>>http://upload.wikimedia.org/wikipedia/commons/7/7c/ >>>>>>Atmospheric_Transmission.png >>>>>> >>>>>>Now please tell me if you think the CO2 absorption spectrum (3rd >>>>>>graph) is similar to the 210K blackbody emission spectrum line in the >>>>>>top graph. >>>>> >>>>> I did not claim that - I merely claimed (using maybe better words >>>>> now >>>>> than before) that CO2 in the atmosphere radiates close as well as a >>>>> blackbody does within the 15um-peaking band. >>>>> >>>>> The 210K spectrum does indeed have its peak close to CO2's 15 um >>>>> band, >>>>> so CO2's 15 um band will absorb and radiate some very significant >>>>> amount at 210K. >>>> >>>>My guess from looking at the spectra would be less than half as much, >>>>assuming the area under the spectrum is proportional to power. >>> >>> Yes, that band looks to me eyeball-estimate worth 20-25% of blackbody >>> radiation at 210 K and less at higher temperatures. >> >>That looks about right to me also. How can we carry on a decent argument >>if you keep agreeing with me? ;-) >> >>>> And water shares the band. >>> >>> The atmosphere according to the above link has around 50% >>> transparency >>> of water vapor in that band, though I'm sure that varies widely since >>> concentration of water vapor in the atmosphere is far from constant. >> >>So shouldn't any effect of changes in CO2 be reduced by roughly another >>50% to account for the water vapor? > >>> In polar areas where surface temperature has more upward mobility, >>> there is less water vapor and CO2 accounts for a higher percentage of >>> GHG effect. >>> >>> Worldwide, CO2 accounts for 9-26% of GHG effect. >> >>Have you seen any derivation of that figure other than the RealClimate >>blog? > > Wikipedia mentions that range, in their article on "greenhouse gases": > > "water vapor, which contributes 36-70% carbon dioxide, which contributes > 9-26% methane, which contributes 4-9% > ozone, which contributes 3-7%" > > And about 1-1/2 paragraphs later, it says: > > "The higher ends of the ranges quoted are for the gas alone; the lower > ends, for the gas counting overlaps.[5][6]" > > Using accounting system making CO2 9%, then water vapor is 36%. > > Reference 5 is noted to be at RealClimate. > > Reference 6 is Kiehl, J. T.; Kevin E. Trenberth (February 1997). > "EarthÂ’s Annual Global Mean Energy Budget" (PDF). Bulletin of the > American Meteorological Society 78 (2): 197-208. > > http://www.atmo.arizona.edu/students/courselinks/spring04/atmo451b/pdf/ > RadiationBudget.pdf > > I see 26% and 60% figures for CO2 and H2O respectively there, page > 203, last column in Table 3. The next page, 204, makes the statement, "latent heat flux is equal to the global mean rate of precipitation." When I read that, the credibility of the rest of the paper was greatly also diminished in my eyes because of the tacit assumption implied. How many others did he make? > > The "Combined with overlap effects" column says CO2 is 32 parts, H2O > is > 75 parts out of 125. > > The first column has CO2 other than overlap being 29 parts out of 125, > and H2O other than overlap accounts for 71 parts out of 125, and where > they overlap is 7 parts out of 125. > > That is for GHG effect in clear air. That same table also has parts > each out of a total of 86 in the first 2 columns for GHG effect where it > is cloudy. > > 36-66% for H2O and 9-26% for CO2 comes from Ref. 5, > > http://www.realclimate.org/index.php?p=142 > > Looks like RealClimate is making CO2 a little less important than the > other reference. Wiki still seems to pretty much hew to the Team party line. > >>> I suspect the wide >>> range is in large part due to water vapor concentration being very far >>> from constant. Another factor is probably diversity of temperature >>> shifting relative radiation abilities of different wavelength bands of >>> different GHGs. >> >>Those seem like important factors that should be measured, not >>estimated. > > <SNIP following material lacking further dispute so far> > > - Don Klipstein (don(a)misty.com)
From: Whata Fool on 24 Dec 2008 23:28 Martin Brown <|||newspam|||@nezumi.demon.co.uk> wrote: >Whata Fool wrote: >> don(a)manx.misty.com (Don Klipstein) wrote: >> >>> In <hj8kk4le5784bdo5pf3r64g5rda9h6mv7r(a)4ax.com>, Whata Fool said in part: >>> >> Sidewalks in NYC can get too hot to walk on barefoot, I suggest >> the ocean surface and the ground on the banks of the Amazon is always >> less than 100 F. > >Probably true for the oceans less clear for shallow pools and unlikely >for some equatorial river banks. Plants make pretty good air >conditioners in terms of shading the ground and transpiring water. Don't guess, check the temperature of shallow natural pools, even with black mud bottoms they don't reach 1oo F. >>>> Doesn't the fact that water evaporation provide a lot of >>>> cooling of the "surface" suggest that the surface would be warmer >>>> without water or GHGs? > >>> The heat goes somewhere - it does not get destroyed. It becomes part of >>> the burden of radiational cooling of the atmosphere by GHGs. >> >> You seem to be contradicting your (and the current thought) premise >> that the atmosphere would be cooler (or even below freezing), by saying >> that cooling the atmosphere is a burden. > >Parts of the surface in direct sunlight would be warmer without GHGs but >the parts in darkness would also get much colder since outgoing long >wave thermal radiation has a free path to escape. This means global >average temperature is lower. It is stupid and useless to average the temperature of air and the solid surface, the amount of energy per unit of mass, and the mass itself is so different. >>> Keep in mind that a blackbody in Earth's orbit, with a GHG-free >>> atmosphere or none at all, would be cooler than Earth is now. And since >>> Earth has thermal IR emissivity being a higher percentage than its >>> absorption of solar radiation, with GHGs removed and albedo unchanged it >>> would be colder than a blackbody. >>> >>> - Don Klipstein (don(a)misty.com) >> >> >> It isn't even rational to say "or none at all", when the sun is >> shining on the east facing slopes of mountains, there would be a lot >> of thermal transfer to nitrogen, with no way for the nitrogen to cool >> at that rate. Oxygen would not be much different than nitrogen. > >He meant no atmosphere at all. As I said, he isn't able to address a simple isolated situation that does not involve GHGs, the Earth is not the moon. >We happen to have a large satellite moon >that provides concrete evidence of the extreme temperature range and >average temperature for an airless body at about the Earths orbit. No kidding? And how does that relate to N2 and O2? >We don't have a handy example of a pure N2 or H2 atmosphere although >some calculations of atmospheric circulations for the solar system >planets based on that simplifying assumption do exist in the literature. We don't need an example, at least people able to think don't. > The biggest factor in determining the nature of the atmospheric >circulation is distance from the sun, spin rate of the planet with >orbital inclination and eccentricity taking third and fourth place. When I mention spin rate (length of day) the AGW nuts claim that isn't a factor. >> Frankly, I don't think you are able to focus on a hypothetical >> situation without drifting back to the learned atmospheric physics. > >You are clueless. Don's patience is admirable, but misguided as there is >no way to educate "What a Fool" - he is well named. The object here is not to educate Whata Fool, it is to determine if GHGs warm or cool the atmosphere. >> Eight hours or more of sun warming the surface to more than 120 F >> and the nitrogen warming and convecting upward would moderate the surface >> temperature almost as much as the present atmosphere, but would not be >> cooled by radiation. > >But it would be cooled by mass air circulation to the cooler poles and >the night side terminator and particularly across the dawn edge where >the temperature gradient will be maximised. It is a heat engine with N2 >as the working fluid. In the sun would get warm, but out of the sun >would get colder. GHGs put simply reflect some of the escaping LW IR >radiation that would otehrwise escape back down onto the ground. > >It is clearly beyond your ability to comprehend. > >Regards, >Martin Brown >** Posted from http://www.teranews.com ** If you think the night cooling by contact with the ground could be equal to or greater than the daytime heating, you aren't very bright, or simply refuse to think about it. There would be a big difference between air temperatures over the poles and over the equator, but how do you get warm air to descend? With GHGs, the warm air that moves from lower latitudes to over the poles could cool and descend, but without GHGs, it just stays warm. Instead of exposing your ego and insolence by remarking about participants in the discussion, please think about the physics, and please try to confine the discussion to the physics. Surely thermodynamics is advanced enough to give an indication of the wind speeds of circulation of an N2 an O2 atmosphere, or even to just model a pure N2 atmosphere. With a 4000 mile radius, it would take too long to circulate air from the equator to the poles in the short nights, and cooling should be far less than heating. Without being able to radiate, N2 would not have the normal reduction in maximum temperature we see on Earth. Readers should remind themselves that the object of this discussion is whether or not GHGs warm the atmosphere, or cool it, more than an atmosphere without GHGs. This is important, because the basic premise of GHG theory is that GHGs warm the atmosphere, even though the "surface" may be considered to be both the air and the solid and liquid surface of the ground-air interface. It is the air temperature that is used in the "global annual average temperature" calculations.
From: Bill Ward on 24 Dec 2008 23:56
On Wed, 24 Dec 2008 10:37:23 -0800, Bill Ward wrote: > On Wed, 24 Dec 2008 02:45:38 +0000, Don Klipstein wrote: > >> In article <pan.2008.12.22.16.51.13.543198(a)REMOVETHISix.netcom.com>, >> Bill Ward wrote: >>>On Mon, 22 Dec 2008 02:11:15 +0000, Don Klipstein wrote: >>> >>>> In article <pan.2008.12.15.07.25.04.110636(a)REMOVETHISix.netcom.com>, >>>> Bill Ward wrote in part: >>>> >>>>>On Mon, 15 Dec 2008 03:49:54 +0000, Don Klipstein wrote: >>>>> >>>>>> In article <pan.2008.12.02.09.04.49.526817(a)REMOVETHISix.netcom.com>, >>>>>> Bill Ward wrote: >>>>>>>On Tue, 02 Dec 2008 05:55:11 +0000, Don Klipstein wrote: >>>>>>> >>>>>>>> In <pan.2008.11.26.21.17.23.310423(a)REMOVETHISix.netcom.com>, Bill >>>>>>>> Ward wrote: >>>>>>> >>>>>>>Do you think that the "wet adiabatic" environmental lapse rate is >>>>>>>related to latent heat, or is it simply less than the dry adiabatic >>>>>>>lapse rate because it's not at equilibrium? >>>>>> >>>>>> It is less due to latent heat. >>>>>> >>>>>> The "1 size fits all figures" that I have heard are 3.5 degrees F >>>>>> per >>>>>> 1,000 feet for the wet one and 5.4 degrees F per 1,000 feet for the >>>>>> dry one. >>>>>> >>>>>>>>> Is it primarily by radiative transfer, or convection? It seems >>>>>>>>> to me >>>>>>>>>it must be convective, simply because warm, wet air is less dense >>>>>>>>>than cold, dry air, and quickly rises to maintain the lapse rate. >>>>>>>> >>>>>>>> Much of the time the answer is a significant factor other than >>>>>>>> radiation and vertical convection. Much of the "global >>>>>>>> convection" involves air movement within a degree of horizontal, >>>>>>>> and often forming clouds when moving upwards. Sometimes the lapse >>>>>>>> rate there is between the "dry adiabatic" and the "wet adiabatic" >>>>>>>> rates and the clouds have billowy cumuliform tops or are >>>>>>>> cumuliform throughout. Sometimes "warm advection" occurs more at >>>>>>>> cloud-top level than at cloud-base level (from the windspeed being >>>>>>>> greater higher up in the troposphere), causing the clouds to be >>>>>>>> stratiform. >>>>>>> >>>>>>>OK, that all sounds plausible, but I'm not sure how much effect the >>>>>>>horizontal component would have, other than the obvious mixing. >>>>>> >>>>>> The horizontal component involves atmospheric heat transfer from >>>>>> the >>>>>> tropics to the poles. It is very significant. It leads to frontal >>>>>> inversions, which cover significant area ahead of warm fronts >>>>>> (including areas where the warm fronts fail to reach at the >>>>>> surface). It leads to existence of stratosphere at middle and upper >>>>>> latitudes at pressure levels below that of the tropical tropopause. >>>>>> >>>>>>>>>IR radiated from the surface would be quickly absorbed by WV, >>>>>>>>>clouds, CO2, and other GHGs, and at 500W/m^2 would be overwhelmed >>>>>>>>>by the 10's of kW/m^2 available from convection of latent heat. >>>>>>>> >>>>>>>> Half the Earth's surface has no clouds overhead at any altitude. >>>>>>> >>>>>>>Surely you mean "at any given time". Or are there really regions >>>>>>>comprising half the Earth's surface that have never had a cloud in >>>>>>>the sky? >>>>>> >>>>>> I did mean "at any given time", and "those given times" in "those >>>>>> given locations" account for half the world lacking clouds at any >>>>>> altitude. >>>>> >>>>>OK, I'll buy that as an average. But I'll bet the tropics are far >>>>>more likely to be cloudy than the polar regions, and that's where most >>>>>of the cooling occurs. >>>>> >>>>>>>> The surface manages to radiate *somewhat* to outer space at night >>>>>>>> when the air overhead is clear - otherwise there would be no such >>>>>>>> thing as nighttime frost when air 2 meters above the surface is at >>>>>>>> +2 degrees C (a fairly common situation). Some of the outgoing >>>>>>>> radiation can easily be absorbed and reradiated a couple or a few >>>>>>>> times by GHGs, but net of that is upward (and upward net is >>>>>>>> reduced by increase of GHGs). >>>>>>> >>>>>>>OK, no argument with that. I look at it as the surface radiating to >>>>>>>a target warmer than 3K space, but it's the same math. >>>>>>>> >>>>>>>>>At night, convection stops, but cooling is not required at night. >>>>>>>>>Convection kicks in during the day, when cooling is needed. >>>>>>>> >>>>>>>> Cooling still occurs at night by radiation. 5 AM temperature >>>>>>>> has a >>>>>>>> great rate of being less than 10 PM temperature. Upper level of >>>>>>>> radiation by atmosphere at night has half of its radiation to >>>>>>>> outer space. That heat comes from radiation from surface - even >>>>>>>> if absorbed and reradiated a couple times along the way. >>>>>>> >>>>>>>Agreed. At night the flux is always outward. >>>>>>> >>>>>>>> The "upper radiation level" also varies greatly with wavelength. >>>>>>> >>>>>>>Do you mean the "effective radiating altitude", which is calculated, >>>>>>>or some sort of integrated spectrum involving all the photons >>>>>>>reaching a surface outside the atmosphere, like a satellite imager? >>>>>>>Neither I, nor apparently Google, is familiar withe the term "upper >>>>>>>radiation level". >>>>>> >>>>>> Looks like I did not choose wrds well - it should have been >>>>>> "effective >>>>>> radiating altitude". >>>>>> >>>>>> Keep in mind that the "effective radiating altitude" is very >>>>>> fuzzy, >>>>>> since some wavelengths radiated by the surface have good atmospheric >>>>>> transparency (and a fairly clear shot to space) as long as there are >>>>>> no clouds, others have low chance of reaching the 500 mb level >>>>>> without being absorbed, and some are in-between - with absorption >>>>>> and reradiation varying directly with concentration of GHGs. >>>>> >>>>>That's my point. It's not well enough known to claim 1.5W/m^2 is >>>>>going to make any difference at all. All it takes is a minor negative >>>>>feedback loop to correct for that small an effect. >>>> >>>> The Ice Ages having temperature swinging 10-plus K from slight >>>> periodic >>>> changes in insolation show that we have a lot of positive feedback. >>> >>>Has that actually been shown, or just inferred? If there were >>>significant positive feedback, it would have shown up in the ice core >>>signal as an exponential runaway to the rail. For long term stability, >>>you need negative feedback. >> >> You can have positive feedback without latchup. Example: Armstrong >> regenerative receiver. > > Right. But as you'll soon notice if you build one, they require constant > and very careful gain tweaking in use, or they break into rail to rail > oscillation. The super-regenerative receiver solved that by using chaos > theory (before it was identified as such) to eliminate that, as it > periodically quenches with negative feedback to stay on the verge of > instability. Of course the superhet obsoleted both until the advent of > digital techniques. > > The point is that systems are not long term stable unless they involve net > negative feedback. Relying on luck to keep the loop gain under +1 is not > a successful strategy. The climate appears long term stable, so I doubt > any net positive feedback. > >> The ice core data do indicate CO2 atmospheric concentration lagging >> temperature by about 800 years. (But temperature lagged CO2 since >> Industrial Revolution.) > > Generally, to cross-correlate signals, you need to detrend them, to reduce > correlation to other unrelated variables which may be overall increasing > or decreasing with time. > > When I look at the recent temperature and CO2 concentrations, they don't > seem to correlate unless you include the fact that they both have been > generally increasing. For the last decade or so, CO2 has been steadily > increasing, while temperature has stopped increasing, and may be > decreasing. The same holds true in the 1940-1975 period. > > You could probably get a better correlation between temperature and the > total number of electronic memory bits produced than you can with CO2. Oops, said it backwards. Computer memory production will likely correlate better with atmospheric CO2 than does temperature. > >>>>>>>>>I don't see how radiative cooling is even necessary below the >>>>>>>>>cloud tops, since there's plenty of cooling capacity from >>>>>>>>>convection. >>>>>>>> >>>>>>>> When frost or dew forms on the ground and on cars and trucks, >>>>>>>> the heat >>>>>>>> loss has a very impressive rate of by being by radiation. >>>>>>> >>>>>>>True, but radiation is peanuts compared to the available cooling >>>>>>>capacity of latent heat during the day. If the surface radiation >>>>>>>were blocked, convection could easily make it up. >>>>>> >>>>>> What about on days when there is no convection past the 750 mb or >>>>>> so >>>>>> level for even a minute? (I see plenty of those even with sky >>>>>> half-clear and cumulus clouds present.) What about in Arctic and >>>>>> upper-midlatitude areas where change in radiation balance during >>>>>> the 18 or whatever hours per day with little convection has a >>>>>> significicant effect on snow/ice cover, and that affects how much >>>>>> solar radiation the surface absorbs? >>>>> >>>>>It's the total transferred power that counts. It doesn't take much >>>>>latent heat convection to make up for a lot of radiation. The place >>>>>to look for changes is where the cooling is greatest, not places >>>>>which are already being warmed by the tropics. >>>> >>>> Cooling is significant in the polar areas. The global insolation >>>> map in >>>> the Wiki article on insolation shows the polar areas getting about >>>> 1/3 as much insolation as the tropics do. Cooling is even more than >>>> 1/3 that of the tropics, since global circulation transfers heat from >>>> the tropics to the polar regions. >>> >>>Doesn't that mean the tropics still provide the majority of the >>>cooling? >> >> Yes, that is true, but that does not negate the significance of >> cooling >> in the polar and near-regions - nor the significance of ease of >> changing temperature of the surface and lower troposphere in the polar >> and near-polar regions. > > How quantitatively do we know the significance of polar cooling? Is > there any reason to believe it would somehow counteract increased > cooling in the tropics? > > >>>> Where the surface can warm significantly before convection occurs >>>> is >>>> probably where the world can warm more if GHGs increase. I would >>>> also expect more warming in areas where warming reduces surface >>>> albedo. >>> >>>Aren't those areas already colder than average? >> >> I would say not - the world has upward anomaly in temperature of >> surface >> and surface-level atmosphere and lower troposphere overall, which is >> greatest in the Arctic. > > I meant actual temperature, not anomaly. The poles are likely below 14C > average temperature. > >>>>>>>>>Once the energy reaches the tropopause, as you imply, it's a >>>>>>>>>pretty straight shot to 3K deep space, since there's not much >>>>>>>>>atmosphere left to absorb IR. >>>>>>>>> >>>>>>>>>Perhaps it's easier to see if you look at the lapse rate as >>>>>>>>>bounded at the top by the effective radiating temperature, and >>>>>>>>>consider the surface temperatures as derived from that and the >>>>>>>>>adiabatic lapse rate. >>>>>>>> >>>>>>>> That gets complicated by half the troposphere having lack of >>>>>>>> clouds at >>>>>>>> any altitude, and there are separate adiabatic lapse rates for >>>>>>>> clear air and clouded air. The global atmospheric average is >>>>>>>> close to the "wet" one, leaving upward mobility of lapse rate in >>>>>>>> the clear half of the world and in clear layers of the atmosphere >>>>>>>> in the clouded half of the world. >>>>>>> >>>>>>>At any given point, the applicable lapse rate should be obvious, >>>>>>>depending on whether cloud is present. I'm not convinced the lower >>>>>>>"average" environmental lapse rate has much to do with latent heat. >>>>>>>It might just be off-equilibrium due to transport lags or the like. >>>>>> >>>>>> It just happens to be that the "average lapse rate below the >>>>>> tropopause" is close to the wet adiabatic one. Close to the >>>>>> equator, it is more than coincidental - global circulation (from >>>>>> atmosphere below_tropical_tropopause_pressure_level as-a-whole) >>>>>> being warmer towards the equator and cooler towards the poles has >>>>>> air in the intertropical convergence zone rising. That largely >>>>>> establishes the lapse rate in the ITCZ as being close to the wet >>>>>> adiabatic one from the levels of the bases of the deep tall >>>>>> tropical convective clouds to the tropical tropopauuse. Below >>>>>> that cloud base level where those clouds form, the lapse rate is >>>>>> close to the dry adiabatic one at hot times of the day, and less >>>>>> at other times. >>>>>> >>>>>> Although it sounds like global circulation merely forces upward >>>>>> air >>>>>> movement in the ITCZ and that should cause clouds other than the >>>>>> billowy cumulus of natural convection, those show up anyway (along >>>>>> with a lot of clear air). Surface temperature in the ITCZ is not >>>>>> uniform. For one thing, some parts of the ITCZ have daylight and >>>>>> others have night. Also, ocean currents cool the ITCZ unevenly. So, >>>>>> upward air movement in the ITCZ occurs in hotspots where natural >>>>>> convection is sufficient to account for the upward global >>>>>> atmospheric circulation in the ITCZ - and the clouds there are >>>>>> billowy thunderheads, with many having anvil tops. >>>>> >>>>>I've often seen precipitation falling out of the anvil, many times >>>>>never reaching the ground. The energy in a thunderstorm is >>>>>staggering, and seems far more than IR could ever provide. Most of >>>>>that energy had to have come from the surface, and there's really no >>>>>way back down. It seems to me it has to radiate to space. >>>> >>>> Little of the surface is covered by thunderheads. >>>> >>>> And the atmosphere at the level of tropical anviltops is so cold, >>>> that >>>> it actually experiences slight warming from radiation. The air >>>> eventually does cool by radiation where it descends. >>>> >>>>>Thermals are what got me started on this issue. I asked myself just >>>>>how much IR it would take to lift a sailplane at a thousand >>>>>feet/minute. I immediately had doubts that IR is significant. The >>>>>energy is clearly mechanical energy of convection, and the cloud (if >>>>>any)sitting on top of the thermal has to represent an order of >>>>>magnitude more energy from latent heat. >>>>> >>>>>Thermals may not be all that common on the average, but when they do >>>>>occur, they must carry orders of magnitude more energy than IR. >>>>> >>>>>When I look (longingly) at pictures of tropical islands, I see very >>>>>familiar looking clouds. I have to assume the dynamics are similar, >>>>>and that they are common in the tropics. So I need a lot of >>>>>convincing evidence before I'll believe their heat transfer ability >>>>>is somehow comparable to an already cold polar surface or similar >>>>>situation. All it would take is a slight modulation of humidity or >>>>>lapse rate to have large effects on the power transmitted, far >>>>>greater than the 1.5W/m^2 CO2 forcing assumed in the climate models. >>>> >>>> I agree that tropical thunderstorms lift warm air accounting for >>>> thermal power densities many times the solar constant. However, that >>>> heat is mostly not radiated at the tropical tropopause - the >>>> anviltops are at about the same temperature as the surrounding clear >>>> air at the same altitude, and it is actually colder at that altitude >>>> in the tropics than in the middle latitudes. >>> >>>I don't see why the actual region where it's radiated to space matters. >>>Once the heat is lifted, there's no way it can be pumped back down to >>>the warmer surface without radiating more energy to an even colder heat >>>sink. >>> >>>Cooling is cooling, no matter where it happens. >>> >>>> Cooling of the tropics is ultimately mostly from radiation from >>>> altitudes lower than the tropical tropopause and from global >>>> circulation. >>> >>>That seems plausible. >>> >>>>>> Do keep in mind that there is global atmospheric circulation at >>>>>> altitudes and pressure levels that are troposphere in the tropics >>>>>> and stratosphere elsewhere. Air rising through the ITCZ to close >>>>>> to the 100 mb level does not all go down there but some descends >>>>>> elsewhere poleward. And a lot of that moves poleward at altitudes >>>>>> where the is little hope of convection to such level from the >>>>>> surface, due to surface being cooler than in the ITCZ. At some of >>>>>> these extratropical-stratospheric altitudes and pressure levels, >>>>>> atmosphere is even usually warmer than it is over the ITCZ because >>>>>> over the ITCZ it is so cold (from cooling by uplifting) that local >>>>>> radiation balance warms the air moving largely horizontally at/near >>>>>> the tropical tropopause level. It cools by radiation in order to >>>>>> descend elsewhere, with much of that done during the descent - >>>>>> especially in the polar regions. >>>>> >>>>>That seems reasonable, but I don't see how it really affects the >>>>>tropical convection cells. That's how the energy got up there in the >>>>>first place. >>>> >>>> I don't think radiation does much to tropical convection cells. >>>> >>>> But if the polar regions warm with increase in reception of solar >>>> radiation, then horizontal temperature gradient will decrease. That >>>> will slow global circulation, which means slightly less cooling of >>>> the tropics. >>> >>>Why? It seems to me it might provide even more effective global >>>cooling by restricting the radiation to warmer areas, rather than >>>letting the warm air escape to the cooler poles. Remember the 4th >>>power term. >> >> For one thing, the tropics only radiate more to the extent they >> actually warm (or 4th power thereof). > > We need to be careful to distinguish between temperature increases in > the radiation layer and those at the surface. If the effective 255K > radiation layer decreases in altitude, it could actually cool the > surface. > >> I expect the tropics to warm only slightly as a result of global >> circulation slowdown by increase of temperature of more extreme >> latitudes. >> >> Also, if we have an increase in GHGs, then radiation directly to >> space >> will be more restricted to coming from upper atmosphere. And if the >> surface albedo decreases from warming of the polar regions, then >> reception of sunlight increases. >> >> But if radiating ability of everywhere at all altitudes from surface >> to upper stratosphere is unchanged and surface albedo is unchanged, >> then changing evenness of surface temperature would not change >> "root-mean-4th_power" temperature, which is what determines radiation >> outgo. >> (Actually that is an oversimplification - for one thing, changing >> radiation distribution only leaves "root-mean-4th_power" temperature >> unchanged if radiation burden is not shifted towards areas where there >> is either more or less water vapor.) >> >> If "root-mean-4th_power" of temperature is unchanged and evenness of >> temperature changes, making the temperature more even will raise the >> average and making it less even will lower the average. >> >> > There so many "ifs" there I don't know how to make any judgment without > knowing more details like actual measurements and mechanisms involved. > >>>> The tropics will warm slightly as a result, and the thunderstorms >>>> would have to become a little more intense. >>> >>>Which would increase the latent heat component. >> >> Yes it would - limiting a few things: >> >> 1. Area covered by tropical thunderstorms - that could decrease in >> response to warming - since their ability to move heat appears to me >> likely to increase more than the amount of heat to be moved should the >> tropics warm. >> >> I have noticed that when there is little net vertical velocity in the >> air in my area (according to appropriate maps) and there are convective >> clouds, there is usually less cloud cover and more clear air when it is >> warmer - even though more precipitation falls from convective clouds >> when it is warmer. >> >> 2. Along with that - warming of the tropics would be limited - for one >> thing by making it easier to move the heat elsewhere. > > How does that jibe with "global circulation slowdown" above? > > > >> - Don Klipstein (don(a)misty.com) |