Solar heat – not CO2 – caused the June 2021 heatwave

Chuck Wiese is the best meteorologist I know. Last year, he retired from flying the big jets for Delta Airlines. – Ed

by Chuck Wiese, Meteorologist   

With the continued and terrible politicization of atmospheric science and climate, I thought I would take a look at the true cause of this historic Pacific Northwest heat wave we just experienced that is now being terminated west of the cascades by a strong push of marine air from off the ocean.

For starters, the synoptic weather pattern that set itself up over our region was handled quite well by the short-term numerical weather forecast models. Before the onset, we saw nearly identical pressure patterns forecast to generate as we typically see with our severest high temperatures. In the climate records, those for Portland were found to occur on July 30, 1965, and both August 8th and August 10th of 1981 at 107 deg F.

These records occurred at the Portland National Weather Service Office located then at the Marine Drive location at the Portland International Airport. The complete records in Portland go back to 1940 for the airport location and downtown Portland back to 1890, but these records at the airport exceeded or equaled any of the records in the downtown location. So they were considered all-time records back to 1890.

So at the peak of this heatwave in Portland which was yesterday, the maximum temperature reached 116 deg F, a new all-time high-temperature record going back to 1890. Several other all-time records were established as well in Oregon and Washington.

This is astonishing if you are caught off guard into believing the old records could not be broken by an obscure factor most meteorologists don’t think about on a day-to-day basis. It’s summer, and so pressure patterns that generate the heat were thought of as a comparative to old records with identical synoptic set-ups.

This is at least how I looked at things initially along with others who saw the “suspiciously high-temperature forecasts” given by the numerical model prediction output that actually forecasted the extreme temperatures accurately.

These only became believable as the model output became repetitious in several runs as we got within 2 days of the expected extreme temperatures. This is common practice in operational meteorology to become suspicious of model output extremes especially since we have seen many occasions where extremes in temperature or precipitation given by models back off from those predictions and self-correct within a couple of days of an extreme event. But it turns out the numerical model output in this situation was correct several days in advance. 

Why was this? What caused the extremes? Was it really “climate change” related to atmospheric CO2 as some are claiming or was it something else? When I looked into the specifics, it turns out that “climate change” or atmospheric CO2 had nothing to do with this heatwave. 

First off, I looked at the “greenhouse gases”. The water vapor optical depths of the 1981 heatwave and today’s extremes were nearly identical as taken off the atmospheric soundings from Salem, OR. So it was not that.

What about atmospheric CO2? In 1981, the Mauna Loa CO2 level was given as 341 ppmv whereas today it is 416 ppmv. Calculating the change in radiative forcing from CO2 as a stand-alone constituent, the difference from 1981 to now is only 1.07 Wm-2. ( Watts per square meter ).

Next, I took the mean temperature of the daily temperature delta or deviation, which was about 90 deg F and plugged that into the derivative of the Stefan Boltzmann equation, dF/dT which gives 6.45 Wm-2K-1 or 6.45 Watts per square meter per degree Kelvin.

Using this relationship, if CO2 acts alone as permitted in this special case, we get 0.963 Wm-2 with a ground emissivity of 0.9 divided by the rate of change of flux with respect to temperature or the 6.45 Wm-2K-1 number which gives 0.15 deg C or a possible contribution of +0.27 deg F. to the heating total.

So CO2’s contribution to this heatwave is far too small to even move the thermometer upwards from the 107 deg F old records to a measurable whole degree F. This is not even measurable with many of the degree of accuracy specifications on many thermometers.

But if you examine the solar radiation dynamics, you get an entirely different picture that explains how we achieved the new records and these numbers were obviously incorporated into the numerical weather model outputs several days in advance. It is important to recognize that when we compare the old records to the new, the atmospheric dynamics in 1965, 1981, and today were nearly identical, meaning the subsiding air that sets the convective temperature cap or potential temperature of the surface started the same.

This dynamic is what the TV guys were calling the “upper air heat dome” to simplify the concept to the layperson. But the timing of these heatwaves was different. In 1981, they occurred in the first week of August and at the end of July in 1965. Today, we are at the end of June or just past the summer solstice or highest sun angle of the year. It turns out this difference of dates is a big deal and actually explains the severity of this heatwave and new maximum temperature all-time records when combined with the upper air dynamics.

The solar radiation reaching the earth’s surface can be calculated anywhere from the relation:

sin( beta) = cos(L) cos( delta) cos (H) + sin(L) sin ( delta ), 

where beta is the solar angle above azimuth or the horizon being solved for, L is earth latitude, delta is the declination angle of the earth to the solar ecliptic plane and H is the hour angle, taken as 15 degrees per hour from solar noon.

By hours or minutes, the sum or integral of the solar radiation can be calculated with the initial condition that the undepleted radiation approaching the surface is roughly 70% of the solar constant at the normal plane 90 degrees perpendicular to the earth’s atmosphere, where the sun is directly overhead an observer on the ground.

The average of the solar “constant” is 1,366 Wm-2 but varies through the year by +/-3% due to the elliptical orbit of the earth around the sun, and reaching the highest value at the winter solstice in the Northern Hemisphere. This change can be calculated directly from the inverse square law of radiation intensity vs. distance.

Using 46 degrees of latitude for Portland, the daily transmitted solar radiation to the surface on June 27th is 2.4894800 x 10^7 Jm-2. ( Joules per square meter ) Over a 15 hour solar day, the average solar radiation transmitted to the surface is 461 Wm-2.

On August 8th, the total surface radiation is 2.0920000 x 10^7 Jm-2 and likewise, over a 14-hour solar day gives an average surface solar insolation of 415 Wm-2. The difference between these two numbers is substantial at a whopping 46 Wm-2!

But this difference is mitigated some due to the elliptical orbit of the earth around the sun which between June 27th and August 8th adds an additional 8 Wm-2 of solar insolation to TOA or 6 Wm-2 to the surface at the perpendicular angle to the atmosphere. With the noon solar angle of the sun calculated at 60.49 degrees above azimuth on August 8th, that reduces those values further at Portland’s latitude to 5.2 Wm-2, with the final difference in solar radiation being 40.8 Wm-2 further reduced to 36.72 Wm-2 with a surface emissivity of .9. This is still quite substantial.

If we divide this difference into the rate of change of flux with respect to temperature of 6.45 Wm-2K-1 given above, we get a surplus temperature of 5.69 deg C or 10.2 deg F compared to the earlier heatwaves of record on July 30, 1965, and on August 8h and 10th of 1981. Add this to these old records of 107 deg F and you get 117.2 deg F. That comes within 1.2 degF of what the new all-time high-temperature record is that was just set for Portland at 116 deg F yesterday.

Around the area, it’s obvious there could never be a perfect prediction using this alone, as the surface canopy around the Portland metropolitan area and surrounding cities has numerous variations that shade part of the canopy at all times while some surfaces have lower and higher specific heats than what is next to them, creating small variations of microclimates that are mixed by wind currents to give a final deterministic temperature.

But the point in all of this is clear. Solar radiation was the clear driver that caused these new all-time temperature records and little else. 

Now a word about “heat domes”. We must remember these systems are NOT created by greenhouse gases! They are connected by the dynamic westerly wind belt surrounding the earth that has the jet stream winds contained within it. This means the creation of a “heat dome” is directly proportional to the strength of the low-pressure systems upstream or downstream or both and those are also referenced as the “cold” areas of low pressure aloft.

Further, it is the low-pressure system generation that causes the strength of the high-pressure system and its residing subsidence that creates the “heat dome” within the high pressure. So a stronger heat dome means a stronger low pressure and a stronger low-pressure system is fed by COLD air from high latitudes being accelerated southward by the decreasing Coriolis force associated with northerly winds.

This comes about from the theory of planetary Rossby wave physics and the subsequent tie to the Sutcliffe development equation that describes the vertical accelerations of wind that advects atmospheric mass upward and downwind from the low-pressure centers to create the high-pressure systems and “heat domes”.

So it should be clear from all of this, that if atmospheric CO2 truly caused the climate to change, that the temperature extremes we just experienced would not be possible because the gradient of temperature across the latitude lines would lessen, thus reducing the potential energy otherwise available to generate low and high-pressure systems.

The physics of this demand that the storms and high-pressure systems weaken, thus reducing the subsidence or strength of the “heat dome” thus setting the potential temperature of the surface LOWER, not higher, as the incorrect climate propaganda tries to assert, and further, the mean position of the jet stream MUST migrate to higher latitudes causing the distribution of atmospheric mass and pressure to become more uniform across the earth, decreasing average worldwide wind speed.

This means extreme weather of every kind inclusive of temperatures would be lessened, but the mean earth temperature would be increased to warmer. Worldwide drought would also become a symptom of this, not regional drought that we now experience and that is part of ocean cycles that drive the Pacific Decadal Oscillation (PDO). 

This does not fit anything we are seeing happening today. These strong high-pressure systems are an indication of a robust supply of cold air at higher latitudes given the season which we see on the daily weather maps and it is noteworthy again that global air temperatures are at only +0.08 deg C over the 30-year mean. The global air temperatures have cooled sharply since the beginning of this year due to the La Nina conditions of the tropical Pacific. 

It is also worth noting that these pressure patterns are created through chaotic and random variation within the atmospheric system and are not predictable in general terms more than about a week ahead of time with any reliability. It is unlikely we will see any repeat of this pattern within the next week to 10 days and no assurance that this warm and hot weather pattern will even persist for the latter part of the summer.

Sometimes the summers can end cooler and wetter and other times hot and dry like now. There is simply no predictability to this except in very general terms as related to the ocean cycles and they are not even correct at all times. But from this data, a later summer heatwave will never reach the records we just set.


  1. Pretty much everything you say here is true. I studied heat transfer as well as a bit of meteorology, so I can follow what you are saying, although I never made a profession out of either. However, I think that you are missing something.

    Since the existence of year-round ice is dependent on the summer temperatures not staying above freezing long enough to melt the snow of the winter before, the increase or decrease of ice is sensitive to very small fluctuations in temperature. If temperatures hover just below freezing for a significant time, the ice will stay, but if the temperature pops up a bit during that same extended time the ice will melt.

    In this way, a temperature increase of just a fraction of a degree can make a significant difference in the glaciers and arctic conditions. Then, once a significant portion of land or water becomes ice-free, even for a short time in the summer, the increased heat absorption multiplies the temperature increase that caused the ice to melt in the first place.

    In this way, the slight temperature increase due to CO2 increase becomes a trigger that sets in motion a massive change in heat absorption. The same change in absorptivity also increases emissivity, which might make one think that the same heat that entered would be just as quickly emitted to space again, but remember that the absorbed heat does not result in a corresponding temperature increase that would drive such reemission.

    It goes into heating underground cold sinks and melting ice, which will capture the heat from year to year, as the on-coming winter will cover the 0C melted ice water under a layer of fresh snow at the normal temperature. The next summer will have a head start at continuing the melting process.

    How else can we explain that the arctic temperature increases have been well above the global average and that the arctic land and ocean are becoming more and more ice-free?

    Now that we have more soggy earth and open ocean water exposed, we can expect great changes in wind patterns. That can explain these unusual, extreme weather patterns such as snow down in southern Missouri, while Siberia is balmy, and this high-pressure area that happened for the first time in June, instead of waiting for August.

    You say that is not caused by the measly 0.27 deg F increase from CO2. Not directly, but, if that 0.27 deg increase pulled the trigger on a vast de-icing of the artic, it very well could have been the indirect cause of having 49.6C in Lytton, BC.

    1. Well, the last time I checked ice extention in the north of our part of the world some days ago there was no decreases or prevalence of ice, and the temperatures of the North Atlantic and the Barents sea were decreasing. Lower temperatures will in due time result in more ice at the North Calotte… So relax, every thing is normal…

  2. Hello Thomas: In this article I wrote, you may not have noticed that I allowed the effect from atmospheric CO2 to be considered in this special condition where the atmosphere under this “heat dome” is isolated from the global system in clear skies.

    But for the entire global system, you cannot treat CO2 in this manner and the reason is because of the earth’s hydrological cycle that is generated by the storm systems connected around the global system.

    The propaganda promoted from climate hysteria is that you can treat atmospheric CO2 in this manner, and even further, amplify water vapor’s effects from the small stand alone effect. But that is not true because the feedbacks to the system with water vapor are negative, not positive, as claimed.

    The total optical depth of the atmosphere cannot exclude the solar radiation wavelengths because of cloud cover and the fact that these GHG’s COOL the troposphere in exchange for a warmer surface. That limits water vapors presence by inducing a destabilizing moist convective current that short circuits the effects from CO2 by taking the latent heat gathered at the surface from the 33 degC surplus temperature and re-radiating it over all wavelengths in the atmosphere to space through cloud formation and a lower optical depth, and at the same time, block incoming solar radiation which has a quanta 30x over CO2, and in general, the wavelengths of energy associated with sunlight and ultraviolet energy are 4x more powerful than GHG’s that radiate in the longer wavelengths of IR.

    So there is no reason to be concerned about CO2 having this effect as you wrote. Arctic sea ice, glaciers and snowpack all have natural fluctuations that are part of the normal climate shifts associated with earth orbital parameters, solar dynamics and ocean cycles. At present, over 50% of the current glacial decline was observed before the year 1950, shortly after the very hot decade of the 1930’s called the “dust bowl” era and atmospheric CO2 was much lower then than now.

    1. I wish we could also take into account the tilt of the earth that, so far, has been known to shift up to 4 degrees over a period of several years. The earth is a miracle that we are only on the cusp of understanding. We still don’t know why the Sahara desert becomes a great inland sea about every 10,000 years and have recently discovered that the change from desert to sea may have occurred over less than 100 years.
      And then there are magnetic polar shifts and ice ages. Oh my.
      But then, I am still awed by the magic of pushing a button and my car unlocks!

  3. Chuck,
    Ed has introduced you as ” the best meteorologist he knows.” Can you give us your educational background and a list of peer reviewed papers you have published?

    1. Dear David,

      There you go again. Since you do not understand this post by Chuck or his two other posts, to save your precious ego, you propose an irrelevant strawman to test my statement.

      Since when do more education and more peer-reviewed papers make you a better whatever?

      Academics does not make you the best. Work and experience in a field and raw intelligence make you the best. And most peer-reviewed papers are junk, like yours.

      Chuck has an excellent education in meteorology and he has worked in meteorology his whole life. He used his education in meteorology every day he piloted a commercial aircraft.

      Chuck does not need a stinkin’ Ph.D. or a ton of peer-reviewed papers to prove he is the best meteorologist I know.

      Take your own case – a Ph.D. in Physics who has spent his life teaching at a university – but you are a moron when it comes to climate physics. It would not matter if you had a million peer-reviewed papers. You would still be a moron. Even your question proves you are a moron.

      I am about to dump you from commenting on my website. You are becoming like David Appel, another Ph.D. in physics who has demonstrated that he is one of the dumbest guys I know.

    2. David,

      As Dr. Berry just said, you must be a moron despite your PHD in Physics. You prove the old adage that “those that can, do, those that can’t, teach”.

      Also, take some advice from Abraham Lincoln “Better to remain silent and be thought a fool than to speak and to remove all doubt.” You should take that to heart.

  4. Ed,
    I agree that a degree doesn’t automatically make you an expert. However, it would be nice to know a little bit more about how Chuck’s education & training have contributed to his working knowledge of the climate system.

    In my experience, a B.S. in Meteorology or Atmospheric Science does not generally pass muster when it comes to understanding the complexities of the climate system, which is why we employ sophisticated, coupled atmospheric-oceanic general circulation models with all of their accounting of energy transfer, whether in the form of cloud-aerosol interactions & their direct & indirect effects on radiative transfer, sensible & latent heat fluxes, etc.

    If Chuck is a hobbyist, that’s fine, but state it plainly. I fail to see how decades of flying commercial aircraft are synonymous with analyzing climate sensitivities & source attribution.

    Comparing solar flux for two different days of the year doesn’t quite cut it, either. Following the same logic, June would be hotter than August, on average, simply because the days are longer, but we know that’s not the case from the historical record. The climate system is a bit more complicated than that, and all factors must be considered together due to their various positive & negative feedbacks.

    1. Dear John,

      My main critique of your comment is it is, like David’s, a critique of the messenger rather than a critique of the message. David could not find an error in Chuck’s message, so he attacked the messenger. That is not the way to do science.

      That said, Chuck has a bachelor’s degree in meteorology from Oregon State University and he is an FAA licensed Airline Transport Pilot and Flight Engineer.

      But in my eyes, Chuck has distinguished himself in his ability to get to the core of a meteorological question quickly and thoroughly, as he does in this post. You can also read two other posts by Chuck here and here.

      Some people stop learning after they get a degree. Other people continue learning. A degree from years ago does not measure what a person knows. Chuck is one of those people who has never stopped learning.

      Read my own story here about my finding a physics error made and published by multiple Ph.D. scientists before I began work on my Ph.D. degree. In those days, no one attacked the messenger, so the readers evaluated my message.

      So, let’s focus on Chuck’s message.

      1. Ed,

        This is not a personal attack. It is important that each of us recognizes his/her own biases & shortcomings. As far as I can tell, Chuck is a solid meteorologist who has been able to keep his skills sharp since earning his degree, despite the fact that commercial pilots are by no means involved in day-to-day operational forecasting and meteorological analysis. Of course, the reasons why a pilot might be interested are obvious.

        Educational background is one objective measure of one’s level of expertise, contrasted with the highly subjective claim of “best meteorologist I know” by a single person. The number of papers published in peer-reviewed journals is another objective metric; it demonstrates one’s ability to successfully defend his or her ideas in a scholarly debate. But yes, I agree that it is more important to discuss the content of the article, which I do above and below.

        The issue here might be that Chuck is looking at this case from the perspective of a meteorologist, rather than looking at what could have led to such an extreme event from a climate perspective. After all, the point of contention seems to be whether this is a single, one-off “stars aligned” type of event, driven by a single, anomalous solar event, or whether this is related to the long-term effects of a significant (22% for CO2 over the last 40 years, according to Chuck’s Mauna Loa numbers) increase in the concentration of well-known, well-established, and long-studied gaseous absorbers in the thermal infrared portions of the EM spectrum.

    2. John: I think what you’re missing is that if you look at Portland’s climate record, there has never been an instance with this level of upper air dynamic support in June that coupled with the high solar angle of the solstice. The calculations bear that out.

      And while it’s true that July or August summer temperatures may contain more 90 or 100 degree days than June because the upper atmosphere reaches its warmest point in late July and early August, (making the subsidence dynamics are better for temperature extremes), that plays against a declining sun angle and the loss of insolation. This makes all time extremes much less likely in late July or August compared to June if the dynamics are right like they were in this case.

      Further, the surface potential temperature as taken from 850 millibars increased to near 116 degF from it’s start near 105 degF at the heatwave onset. That is a strong indication that the extra heat energy absorbed at the surface from higher solar radiation was convected to the top of the boundary layer to continue to allow the surface temperature to climb to progressively higher values unimpeded at the start of each solar day before free-air convection capped it, while their was no change to the blocking dynamics.

      1. But Chuck, read what you just said: “there has never been an instance with this level of upper air dynamics support in June that coupled with the high solar angle of the solstice.”

        So what do you think could have led to such an instance? Your analysis of the meteorological situation seems solid, although I haven’t looked at the data, myself. But aren’t you analyzing the symptoms, and not the cause?

        High temperatures each year for Portland, OR: June seasonal highs are rare, and hardly ever above 100 F.

        What has changed? Why was this such an extreme departure from the record highs of the past? What led to this synoptic situation? I expect we’ll see several studies in the literature examining this event, many of which will be attribution studies with detailed & robust simulations, looking not only at the solar flux that day but what led to such a pattern. They’ll also likely look at the probabilities of observing such an event with and without the most obvious climate forcings, such as substantial increases in several absorbing constituents. Perhaps we can discuss further at that time and share the results and findings from those studies, and discuss their implications.

  5. John: I explained the upper air dynamics. Subsidence, created by high pressure systems that give us our heat waves are the result of the strength of low pressure systems either upstream, downstream or both of the high pressure system. The low pressures systems ability to transport atmospheric mass downstream and develop high pressure subsidence is a direct reflection of the intensity of the low pressure, and that is dependent on the availability of high latitude cold air to develop frontogenesis.

    This was all present in the synoptic situation, so it is apparent that the intensity of the blocking that contributed to the onset of this heat wave was the result of the cold air supply that developed the low pressure upstream. This runs contrary to the claims of CO2 warming, because high latitude cold is required to weaken with the CO2 warming hypothesis.

    The atmosphere’s circulation is highly chaotic and random. So with the CO2 warming hypothesis failing, it was only a matter of time that this kind of high pressure blocking would occur in June, which it hasn’t in the records going as far back as 1940 for upper air observations and 1890 for the instrumental temperature record.

  6. I am not a scientist but one thing I think keeps getting confused is the term “sensitivity” and “forcing” in an open, dynamic (and very fluid) system. Our climate is far from sensitive to a W/m^2 flux change to justify CO2 warming. CO2 is a passive radiator it does not increase temperatures. The troposphere is not in thermal equilibrium or isolated so radiative forcing “sensitivity” has to be from a valid source, such as solar forcing or geothermal.

    Yes I understand the QED process of IR in relation to the surface and the dipole moments in ghgs which is why I understand that the climate is not that sensitive to low level IR fluxes. The only way to claim that all climate is sensitive to any change in thermal energy is to claim that all energy equals heat (as in real physics only the net difference is counted as heat in any system) although climate “scientists” have argued that point with me far too much (that and atmospheric insulation changes current surface temperatures). No known physics supports any of those claims.

    COE: Energy can neither be created nor destroyed. Notice it says nothing about heat.

    The Sun is the main provider of thermal energy with some selective geothermal which even selectively can melt an incredible amount of ice at the poles. WAA can cause some melting at the poles (maybe some inversions). It only takes a few weeks of warm weather to melt a large amount of ice and snow in a climate that can’t replenish that loss easily (the poles are typically too cold for precipitation).

    It is however, just as easy to follow warm weather anomalies from the tropics out to the poles as it is to follow cold weather anomalies from the poles to the tropics (much like a Carnot cycle). Sensitivity in an open system that mainly cools by conduction/convection/advection is simply irrelevant or inconsequential in regards to the troposphere and the surface.

  7. I agree.

    The idea that Man caused changes in atmospheric CO2 content will result in the Earth being forced to establish a dystopian, Eco-Fascist/Socialist, movement, in a desperate attempt to save Humanity, is pure Collectivist propaganda.

    While Atmospheric Scientists may endlessly argue about every nuance of the ebb and flow of this trace, CO2, gas, in Reality it plays no meaningful role in this planet’s climate. CO2 follows, and does not cause, changes in climate.

    Once one understands removing the sum totality of all anthropocentric CO2 from the planet’s atmosphere would have ZERO impact on its Climate, the entire subject becomes MOOT and of no consequence, whatsoever…

    Any political and economic activity undertaken to reduce, or punish, a population, or industry, for its purported creation of CO2 is either a total waste of effort and money…or a deliberate crime.

  8. CD, excellent comments. Can I get in touch with you off here and Joe’s site? I will have Dr. Berry send you my email address if you like. There are several things I’d like to discuss with you. BTW, I enjoy your comments over at COS. You have done a great job of educating yourself!

    1. Don’t be ashamed to ask questions on Joe’s site or think it’s stupid. I knew absolutely nothing about climate or physics 3 years ago, you have to be willing to ask the hard questions and grind until you have a satisfied answer. I hate not knowing something and I know I will never know everything, so it is a constant learning curve. The more you learn, the more you should learn you have even more to learn. Even if my IQ was a 180 and I had multiple PhDs I would not be satisfied in my quest for knowledge, ever, until I was dead.

  9. “But the point in all of this is clear. Solar radiation was the clear driver that caused these new all-time temperature records and little else.”

    100% agree, ignoring the true power of the sun is why we have this political climate hysteria in the firs place.

    Very good presentation.

  10. Chuck or Dr. Berry,

    So I have a question, just a peaked curiosity of mine which I asked over at WUUT and got a few good answers and some speculations but nothing complete just more pieces to the puzzle. I asked it over at Quora in May to all the “adiabatic experts” and still haven’t received one reply.

    “What causes a parcel of air in the dry adiabatic lapse rate to descend once it is stably buoyant under its potential energy? {This would be just under the tropopause.}”

    Typical physicists (not atmospheric physicists) treat this as a vertical solution only, meaning ghgs (with a dipole moment) has to eject some of that energy out of the parcel of air to break LTE and allow it to descend.

    This would be true if the atmosphere was static but it does not apply to a dynamic fluid atmosphere. Anyway, any input from yourself or Dr. Berry would be greatly appreciated.

  11. For clarification, the breaking of LTE with ghgs is certainly true, just not the only means available for this puzzle.

  12. Hello CD Marshall: In answer to your question, the atmosphere is seldom in any state of “bouyant equilibrium”. This is so because the earth’s atmosphere is constantly being heated unequally across all the latitude lines surrounding the earth. This unequal heating causes the displacement of atmospheric mass in the lower latitudes that constantly try and move excess heating northward to the poles. The Coriolis force allows for the formation of frontogenesis ( the creation of sharp temperature boundary’s that generate mid latitude cyclone development ) and those cyclones or low pressure areas that develop are transporting atmospheric mass upward and downstream of the low pressure to create the high pressure systems where the excess mass from hydrostatic balance causes the air within such a system to descend and warm through the dry adiabatic lapse rate in reverse. But only to a point of re-establishing an over-all hydrostatic balance. Likewise on ascent with low pressure, the cooling is dry adiabatic until condensation occurs, and from there, the latent heat picked up from the surface is given back to the troposphere.

    In the situation you specifically describe, radiation emission in the long wave IR frequencies will lead to cooling of the parcels of air near hydrostatic equilibrium affected, and if the density of those parcels begins to exceed that of the parcels underneath, convection ensues to re-establish equilibrium, meaning the parcels you describe in your example would descend because they changed their internal energy composure in hydrostatic equilibrium through radiative emission.

    In real meteorological conditions, we see this phenomena happen frequently near the top of the atmospheric water vapor boundary layer where strong radiational cooling from the water vapor will cause a convective overturn, leading to condensation, release of latent heat, and which subsequently develops a vigorous convective overturn to develop nocturnal thunderstorms where no solar insolation is even involved..

    Processes like this along with advection of atmospheric mass through circulation are what always keep the atmosphere in a state of imbalance, but always using the hydrostatic laws to try and achieve a rebalancing act.

    It is also important to remember that the vertical displacement of air by advection and lifting is done without changing the total energy within the system. The cooling and warming of the layer as a result is simply the exchange of gravitational potential energy for thermal energy as defined by the dry lapse rate itself, which is Ld = g/Cp. Ld is the dry lapse rate, g is the earth’s gravitation constant, and Cp is the specific heat of dry air, at 1.003 Jg-1 from whose molecular weight is 29 gmole-1. The value is 2.978 degC/1000ft or 5.36 degF/1000 ft.

    However, evaporation, condensation, and radiation all take away or add energy to the system depending on the source, and it is the hydrological cycle from water and its associated vapor phase that composes these processes that maintains a stable earth optical depth regardless of what atmospheric CO2 is doing.

  13. I just noticed a typo in my post above. The dimension of temperature was accidentally omitted, so the units should be Cp = 1.003 Jg-1K-1, or Joules per gram per degree Kelvin.

    Chuck Wiese

Leave a Reply

Your email address will not be published.

This site uses Akismet to reduce spam. Learn how your comment data is processed.