NOAA on water vapor – 2019 edition

Posted: July 22, 2019 by oldbrew in atmosphere, radiative theory, Temperature, Uncertainty
Tags: ,

[click on image to enlarge]


NOAA’s latest offering on this topic is here. Of course we’re pitched into the world of ‘greenhouse gas’ theory. But it seems to be a world of considerable uncertainty, if the phrases highlighted (by the Talkshop) are anything to go by. Most attention is given to CO2 in the media, but it’s only a very minor player in the atmosphere (0.04%). There’s no accepted figure for ‘water vapor’ (NOAA uses US spelling) as exact data doesn’t exist, although ballpark estimates from various readings can be found. Why do greenhouse gas believers obsess about CO2 when they don’t know a lot about what’s going on with water vapor, which is on the face of it far more important to their theory?

Water Vapor is the most abundant greenhouse gas in the atmosphere, which is why it is addressed here first. However, changes in its concentration is also considered to be a result of climate feedbacks related to the warming of the atmosphere rather than a direct result of industrialization.

The feedback loop in which water is involved is critically important to projecting future climate change, but as yet is still fairly poorly measured and understood.

As the temperature of the atmosphere rises, more water is evaporated from ground storage (rivers, oceans, reservoirs, soil). Because the air is warmer, the absolute humidity can be higher (in essence, the air is able to ‘hold’ more water when it’s warmer), leading to more water vapor in the atmosphere.

As a greenhouse gas, the higher concentration of water vapor is then able to absorb more thermal IR energy radiated from the Earth, thus further warming the atmosphere. The warmer atmosphere can then hold more water vapor and so on and so on. This is referred to as a ‘positive feedback loop’.

However, huge scientific uncertainty exists in defining the extent and importance of this feedback loop. As water vapor increases in the atmosphere, more of it will eventually also condense into clouds, which are more able to reflect incoming solar radiation (thus allowing less energy to reach the Earth’s surface and heat it up).

The future monitoring of atmospheric processes involving water vapor will be critical to fully understand the feedbacks in the climate system leading to global climate change. As yet, though the basics of the hydrological cycle are fairly well understood, we have very little comprehension of the complexity of the feedback loops.

Also, while we have good atmospheric measurements of other key greenhouse gases such as carbon dioxide and methane, we have poor measurements of global water vapor, so it is not certain by how much atmospheric concentrations have risen in recent decades or centuries, though satellite measurements, combined with balloon data and some in-situ ground measurements indicate generally positive trends in global water vapor.

Comments
  1. Pablo says:

    The whole crazy idea is that “greenhouse gases” warm the Earth above its theoretical blackbody temperature of minus 18ºC… so 33ºC of warming down to mostly water vapour.

    If there is water vapour in the atmosphere it is only there because it has evaporated from somewhere warm and cooled it by doing so and taken with it latent heat to be released on condensing at higher altitudes.

    That creates a reduction of the dry lapse rate of 9.8C/km to one of 6.5C/km which results in an increase of potential temperature of 3.3ºC/km.

    Assuming a 10km tropopause, that is a warming of 33ºC at that altitude due to the magic of latent heat.

    To quote from Joe Postma:

    “Solar heating on the ocean extends to about 200m in depth, and the Pacific and Atlantic circulation patterns are parallel with the equator for most of their width [36], allowing lots of time to absorb the relevant amount of solar energy. When continental obstacles get in the way, the circulation patterns divert north or south and eventually run through the polar regions and then back again to the equator. The amount of internal heat of a 1kg block of ice at 130C is approximately 600,000 J (evaluated by numerically solving the H2O problem with temperature- dependant specific heat and the latent heat plateau) with about half of that being latent heat. And so 200m deep of a 1 square meter column is about 120 GJ of thermal energy. Given an equatorial average solar input to the ocean of approximately 31 MJ per day for a square meter under the solar zenith, this column of water holds about 3,871 days or 10.5 years’ worth of solar heating. Given that, relative to the scale of a square meter, the hemispherical surface is approximately flat for several million square kilometers under the solar zenith (and one square kilometer = one million square meters), there is clearly a tremendous amount of stored solar energy in this system which will take from centuries to many millennia to cool as equatorial water sheds its heat in the north and south as it circulates through. If you take the entire mass of ocean at 1.4×1021 kg, and if most of it is liquid, and the latent heat of fusion of ice is 334,000 J/kg, then this is 4.67×1026 J of stored “hidden” energy. Given that the global absorbed solar insolation is 1×1022 J per day, that’s about 121 years’ worth of solar energy stored in the latent heat. The latent heat component being on the order of half of the total energy for water at 130C, means that there will be a significant barrier to cooling below 00C as the current circulates through the poles, keeping these regions much warmer than they would otherwise be. This of course will skew-high the characterization of the average global surface temperature and thus provide an “interpreted appearance” of a GHE when there actually is none.”

  2. oldbrew says:

    However, huge scientific uncertainty exists in defining the extent and importance of this feedback loop.

    ‘and importance’ – but we should take it seriously anyway? At least they acknowledge some of the issues.

  3. JB says:

    “…we have very little comprehension of the complexity of the feedback loops. ”

    As also on the concept of Green houses, then the regulation of gases within them. Let them unravel the complexity of what constitutes a house, then make it fit the earth’s atmosphere.

    Oh, sorry. I lost my thought there. They admitted to having very little comprehension….

  4. pochas94 says:

    Also not understood is the thermodynamic reversibility of cloud formation, which means that the energy balance at cloud level must not change as the cloud forms. It does change when it rains.

  5. Curious George says:

    “fairly poorly measured and understood” – a settled science, exactly.

  6. BoyfromTottenham says:

    Thanks, Pablo. Useful figures to play with. Can you also tell us about how much CO2 would be dissolved in this 200 metre deep x 1 m2 column of sea water, and perhaps even how much CO2 would outgas from it if it’s temperature rose by say 1 degree C? What, waaay more than that generated from humans burning fossil fuels? Gee whizz.

  7. tom0mason says:

    What an admission from NASA!
    The feedback loop in which water is involved is critically important to projecting future climate change, but as yet is still fairly poorly measured and understood.
    and
    As yet, though the basics of the hydrological cycle are fairly well understood, we have very little comprehension of the complexity of the feedback loops.

    And yet so many people believe Climate Models™ are based on basic physics of all the natural variables, including water in all its forms, are known, understood and quantified.
    But with this, water’s basic physics as assessed by NASA is “poorly measured and understood” resulting in “very little comprehension of the complexity of the feedback loops.”
    How can anyone think that any Climate Model™ can do even a slightly adequate job when the basics of this planet’s major weather/climate element (water) is so poorly quantified and understood.

    Is it important? Well, those Climate Models™ are the linchpin for the UN to extract money and power from everyone in the world!
    Only the reason for foolish governments to sheepishly follow the UN-IPCC’s dumb idea of decarbonization is the utter belief confidence level espoused by the UN-IPCC in the results from those Climate Models™.
    The main reason that kids believe in some extinction event in their lifetimes is because of the UN-IPCC and the ‘projected scenarios’ (aka predictions) from Climate Models™.
    The only reason XR idiots have any traction is the belief in those Climate Models™ predictions.

    If as said here by NASA, water is not and has not been properly assessed, quantified, and understood why should anyone believe what the UN-IPCC and the Climate Models™ say?

  8. tom0mason says:

    Ooops, not NASA but NOAA.

  9. ivan says:

    tom, there you see why non of the climate models have been independently validated, yet as you say there are too many governments in thrall to the NWO of the UN – an institution that is well past is use by date and should be disbanded.

  10. cognog2 says:

    It is not in the interests of the IPCC et al (The Greens?) to understand the behaviour of water; for the scientific facts of the matter would conclude that water provides a strong NEGATIVE feedback to the GHE and this fact alone would scupper the whole CAGW message.

    Briefly:
    At phase change of water (evaporation) absorbed radiation is used to alter the the molecular structure rather than increasing temperature. Thus no warming.
    The energy involved amounts to some 680 Watthrs/kg of water evaporated and is referred to as Latent Heat.

    This new structure renders water lighter than dry air and thus generates an upward force due to buoyancy to drive the water up into the clouds, carrying with it the Latent Heat for eventual dissipation both to the atmosphere and space. This is done by condensation back into the liquid which then returns to earth as rain, snow, ice etc. often cooler than than when the evaporation started in the cycle.
    In engineering terms this cycle is referred to as the Rankine Cycle about which a great deal is known. One salient fact being that at constant pressure any increase in energy input results in an increase in evaporation rate rather than an increase in temperature. It is this fact which provides water with its thermostatic properties, providing stability to global temperature.

    Here, back on earth we use this cycle on a daily basis to keep cool and control temperature.
    We sweat. We build cooling towers for our power plants. We make sure we have water in the engines under the bonnet. We dive into the pool to cool off. We drink plenty so we can keep sweating. I could go on.

    In simple terms one can say that our Earth sweats to keep cool, just like you and I.

    Sadly all the above is anathema to the Green Machine as it knocks the hysteria on the head.

  11. Power Grab says:

    I reckon it’s one of their money-making strategies to “admit” that they don’t completely understand a thing like water vapor. Isn’t it just another way of saying, “Please send cash”?

  12. Phoenix44 says:

    The process of modeling is corrupted as with all aspects of climate science. The modelers know that a model using first principles doesn’t look like either the past or the near future. But instead of looking at the claimed first principles they nudge and fudge and fiddle their models until it kind of looks like the past and if they run it enough times they get one run that kind of matches some of the future. And instead of looking at the basic assumptions they call for bigger models and more powerful computers – but neither can solve the problem if the basic assumptions are wrong.

    If the science was not corrupted, different teams of modelers would be running different basic assumptions about CO2, feedbacks, water, the sun. But they do not because the basics are fixed even though they are clearly wrong.

  13. oldbrew says:

  14. pochas94 says:

    Cloud formation is a thermodynamically reversible process, which means that energy flows at cloud level must remain unchanged as the cloud forms. Are there any irreversible processes involved? Yes, those involving mixing, which cannot be reversed. When a raindrop falls to earth, that is irreversible. When a warm air mass mixes with a cooler one and causes precipitation, that is irreversible. Evaporation/condensation is the mechanism that stabilizes surface temperatures. Cloud cover seems to correlate with surface temperature, but that is incidental only. If the cloud is not producing precipitation, it is not affecting surface temperature, although it will affect (reduce) the day/night temperature swings. Indeed, the absence of a cloud allows surface temperatures to rise which, according to the Stefan-Boltzmann fourth power radiation law, causes increased radiation to space, that is, cooling.

  15. craigm350 says:

    Reblogged this on WeatherAction News and commented:
    Joe Bastardi has been banging the WV drum quite a lot of late. Paul Homewood played some of his comments last year;

    Well, what is the number one source of thermal energy on the planet, with 99.9%? The oceans. What is the prime source of water vapor (and arguably CO2)? The oceans.

    The recent Super El Nino sent an immense amount of water vapor into the pattern. I have already opined that this has a very long life as far as the effect on the planetary temperature goes because very tiny amounts of water vapor left over in the pattern have their biggest effect on the arctic temps in their cold season.

    So, while the Earth’s temperatures, where it’s above freezing much of the time, return to normal, the amount of warmth left in the Arctic areas continue to skew the Earth’s temperatures.

    It also leads to interesting other feedback aspects, which we have to deal with in forecasting. So, it is very important to us. But also understanding the source and those implications are important.

    https://notalotofpeopleknowthat.wordpress.com/2018/06/15/joe-bastardi-on-water-vapour-el-ninos/

  16. Tim Crome says:

    There cannot be a positive feedback driven by CO2 or water vapour, if there was the atmosphere would have warmed to unbearable levels b/millions of years back.

    All logic suggests there must be negative feedbacks that quickly restore temperatures to “normal” levels in the event of a major upset (volcanic eruption, meterite, etc..).

  17. pochas94 says:

    An example of clouds producing a warm-above-cold temperature inversion is the marine layer fog seen every morning off the coast of California. It is there because radiation from the humid layer above the warm ocean continues at night, reducing the layer temperature below the dew point and the resulting fog temporarily cuts off radiation from the surface to space. The sun eventually heats the marine layer above the dew point, the fog burns off, and normal convection resumes, but while the fog is present radiation to space has been suppressed. All clouds represent local temperature inversions.

  18. oldbrew says:

  19. pochas94 says:

    If you’re looking at cloud tops, yes, OLR will be reduced. But the reflected solar is replaced by reflected downwelling IR at the surface. It’s not all about albedo.

  20. pochas94 says:

    And, if those clouds are raining out, there is your cooling effect.

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