Researchers find biases in warming patterns in climate models of monsoons

Posted: May 10, 2022 by oldbrew in climate, modelling, predictions, research, Temperature
Tags:


Are ‘corrections’ the answer? Avoiding the need for them might be better. The researchers observe that ‘the projected warming in response to greenhouse gases is too great’. This has been known for years but the penny of reliance on a certain climate theory has yet to drop, it seems.
– – –
Climate projections are crucial for adaptation and mitigation planning says Eurekalert.

The output of the latest round of the Coupled Model Intercomparison Project, phase 6 (CMIP6) has been widely used in climate projections.

However, a subset of CMIP6 models is “too hot” and the projected warming in response to greenhouse gases is too great.

How to tackle the “hot model” problem at the regional scale had previously been unclear.

A research team from the Institute of Atmospheric Physics (IAP) of the Chinese Academy of Sciences (CAS) has revealed that the latest CMIP6 climate models tend to overestimate future Afro-Asian summer monsoon (AfroASM) rainfall and runoff due to present-day biases in warming patterns.

By constraining biases, however, the rainfall increase is 70% of the raw projection. The study was published in Nature Communications on May 10.

The AfroASM includes the West African monsoon, South Asian monsoon, and East Asian monsoon.

The research team identified the leading mode of variability among CMIP6 models in projecting future changes in AfroASM rainfall. They found that projection uncertainty was related to the bias in present-day interhemispheric thermal contrast (ITC).

Since large-scale monsoon circulation is driven by ITC due to moist static energy gradients, models with a larger ITC trend over the past thirty years tend to project more precipitation increases.

Since most CMIP6 models tend to overestimate present-day ITC trends, the team corrected the raw projection by designing an emergent constraint technique.

The increase in precipitation in the constrained projection is ~70% of the ensemble mean of the CMIP6 models. The area of land with a significant increase in precipitation is ~57% of the raw projection.

The research team further extended its analysis to runoff, which is a mirror of potential water availability. In the constrained projection, ~27% of land area in the AfroASM region will witness a significant increase in potential water availability, which is ~66% of the raw projection.

Regionally, the impact of the observational constraint is most pronounced in the West African monsoon region where the fraction of land area with increased water availability is ~55% of the raw projection.

This study provides a solution for tackling the “hot model” problem at regional scales. The emergent constraint technique reported in the study is based on the physical link between a modelled but observable variable in the present day and a projected variable in the future climate system.

Full article here.

Comments
  1. […] Researchers find biases in warming patterns in climate models of monsoons […]

  2. Philip Mulholland says:

    When the Ptolemaic model of an Earth centered planetary system failed to accurately predict planetary motion the solution was to invoke the concept of epicycles.
    By doing this they corrected the error but did not address the root cause of the problem, namely a false model.
    Climate science is built on the false model of radiative energy feedback and climate science will continue to fail until this false model is abandoned .

  3. oldbrew says:

    See table 2 here…
    https://clintel.org/the-greenhouse-effect-summary-of-the-happer-and-van-wijngaarden-paper/

    ‘It is very clear from this table that all GHGs are saturated and adding to the current concentrations will make very little difference.’

  4. Gamecock says:

    ‘However, a subset of CMIP6 models is “too hot” and the projected warming in response to greenhouse gases is too great.’

    Petitio principi.

    They would have to know the future to know that their projection is too great. If they know, what is the purpose of models?

  5. oldbrew says:

    They’re looking in the rear view mirror it seems…

    ‘most CMIP6 models tend to overestimate present-day ITC trends’

  6. Phoenix44 says:

    “an emergent constraint technique”

    Laughable. They just fudge the model.

    The models get it wrong. Because the models are not right. Why can’t they admit that? If the simply “constrain” the outputs, they are fudging it all.

  7. Gamecock says:

    “fudging it”

    To model the atmosphere, you have to know how it works.

    We don’t know. Even extremely localized weather predictions are only good for 2 or 3 days, yet they claim to predict what will happen decades – generations – out.

    To get valid results from a real model, you have to have valid input data as a starting point. Man’s measurements of atmospheric and ocean conditions are superficial. AND, there are significant flaws in the EXISTING terrestrial network of weather stations, as Anthony Watts points out. AND, as Tony Heller points out, weather data is frequently “adjusted” by the experts.

    Climate scientists claim they need bigger computers. They need an infinitely larger data collection network. They need to understand atmospheric behavior before they can model it.

    Limited data going into a model designed by people with minimal understanding. “fudging it” is charitable.

    It is completely fake. Yet they have managed to get the attention of leftist Western politicians. Not because of “the science,” but because their assertions support the political goals of the leftist Western politicians.

    As the effect of claiming Climate Change! fades, the Left will drop it like a bad transmission. They don’t care about the weather or Gaia . . . they are just a tool to get people to accept the unacceptable.

  8. ivan says:

    Since the models have been proven to be garbage why do they expect anything but garbage output, after all the old adage that goes back to the beginning of computers Garbage In = Garbage Out. Maybe sometime in the future they will relearn that, it would happen quicker if they tried to get their models validated.

  9. stpaulchuck says:

    oldbrew says:
    May 10, 2022 at 1:05 pm
    [reference to GHG saturation]

    I was reading a refutation of the saturation concept/model the other day. I’ll have to see if I can find it and post a link. You guys who are way more educated in the science of this atmospheric stuff than I am can then check it out for error.

    Personally, I like the concepts of the saturation idea, but then “the Earth is flat….” so I’ll not take an absolute stance on it (yet).

  10. stpaulchuck says:

    here ya go guys, it’s over on Skeptical Science:

    https://skepticalscience.com/co2-not-saturated-basic.html

    I got lost in the discussion after the article. Can anyone help an old engineer understand what’s true and what’s not here?

    [reply] a warmist’s website

  11. oldbrew says:

    Exhaustive study finds more CO2 and water molecules will not cause dangerous warming

    Precision research by physicists William Happer and Willem van Wijngaarden has determined that the current levels of atmospheric carbon dioxide and water vapor are “saturated.” In radiation physics that means adding more CO2 or water molecules will bring modest warming that will benefit plant growth, and thus all life on Earth. More CO2 and H2O will not cause dangerous warming.

    From this point forward, emissions from burning fossil fuels will bring little additional global warming, and what does occur will improve forests, grasslands and agriculture. There is no climate emergency.

    This finding is astounding, paradigm shattering, contrary to what alarmist scientists have told us for decades. Scientifically, it resolves a huge uncertainty that has plagued climate science for over a century: How should saturation be measured, and what is its extent regarding the primary greenhouse gases?

    https://www.heartland.org/news-opinion/news/slight-beneficial-warming-from-more-carbon-dioxide

    Dependence of Earth’s Thermal Radiation on Five Most
    Abundant Greenhouse Gases
    W. A. van Wijngaarden1 and W. Happer2
    1Department of Physics and Astronomy, York University, Canada, wlaser@yorku.ca
    2Department of Physics, Princeton University, USA, happer@Princeton.edu
    June 8, 2020

    Fig. 9 as well as Tables 2 and 4 show that at current concentrations, the forcings from all greenhouse gases are saturated. The saturations of the abundant greenhouse gases H2O and CO2 are so extreme that the per-molecule forcing is attenuated by four orders of magnitude with respect to the optically thin values. [bold added]

    Click to access 2006.03098.pdf

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