It’s always good to chat with Roger Pielke Senior. He’s informative, and more open minded than most climate scientists. Here’s a transcript of the conversation we just had on twitter.
Rog Tallbloke @RogTallbloke
Roger. Mt Everest summit winter avg -30C. Base camp -17C. Air pressure difference 20kPa. What really causes Earth’s ‘greenhouse effect’, 1% of water vapour + 0.04% CO2 or 100% of atmospheric MASS. Think man, think! CC @RogerAPielkeSr
Roger A. Pielke Sr@RogerAPielkeSr The LW radiative effect of CO2 and water vapor in the Earth’s atmosphere is succinctly summarized in https://pielkeclimatesci.wordpress.com/2006/05/05/co2h2o/… and https://pielkeclimatesci.wordpress.com/2007/08/24/further-analysis-of-radiatve-forcing-by-norm-woods/…
Relative Roles of CO2 and Water Vapor in Radiative ForcingIn the second edition of our book “Cotton, W.R. and R.A. Pielke, 2007: Human impacts on weather and climate, Cambridge University Press, 330 pp”, we present a new analysis completed for…pielkeclimatesci.wordpress.com
Rog Tallbloke @RogTallbloke Thanks Roger, I understand the current paradigm. I want you to lay it to one side and consider another way of looking at the GHE. Then we can compare the two concepts and see their strengths and weaknesses relative to each other. May the best theory win!
Roger A. Pielke Sr@RogerAPielkeSr Radiative transfer in the clear atmosphere is a very well established and accepted concept in physics. Framework is discussed in detail in http://store.elsevier.com/Mesoscale-Meteorological-Modeling/Roger-A-Pielke-Sr/isbn-9780123852373/….
Rog Tallbloke @RogTallbloke I agree it’s well established, but that doesn’t mean it’s correct: 1) Convection is not properly coupled in models because it is parameterised not calculated in a simultaneous equation with radiation. 2) Everything radiates according to its temperature, not the other way round.
Roger A. Pielke Sr@RogerAPielkeSr Point #1 is certainly correct & I have published on this as ideal application of machine training. But #2 is grossly incomplete wrt radiative transfer as it is transmission/absorption/reflectivity as a func of wavelength that needs to be determined. In clear air, solidly known.
Rog Tallbloke @RogTallbloke Thank you. I ran out of space to flesh out point #2 so let’s take a closer look in the next tweet. Please link the paper you refer to in agreement with point #1. Sincere thanks.
Roger A. Pielke Sr@RogerAPielkeSr Pielke Sr et al 2006: A new paradigm for parameterizations in numerical weather prediction and other atmospheric models. National Wea. Digest, 30, 93-99. https://pielkeclimatesci.files.wordpress.com/2009/10/r-296.pdf…
Rog Tallbloke @RogTallbloke Excellent: “models are composed of a dynamical core, which represents advection, the pressure gradient force, and gravitational acceleration; and of a set of parameterizations that represent all other physical processes”. You agree the lapse rate is fundamental. Good start.
Rog Tallbloke @RogTallbloke Can we agree then, that if the surface air pressure was significantly reduced by a loss of atmospheric mass, the surface temperature would fall until a new equilibrium was reached?
Roger A. Pielke Sr@RogerAPielkeSr If the mass above is reduced, the optical path length from TOA to sfc associated with radiative absorption and remittance from a gas will, of course, will be reduced. And, if you lower p, T lowers by ideal gas law.
Rog Tallbloke @RogTallblokeWe are in agreement then, that both radiative transfer and air pressure play a role in elevating surface T above that of an airless body. So the question becomes; “above min required to radiate heat to space from altitude, how much do each contribute?” Is that a fair assessment?
Roger A. Pielke Sr@RogerAPielkeSr Vertical radiative flux divergence in the atmosphere is a function of the vertical pressure distribution. The question as to contributions is not well posed. On the moon, sfc T is from balance of solar flux absorbed at sfc, radiative emittance from sfc and ground conduction.
Rog Tallbloke @RogTallbloke Agree about the Moon, see paper below for exhaustive treatment, it turns out that the Moon’s average sfc T is ~198K. This means Earth’s ‘greenhouse effect’ is around 90K !! Have a read please, then I’d like to get back to the ideal gas law next.
On the average temperature of airless spherical bodies and the magnitude of Earth’s atmospheric…The presence of atmosphere can appreciably warm a planet’s surface above the temperature of an airless environment. Known as a natural Greenhouse Effect (GE), this near-surface Atmospheric Thermal…springerplus.springeropen.com
Roger A. Pielke Sr@RogerAPielkeSr Roger- I don’t want to spend more time on this subject. The “greenhouse gas effect” is fundamental physics and I present the reason why in my modeling book. To falsify that conclusion, you need to refute formally using established framing and publishing peer reviewed papers.
Rog Tallbloke @RogTallbloke As you wish. Thank you for the discussion. I hope you’ll read the paper I linked and come back to it sometime, because the empirical data from Vavasada et al is solid (Lunar Orbiter DIVINER experiment) and the 90K greenhouse effect isn’t going away. It needs investigating.
via Tallbloke’s Talkshop
October 14, 2020 at 12:48PM