Old news - why it gets hotter at the Arctic and not so much at the quator

[GregLocock]

https://journals.ametsoc.org/view/journals/atsc/40/7/1520-0469_1983_040_1659_elttaa_2_0_co_2.xml

Studies of paleoclimate and modern observations indicate that evaporative effects limit thermal response in equatorial regions. We develop a latitude-resolved, steady-state energy balance model which incorporates the effect of an evaporative constraint on the variation of equatorial temperature with solar luminosity. For a diffusive model of surface heat transport the constraint requires the diffusion coefficient to vary with insolation. We find that the movement of the iceline with insolation is four times larger than in standard energy balance models with a constant thermal diffusion coefficient. This is a consequence of the global energy balance which forces temperature changes to occur at high latitudes when they are evaporatively buffered at the equator. Nonlinear temperature-ice albedo feedback at high latitudes then amplifies the response leading to greater sensitivity in the vicinity of current climate.

This is from 1983. Any climate model that cannot accurately account for clouds/water vapor will tend to run hot where people live, and cold where polar bears live.

Cheers

Greg Locock


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[TugboatEng]

Is it extra evaporation (latent heat) that reduces the impact? There isn't more sunlight impacting the oceans. The albedo of the oceans hasn't changed. That's why I made the enthalpy argument earlier. The equatorial regions already have more moisture in the air and that alone is enough to have significant dampening effect due to more enthalpy being required to cause temperature change.

 

[rb1957]

climate is complicated and we are fools to think we know it all and idiots to believe what a model tells us ('cause the model was developed by scientists).

drawing conclusions based on incomplete data is equally foolish (but then when can we have complete data ?),
and it is unscientific to continue to support a theory ('cause it Has to be right) when the predictions of that theory are not upheld.

"Hoffen wir mal, dass alles gut geht !"
General Paulus, Nov 1942, outside Stalingrad after the launch of Operation Uranus.

 

[dik]

There's less ice to reflect the heat, and more 'dark' water to absorb it...

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[TugboatEng]

I'm sure clouds and ice have similar albedo. More moisture in the air means more clouds.

 

[GregLocock]

Clouds are complicated, Ice is less so. dik is correct, the melting of the Arctic is a positive feedback effect. But the funny thing, if you read that paper, is that the real world behaves in almost the opposite fashion for this far more important effect to the global circulation computer models. All the whining and wetting of knickers is based on the models.

Cheers

Greg Locock


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[TugboatEng]

Over in the other thread, I linked a study about sublimation that showed that it occured at the same rate as evaporation under the same conditions.

https://phys.org/news/2018-10-sublimation-solid-ice-quickly-evaporation.html

The amount of moisture in the air was the biggest factor. Diffusion removed the moisture so more sublimation or evaporation can occur. It's crazy seeing experts discover these things in the last few years when we know we can blow on something with air and it dries faster, or it dries faster in lower relative humidity.