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What is the relation of latent heating and the global circulation of the atmosphere? Do you know some references about this relationship?

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Latent heat is released when water vapor turns to liquid\solid water. So latent heat is released where there is precipitation. So you're looking primarily at places where there is lots of moist convection... the ITCZ near the equator and then the midlatitudes.

I would believe that all of that latent heat release aloft should mean more heat is moved Poleward in the upper atmosphere branches of global circulation than would be moved by dry convection. And would therefore make the circulation more efficient, perhaps having a long-term effect of allowing reduced horizontal wind magnitudes in comparison to a dry world (the resulting reduction in instability means weaker updrafts and the better transport Poleward means smaller temperature\pressure imbalances and thus less wind than a world without moisture).

Offhand I don't know the literature well... Google Scholar helps though you run into a lot of climate model parameterization articles using most terms.

The nature of the global circulation of the atmosphere should be fairly stalwart, as Lorenz was pretty big in the field I believe. It talks about how latent heat in the tropics enhances the updraft winds in the ITCZ on page 17 a small bit. The paper seems to suggest it would increase the global circulation strength by increasing those velocities.

Response of the Hadley Circulation to Convective Forcing in the ITCZ looks like it might have potential too.

My most successful search term set seemed to be "global circulation" "latent heat" -simulation -co2 though it still wasn't amazing. But probably some other good articles to find if you thumb through them.

I'm certainly not a top expert in the field, but hope these thoughts and links add at least a little potential help or a starting point for you.

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Latent heat release is critical for the general circulation, in particular the tropical overturning circulation (Hadley & Walker circulations). The release of latent heat is the dominant diabatic heating of the tropical atmosphere, and provides much of the upward mass flux in the deep tropics (the ascending branch of the overturning circulation). In contrast, at higher latitudes the radiative cooling becomes the dominant diabatic term.

This is discussed in some of the standard text books. One example is in The Physics of Climate by Peixoto and Oort, in their Chapter 13. Here is a paraphrase of their section 13.3.1:

Diabatic processes are the sources and sinks of internal energy within the atmosphere, so they play a crucial role in many phenomena like convection, fronts, etc. Following Newell et al. (1970), estimates of the zonal average diabatic heating terms are shown in a figure (13.2). The net radiative heating is generally negative, but in parts of the tropical stratosphere it becomes slightly positive because of absorption by ozone. The latent heat release (estimated from precipitation) have three local maxima associated with strong convection in the ITCZ and with the polar fronts in both hemispheres. Boundary layer heating is confined to the lowest levels, as expected. The release of latent heat dominates in the tropics where it leads to net heating. At high latitudes, radiative cooling becomes dominant.

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  • $\begingroup$ Can you summarize the discussion in Peixoto and Oort? $\endgroup$ – arkaia Oct 26 '16 at 20:24
  • $\begingroup$ Sure. Here's a quick paraphrase of their Section 13.3.1 "Diabatic heating in the atmopshere" $\endgroup$ – brian Oct 27 '16 at 15:12

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