But how
much increased evaporation was necessary to create appositive feedback.
Not exact matches
During the dry season, with no fog layer to reflect sunlight, the smaller cloud cover allows plants to receive
much higher radiation,
increasing evaporation and photosynthesis rates, another process missed by the GCMs.
This additional precipitation is sustained by more energy leaving the surface by
evaporation — that is, in the form of latent heat flux — and thereby offsets
much of the
increase in longwave flux to the surface.
Annual average
evaporation (Figure 10.12)
increases over
much of the ocean, with spatial variations tending to relate to those in the surface warming (Figure 10.8).
Part way there, but no quantitation yet: of the 3.77 W / m ^ 2 radiated back dowwnard, most goes to
increased rate of
evaporation of the water at the surface, and
much less goes to
increased mean temp
increase at the surface; hence
increased rate of non-radiative transfer of heat from surface to upper atmosphere, slight
increase in rainfall as hydrological cycle is faster, and slight
increase in cloud cover.
I don't have any references, but since IR only penetrates the nano - skin of ocean water and absorption and reemission is a VERY rapid process, then as I understand it, there is very little heating of the water, and hence not
much in the way of
increased evaporation.
To find out exactly how
much greening Arctic warming would bring, the team used a model that projected how temperature changes would affect snow cover, vegetation, and the
increased evaporation and transpiration from plants in the Arctic.
The main message of the figure below is that the precipitation and
evaporation increase at a
much lower rate than Clausius — Clapeyron would predict, about 2 - 4 % per degree K.
As the temperature
increases, the water vapor pressure (hence by inference the water
evaporation rate on non-dry surface)
increases supralinearly; that is, a 1K
increase from 288 K is
much less than a 1K
increase from 308K.
Scientists have found that global warming is melting Bolivia's glaciers and has
increased evaporation rates by as
much as 200 percent near its key lakes.
Moreover, the large
increase in observed
evaporation (vs the
much smaller
increases in the model outputs) is not a simple direct function of
increased sea surface temperatures.
By comparison, climate models consistently predict a
much lower
increase (1 % -3 % / K) in
evaporation and rainfall.
The pan
evaporation level was observed to decrease considerably during
much of this period, despite the
increasing temperature.
Whether or not
increased backradiation from an
increased CO2 concentration causes the heat content (of a body of water) to
increase, is determined by how
much of that «energy in» flux gets converted into energy out flux in form of
evaporation, etc..
So
evaporation doesn't control sea surface temperatures, but it does couple that surface temperature to the overlying air temperature, but importantly one needs to satisfy the TOA budget to determine what that temperature is, i.e., it wouldn't be correct to assume there's an upper bound on SSTs after which
evaporation is so efficient that the temperature can't
increase much more.