The steady increase in global temperatures, including average temperatures in Australia, means that even when rainfall is at or near the historical average, conditions are drier than before
because evaporation rates are higher.
Not exact matches
There are some various proposed mechanisms to explain this that involve the surface energy balance (e.g., less coupling between the ground temperature and lower air temperature over land
because of less potential for
evaporation), and also lapse
rate differences over ocean and land (see Joshi et al 2008, Climate Dynamics), as well as vegetation or cloud changes.
... the higher up you go the less water vapor you normally get
because it is too cold to have available water vapor (the
rate of condensation strongly exceeds the
rate of
evaporation)... unless you warm it and «suddenly water vapor just appears» where it was mostly absent before.
Regardless of whether it caused a particular drought, AGW makes droughts worse
because higher temperatures increase
evaporation rates.
Another paper criticized Wentz's analysis
because he did not consider other factors which play a role in precipitation such as global brightening during the period of study; and the error bars in Wentz's estimate of the
evaporation rate increase was considerable.
that is
because the water vapor pressure is supralinearly related to temperature: that is, a temp rise from 289K to 290K has a larger effect on vapor pressure (so, most likely, on the
evaporation rate) than does a temp rise from 288K to 289K.
It is often said that
because the temperature gradient (from subskin to skin) changes then the
rate of upward energy flow must slow down but that would not be the case if the enhanced
rate of
evaporation speeds up the
rate of flow again to negate the expected slowdown from a decreased gradient.
However on balance I think that the extra DLR just results in a zero effect on the «normal» upward energy flow
because all the DLR would be used up in enhancing the
rate of
evaporation and accounting for the energy deficit caused by that enhancement of
evaporation by virtue of the enthalpy of vapourisation (vapourisation has a net cooling effect).
Warmer water surfaces from extra downwelling infra red can not cause warming of the ocean bulk
because the
rate of
evaporation increases proportionately to the extra energy available and the latent heat of
evaporation is then taken mostly from the water.It is then no longer available to warm the ocean bulk.
An increased
rate of
evaporation and convection will move the additional energy at the surface to a higher layer in the atmosphere and
because evaporation carries energy in what's called «latent heat» there will be no measurable rise in temperature near the surface as thermometers measure what's called «sensible heat».
It is way down
because of the extremely high
rate of
evaporation through sand dunes.