«If you find wet get wetter, dry get drier, occurring increasingly in tandem
with poleward expansion, there's just almost no way that can happen naturally,» Marvel said.
Not exact matches
However, there is also the
expansion of the Hadley Cells where water vapor from tropical ocean evaporation rises, water in the form of rain falls out as the air cools
with increased altitude, then dry air descends at
poleward edge of the cells in the dry subtropics.
What they discovered was that the
poleward shift of the clouds, which occurs in both the Northern and Southern Hemispheres, connected more strongly
with the
expansion of the tropics, defined by the general circulation Hadley cell, than
with the movement of the jets.
So you need to look at a wide range of indicators all of which have independent sources of error (for instance, errors in satellites are not likely to be correlated
with errors in weather stations or ocean buoys) and see if your understanding matches all of the different aspects that you expect from the theory (stratospheric cooling, ocean warming, Arctic melt,
poleward and upward
expansion of biomes etc...).
The
expansion of the tropical belt that we attribute to black carbon and tropospheric ozone in our work is consistent
with the
poleward displacement of precipitation seen in these models.