We estimate climate warming related 21st century changes of moisture transports from the 
descending into the ascending regions in the tropics.  Unlike previous studies which employ 
time and space averaging, we here use homogeneous high horizontal and vertical resolution data 
from an IPCC-AR4 climate model.  This allows for estimating changes in much greater detail, 
e.g. the estimation of the distribution of ascending and descending regions, changes in the 
vertical profile and separating changes of the inward and outward transports.

We found low level inward and mid-level outward moisture transports of the convective regions 
in the tropics increase in a simulated anthropogenically warmed climate as compared to a 
simulated 20th century atmosphere, indicating an intensification of the hydrological cycle.  
Since an increase of absolute inward transport exceeds the absolute increase of outward transport
 the resulting budget is positive, meaning that more water is projected to converge in the moist 
tropics.  The intensification is found mainly to be due to the higher amount of water in the 
atmosphere, while the contribution of weakening wind counteracts this response marginally.  In
 addition we here investigate the changing statistical properties of the vertical profile of 
the moisture transport and demonstrate the importance of the substantial outflow of moisture 
from the moist tropics at mid-levels.