Open AccessA simple explanation for the increase in relative humidity between 11 and 14 km in the tropics
Author(s) -
Folkins Ian,
Kelly K. K.,
Weinstock E. M.
Publication year - 2002
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2002jd002185
Subject(s) - relative humidity , tropics , atmospheric sciences , convection , lapse rate , environmental science , climatology , humidity , descent (aeronautics) , meteorology , precipitation , supersaturation , physics , geology , thermodynamics , fishery , biology
We use a very simple model with no adjustable parameters to simulate the increase in relative humidity between 11 and 14 km in the tropics. The rate of increase in relative humidity, in this interval, appears to be largely determined by the shape of the convective detrainment profile, the temperature profile, and the level of zero radiative heating. It appears to be unaffected by evaporative moistening or the complex three‐dimensional structure of convective systems. We also show that the rapid increase in the fraction of supersaturated air parcels above 150 mb (∼14.5 km) is associated with a transition from large scale descent to ascent.