Multi-decadal Trends in Tropical Convective Available Potential
Energy
A. Gettelman, D. J. Seidel, M. C. Wheeler, and R. J. Ross
2002: Journal of Geophysical Research, 107(D21), 4606-4613.
Abstract
Time series of convective available potential energy (CAPE)
calculated from 15 tropical radiosonde stations indicate
mostly positive trends in CAPE during 1958--1997. Increases in CAPE
are associated with increases in near-surface temperature and water vapor,
consistent with previous studies. The predominantly positive trends
appear mostly as a shift in the middle 1970's, consistent with the
time of an apparent shift of the background state of the climate system,
as documented by others. A general circulation model
of the atmosphere forced by observed sea surface temperatures
does not reproduce these overall increases in CAPE,
although it does reproduce the temperature trends.
The observed changes imply significant changes to
the tropical atmosphere over the last 40 years, and potential limitations of
climate model simulations.