Scaling of Precipitation Extremes over a Wide Range of Climates Simulated with an Idealized GCM
Extremes of precipitation are examined in a wide range of climates simulated with an idealized aquaplanet GCM. The high percentiles of daily precipitation increase as the climate warms. Their fractional rate of increase with global-mean surface temperature is generally similar to or greater than that of mean precipitation, but it is less than that of atmospheric (column) water vapor content. A simple scaling is introduced for precipitation extremes that accounts for their behavior by including the effects of changes in the moist-adiabatic lapse rate, the circulation strength, and the temperature when the extreme events occur. The effects of changes in the moist-adiabatic lapse rate and circulation strength on precipitation extremes are important globally, whereas the difference in the mean temperature and the temperature at which precipitation extremes occur is important only at middle to high latitudes.
© 2009 American Meteorological Society. Manuscript received 30 June 2008; in final form 8 April 2009. We are grateful for support by the National Science Foundation (GrantATM-0450059) and a David and Lucile Packard Fellowship. The simulations were performed on Caltech's Division of Geological and Planetary Sciences Dell cluster. Some preliminary results of this work were reported in Schneider and O'Gorman (2007).
Published - OGorman2009p6403J_Climate.pdf