CR 28:53-65 (2004)  -  doi:10.3354/cr028053

Sensitivity of present and future surface temperatures to precipitation characteristics

Barry H. Lynn1,2, Leonard Druyan1,2,*, Christian Hogrefe3, Jimy Dudhia4, Cynthia Rosenzweig2, Richard Goldberg1,2, David Rind2, Richard Healy1,5, Joyce Rosenthal6, Patrick Kinney7

1Center for Climate Systems Research, Earth Institute at Columbia University, Armstrong Hall, 2880 Broaday, New York 10025, USA
2NASA/Goddard Institute for Space Studies, New York, New York 10025, USA
3New York State Department of Environmental Conservation, Albany, New York 12203, USA
4National Center for Atmospheric Research, Boulder, Colorado 80306, USA
5Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543, USA
6Columbia University School of Architecture, Planning and Preservation, New York, New York 10027, USA
7Columbia University School of Public Health, New York, New York 10032, USA
*Corresponding author. Email:

ABSTRACT: A model simulation study shows that different diurnal cycles of precipitation are consistent with radically different present and future climate characteristics. In projected future climate scenarios, divergence in the time of day and type of precipitation had very divergent impacts on the radiation balance and consequently on surface temperatures. The relationship between the diurnal cycle of precipitation versus the present and future climate was examined using the GISS-MM5 (Goddard Institute for Space Studies Mesoscale Model 5) regional climate modeling system with 2 alternative moist convection schemes. June-August (JJA) mean surface temperatures of the 1990s, 2050s, and 2080s were simulated over the eastern US on a double nested 108/36 km domain, with the 36 km domain centered over the eastern US. In the 1990s, one model version simulated maxima in (convective) precipitation during the early morning, while the second model simulated the hour of precipitation maxima with considerable spatial variability (in better agreement with observations). In the futuristic climate scenarios, differences in the time of day of precipitation had very important impacts on the radiation balance at the surface. One version gave more precipitation at night and fewer clouds during the day, promoting higher surface temperatures. The alternative version created more precipitation during the day, consistent with diminished absorption of solar radiation at the surface and consequently lower surface temperatures. The results demonstrate the importance of improving cumulus parameterizations in regional mesoscale and global climate models and suggest that such improvements would lead to greater confidence in model projections of climate change.

KEY WORDS: Climate change · Surface temperatures · Model assessment

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