Sunday, July 15 at 2 pm PROGRAM "Precipitation variations in the Southwestern United States" presented by Bob Harper

Climate models tend to predict an increasingly arid 
future for the Southwestern United States, in large
part because of increased evaporation due to rising
global temperatures.  But current climate models do
not handle precipitation well, and are not able to 
accurately model natural variability.

This talk will leave the climate models, 
and present actual precipitation data across 
the Southwestern United States from 1860 to the 
present, focusing on the long term natural variability, 
which to date is much larger than any global warming
related precipitation component.  Multi-decadal variations 
of average precipitation of +/-20% around the long 
term mean are largely driven by Pacific Ocean sea surface
temperature changes.  

Presented by Bob Harper.  He has a A.B. in Applied Mathematics from Harvard University (1965) & a PhD in Space Physics from Rice University (1972).  His dissertation was on the dynamics of the Earth's Upper Atmosphere. Harper was also a geophysicist in the Petroleum Industry.

Light refreshments afterwards.