The past and future of hydroclimate in southwest North America
Tuesday October 26th
Room 417 Schermerhorn Hall
Summary: Southwest North America (SWNA) has experienced a series of severe multiyear droughts in the period since European settlement some of which have seriously impacted the social history of the region. Climate modeling has recently revealed that these droughts were caused by small, naturally occurring changes in tropical sea surface temperatures. The modern era droughts, however, pale in comparison with a series of megadroughts of multidecadal duration during the Medieval period. The megadroughts are clear from tree ring reconstructions and are still visible in the western landscape. The causes of the megadroughts are unknown but I'll speculate on them anyway. As for the future, SWNA is robustly projected to become more arid as a consequence of rising greenhouse gases and global warming and general drying and poleward expansion of the subtropical dry zones. The mechanisms for this are distinct from those of naturally-occurring drought. Drying of SWNA, including Mexico, is going to place severe stress on water resources in a place where existing supplies are already stretched.
Richard Seager is a Lamont Research Professor with the Palisades Geophysical Institute at Lamont-Doherty Earth Observatory. Richard's interests are in climate variability and change on timescales of seasons to millennia and in particular the causes of multiyear droughts around the world and how climate change will impact global hydroclimate.He analyzes observations, proxy climate records and model simulations and also uses idealized modeling to understand the basic climate dynamic processes in the atmosphere and ocean that generate global climate variability and change.
Richard completed his B.Sc. at Liverpool University, and his Ph.D. at Columbia University.
Future talks are scheduled for Tuesdays from 12:15-1:00pm in Room 417 Schermerhorn Hall. Attendees are welcome to bring their lunch.
All are welcome to attend!