DATE: FRIDAY, March 3, 2017 TIME: 2:30 P.M. - Room 223 (Refreshments served at 2:15 pm) PLACE: Environmental & Natural Resource Sciences Bldg. 14 College Farm Road, New Brunswick, New Jersey
THE NORTH AMERICAN MONSOON IN A SUITE OF HIGH-RESOLUTION GENERAL CIRCULATION MODELS: GULF SURGES AND CLIMATE CHANGE
The North American monsoon (NAM) is one of the smallest-scale monsoons, but has a major role for water resources in northwestern Mexico and in the southwestern United States (SW US). Particularly over the SW US, convection is modulated, at the synoptic timescale, by intrusions of moist air masses from the tropical Pacific into the Gulf of California, known as gulf surges. To what extent are these transients resolved in state-of-the art GCMs? In this talk I provide a detailed analysis of gulf surges in a suite of global models developed at the Geophysical Fluid Dynamics Laboratory (CM2.1, FLOR, CM2.5, CM2.6, HiFLOR) with same physics but varying atmosphere and ocean resolution ranging from 2 to 0.25 degree. I will show that increasing atmospheric resolution greatly improves the temporal and spatial representation of gulf surges. Finally, using the same models, I investigate how global warming affects the NAM. This remains an elusive and challenging question, not least because coarse resolution and systematic biases limit the reliability of global and regional climate models. Here I investigate the impact of CO2 forcing using idealized nudged-SST simulations with different boundary conditions.