HR: 1340h
AN: GC33A-1249    [Abstracts]
TI: Volatility of California Precipitation: Effects of Moisture Supply and Topography in a Mediterranean Climate
AU: * Gershunov, A
EM: sasha@ucsd.edu
AF: Scripps Institution of Oceanography, UCSD 9500 Gilman Drive, La Jolla, CA 92093-0224 United States
AU: Kanamaru, H
EM: hkanamaru@ucsd.edu
AF: Scripps Institution of Oceanography, UCSD 9500 Gilman Drive, La Jolla, CA 92093-0224 United States
AU: Panorska, A
EM: ania@unr.edu
AF: Anna Panorska, Department of Mathematics and Statistics University of Nevada, Reno, NV 89557 United States
AU: Cayan, D
EM: dcayan@ucsd.edu
AF: Scripps Institution of Oceanography, UCSD 9500 Gilman Drive, La Jolla, CA 92093-0224 United States
AU: Cayan, D
EM: dcayan@ucsd.edu
AF: US Geological Survey, 9500 Gilman Dr., La Jolla, CA 92093-0224 United States
AB: California's climate is marked with infrequent but copious precipitation events preferentially enhanced by complex topography. In California, the presence or absence of daily precipitation extremes contributes significantly to the annual water supply and largely determines flood risk. We explore the intimate connection between topography and the volatility of daily precipitation in California, i.e. the magnitude of extreme events relative to typical amounts. Physical mechanisms producing extreme precipitation amounts will be elucidated with respect to synoptic systems and how they interact with California's topographic features. We will show that volatility is closely linked to the direction of moisture flux in individual storms relative to aspect and slope of major mountain ranges. We will also examine the contribution of daily extremes to total seasonal precipitation in wet and dry years. Parallel investigations will be performed on daily precipitation from station observations and a fine resolution dynamical Reanalysis over California. These results will contribute to the understanding of synoptic meteorological conditions that give rise to extreme hydrologic events over California's complex topography. The insight applied on climatic timescales to observations and modeling of storm tracks will also advance the conceptual understanding of possible effects of global climate change on California mountain hydrology.
DE: 1620 Climate dynamics (0429, 3309)
DE: 1817 Extreme events
DE: 1833 Hydroclimatology
DE: 1840 Hydrometeorology
DE: 3354 Precipitation (1854)
SC: Global Climate Change [GC]
MN: Fall Meeting 2005