HR: 0800h
AN: GC11A-0137    [Abstracts]
TI: Investigating Changes in Large-Scale Indicators of Extreme Weather
AU: * Gilleland, E
EM: ericg@ucar.edu
AF: National Center for Atmospheric Research, PO Box 3000, Boulder, CO 80307-3000, United States
AU: * Gilleland, E
EM: ericg@ucar.edu
AF: National Severe Storms Laboratory, 120 David L Boren Blvd, Norman, OK 73072, United States
AU: Pocernich, M
EM: pocernic@ucar.edu
AU: Brown, B
EM: bgb@ucar.edu
AU: Brooks, H
EM: Harold.Brooks@noaa.gov
AB: Previous studies have shown a link between concurrently high values of convective available potential energy (cape) and vertical shear (0-6 km wind vector magnitude difference) and smaller scale severe weather. Here, we study a global reanalysis data set containing these two indicators, and explore how modeled extreme return levels have changed over a 42-year period. Data are fit to extreme-value distributions with temporal covariates, and return level estimates are compared. It is found that some parts of the world have seen a decrease in these large-scale indicators (e.g., Southern S. America), while other areas (e.g., Eastern China) have experienced a marked increase in these return levels, suggesting a likelihood of increases in the frequency of severe weather events. Future work will include an application of this methodology to the output of climate prediction models.
DE: 0399 General or miscellaneous
SC: Global Environmental Change [GC]
MN: 2007 Fall Meeting