HR: 12:00h
AN: A52B-11    [Abstracts]
TI: Effects of Climate Oscillators on January Monthly Extreme Temperatures in North America
AU: * Brolley, J M
EM: justinbrolley@yahoo.com
AF: Center for Ocean-Atmospheric Prediction Studies, Florida State University 200 RM Johnson Building, Tallahassee, FL 32306, United States
AU: O'Brien, J J
EM: jobrien@coaps.fsu.edu
AF: Center for Ocean-Atmospheric Prediction Studies, Florida State University 200 RM Johnson Building, Tallahassee, FL 32306, United States
AB: The El Nino-Southern Oscillation (ENSO), the Pacific Decadal Oscillation (PDO), and the Polar Vortex Oscillation (PVO) produce conditions favorable for monthly extreme temperatures and precipitation. These climate modes produce conditions that favor regional cold and warm spells, and these extremes impact agriculture, energy, forestry, and transportation. The above sectors prefer the knowledge of the worst (and sometimes the best) case scenarios. This study examines the extreme scenarios for each phase and the combination of phases that produce the greatest monthly extremes. Data from Canada and the United States are gathered from the Historical Climatology Network (HCN). Monthly data are simulated by the utilization of a stochastic model in order to simulate joint-probability distributions of temperature with respect to phases of climate oscillators. This stochastic method simulates monthly data by the stochastic selection of daily data with identical ENSO, PDO, and PVO characteristics. In order to test the quality of the simulation, monthly simulations for PDO and PVO categories are compared with the observations. The simulated data are arranged, and the tenth and ninetieth percentiles are analyzed. The magnitudes of temperature anomalies are the greatest in the western Canada and the southeastern United States during January. Western Canada has its coldest (warmest) Januaries when the PDO and PVO are low (high). These conditions tend to occur during La Niņa (El Niņo) or neutral ENSO. The southeastern United States has its coldest Januaries during high PDO and low PVO and warmest Januaries during low PDO and high PVO. Although extremes occur during El Niņo or La Niņa, many stations have the highest or lowest temperatures during neutral ENSO. The magnitudes of the temperature anomalies and the corresponding phase combinations vary regionally.
DE: 3309 Climatology (1616, 1620, 3305, 4215, 8408)
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting