HR: 0830h
AN: A41A-01    [Abstracts]
TI: Looking Past ENSO, What is Causing the Recent Extreme Climate Signals?
AU: * Pegion, P
EM: pegion@gmao.gsfc.nasa.gov
AF: NASA-GSFC, Global Modeling and Assimilation Office, NASA Goddard Space Flight Center Mailstop 610.1, Greenbelt, MD 20771 United States
AU: * Pegion, P
EM: pegion@gmao.gsfc.nasa.gov
AF: Science Applications International Corporation, 4600 POWDER MILL ROAD SUITE 400, Beltsville, MD 20705 United States
AU: Schubert, S
AF: NASA-GSFC, Global Modeling and Assimilation Office, NASA Goddard Space Flight Center Mailstop 610.1, Greenbelt, MD 20771 United States
AU: Suarez, M
AF: NASA-GSFC, Global Modeling and Assimilation Office, NASA Goddard Space Flight Center Mailstop 610.1, Greenbelt, MD 20771 United States
AB: Over the past few years, there have been large climate signals not associated with El Nino and the Southern Oscillation (ENSO). Because ENSO is our best source of seasonal predictability, forecasts have done poorly predicting these events. Since the El Nino of 1997/8, western portions of the United States have been experiencing a major drought. The two years after the El Nino, the Pacific Ocean was in a La Nina state, which is typically associated with drought in the South Western United States, but more recently the La Nina conditions have disappeared. Since then a weak El Nino has come and gone, but the drought failed to break. Also, the summer of 2003 was the warmest on record for many parts of Europe. Statistical analysis of historical data suggests that such a large anomaly is extremely unlikely to occur, but alas it did. This study will investigate whether these events are driven by the chaotic nature of the atmosphere, or whether there is a signal in the sea surface temperature (SST) that is potentially predictable. The results to be presented are from the NSIPP-1 AGCM, which is the atmospheric model used in the seasonal forecasts generated by the Global Modeling and Assimilation group at NASA Goddard. The model failed to persist the drought into the 21st Century, nor did it capture the magnitude of the warm anomalies over Europe when forced with observed SSTs. A series of higher resolution runs (0.5 degree) are being carried out to assess the impact the increase of resolution has on the simulation of rainfall and temperature anomalies. Also, idealized experiments will assess the model's sensitivity of SSTs outside of the tropical Pacific Ocean and initial conditions.
DE: 1812 Drought
DE: 3300 METEOROLOGY AND ATMOSPHERIC DYNAMICS
DE: 3354 Precipitation (1854)
SC: Atmospheric Sciences [A]
MN: 2005 Joint Assembly