HR: 14:50h
AN: A43B-06    [Abstracts]
TI: Atmospheric response to North Pacific Oceanic Variability in an Coupled Model
AU: * Liu, Z
EM: zliu3@wisc.edu
AF: Univ. Wisconsin-Madison, 1225 W . Dayton St., Madison, WI 53706 United States
AU: Wu, L
EM: lixinwu@wisc.edu
AF: Univ. Wisconsin-Madison, 1225 W . Dayton St., Madison, WI 53706 United States
AB: Atmospheric response to a mid-latitude winter SST anomaly is studied in a coupled ocean-atmosphere general circulation model. The role of ocean-atmosphere coupling is examined with ensemble experiments of different coupling configurations. The atmospheric response is found to depend critically on ocean-atmosphere coupling. The full coupling experiment produces the strongest warm-ridge response and agrees the best with a statistic estimation of the atmospheric response. The fixed SST experiment and the thermodynamic coupling experiment also generate a warm-ridge response, but with a substantially weaker magnitude. This weaker warm-ridge response is associated with an excessive heat flux into the atmosphere, which tends to force an anomalous warm-low response and therefore weakens the warm-ridge response of the full coupling experiment. Our study suggests that the atmospheric response is associated with both the SST and heat flux. The SST forcing favors a warm-ridge response, while the heat flux forcing tends to be associated with a warm-low response. The correct atmospheric response is generated in the fully coupled model which produces the correct combination of SST and heat flux naturally.
DE: 0300 ATMOSPHERIC COMPOSITION AND STRUCTURE
SC: Atmospheric Sciences [A]
MN: 2005 Joint Assembly