Atmosphere–Ocean Variations in the Indo-Pacific Sector during ENSO Episodes

作者：Ngar‐Cheung Lau, Mary Jo Nath · 发表于：Journal of Climate · 年份：2003 · DOI：10.1175/1520-0442(2003)016<0003:aoviti>2.0.co;2 · 被引用次数：453 · 研究领域：Oceanographic and Atmospheric Processes、Climate variability and models、Marine and coastal ecosystems

The influences of El Niño–Southern Oscillation (ENSO) events on air–sea interaction in the Indian–western Pacific (IWP) Oceans have been investigated using a general circulation model. Observed monthly sea surface temperature (SST) variations in the deep tropical eastern/central Pacific (DTEP) have been inserted in the lower boundary of this model through the 1950–99 period. At all maritime grid points outside of DTEP, the model atmosphere has been coupled with an oceanic mixed layer model with variable depth. Altogether 16 independent model runs have been conducted. Composite analysis of selected ENSO episodes illustrates that the prescribed SST anomalies in DTEP affect the surface atmospheric circulation and precipitation patterns in IWP through displacements of the near-equatorial Walker circulation and generation of Rossby wave modes in the subtropics. Such atmospheric responses modulate the surface fluxes as well as the oceanic mixed layer depth, and thereby establish a well-defined SST anomaly pattern in the IWP sector several months after the peak in ENSO forcing in DTEP. In most parts of the IWP region, the net SST tendency induced by atmospheric changes has the same polarity as the local composite SST anomaly, thus indicating that the atmospheric forcing acts to reinforce the underlying SST signal. By analyzing the output from a suite of auxiliary experiments, it is demonstrated that the SST perturbations in IWP (which are primarily generated by ENSO-related atmosphe...