Abstract ATM-9521389 Neelin, J. David University of California, Los Angeles Title: Studies in Ocean-Atmosphere Interaction This research aims to contribute to understanding climate phenomena that arise by interaction between ocean and atmosphere, and the mechanisms that produce them. Methods developed under the previous NSF grant will be applied but with a change in emphasis in several areas: 1) A new approach will be used for the tropical atmospheric modeling component, based on a method designed to parlay theoretical developments from the previous grant into a new type of nonlinear model. Analytical results for vertical structure that apply under certain convective conditions are used as a basis for numerical models that are valid more generally, but retain high accuracy for low cost near convection regions. This is combined with an efficient treatment of long-wave radiation. More importantly, the models are easy to analyze for insight into the atmospheric side of three-dimensional ocean-atmosphere feedbacks. 2) Investigations into the role of ocean-atmosphere interaction in maintaining the tropical climatology were begun under the previous grant leading to the "climatological version of the Bjerknes hypothesis". This suggest that three-dimensional feedback between trade winds, ocean circulation and gradients of sea surface temperature (SST) are important to the climatological configuration of warm and cold SST regions. The PI will expand this work and attempt to bridge the gap between this hypothesis involving relative SST values and work by other investigators on the processes regulating absolute SST values. 3) Work on modes of tropical interannual variability was a mainstay of the previous grant. The theoretical component of this continues but with less emphasis relative to the above topics. Instead method applied previously to the tropics are to be adapted for midlatitude coupled variability, with the aim of providing a the oretical counterpart for numerical modeling efforts underway by other investigators. This work is important because it seeks new knowledge relevant to our ability to model and predict climate.
