The heat budget of the upper ocean in the southeast Pacific will be studied using ocean general circulation model (OGCM) experiments The primary goal is to improve the understanding of upper ocean processes that control sea surface temperature variability in the stratocumulus cloud deck region, which may play an important role in formation and maintenance of marine boundary layer clouds. The data collected during recent field observations will be utilized to create surface forcing fields to integrate the OGCM and to validate the model performance. Gridded surface flux data sets will be created to force the OGCM based on a variety of recent satellite measurements. The flux estimates will then be compared with those derived from in-situ observations including the surface meteorological data from the IMET buoy at 20.S, 85.W and the intensive field measurements in the stratocumulus deck region conducted during the fall of 2001. Also, the performance of the OGCM will be evaluated based on the comparison with in-situ data of the upper ocean and satellite observations. Mean and variability of upper ocean heat budget will be calculated from the model output, and physical processes responsible for balancing surface heat fluxes will be examined. A particular emphasis is given to the role of Rossby waves, atmospheric subseasonal variability, and penetrative solar radiation in seasonal to interannual variations of upper ocean heat balance. The analysis of the model output in the entire stratocumulus deck region will also elucidate how accurately large-scale upper ocean variability in this region is represented by mooring observations at a particular point.
Broader impacts: Proper representation of air-sea coupled processes in the stratocumulus deck region in global climate models is one of the major challenges for their further improvement. The proposed research will improve understanding and modeling of these processes, leading to better climate simulations and associated societal benefits. The project will also fund a postdoctoral scientist for participating in interdisciplinary research.
