Climate Variability in Ocean Surface Turbulent Fluxes

Florida State University, Tallahassee FL

Investigators

Abstract

0136934 O'Brien Ocean surface turbulent fluxes will be examined for climate-related variability. SSTs, winds, and pressures are typically examined in such studies. The observed changes in winds (speed and direction) and SSTs alter turbulent surface fluxes, which have a far-reaching influence on regional climatologies. It is expected that surface turbulent fluxes (stress, sensible heat, and latent heat) are more directly linked to climate-related changes than winds and pressures. Similar approaches will be applied to two overlapping periods. We will objectively derive a high quality set of monthly surface fluxes (and related fields), covering 1950 to 2005, for the global oceans north of ~30 degrees S to examine variability on a wide range of spatial and temporal scales (seasonal to decadal). We will also create similar daily fields (including surface radiative fluxes) from July 22, 1999 through 2005, with greater spatial resolution. Our goal is to produce the most accurate flux fields available. Variability on many time scales will be identified by applying traditional techniques such as Empirical Orthogonal Functions to appropriate regions. The location and time scale of the variability in turbulent fluxes, surface winds, and SSTs will be associated with known climate related oscillations. These objective analyses will provide insight into the processes through which surface fluxes, winds and SSTs are connected to climate change. The surface flux data set will also facilitate a wide range of studies relating ocean surface flux variability to regional climate change. In order to reduce the know biases in reanalysis surface fields, in-situ (ship and buoy) and satellite observations will be objectively combined to create a better turbulent-flux product. The surface flux fields developed though this study can be used to help validate flux fields created with couple ocean-atmospheric models. The satellite-related surface flux fields used in this study will be indirectly validated in-house by forcing a high resolution ocean model for the Gulf of Mexico, and our monthly products will be validated externally by long-time collaborators. Our in-situ based monthly products will be compared to the satellite products. All of the objective fields will be made publicly available.