In this research we characterize and understand the nature and causes of the large-scale fluctuations in the midlatitude North and South Pacific Oceans on time scales from interannual to decadal. An understanding of these fluctuations will lead to increased predictability of the upper ocean circulation and thermal structures, both of which are important to the climate variability on longer time scales.
We conduct careful analyses of the multi-year altimetry data from the T/P, Jason-1 and OSTM missions. We will first document the large-scale sea surface height fluctuations on the interannual-to-decadal time scales. The observed signals will be compared against other oceanic data and atmospheric variables with the guidance of our understanding of the ocean dynamics. Our next step is to clarify the causes for the observed low-frequency changes. To do so, we use both simplified dynamic models and ocean general circulation model outputs with realistic topography and surface boundary conditions. Through combining the altimetric data and the ocean models with various complexity, we seek to identify the roles played by different physical processes. Efforts will also be directed to clarify the extent to which the large-scale, low-frequency changes in the midlatitude ocean circulation effect the anomalous SST signals and the dynamics underlying the interaction of oceanic motions with various horizontal length scales.
This research directly contributes to the two research themes set out by the OSTST: 1) To support studies in physical oceanography utilizing TP/Jason/OSTM mission data, as well as other satellite and in situ data and/or models, and 2) To support studies of higher-resolution merged altimetric data sets for the purpose of examining the role of mesoscale eddies and western boundary currents in the general circulation of the ocean.
Investigating Midlatitude Ocean and Climate Dynamics using Satellite Altimetry and Modeling Analysis