The PIs will extend in time and expand in scope the satellite data development and satellite-based analyses of ocean climate variability in the Northeast Pacific (NEP), begun during the GLOBEC Pilot Project phase (1997 - 00). The overall scientific problem is to characterize and quantify the dominant modes of variability in the NEP as embodied by satellite measurements of surface transports, temperature and chlorophyll patterns. Our analyses address multiple spatial and temporal scales using merged satellite data products over GLOBEC target study regions in both the California Current (CCS) and the coastal Gulf of Alaska (CGOA).
GLOBEC NEP field studies require both spatial and temporal context. The primary goal of this project is to quantify the degree of seasonal and interannual variability in small scale and mesoscale circulation patterns in each of the process study sites, and to relate changes in this variability to the seasonal and interannual changes in the strength of forcing by local winds and basin scale circulation. This goal will be accomplished through a systematic analysis of spatial temporal scales utilizing satellite measurements. The PIs will define and quantify a) small event-scale coastal features such as fronts, eddies and convergences (50 m - 100 km). These features are thought to be critical to local success/ survival of GLOBEC target species, b) mesoscale circulation / seasonal variability over the shelf, upwelling fronts, coastal jets, buoyant plumes and eddies (10 km - 500 km) - these also affect transport and retention of populations; and c) forcing and processes at basin and interannual scales (100 km - 10,000 km). A second, related goal is to quantify changes in the timing and strength of seasonal transitions in both study regions. Specific objectives of the project are divided into two aspects of satellite oceanography, with which the three PIs have extensive experience: 1) Acquire, process, subset, QC, and archive satellite data in the NEP region at multiple scales and make these data electronically available to others in the program; 2) analyze these data, in conjunction with ancillary data, to address GLOBEC research goals at basin- meso- and nearshore scales. The core data sets are altimeter fields, NOAA AVHRR and NASA SeaWiFS data at both l km and 4 km resolution and synthetic aperture radar (SAR) imagery. These are supplemented with model and buoy winds, tide gauge sea levels and in situ data. Close collaboration with investigators carrying out field measurements will link scales and patterns determined in the satellite data analyses to 3D in situ processes.