89th American Meteorological Society Annual Meeting

Tuesday, 13 January 2009: 9:30 AM
Role of nearshore winds in connecting variability of river discharge with offshore bio-optical properties
Room 128A (Phoenix Convention Center)
Steven L. Morey, COAPS, Tallahassee, FL; and M. A. Bourassa and D. S. Dukhovskoy
Maps of satellite-derived estimates of monthly-averaged chlorophyll a concentration over the northern West Florida Shelf show high interannual variability concentrated near the coastline and extending at least 150 km offshore over this wide shelf in a tongue-like pattern from the Apalachicola River during the late winter through early spring. The spatial pattern of these anomalies encompasses clusters of spawning habitats for regionally important finfish. The chlorophyll concentration anomalies are consistent with variations in the flow rate of the Apalachicola River at interannual time scales, which are linked to precipitation anomalies over the watershed. This study examines the interannual variability of the watershed river ocean system and mechanisms by which interannual terrestrial climate variability is linked with variability over the northern West Florida Shelf. A series of numerical model experiments forced by satellite scatterometer-derived wind fields shows that intermittent episodes of offshore transport of the Apalachicola River plume across the inner shelf under upwelling-favorable winds provides the physical mechanism for connecting the variability of the river discharge with oceanic variability over the middle and outer shelf.

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