Presenting Author: Dr. Steve Morey
Satellite ocean color derived estimates of monthly chlorophyll a concentration over the northern West Florida Shelf show high interannual variability concentrated near the coastline and extending at least 150 km offshore in a tongue-like pattern from the Apalachicola River during the late winter through early spring. These anomalies are consistent with interannual variability in the flow rate of the Apalachicola River, which is a dominant nitrogen source to the region. A series of numerical model experiments are conducted to explain the physical mechanism responsible for connecting the variability within the river plume, which is traditionally thought to follow the coastline, with the offshore environment. Results show no connectivity under climatology surface wind forcing. However, experiments forced by wind fields derived from satellite scatterometer data capturing synoptic scale weather features show intermittent episodes of offshore transport of the Apalachicola River plume across the shelf under upwelling-favorable winds. A series of these offshore-directed plumes during the winter â€“ spring season alters the monthly averaged hydrographic and biochemical properties offshore, with the oceanic anomalies varying with anomalous wet and dry conditions over the region.
2019 International OVWST Meeting
May 29-31 in Portland, Maine, USA