The Upwelling Phenomenon in the Gulf of Panama: A Seasonal Event.

Abstract

Panama is unique in having "four distinct oceans" due to seasonal and stationary changes in physical and chemical conditions influenced by the dynamic position of the Intertropical Convergence Zone (ITCZ). The Gulf of Panama, part of the Panama Bight climate zone, experiences significant seasonal variations. From December to April, the ITCZ's southern position and north trade winds from the Bermuda high induce sea level drops, upwelling of deep-sea waters, and significant drops in sea surface temperature (14° to 22°C). This upwelling leads to increased salinity, nutrient-rich waters, and supports a valuable fisheries industry. From May to October, the ITCZ migrates north, halting the upwelling, increasing sea surface temperature (28° to 31°C), and decreasing salinity due to freshwater influx.

Since 2017, the Physical Monitoring Program (PMP) of STRI has been collecting data from seven sites along the Gulf of Panama, monitoring water column parameters with multiparametric sondes and cross-verifying with satellite data. Sites range from near Taboga Island to the Las Perlas archipelago, with varying depths and distances from Panama City. Data analysis includes trends and summary statistics.

Satellite data from NOAA and Copernicus Marine Service are used to track sea surface temperature anomalies and wind variables. Historical data since the 1980s identified the first three consecutive upwelling events in the Gulf, influenced by strong north winds associated with the Bermuda High and the southward ITCZ shift. This report, highlighting ecological, social, and economic impacts, is crucial for understanding the region's marine dynamics, particularly during La Niña phases of the El Niño-Southern Oscillation (ENSO) phenomenon.