Marine Heatwave and Its Potential Impacts to Upwelling Regions Around the Philippines

The global ocean has warmed substantially over the past century, with far-reaching implications for marine ecosystems. Concurrent with long-term persistent warming, discrete periods of extreme regional ocean warming, known as marine heatwaves (MHWs), have increased in frequency. A comprehensive understanding of the physical processes controlling MHW life cycles is pivotal for improving our knowledge of MHWs, yet such understanding is still lacking in the context of the Philippines. This study seeks to elucidate the mechanisms driving upwelling induced by Ekman pumping and assess the influence of MHWs on this process. Additionally, we have developed a MHW tracker specific to the Philippines, providing daily updates on MHW events across the Philippine seas. This tool is essential for local government units to identify MHW occurrences, helping them to protect marine ecosystems and the communities that rely on them.

To achieve this, we will utilize the OSTIA global sea surface temperature reprocessed product for robust detection of MHWs. This satellite-derived sea surface temperature (SST) will be complemented by available historical in situ data (e.g., from cruises, temperature loggers or moorings) for validation. The dataset offers daily gap-free maps of foundation SST and ice concentration at a horizontal grid resolution of 0.05 degrees, using both in-situ and satellite data, available from October 1, 1981, to the present. Additionally, we will employ the Global Ocean Hourly Reprocessed Sea Surface Wind and Stress dataset, available from January 11, 2007, to March 21, 2024, at a horizontal spatial resolution of 0.125 degrees. This will be used to compute the Ekman pumping velocity to provide an estimate of the upwelling or downwelling proportional to the wind stress curl.

Furthermore, the Global Ocean Physics Analysis and Forecast at 1/12 degree provides 10-day 3D global ocean forecasts updated daily. This includes parameters such as temperature, salinity, currents, sea level, mixed layer depth, and ice from the surface to the ocean floor. This dataset will be used to examine the water column response to wind patterns and the anomalously warm ocean conditions associated with MHW perturbations. Datasets were provided by the E.U. Copernicus Marine Service Information.