Fronts in the eastern Luzon

Oceanic fronts based on thermal gradients have been detected in several areas of the Pacific coastal and marginal seas. As fronts are often associated with areas of high biological productivity, the presence of fronts in the vicinity of the Bicol Shelf and the Benham Rise east of Luzon is explored in this study.  Here, spatial and temporal presence of fronts in the study area is explored based not only on temperature but also on chlorophyll gradients.  Daily sea surface temperature or SST data from Pathfinder Advanced Very High Resolution Radiometer (AVHRR ,1981 to 2012) and chlorophyll data from Moderate-resolution Imaging Spectroradiometer (MODIS,2002 to 2014) are used to detect the location of fronts and their frequency of occurrence. Western boundary fronts were found off the coast of Palanan, Isabela and Cagayan, Cagayan while shelf-slope fronts were found associated with the Bicol Shelf break. Analysis further shows that chlorophyll fronts are not always associated with thermal fronts, pointing to different physical processes related to the complex hydrodynamics of the area.