Characterizing the surface spatial distribution and variability of the San Matías Meridional Front from a geostationary satellite perspective

This study investigates the use of Clear Sky Mask (CSKY) and Sea Surface Temperature (SST) products derived from the Advanced Baseline Imager (ABI) sensor onboard the GOES-16 geostationary satellite, focusing on the North Patagonian Gulfs on the Patagonian Shelf, Argentina. The CSKY mask is useful to identify both cloud cover and unreliable SST data, applicable to both the ABI sensor and the VIIRS sensor on the SNPP polar satellite. A three-year analysis of cloud cover revealed extended periods of continuous clear conditions (> 24 h) in the region. During these intervals, SST data from the ABI sensor were validated against those from the VIIRS sensor, showing a spatially coherent structure with a coefficient of determination (R2) of 0.99, albeit with a mean offset of 0.81°C. For the first time, the semidiurnal cycle of the Meridional Front is presented over the mouth of the San Matías Gulf during the warm season. Our findings indicate that this front, referred to as the western front, frequently exhibits semidiurnal displacements that significantly exceed the seasonal and fortnightly variability reported in previous studies. Additionally, towards late summer and into autumn, the presence of an eastern front with similar behavior was observed, resulting in a bi-frontal structure. The separation between these fronts increases towards the end of summer and autumn. Consequently, the ABI GOES-16 offers new opportunities to study the high-frequency variability of fine-scale phenomena in the region.