Temperature Spatiotemporal Correlation Scales in the Brazil-Malvinas Confluence from High-Resolution In Situ and Remote Sensing Data

Abstract

Ocean frontal systems may act both as barriers and mixers between different water masses, the latter thanks to very energetic structures with relatively short temporal and spatial scales. Here, we explore the high-frequency temperature variability in the Brazil-Malvinas Confluence through the joint analysis of novel high-resolution SeaSoar measurements and sea surface temperature imagery. Surface spatiotemporal correlation scales range between 1.5 and 6 days and between 20 and 50 km, with the shortest scales along the shelf-break path of the Brazil Current and over the confluence and the longest ones along the Malvinas Current. The spatial scales display minima along the front, at the surface because of the presence of brackish shelf waters and at the subsurface due to both mesoscale and submesoscale thermohaline intrusions. The smallest cross-frontal vertical correlations, in the 5- to 10-m range, are associated with submesoscale processes. Overall, temperature variability is enhanced at depth in the frontal system.