Atmospheric Response to Mesoscale Ocean Eddies in the Maritime Continent

Abstract

Mesoscale ocean eddies contribute to the mixing and transport of water properties throughout the global ocean. Sea surface temperature anomalies associated with these eddies can influence atmospheric boundary layer stability, and thus the formation of clouds. The Maritime Continent experiences the modulation of convection and precipitation by processes operating over multiple spatial and temporal scales. However, mesoscale air-sea interactions, such as those associated with the eddies the region generates, remain understudied. Applying a sea surface height-based eddy detection and tracking algorithm, we show that lower latitude eddies, such as those in the Maritime Continent, are generally fewer in number, weaker, and shorter-lived, but larger and faster-propagating, compared to those at higher latitudes. Crucially, we highlight that eddies in the Maritime Continent can significantly modify air-sea heat exchange and the near-surface wind field. However, changes to column water vapor, cloud, and rainfall are less distinct. Compared to the Kuroshio Extension, a representative case study for the extratropics, atmospheric anomalies associated with eddies in the Maritime Continent are weaker, and decreasing in magnitude toward the lower latitudes. We hypothesize that weaker sea surface temperature anomalies associated with eddies in the Maritime Continent, coupled with their faster propagation and intraseasonal variability in convection over the region, reduce the likelihood and intensity of the instantaneous atmospheric imprint. This study therefore emphasizes the importance of the spatial and temporal scales with regard to air-sea interactions and their influence on cloud and rainfall across the Maritime Continent.