Processes controlling the accelerated warming of the Arabian Sea

Abstract

ABSTRACTThe Arabian Sea (AS) has undergone a regime shift after 1995, manifesting the disruption of its natural decadal cycle over‐riding a secular rise in its sea‐surface temperature (SST). Using a suite of in situ and remote sensing data, we show that the rate of post‐1995 accelerated warming is spatially different, due to regionally and seasonally differing oceanographic processes. Along parts of the western boundary, the accelerated warming was mediated by a reduction in the post‐1995 linear trend of wind speed during summer monsoon leading to reduced upwelling and also reduced evaporation trend. In the northeast AS, post‐1995 increase in specific humidity during late winter, lead to a decrease in the evaporative cooling and subsequent convective mixing resulting in the increased rate of warming. The continued warming seen in the northeast AS until spring inter‐monsoon was due to the increasing net heat flux trend into the ocean along with reducing trend in evaporation. The accelerated warming in the central AS was linked to the reduced wind speed trend.