ASIRI: Air-Sea Interactions in Northern Indian Ocean (And it's Relation to Monsoonal Dynamics of the Bay of Bengal)

摘要

Monsoons are caused by large amplitude land-ocean temperature differentials resulting from the seasonal cycle of solar forcing on oceans and land. One of the most prominent is the Indian Ocean Monsoons (IOMs), which affect the lifestyles of more than a billion people in Southeast Asia. The IOMs are strongly modulated by air-sea interactions, particularly in the Bay of Bengal (BOB), thus determining sub-seasonal variability of the region. The summer monsoons are southwesterly, the resulting BOB circulation is anticyclonic, and strong upwelling occurs along the western boundary of BOB. Modulations of air-sea interactions, among other factors, lead to recurring monsoon breaks sandwiched between active wind periods. In the autumn, the monsoon winds switch to northeasterly, leading to the reversal of ocean currents, which occurs through a set of dynamical adjustments arguably involving coastal Kelvin waves and Rossby wave radiation. Notwithstanding their contributions to monsoonal dynamics and regional ocean-atmosphere processes, air-sea interactions in BOB have not been studied in depth. In particular, the available measurements are meager compared to modeling studies.