JpGU-AGU Joint Meeting 2017

講演情報

[EE] 口頭発表

セッション記号 A (大気水圏科学) » A-CG 大気水圏科学複合領域・一般

[A-CG45] [EE] 熱帯インド洋・太平洋におけるマルチスケール大気海洋相互作用

2017年5月20日(土) 09:00 〜 10:30 302 (国際会議場 3F)

コンビーナ:名倉 元樹((独) 海洋研究開発機構)、H Annamalai(University of Hawaii at Manoa)、清木 亜矢子(海洋研究開発機構)、今田 由紀子(気象庁気象研究所)、座長:名倉 元樹(海洋研究開発機構)、座長:清木 亜矢子(海洋研究開発機構)

09:00 〜 09:15

[ACG45-01] Coupled Physical Processes in the Bay of Bengal and Monsoon Air-Sea Interaction

★招待講演

*Debasis Sengupta1 (1.Indian Institute of Science)

キーワード:Salinity, Near-surface stratification, Freshwater dispersal, Air-sea interation

The Bay of Bengal (BoB) receives about 4000 km3 of freshwater every year from summer monsoon rainfall and river discharge. The freshwater persists in the northern BoB for about three seasons, resulting in a near-surface stratified layer (usually less 30 m deep) with warm subsurface water. The meso-scale eddy flow and wind-driven shallow Ekman flow play major role in dispersing the riverwater in the Bay. The pathways of the riverwater can have significant year-to-year changes. The freshwater further strengthens the near-surface currents by squeezing the Ekman layer. As part of the OMM-ASIRI initiative, in the last four years we made intense fine-scale observations of near-surface temperature, salinity and currents in the north BoB from various platforms like moorings, research ships and other autonomous instruments including gliders, Lagragian floats. Our ship-based observations suggest presence of strong submesoscale (order 10 km) fronts, which could set the near-surface stratification by slumping the denser water under the light water. The shallow mixed layer influences the air-sea interaction on diurnal to subseasonal timescales. The monsoon active-break spells modulate the mixed layer depth, winds, air temperature and humidity just above the ocean surface. We discuss the relevence of these processes in observations and model simulations.