ASIRI : SST Control by Subsurface Mixing during Indian Ocean Monsoons

1. ASIRI: SST Control by Subsurface Mixing during Indian Ocean Monsoons Moum/Shroyer PE 0601 Project Activities and Results 1 upgradeχpods with new velocity sensors (compensated pitot tubes) 2 maintainχpods on NRL, RAMA, OMM moorings in BoB (2013-2017) 3 compute turbulent heat flux beneath the surface from χpod measurements – compare to surface fluxes 4 air-sea heat flux divergence prescribes SST evolution 5 integrate analysis withshipboard, satellite and Indian / Sri Lankan meteorological measurements • Objectives: • to obtain the long-term mixing measurements necessary to quantify the effects of monsoon cycles on SST • Approach: • directly measure turbulent mixing over a broad expanse of international waters in the Bay of Bengal during monsoons • Payoff: • long time series measurements using χpods on moorings unambiguously show the cold tongue in the equatorial Pacific, a region critical to global heat storage, is maintained by ocean mixing (Moum et al., Nature 2013). Monsoon prediction is notoriously poor. We suspect this results from inadequate model representation of mixing. This project directly provides the measurement basis for improved representations.