Acoustic Detection of Rainfall using Ocean Gliders in the Tropical Indian Ocean

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Rainfall is of fundamental importance to people's livelihoods and is a critical part of our climate system. Nowhere is this more true than in the Maritime Continent region of southeast Asia, the engine room of the global atmosphere. But rainfall is notoriously difficult to measure at sea, and we know little about the interplay of weather systems and ocean-atmosphere interactions that occur there. TerraMaris will combine air-, sea- and land-based measurements from Java, Christmas Island, and the tropical Indian Ocean, to improve our understanding of rainfall in this critical region. You will join the international TerraMaris field campaign from November 2019 to March 2020, deploying autonomous underwater vehicles, known as ocean gliders, to measure sound deep in the ocean. From these novel measurements, you will determine rainfall and wind speed from the noise these processes make at the sea surface, but which can be heard even in the ocean's interior. Specific questions are: How deep in the ocean can you 'hear' rain and wind? How do you distinguish the sound of rain and wind from other ocean noise? How do these acoustic measurements compare with other observations? You will also take part in the land campaign, launching radiosondes (weather balloons), from Christmas Island. You will receive training in glider and radiosonde operations before your fieldwork. You will analyse your observations, in combination with satellite and other global data sets, to better understand the processes that drive weather systems over the Maritime Continent. In particular, you will quantify the development of the daily cycle of atmospheric convection, with clouds and rain over the islands during the day and offshore overnight. Your work will pin down the importance of the ocean in this process.