The Megha-Tropiques Mission: first results two years after launch

The Megha-Tropiques mission is an Indo-French mission built by the Centre National d'Études Spatiales and the Indian Space Research Organisation launched in October 2011. Megha means cloud in Sanskrit and Tropiques is the French for tropics. The major innovation of MT is to bring together a suite of complementary instruments on a dedicated orbit that strongly improves the sampling of the water cycle elements in the tropical regions. Indeed the low inclination on the equator (20°) combined to the elevated height of the orbit (865km) provides unique observing capabilities with up to 6 over-passes per day for the best case.

The scientific objective of the mission focus on the tropical water and energy budget. To nourrish this broad objective, the following payload have been operated: SCARAB : wide band instrument for inferring longwave and shortwave outgoing fluxes at the top of the atmosphere (cross track scanning, 40 km resolution at nadir); SAPHIR: microwave sounder for water vapour sounding: 6 channels in the WV absorption band at 183.31 GHz. (cross track, 10 km) and MADRAS: microwave imager for precipitation: channels at 18, 23, 37, 89 and 157 GHz, H and V polarisations. (conical swath,<10 km to 40 km).

In this presentation,a short status of the mission will be given. Then the emphasis will be put on the geophysical product validation efforts (that included dedicated field campaigns in the tropics) of the precipitation product, humidity retrieval results as well as the measurements of the broad band radiative fluxes at the top of the atmosphere. Early results from assimilation experiments using SAPHIR will also be shown.

Finally, the results of combining this spacecraft and other microwave imaging missions in the framework of GPM for daily accumulated precipitation estimates will be discussed.