ESA’s Soil Moisture and Ocean Salinity Mission - An overview on the mission's performance and scientific results
Mecklenburg, Susanne1; Kerr, Yann2; Font, Jordi3; Martin-Neira, Manuel4; Delwart, Steven5; Drusch, Matthias4; Buenadicha, Guillermo6; De la Fuente, Antonio5; Daganzo-Eusebio, Elena4; Crapolicchio, Raffaele7

The Soil Moisture and Ocean Salinity (SMOS) mission, launched on 2 November 2009, is the European Space Agency's (ESA) second Earth Explorer Opportunity mission. The scientific objectives of the SMOS mission directly respond to the current lack of global observations of soil moisture and ocean salinity, two key variables used in predictive hydrological, oceanographic and atmospheric models. SMOS observations also provides information on the characterisation of ice and snow covered surfaces and the sea ice effect on ocean-atmosphere heat fluxes and dynamics, which affects large-scale processes of the Earth's climate system.

This paper will provide an overview on the various aspects of the SMOS mission, such as 1. The performance of the mission after 4 years in orbit: The SMOS mission has been in routine operations since May 2010, following the successful completion of the 6-months commissioning phase. SMOS has so far provided very reliable instrument operations, data processing and dissemination to users. 2. An overview on the SMOS data products: SMOS provides continuously level 1 (brightness temperature) and level 2 (soil moisture and ocean salinity) to its scientific user community since summer 2010. SMOS also provides brightness temperature data (level 1 data) to ECMWF in near-real time (NRT), who assimilates the data into their forecasting system. New services have been established to deliver a tailored NRT data product via the WMO's GTS and EUMETSAT's EUMETCast data dissemination systems to other operational agencies. This will open up new operational applications for SMOS data. New data products are under development, responding to the requirements of the science community in particular in the area of hydrology, climate, land use and ship routing, namely a frozen soil indicator, data products for freeze/thaw periods, sea ice thickness and vegetation water content. 3. An overview on the SMOS data quality and the overall validation approach: SMOS data products are continuously improved and approach the scientific mission objectives. The paper will provide an overview on the MIRAS instrument performance, including the instrument calibration and level 1 brightness temperature data processing, as well as on the achieved quality for the level 2 data. 4. The RFI status: SMOS was the first satellite mission operating in the protected L-Band at the time. Even though the International Telecommunication Union (ITU) Resolution 750 (World Radiocommunications Conference (WRC)-12) was adopted to protect the passive L-Band (1400-1427 MHz), in which SMOS operates, and ITU Radioregulation footnote 5.340 prohibits all emissions in this band, strong interference sources have been detected worldwide. The majority of RFI sources can be found in Southern Europe, China, Southern Asia and the Middle East. The paper will provide an update on progress made with regards to the RFI status and its effect on the data.