November 7, 2011

Since 2009 Ocean monitoring by SMOS

SINCE 2009 OCEAN MONITORING BY SMOS Update: 11/07/2011
Logo 50 ans de résultats scientifiques
Logo 50 ans de résultats scientifiques
Since 2009, the SMOS mission has been measuring the superficial soil moisture, plant canopy water content and ocean salinity with a 43-km spatial resolution and a revisit capability of less than three days. It is the first time these variables are directly, continuously and precisely measured from space with an extremely innovative instrument. These data did build an outstanding information source and were already used to monitor various extreme events.

The SMOS mission, which was launched on November 2009, is very ambitious for three reasons:

  • Objectives: dedicated to systematically measure highly significant physical quantities (soil moisture and ocean salinity) for the climatic system;
  • Predetermined innovative technique of interferometric radiometry;
  • Quantity extraction choices which implement explicit modelling of the radiation transfer.

Even if the exhaustive evaluation of the SMOS data will not be possible until the end of the mission and probably even later, the first results can already be appreciated as well as the possibility to successfully confront the challenges of SMOS.

The flight commissioning of SMOS (a CNES/ESA/CDTI mission) ended in May 2010. Since then, apart from calibration periods, the satellite performed sustained observations of the soil moisture at the Earth's surface, producing two years of unique data.

The only real problem experienced by SMOS is the large quantity of illegal radio pollution in the protected range. Many frequency protection agencies devoted themselves to solve this problem and many countries achieved it. More than 100 sources have been switched off in Europe.

The international science community have been exploiting these data for purposes of validation because of their originality and applications are being developed.
For example, the European Centre for mid-term meteorological forecasts is currently testing the assimilation of SMOS data in their forecasting model.

Other teams are working on the disintegration of the measurements to make the water management easier on watersheds and to pinpoint and monitor the water available in the root zone.

The SMOS measurements allow the seasonal moisture evolutions to be monitored in the inter-tropical area and on our continents.

Thanks to the measurements' high-precision, some extreme events could be monitored and anticipated such as flooding (Pakistan, Australia, United States).

Risks such as the cyclone Yasi in January 2011 were anticipated.

Droughts like in Europe in spring 2011 and in the United States in summer 2012 were precisely and quickly monitored.

After such a short presence in orbit, it is far too early too assess the situation. All the efforts focus on the satellite characterization, calibration and on the development of the robust and reliable inversion algorithms. Since salinity is more demanding in terms of system performance, it is the most important point of the system validation. About the calibration system, it was showed to be reliable by monitoring the Antarctica. By analysing the latter, the scientific return on this region about the climatic monitoring was also showed to be extremely promising. The high-latitude areas also showed the high potential of SMOS by monitoring for the first time the freeze-thaw cycles in Finland.

The first results obtained from SMOS also showed its high potential concerning oceans by releasing the first global salinity maps measured from space, hurricane monitoring and altimetric data coupling.

Thanks to this set of very promising results, a new concept can be considered to follow-up SMOS. A SMOSNext instrument with a 10-time higher resolution and a sensitivity increased by three to allow new coastal applications and water management and monitoring applications to be implemented.


See also