Correction of the L3 daily SM and VOD from CATDS.

Category : L3

The SMOS level 3 soil moisture was developed to take advantage of several revisits of the same point in 7 days. This multi-orbit retrieval was supposed to stabilize the VOD and so to improve the SM retrieval quality. Unfortunately,  it was not the case leading to poor performances of the L3SM when compared to other soil moisture product.

This was not good so….

So we have worked on this issue for some time to identify the issue and correct it . We found the issue (Arnaud and Philippe) and the modification has been implemented in the operational processor since mid July 2019. The figure below presents the time series of level 3 SM and VOD L3 (in blue) for a site in Australia. Before the modification (left hand side of the vertical dotted line), one can noticed spurious peaks of SM (indicated by green circles) that are not present in other SM products (ESA level 2 in orange, SMOS IC in red). These poor retrievals are also noticeable in the VOD plot, where high values are reported.

new L3

Figure showing the temporal behaviour of soil moisture and VOD retrievals before and after the « bug » correction in July 2019.

With the correction, SMOS level 3 performs normally. A complete reprocessing with the corrected algorithm will be done in 2020, taking advantage of the general reprocessing  with the new L1 and L2  processors.

Arnaud Mialon CESBIO

SMOS is 10 years old! Happy Birthday and many happy returns

Category : Satellite

Yes indeed!

10 years ago, early in the day with a completely overcast sky, SMOS soared into the skies.

And after that, dutifully and without almost no interruption, the mission has delivered an outstanding data stream … So congratulations to the project team who did this wonderful mission, and thanks to the operation teams who do the utmost to deliver the data in a timely and quality driven fashion…

So where are we after ten years? …

On top of all that was planned in terms of soil moisture and Sea surface salinity…


Figure 1 from Dimitry Khvorostyanov (LOCEAN)

SMOS is used operationally at ECMWF in the IFS since June 2019

SMOS is used operationally to infer sea ice thickness, freeze thaw and also measures the internal temperature of the Antarctica Ice sheet…


Figure 2 Sea Ice extent dévolution since SMOS Launch (Lars Kaleschke AWI)

SMOS is able to quantify high levels of biomass (300 t/ha) using the L-VOD this is also un precedented. It proved it ability to detect droughts in advance and help forecasting floods.


Figure 3 SMOS VOD (Arnaud Mialon)

SMOS is used to improve rainfall estimates from satellite over both land and oceans, is unique for monitoring High winds (hurricanes and tornadoes)

Etc etc … I stop here as the list is too long and will get soon boring.  All I may add is that very novel uses are still coming out or on the verge of popping out (liquid water in snow and ice, green house gas emissions, …) so stay tuned.

Last but not least, we now have 10 years of continuous data at reach. We can start to study tele-connections, climate trends  indicators  or hints of them etc. The treasure box is far from being exhausted, believe me.

I may be biased but I do not think any mission can claim more results in so little time than SMOS -especially for an explorer missions. Did you realise we have already over 1400 publications  (h index of 68) in WoS? including 3 (and several more coming) in Nature journals and 20 highly cited papers?

So to make a long story short,

long life to SMOS !

Many thanks to all those who work every day with much dedication to provide us with the good data.

If as a user you have new results let us know! We like to keep abreast of all what is going on! This blog could be your sounding board

And let’s hope our decision makers will soon come to their sense and enable a SMOS/L- band radiometer follow mission to emerge – if only to satisfy the operational users!

SMOS Mission Extended to 2021!

Category : CATDS, Data, L1, L2, L3, L4, Non classé, Satellite

I am glad to inform you that yesterday the Program Board for Earth Observation (PB-EO) of ESA voted the SMOS mission extension following the ACEO (Advisory Committee for Earth Observation) review report:

« Member states’ delegations were very positive about both the achievements so far as well as the detailed plan being put forward for the extension. « 

CNES (the French Space Agency also funding the mission exploitation), has already granted funding until 2021 (actually 2019 with extension to 2021 pending PB-EO vote which we now have).

So, should everything go nicely with the satellite and platform, we have data guaranteed until  2021!

Congratulations and many thanks to all the actors of this success.

SMOS is now over 9 year old and still going strong by the way!


8+ years of soil moisture and ocean salinity data over the globe from SMOS

Category : CATDS, L2, L3, Ocean

This animation was prepared by Dimitry Khvorostyanov from LOCEAN with SMOS data from CATDS (Soil moisture level 3 and Ocean salinity debiased V3)


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