Soon 8 candles for SMOS!!!!! (5/8)

Category : CATDS, L2, L3, Model, Ocean

Another post from Jacqueline…and Jérôme

Water cycle in the Bay of Bengal

J. Vialard , S. Marchand et al. (LOCEAN)

The Bay of Bengal receives large amounts of freshwater from the Ganges-Brahmaputra river and monsoonal rainfall. The associated very low surface salinities induce a very stable stratification that inhibits vertical mixing of heat and nutrients. This has strong consequences for the climatological rainfall, intensification of tropical cyclones and ocean productivity in this region.

Available climatologies based on in situ data (e.g. World Ocean Atlas, top row) do not resolve the very strong horizontal gradients in this region. SMOS data (middle row) reveal that the narrow, coastal-trapped East-Indian Coastal Current transport the freshwater plume of Ganges-Brahmaputra along the Indian coast from October to December, resulting in large horizontal gradients (typically ~5 pss between coastal and offshore waters). The 8 years-long time series reveals a strong inter-annual variability of the freshwater plume southward extent, which can be related to Indian Ocean climate variability.


Caption: World ocean atlas (derived from in situ data, top row) and SMOS (middle row) (SSS climatology (altimeter-derived surface current climatology are overlaid on both panels). (Bottom row) Latitude-time section of SMOS SSS along the east coast of India. The southward extent of the freshwater plume varies depending on Indian Ocean climate variability associated with the Indian Ocean Dipole (Akhil et al. in prep.). (SMOS CATDS CPDC L3Q SSS)

To know more about associated work:

Akhil, V.P., F. Durand, M. Lengaigne, J. Vialard, M.G. Keerthi, V.V. Gopalakrishna, C. Deltel, F. Papa and C. de Boyer Montégut, 2014: A modeling study of the processes of surface salinity seasonal cycle in the Bay of Bengal, J. Geophys. Res. Oceans, 119, doi:10.1002/2013JC009632.

Akhil, V. P., M. Lengaigne, J. Vialard, F. Durand, M. G. Keerthi, A. V. S. Chaitanya, F. Papa, V. V. Gopalakrishna, and C. de Boyer Montégut, 2016a: A modeling study of processes controlling the Bay of Bengal sea surface salinity interannual variability, J. Geophys. Res. Oceans, 121, 8471–8495, doi:10.1002/2016JC011662.

Akhil, V.P., M. Lengaigne, F. Durand, J. Vialard, V.V. Gopalakrishna, C. de Boyer Montégut and J. Boutin, 2016b: Validation of SMOS and Aquarius remotely-sensed surface salinity in the Bay of Bengal, IJRS, 37,  doi: 10.1080/01431161.2016.1145362

Boutin, J., J.L. Vergely, S. Marchand, F. D’Amico, A. Hasson, N. Kolodziejczyk, N. Reul, G. Reverdin (2017), Revised mitigation of systematic errors in SMOS sea surface salinity: a Bayesian approach, Remote Sensing of Environment, in revision.

Chaittanya, A.V.S., M. Lengaigne, J. Vialard, V.V. Gopalakrishna, F. Durand, Ch. Krantikumar, V. Suneel, F. Papa and M. Ravichandran, 2014: Fishermen-operated salinity measurements reveal a “river in the sea” flowing along the east coast of India, Bull. Am. Met. Soc., 95, 1897-1908.

Fournier, S., J. Vialard, M. Lengaigne, T. Lee, M.M. Gierach, A.V.S. Chaitanya, Unprecedented satellite synoptic views of the Bay of Bengal “river in the sea”, 2017: J. Geophys. Res., in (minor) revision.

Was 2015 a « DRY » year? and what about 2016?

Category : CATDS, L4

Several extreme drought events occurred in 2015 around the globe. At CESBIO, combining hydrological modelling and remotely sensed surface soil moisture from SMOS, we monitored a number of them. We used CATDS (Centre Aval de Traitement des données SMOS) products.

The aproach was to use our root zone soil moisture information derived from SMOS to infer a water scarcity index. Water scarcity in the root zone (0-1.5m) is actually an efficient early warning system for agricultural droughts.


The figure above shows 5 of the major droughts which occurred in 2015. The small focus maps show the drought index during the drought events in each of the regions of interest. The losses caused by these droughts amount to billions.

So the next question is: are we facing long drought events that can impact food security at global scale?

In 2016 we may see even worse conditions. Our drought index seem to provide an alarming forecast. This was showcased by ESA during the Living Planet Symposium LPS2016 with this post using our latest root zone soil moisture map (see Water for crops – the SMOS root zone soil moisture).

We also produced the drought index map over North America for 2016 and it seems that after the Alberta fires and last year drought in the West coast of the US, the Eastern coast is now at risk. This forecast may change but it is clear that extremes conditions are breaking very old records, beyond the contribution of the El-Nino effect.


SMOS RSE special issue deadline postponed

Category : Cal/Val, Data, L1, L2, L3, L4, Model, Ocean, ground measurements

Dear colleague,

With regards to your potential contribution to the Special Issue on SMOS in Remote Sensing of Environment, we would like to notify you that the deadline for full paper submissions has been extended until 31st July 2015. Please be aware that this deadline change is final and no exceptions will be allowed after this date.

In case you have already submitted your paper, please disregard this message.

To submit your paper, please go to and select the option ‘submit paper’ from the menu bar near the upper left corner of the page. During the submission process, please make sure to select ‘SMOS 5 Years’ in the dropdown menu when choosing the article type, as demonstrated in the attached image.

Accepted papers will be published online as soon as possible following a final editing procedure by the Publisher. Once again, we encourage you to critically check your list of authors against the RSE guidelines on authorship ( to ensure appropriate representation of effort.

We look forward to receiving your contributions.

Yours sincerely,
Susanne Mecklenburg
On behalf of the editors for the Special Issue on SMOS in RSE

End of of the SMOS fortnight at ESAC !!

Category : CATDS, Tools, Training

A very busy two weeks at ESAC have just finished.

First a training course took place at ESAC during one week (May 18-22). It was the third SMOS training course but this time ESA took care (very efficiently!) of the logistics and provided us with very nice facilities (thank you Antonio!!)


(all photos courtesy of Ali Mahmoodi)

This training course was aimed at newcomers wanting to learn how to use SMOS. With lectures intersped with practicals the students (18) were intitated into the different SMOS levels. The course also included a visit of the ESAC facilities together with a fine « BBQ ».


Some of the students stayed on to take advantage of the SMOS Conference which was also a success . The presentations covered all the SMOS aspects together with presentations and posters of equivalent missions (Aquarius and SMAP) recent results and synergisms. Evening were busy with spontaneous picnics and a gorgeous banquet

The presentations will be made available by ESA on its SMOS conference site.

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