Antarctica’s internal ice sheet temperature from SMOS

Category : CATDS, Data, L4

The new version of the internal ice sheet temperature estimated from SMOS over Antarctica is now available.This dataset is based on the combination of L-band (1.4 GHz) passive microwave observations with glaciological and emission models. The study highlights the potential of low microwave frequencies for investigating the internal temperature of the ice sheet.


Figure : Ice temperature (K) derived from SMOS at depths of 1000 m (left) and 1500 m (right).

For more information see –>  G. Macelloni, M. Leduc-Leballeur, F. Montomoli, M. Brogioni, C. Ritz, G. Picard, 2019, On the retrieval of internal temperature of Antarctica Ice Sheet by using SMOS observations, Remote Sensing of Environment, 233, doi:10.1016/j.rse.2019.111405

Datasets are available at CATDS

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)


SMOS retrieves salinity closer to the coast line

Category : L2, L3, Ocean

From J Boutin, and colleagues from LOCEAN

Salinity observing satellites have the potential to monitor river fresh-water plumes mesoscale spatio-temporal variations better than any other observing system. In the case of the SMOS mission, this capacity was hampered due to the contamination of SMOS data processing by strong land-sea emissivity contrasts.


With the new systematic error mitigation, SMOS SSS becomes more consistent with the independent SMAP SSS close to land, for instance capturing consistent spatio-temporal variations of low salinity waters in the Bay of Bengal and Gulf of Mexico (see Figure 1 below). The standard deviation of the differences between SMOS and SMAP weekly SSS is less than 0.3 pss in most of the open ocean. The standard deviation of the differences between 18-day SMOS SSS and 100-km averaged ship SSS is 0.20 pss (0.24 pss before correction) in the open ocean (see Figure 2 below). Even if this standard deviation of the differences increases closer to land, the larger SSS variability yields a more favorable signal-to-noise ratio, with r2 between SMOS and SMAP SSS larger than 0.8. The correction also reduces systematic biases associated with man-made Radio Frequency Interferences (RFI), although SMOS remains more impacted by RFI than SMAP. This newly-processed dataset will allow the analysis of SSS variability over a larger than 8 years period in regions previously heavily influenced by land-sea contamination, such as the Bay of Bengal or the Gulf of Mexico.

The new SMOS SSS products are available at CATDS (’CEC LOCEAN debias v2′ produced by LOCEAN/ACRI expertise center and ‘CPDC L3Q’ produced by the near real time CATDS chain). The paper is available here (the link is freely active during 2 months).


Figure 1: SMOS SSS corrected according to (a,d) Kolodziejczyk et al. (2016) methodology, (b, e) the method described in this paper (CEC); (c, f) SMAP SSS, in two areas : (a, b, c) : Bay of Bengal - August 21st 2015; (d, e, f) : Gulf of Mexico – August18th 2015.SMOS and SMAP SSS is averaged over a SMOS repetitive orbit sub-cycle (18 days) and two SMAP repetitive orbit cycles (16 days) respectively. Striking fresh SSS features in better agreement with SMOS (new version) and SMAP are indicated with white arrows.


Figure 2: Statistics of ship comparisons (May 2010-August 2016) binned as a function of the distance from the nearest coast: top) mean difference; bottom) standard deviation of the differences; the black line indicates the standard deviation of ship SSS in each class. Ship and SMOS SSS are integrated over 100 km. Orange: monthly SMOS L3P SSS (without error mitigation) ; pink : monthly SMOS L3Q (with error mitigation; near real time processing); light blue : 18-day SMOS CEC (with error mitigation; LOCEAN/ACRI expertise center processing); green : ISAS (Argo optimal interpolation).

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