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)

Enjoy

Special Issue « New Outstanding Results over Land from the SMOS Mission »

Category : Data

from Amen Al-Yaari and Arnaud Mialon

Call for publications

Dear Colleagues,

Surface soil moisture (the water content in the first centimeters of soil) is an essential climate variable that plays an important role in land–atmosphere interactions. Soil moisture is widely used in improving climate model predictions/projections, weather forecasting, drought monitoring, rainfall estimations, etc.

Monitoring surface soil moisture at a global scale has recently become possible thanks to microwave remote sensing. SMOS (Soil Moisture and Ocean Salinity) was the first dedicated soil moisture mission that has been in orbit for eight years. The SMOS satellite was launched by the European Space Agency (ESA) in 2009, carrying on board a radiometer in the L-band frequency with a native spatial resolution of ~43 km. Since then, soil moisture and vegetation optical depth (VOD) have been retrieved from multi-angular brightness temperature observations relying mainly on a radiative transfer model.

This is a dedicated Special Issue on SMOS. We welcome studies on all subjects that are related to the SMOS satellite and its products.

Potential topics include, but are not limited to, the following:

  • the improvements in the soil moisture/VOD retrieval algorithms;
  • the evaluation/validation of the SMOS soil moisture and VOD products;
  • SMOS synergy with other remote sensing observations or models simulations;
  • SMOS soil moisture/VOD applications for agriculture, hydrology, etc.

Dr. Amen Al-Yaari
Dr. Arnaud Mialon
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All papers will be peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Remote Sensing is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 1800 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI’s English editing service prior to publication or during author revisions.

http://www.mdpi.com/journal/remotesensing/special_issues/smos_rs

A new debiased Seas surface Salinity map from LOCEAN

Category : CATDS, Cal/Val, L2, Ocean

New info from Jacqueline Boutin!

A new version (version 3) of debiased SMOS SSS L3 maps generated by the
LOCEAN CATDS expertise center is available at CATDS.

This third version of Level 3 SMOS SSS corrected from systematic biases
uses an improved ‘de-biasing’ technique: with respect to version 2, the
adjustment of the long term mean SMOS SSS in very dynamical areas, like
in river plumes, and the bias correction at high latitudes have been
improved. See more information and data link HERE

These products will be presented at IGARSS next week (poster 3447).

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.

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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).

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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.

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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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