Given the interferometric characteristics of SMOS, SMOS snapshots are full-polarization brightness temperatures rendered on a hexagonal grid (the so-called synthetic antenna). In fact, what the instrument actually measures are the cross-correlations of all pairs of receivers, from which a visibility function can be derived. The vector of visibilities is linearly related to brightness temperatures TB by means of a reconstruction matrix G. Due to the imperfect knowledge of the matrix G, the difficulties to invert such a big matrix together with some aliasing effects, spurious spatial correlations on brightness temperature snapshots are induced. BEC team is investigating the scope of such correlations. The shape of the found correlations reveals a clear geometrical pattern.
Experimental SMOS SSS maps of the Mediterranean Sea are being computed at BEC using a new methodological approach to cope with land and RFI contamination. Three different products are being analysed: monthly binned maps at a 1×1 deg grid; optimal interpolated maps at 0.25×0.25 deg; and daily products at 0.25×0.25 deg through fusion with Reynolds SST. The preliminary assessment of the monthly product shows an RMS with respect to ARGO of 0.35 psu. These maps will be available soon in our CP34-BEC data distribution system, so keep watching!
With its more than 3500 automatic profilers, the Argo array is one of the most important component of the Global in-situ Ocean Observing System. The array provides measurements of temperature and salinity profiles down to 2000 m. These data are rapidly expanding the historical database of the ocean sub-surface (specially in the case of ocean salinity) and are providing novel information about the ocean’s vertical structure and its variability. Moreover, these data allow real-time monitoring, model-constraining and contribute to calibration and verification efforts.
The Euro-Argo (www.euro-argo.eu) research infrastructure, designed to coordinate the European contribution to Argo, is part of the European Strategy Forum on Research Infrastructures (ESFRI). Euro-Argo is expected to provide additional 50 floats per year and support about the 25% of
the Argo array.
Since more than a year ago, the Barcelona Expert Center (BEC) team researches on the capabilities of SMOS for the characterizations of the Cryosphere.
First maps of the Arctic Sea Ice concentration from SMOS data have been produced for the year 2014, with the algorithm explained bellow.
Two indices have been chosen to compute ice concentration: Angular Difference (AD=TBV(θ_2)-TBV(θ_1)) and Polarization Difference (PD=TBV-TBH). The sensitivity of those indices to ice salinity and temperature is much less (about 60%) than that of raw TB’s, but they are still quite sensitive to the physical state (sea or ice). This property is very convenient for the empirical characterization of the physical state, because the distribution of the geophysical parameters is not very well known (specially for the ice salinity).
With the L4 all-weather product, we plan to extend the downscaling approach to other climatic regions. See Fig. 1 for an example of its application over Europe on July 1, 2014 (ascending passes). The version 2.0 is also provided (Fig. 2) to illustrate the differences between the two versions.
At Barcelona Expert Center (BEC) we are able to provide a Level 4 (L4) Surface Soil Moisture (SSM) product with 1 km spatial resolution that meets the requirements of land hydrology applications. To do so, we use a downscaling method that combines highly-accurate, but low-resolution, SMOS radiometric information with high resolution, but low sensitivity, visible-to-infrared imagery to SSM across spatial scales. A sample L4 SSM map from September 1, 2014 (6 AM) is shown in Figure 1.
This downscaling approach was first presented in  along with results of its application to a set of SMOS images acquired during the commissioning phase over the Oznet network, South-East Australia. Using reprocessed SMOS data obtained with the latest L1 and L2 processors, we have further developed and validated this technique; we now use SMOS polarimetric and multi-angular information in the downscaling method, which results in improved fine-scale soil moisture estimates .
In addition to contribute to the build-up of the Argo system by deploying eight Argo profilers during January 2015, the One Planet, One Ocean & Pharmaton ship carried a Sea Bird SBE37-SI MicroCAT instrument to collect continuous (every minute) sea surface temperature and salinity measurements.
The Gulf Stream plays a major role in the meridional transport of heat and salt across the North Atlantic Ocean. The Gulf Stream acts as a barrier between the cold (10-18 °C) and relatively fresh (salinity around 30-32 in the practical salinity scale) waters of the Labrador Current and the warm (23 °C), salty (36), clear, and unproductive waters of the Sargasso Sea. After leaving Cape Hatteras, the Gulf Stream forms large-amplitude meanders that may loop back onto themselves and break off the stream forming detached rings. Warm-core anti-cyclonic rings bring significant amounts of warm tropical water to the continental slope and shelf seas north of the Gulf Stream. Similarly, cold-core cyclonic rings bring cold, nutrient-rich shelf water, to the biologically barren Sargasso Sea waters. Detection of cold-core rings from satellite data has been quite elusive so far as the surface temperature signature rapidly disappears.
The Barcelona World Race Ocean Campus has organised five courses on Instructure Canvas platform to provide the 2014-2015 round the world regatta followers with basic knowledge about the science of oceanography and other subjects like meteorology, telemedecine, chronobiology or nutrition. One of these MOOCs is “Oceanography: a key to a better understanding of our world” that includes a module on ocean remote sensing instructed by Jordi Font. This free course will start on April 20th and does not require previous knowledge in oceanography. Feel free to join us in this worldwide adventure!