New study on the detection of cold-core rings in the Gulf Stream area using remote sensing platforms

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.

Figure 1

Sea Surface salinity on August 23, 2015 according to various SSS products with superimposed OSCAR velocities. The plot on (a) correspond to the one-degree binned Aquarius L3 map. The other three maps show the fusion of the map shown in (s) with: AVISO SSH (b); SMOS SSS (c); and AVHRR SST (d).

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Nodal sampling: removing tails and ripples from SMOS Brightness Temperatures

Since the beginning of SMOS mission, one of the problems that has strongly affected the quality of the retrieval of SSS from SMOS Brightness Temperatures (BT) is the presence of large human-generated Radio Frequency Interference (RFI) sources, as shown in the following figure:

Image acquired over a coastal area in Europe; several strong RFI sources and their trails are very noticeable

Image acquired over a coastal area in Europe; several strong RFI sources and the associated tails are very noticeable

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