LOCEAN, LOPS, AARI and ACRI-ST have derived improved SMOS SSS maps over the Arctic Ocean based on new SST corrections and new sea ice filtering applied to SSS retrieved from SMOS satellite measurements.

The first version of level 3 (L3) SMOS ARCTIC SSS (weekly and monthly) covers a period from June 2010 to November 2019 above 60°North. The dataset is derived using uncorrected SSS from ESA SMOS SSS v662 level 2 (L2, https://smos.argans.co.uk/docs/deliverables/delivered/ATBD/SO-TN-ARG-GS-0007_L2OS-ATBD_v3.13_160429.pdf). SSS values are reprojected in an Equal-Scalable Earth Grid 2 (EASE, https://nsidc.org/data/ease) with a Northern Hemisphere Azimuthal projection and a resolution of 25km.

REMSS Microwave+Infrared Sea Surface Temperature (SST) optimal interpolation product (http://www.remss.com/measurements/sea-surface-temperature/oisst-description/) is used in order to correct SST related biases.

7-day moving averages of SMOS ESA L2 parameters are produced each day for L3 SSS weekly product. An average considering each day of the month is computed for L3 SSS monthly product. Weekly and monthly uncertainties are estimated through an error propagation of SMOS ESA v662 L2 uncertainty estimates.

Feedbacks from users about the quality of these new products are very welcome, as they are experimental. 

Version of the product:

V1.0: debiasing and sea ice filtering using ACARD + SST effects correction using REMSS SST 

V1.1: generalization of bias correction using ACARD + sea ice filtering using ACARD + SST effects correction using REMSS SST (Methodology presented in "New insights into SMOS sea surface salinity retrievals in the Arctic Ocean »; Supply et al, 2020 ; https://doi.org/10.1016/j.rse.2020.112027)