MERCATOR OCEAN JOURNA, 
SEPTEMBER 2021 
adjusted collated sea surface temperature 
adjusted collated sea surface temperature (kelvin) 
a LS TEL La zn 
2,7E+0D2 2,8E+02 2,8E+02 2,9E+ 22 DE +02 3.0E+02 
Data Min= 27E402, Max= 3.0E+02 
-igure z: Example of the daily L3S Sea Surface Temperature product (SST_GLO_SST_L3S_NRT_OBSERVATIONS_010_010) in December 2020 
including satellite observations from Seviri on MSG, VIIRS NPP. VIIRS N20, SLSTRs on Sentinel-3A and S3B, GOES16, GOES17, Himawari, MSG 
Indian Ocean, AVHRR on Metop-B, AMSRE 2 and GMI 
1.2 Atlantic (European North West Shelf and lberia 
Biscay Irish seas) products 
A new reprocessed foundation SST dataset was generated 
over the North West Shelves in 2017 and updated in 2018 
‚NWS). The SST Level 4 analysis product was reconstructed 
daily from the global Advanced Very High Resolution 
Radiometer (AVHRR) Pathfinder dataset for the 1982-2014 
time period. This includes global AVHRR observations from 
NOAA polar orbiting satellites. The spatial resolution is 
1/25°. The absence of valid SST values was mainly due to 
clouds. The data used in our reprocessing were the daily 
files from 1982 to 2014. During the 2015-2017 period, 
operated data were the real time AVHRR L2 products. The 
reconstruction of the daily gap-free SST timeseries relied 
on the interpolation at each point of the timeseries with a 
Kalman smoother. In 2019, the area was extended to the 
European North West Shelf and Iberia Biscay Irish seas. 
“his spatial extension enabled the coverage of the Canary 
upwelling system. In 2020, timeseries were reprocessed 
from 1982 to 2019 with a new input dataset: ESA CC. 
data (11 AVHRRs and 3 ATSRs) and C3S data (AVHRRs 
and SLSTR). Prior to this interpolation, an input data 
intercalibration step was added. 
In addition to the reprocessed product, an operationa 
Level 4 product was delivered daily over the European 
North West Shelf and Iberia Biscay Irish seas with a spatia 
resolution of 1/50° (Figure 3). The input data have evolved 
zontinuously as in the global L3S product. Initially, the 
product covered the European North West Shelves. The 
area was then extended to the European North West Shelf 
and Iberia Biscay Irish seas in 2019.