Ocean Sci., 15, 199-214, 2019
https://doi.org/10.5194/os-15-199-2019
© Author(s) 2019. This work is distributed under
the Creative Commons Attribution 4.0 License.
Ocean Science
The Copernicus Surface Velocity Platform drifter with Barometer
and Reference Sensor for Temperature (SVP-BRST):
genesis, design, and initial results
Paul Poli 1 , Marc Lucas 2 , Anne O’Carroll 3 , Marc Le Menn 4 , Arnaud David 5 , Gary K. Corlett 3 , Pierre Iilouch 10 ,
David Meldrum 6 , Christopher J. Merchant 7 , Mathieu Belbeoch 8 , and Kai Herklotz 9
'Météo-France Centre de Météorologie Marine, Brest, France
2 Collecte Localisation Satellites, Ramonville-Saint-Agne, France
3 European Organisation for the Exploitation of Meteorological Satellites, Darmstadt, Germany
4 Service Hydrographique et Océanographique de la Marine, Brest, France
5 NKE Instrumentation, Hennebont, France
6 Scottish Association for Marine Science, Oban, UK
department of Meteorology, University of Reading and National Centre for Earth Observation, Reading, UK
8 WMO-IOC Joint Technical Commission for Oceanography and Marine Meteorology in-situ Observing
Programmes Support Centre, Plouzané, France
9 Bundesamt für Seeschifffahrt und Hydrographie, Hamburg, Germany
10 formerly at: Météo-France, Plouzané, France
retired
Correspondence: Paul Poli (paul.poli@shom.fr)
Received: 21 September 2018 - Discussion started: 26 October 2018
Revised: 17 January 2019 - Accepted: 4 February 2019 - Published: 1 March 2019
Abstract. To support calibration and validation of satel
lite sea surface temperature (SST) retrievals, over 60 high-
resolution SST (HRSST) drifting buoys were deployed at
sea between 2012 and 2017. Their data record is reviewed
here. It is confirmed that sea state and immersion depth
play an important role in understanding the data collected
by such buoys and that the SST sensors need adequate insu
lation. In addition, calibration verification of three recovered
drifters suggests that the sensor drift is low, albeit negative at
around —0.01 Kyear -1 . However, the statistical significance
of these results is limited, and the calibration procedure could
not be exactly reproduced, introducing additional uncertain
ties into this drift assessment. Based on lessons learnt from
these initial buoys, a new sensor package for the Surface
Velocity Platform with Barometer (SVP-B) was designed
to serve calibration of SST retrievals by European Union’s
Copernicus satellites. The novel sensor package includes an
HRSST sensor calibrated by a metrology laboratory. The
sensor includes a pressure probe to monitor immersion depth
in calm water and acquires SST data at 1 Hz over a 5 min in-
terval every hour. This enables the derivation of mean SST
as well as several percentiles of the SST distribution. The
HRSST sensor is calibrated with an uncertainty better than
0.01 K. Analysis of the data collected by two prototypes de
ployed in the Mediterranean Sea shows that the buoys are
able to capture small-scale SST variations. These variations
are found to be smaller when the sea state is well mixed and
when the buoys are located within eddy cores. This affects
the drifter SST data representativeness, which is an aspect of
importance for optimal use of these data.
1 Introduction
The Earth Observation Copernicus Sentinel program, funded
by the European Union, Iceland, and Norway, has driven the
development of new space-borne sensors, with new ground
segments and data processing chains. Of particular interest to
oceanographers is the acquisition of high-quality sea surface
Published by Copernicus Publications on behalf of the European Geosciences Union.
