Title Long-term observations of daily acoustic travel time along the SAMBA transect at PIES Mooring P4 (October 2019 – October 2021)
Project South Atlantic Meridional Overturning Circulation (SAMOC-SA)
Authors

Sabrina Speich
Ecole Normale Supérieure (ENS) Laboratoire de Météorologie Dynamique (LMD); role: Marine Scientist; contact details: email: sabrina.speich@lmd.ens.fr

Tarron Lamont
Oceans and Coastal Research, Department of Forestry, Fisheries and the Environment (DFFE); role: Marine Scientist; contact details: email: tlamont@dffe.gov.za

Gavin Louw
Oceans and Coastal Research, Department of Forestry, Fisheries and the Environment (DFFE); role: Marine Scientific Technician; contact details: email: glouw@dffe.gov.za

Marcel van den Berg
Oceans and Coastal Research, Department of Forestry, Fisheries and the Environment (DFFE); role: Marine Scientific Technician; contact details: email: mvdberg@dffe.gov.za

Chris Meinen
Atlantic Oceanographic and Meteorological Laboratory (AOML); role: Marine Scientist; contact details: email: chris.meinen@gmail.com

Rigoberto Garcia
Atlantic Oceanographic and Meteorological Laboratory (AOML); role: Marine Scientist; contact details: email: Rigoberto.Garcia@noaa.gov

Renellys Perez
Atlantic Oceanographic and Meteorological Laboratory (AOML); role: Marine Scientist; contact details: email: Renellys.C.Perez@noaa.gov

Shenfu Dong
Atlantic Oceanographic and Meteorological Laboratory (AOML); role: Marine Scientist; contact details: email: Shenfu.Dong@noaa.gov

Publisher Department of Forestry, Fisheries and the Environment (2023)
Contributors

Contact Person: Gavin Louw
Oceans and Coastal Research, Department of Forestry, Fisheries and the Environment (DFFE); role: Marine Scientific Technician; contact details: email: mrgavinl@gmail.com

Abstract Here we present processed travel time from a Pressure-equipped Inverted Echo Sounder (PIES) located at a depth of 4500m at location P4 (34.500°S; 14.630°E) along the South Atlantic MOC Basin-scale Array (SAMBA) transect in the Cape Basin region of the South Atlantic Ocean, between 12 October 2019 and 01 October 2021. The South African component of the international South Atlantic Meridional Overturning Circulation project (SAMOC-SA) aims to characterise the time-mean and time-varying components of the SAMOC in the South Atlantic Ocean and monitor the variability of the main Southern Ocean frontal systems associated with the Antarctic Circumpolar Current (ACC), south of Africa.
Methods A bottom-mounted, upward-looking, Pressure-equipped Inverted Echo Sounder was deployed at a depth of 4500m at location P4 (34.500°S; 14.630°E) along the South Atlantic MOC Basin-scale Array (SAMBA) transect in the Cape Basin region of the South Atlantic Ocean. The instrument measured hourly bottom pressure and acoustic travel time (Tau), between 12 October 2019 and 01 October 2021. Measurements were de-tided, de-drifted, and de-spiked, using standard published University of Rhode Island (URI) software and protocols. A 72-hour 2nd order Butterworth filter was applied to hourly bottom pressure and acoustic travel time (Tau) observations. Tau values were then calibrated to a nominal pressure of 1000 db, and together with pressure observations, Tau was then subsampled to one value per day at noon (UTC). Bottom pressure anomalies have been computed relative to the record length average.
Data
Attribution-ShareAlike 4.0 International (CC BY-SA 4.0)
Temporal extent 12 Oct 2019 – 01 Oct 2021
Geographic extent

Cape Basin, South Atlantic Ocean

North: -34.5
South: -34.501
West: 14.63
East: 14.631

Vertical extent Max: -4500 m
Min: -4500 m
Keywords currents, moorings, PIES, Pressure-equipped Inverted Echo Sounder, SAMBA transect, SOUTH ATLANTIC OCEAN
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