Sea Turtles for Ocean Research and Monitoring: Overview and Initial Results of the STORM Project in the Southwest Indian Ocean

Olivier Bousquet,Arthur Vidard,Stéphane Ciccione,Philippe Gaspar,Soline Bielli,Marion Bocquet,Mayeul Dalleau,Elisabeth Remy

doi:10.3389/fmars.2020.594080

Abstract

Surface and sub-surface ocean temperature observations collected by sea turtles (ST) during the first phase (Jan-2019 – April 2020) of the Sea Turtle for Ocean Research and Monitoring (STORM) program are compared against in-situ and satellite temperature measurements, and later relied upon to assess the performance of Glo12 ocean model forecasts over the west tropical Indian Ocean. The evaluation of ocean temperature profiles collected by STs against collocated ARGO drifter measurements show good agreement, with imperceptible discrepancies at all sample depths (0-250m). Comparisons against various operational satellite sea surface temperature (SST) products indicate a slight overestimation of ST-borne temperature observations of ~ 0.1° +/- 0.6° that is consistent with expected uncertainties on satellite derived SST data. Comparisons of ST-borne surface and subsurface temperature observations against Glo12 operational ocean model forecasts demonstrate the good performance of modelled surface and subsurface ( 50m), the model is however shown to significantly underestimate ocean temperatures as already noticed from global evaluation scores performed operationally at the basin scale. The distribution of model errors also shows significant spatial and temporal variability in the first 50 m of the ocean, which will be further investigated in the next phases of the STORM project.

Highlights

Because sea temperature has a strong influence on climate dynamics and global transport of ocean water masses, knowledge and observation of this parameter is fundamental to achieve realistic forecasts and simulations of the coupled ocean-atmosphere system at all spatial and temporal scales
In order to qualitatively assess the realism of temperature structures sampled by sea turtles (ST), Figure 5 presents mean temperature profiles derived from the analysis of the data collected by the ST “SAMSON” and “BRICE” between 20◦S and 6◦N (∼3,000 km)
∼21/2 months were required for individual “SAMSON” to travel the 3,000 km from Reunion to the Gulf of Oman, compared to just over 3 months for ST “BRICE”

Summary

Introduction

Because sea temperature has a strong influence on climate dynamics and global transport of ocean water masses, knowledge and observation of this parameter is fundamental to achieve realistic forecasts and simulations of the coupled ocean-atmosphere system at all spatial and temporal scales. The accuracy of temperature observations collected by STs is assessed in section “Evaluation of Sea Turtle Temperature Measurements” through comparisons with in situ (ARGO) in-depth data and satellite-derived SST datasets.

Results

Conclusion