A novel approach dedicated to build a climate oceanographic observatory in the central South Pacific: THOT (TaHitian Ocean Time series)
Elodie Claire Martinez1, Herve Claustre2, Martine Rodier1, Antoine Poteau2, Christophe Maes3, Alexandre Mignot4, Marc Taquet1, Cédric Ponsonnet5, Keitapu Maamaatuaiahutapu6 and Victoire Laurent7, (1)IRD, Ifremer, UPF and ILM, UMR-241, Ecosystèmes Insulaires Océaniens (EIO), Tahiti, French Polynesia, (2)Sorbonne Universités, UPMC Univ Paris 06, INSU-CNRS, Laboratoire d’Océanographie de Villefranche-sur-Mer (LOV), Villefranche-sur-mer, France, (3)Université Brest, Ifremer, CNRS, IRD, Laboratoire d ’Océanographie Physique et Spatiale (LOPS), IUEM, Brest, France, Brest, France, (4)MIT, EAPS, Cambridge, MA, United States, (5)Direction des Ressources Marines et Minières, Tahiti, French Polynesia, (6)Laboratoire de Géosciences du Pacifique Sud, University of French Polynesia, Faa'a, French Polynesia, (7)Météo-France Tahiti, Tahiti, French Polynesia
Abstract:
Through various physical, chemical and biological processes as well as their synergetic interactions, oceans play a key-role in the modulation of climate system and carbon cycle. Ocean dynamic in French Polynesia (central South Pacific) is involved in El Niño Southern Oscillation (ENSO) which is the dominant mode of interannual variability in the Pacific with strong effects at global scale. It also modulates the decadal oscillation of the Pacific Ocean and longer-term trends. Furthermore, being part of the South Pacific subtropical gyre, variability of the French Polynesia waters is representative of those in the subtropical gyres of the global ocean. To observe and characterize climate changes in this region, the deployment of long-lasting oceanographic survey stations is necessary to follow the evolution of oceanographic key parameters (e.g., density, O2, phytoplankton biomass). However, presently there is no long-term open ocean observatory in the central South Pacific.
The objective of the TaHitian Ocean Time-series (THOT) project is to set up an open-ocean oceanographic station to observe and improve the understanding of climate changes in the French Polynesia waters as representative of subtropical gyre and Pacific scales. This project will be part of existing international programs on climate and ocean observations (e.g., Bio-ARGO) and will complement long-term observations for global ocean.
The deployment of a mooring station, such as those already existing, is complex in French Polynesia due to its geographical, scientific, logistical and technological remote context. Thus the originality of THOT is to set up within the next two years a long-lasting station to observe climate changes based on the development and the deployment of a wave glider able to get back and replace a physical-biogeochemical profiling float to its initial position every few days. Meanwhile, four standard bio-argo floats will be regularly deployed in the area of interest offshore Tahiti.
