The water stable isotopes of sea water

• Main Author: Benetti, Marion
• Other Authors: Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN), Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS-PSL), Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales Toulouse (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales Toulouse (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Université Pierre et Marie Curie - Paris VI, Catherine Pierre, Gilles Reverdin
• Format: Doctoral or Postdoctoral Thesis
• Language: French
• Published: HAL CCSD 2015
• Subjects: North Atlantic; Stables Water Isotopes; Isotopes; Atlantique-Nord; Evaporation; Convection; Subpolaire; Subtropiques; [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry; Arctic; Sea ice
• Online Access: https://theses.hal.science/tel-01195581; https://theses.hal.science/tel-01195581/document; https://theses.hal.science/tel-01195581/file/these_archivage_2607864o.pdf

This thesis focuses on two regions of the North Atlantic: the subtropical gyre and the subpolar gyre. This large coverage allows an investigation of the water cycle in different hydrological regimes, where various processes take place such as sea ice seasonal cycle, rivers runoff, continental ice melt and advection of air and water masses. In the subtropical region, the variability of the isotopic composition of the water vapor is studied to understand the role of evaporation and mixing with free troposphere in humidity and isotopic compositions at the ocean surface. In particular, new data collected during summer 2012 (STRASSE cruise) gave the opportunity to explore kinetic fractionation processes during oceanic evaporation and air renewal in the atmospheric boundary layer. In the subpolar region, the surface circulation is cyclonic and transfers cold and fresh water from the arctic region to the interior of the subpolar gyre. For this thesis, data were collected between 2010 and 2014 from oceanographic cruises and commercial vessels to study the gyre interior and the main coastal currents carrying water from the arctic to lower latitudes. The study is mainly focused on the Labrador Current. There, isotopic measurements are used to identify the freshwater sources and to consider the following questions: How is the salinity of fresh currents affected by the sea ice formation and melting? How is the contribution of meteoric waters changing in a context of an acceleration of the melting of continental glaciers? Ce travail de thèse s’intéresse à deux zones de l’Atlantique Nord : la région subpolaire et la région subtropicale. Cette large couverture permet d’étudier le cycle de l’eau dans des régions hydrologiquement différentes, où des processus variés rentrent en jeu comme l’évaporation, la convection atmosphérique, la formation des précipitations, le cycle saisonnier de la glace de mer, les apports des rivières et des glaciers, et l’advection des masses d’eau et des masses d’air. Dans la région subtropicale, ...