FN Archimer Export Format
PT J
TI Locations and mechanisms of ocean ventilation in the high-latitude North Atlantic in an eddy-permitting ocean model
BT 
AF MacGilchrist, Graeme A.
   Johnson, Helen L.
   Marshall, David P.
   Lique, Camille
   Thomas, Matthew
   Jackson, Laura C.
   Wood, Richard A.
AS 1:1;2:1;3:2;4:3;5:4,5;6:6;7:6;
FF 1:;2:;3:;4:PDG-ODE-LOPS-OH;5:;6:;7:;
C1 Department of Earth Sciences, University of Oxford, Oxford, U.K.
   Department of Atmospheric, Oceanic and Planetary Physics, University of Oxford, Oxford, U.K.
   Univ. Brest, CNRS, IRD, Ifremer, Laboratoire d’Océanographie Physique et Spatiale (LOPS), IUEM, Brest, France
   National Oceanic and Atmospheric Administration, Geophysical Fluid Dynamics Laboratory, Princeton, U.S.A
   University Corporation for Atmospheric Research, Boulder, Colorado, USA
   Hadley Centre, Met Office, Exeter, U.K.
C2 UNIV OXFORD, UK
   UNIV OXFORD, UK
   IFREMER, FRANCE
   NOAA, USA
   UNIV CORP ATMOSPHER RES UCAR, USA
   MET OFF, UK
SI BREST
SE PDG-ODE-LOPS-OH
UM LOPS
IN WOS Ifremer UMR
   copubli-europe
   copubli-int-hors-europe
IF 5.148
TC 16
UR https://archimer.ifremer.fr/doc/00646/75833/76825.pdf
LA English
DT Article
DE ;North Atlantic Ocean;Atmosphere-ocean interaction;Lagrangian circulation/transport;Ocean circulation;Boundary currents;Diapycnal mixing
AB A substantial fraction of the deep ocean is ventilated in the high-latitude North Atlantic. Consequently, the region plays a crucial role in transient climate change through the uptake of carbon dioxide and heat. However, owing to the Lagrangian nature of the process, many aspects of deep Atlantic Ocean ventilation and its representation in climate simulations remain obscure. We investigate the nature of ventilation in the high latitude North Atlantic in an eddy-permitting numerical ocean circulation model using a comprehensive set of Lagrangian trajectory experiments. Backwards-in-time trajectories from a model-defined ‘North Atlantic DeepWater’ (NADW) reveal the locations of subduction from the surface mixed layer at high spatial resolution. The major fraction of NADW ventilation results from subduction in the Labrador Sea, predominantly within the boundary current (̴ 60% of ventilated NADW volume) and a smaller fraction arising from open ocean deep convection (̴ 25%). Subsurface transformations — due in part to the model’s parameterization of bottom-intensified mixing—facilitate NADWventilation, such that water subducted in the boundary current ventilates all of NADW, not just the lighter density classes. There is a notable absence of ventilation arising from subduction in the Greenland-Iceland-Norwegian Seas, due to the re-entrainment of those waters as they move southward. Taken together, our results emphasize an important distinction between ventilation and dense water formation in terms of the location where each takes place, and their concurrent sensitivities. These features of NADW ventilation are explored to understand how the representation of high-latitude processes impacts properties of the deep ocean in a state-of-the-science numerical simulation. 
PY 2020
PD DEC
SO Journal Of Climate
SN 0894-8755
PU American Meteorological Society
VL 33
IS 23
UT 000615171300007
BP 10113
EP 10131
DI 10.1175/JCLI-D-20-0191.1
ID 75833
ER

EF