Role and Variability of Mesoscale and Submesoscale Dynamics along the West Coast of Greenland
Abstract
Greenland Ice Sheet (GrIS) mass losses have accelerated over the recent decades resulting in freshwater input to the adjacent seas. Freshwater fluxes set the upper stratification in the Labrador Sea (LS) and play an important role also because ecosystem processes (and therefore oxygen and carbon cycling) are highly sensitive to such stratification. To investigate the role of model resolution and submesoscale circulations in exporting heat and salinity anomalies towards the center of the LS, we perform a set of regional simulations with varying horizontal resolution (from 1km, HR case, to 15km, LR case) over the period 2008-2013, with and without meltwater inflows from the Greenland fjords. The seasonal cycling of submesoscale activity at the ocean surface at the highest resolution attempted displays a clear maximum during summer, between mid-June and the end of August. Intense lateral density gradients created by summer time meltwater inflow, are responsible for the summer peak. During the winter time, submesoscale activity is low but mesoscale variability is at its maximum, and the distribution of near-surface vorticity is comparable across resolutions and in presence/absence of meltwater. Despite the volumetric large and seasonal fresh water inputs, the area of enhanced summer submesoscale activity is confined along the coast by the strong coastal current system, and such confinement is greater, in the model, at the highest resolution. We further discuss implications for the Labrador Sea contribution to the AMOC and for the heat and freshwater transport in the basin.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFMOS51B..06T
- Keywords:
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- 1635 Oceans;
- GLOBAL CHANGEDE: 4215 Climate and interannual variability;
- OCEANOGRAPHY: GENERALDE: 4513 Decadal ocean variability;
- OCEANOGRAPHY: PHYSICALDE: 4520 Eddies and mesoscale processes;
- OCEANOGRAPHY: PHYSICAL