Winter (sub)mesoscale variability in the central Arctic Ocean : eddy observations and modeling during the MOSAiC drift.

Abstract:

(Sub)mesoscale variability, in particular eddies, plays a significant role in the upper ocean dynamics. However, application of standard methods to observe eddies in open water, such as satellite remote sensing, has so far been challenging in ice-covered seas. In-situ data, in particular during winter, are limited and the numerical models not well constrained in the central Arctic. There is a significant gap in understanding of the role of eddies in mixing and transports.
Recent advances in numerical modeling techniques allow high-resolution Arctic Ocean models that are capable of resolving dynamics at (sub)meso-scales (O(1) km). By combining such a model with in-situ data collected during the international Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC), we investigate the (sub)mesoscale variability in the Arctic Ocean thermohaline field, and the occurrence of under-ice eddies, in particular.
Here, we analyse oceanographic data collected in winter from the MOSAiC central observatory (CO) and several oceanographic buoys distributed around this site in a 60 by 60 kilometres area, and identify and characterize several eddy-like structures. In a next step, we will combine the observed eddy properties with assimilation of buoy data to initialize and run a 3D ocean model applied to a domain representing the conditions during MOSAiC.
We expect that our 3D numerical studies of eddy properties will contribute to a better characterisation and understanding of (sub)mesoscale dynamics in the Arctic Ocean and its role in vertical transport of energy and mass.