Cooperative Institute for Research in Environmental Sciences

Exploration of turbulent heat fluxes and wind stress curl during wintertime mesoscale wind events around southeastern Greenland

Alice K. DuVivier and John J. Cassano

2014, Journal of Geophysical Research, Accepted pending revisions

The strong, mesoscale tip jets and barrier winds that occur off the coast of southern Greenland have the potential for strongly impacting ocean circulation, in particular deep convection. Different winter (NDJFM) wind patterns were identified using the self-organizing map (SOM) technique, and differences in the patterns with respect to the implications on ocean forcing have been examined. Differences in turbulent heat fluxes and wind stress curl were analyzed for three datasets: the ECMWF Interim Reanalysis (ERA-I) and two regional simulations using the Weather Research and Forecasting (WRF) model at 50 km and 10 km resolutions. Manifestations of similar wind patterns had variable surface forcing that would impact ocean preconditioning and convection differently. The representation of sea ice was found to strongly impact the near-surface atmospheric temperature and moisture. This resulted in the largest turbulent flux differences occurring over the marginal ice zone (MIZ) because of differences in sea ice thickness and concentration for the different datasets. Differences in the near-surface temperature is the primary driver of differences in the sensible heat fluxes, while differences in the latent heat fluxes are driven by a combination of differences in moisture and wind. The strength and location of wind stress curl has implications for ocean preconditioning, and it was found that WRF had larger magnitude wind stress curl than ERA-I and particular wind patterns with strong wind stress curl would have the largest impact on preconditioning.