New insights into the role of atmospheric conditions in Labrador Sea deep convection

  • 10 June 2016
  • Number of views: 1559

A study partially supported by CPO's Climate Variability and Predictability Program concluded that the abrupt deep convection of the 2008 winter in the Labrador Sea is associated with unusual atmospheric conditions in the western North Atlantic and large-scale cooling in North America. A report of the study, which also suggests atmospheric responses to La Niña strongly influence the deep convection in the Labrador Sea, appears online in the Journal of Climate.

Daily time series of (a-b) turbulent heat fluxes, and (c-d) 10-m air temperatures (SAT), (e-f) zonal (black) and meridional (gray) winds, and (g-h) wind speed for the 2007 (left column) and 2008 (right column) winters averaged over the central Labrador Sea from the Coordinated Ocean-ice Reference Experiments phase 2 (CORE-II). Also shown are turbulent heat fluxes from the (a-b) Objectively Analyzed Air-Sea Fluxes data set, and (c-d) SAT and (g-h) wind speed from the Arctic System Reanalysis product. Positive zonal (meridional) winds denote westerlies (southerlies). The climatological cycle (1949-2009) of the CORE-II turbulent heat flux (a-b) and SAT (c-d) is also displayed (dashed line). Courtesy of Kim et al.

Researchers examined atmospheric and oceanic conditions employing reanalysis data, hindcast simulations, and a long-term analysis of deep convection in the Labrador Sea. The anomalous deep convection in the 2008 winter contrasts with the previous winter, which was accompanied by a stronger North Atlantic Oscillation despite having a shallow deep convection, the report states. Also, circulation anomalies in the western North Atlantic in the 2008 winter were accompanied by unusually cold near-surface temperature in part of northern North America and the subpolar North Atlantic.

The Labrador Sea is a region of major, open-ocean convective mixing. The report states the published findings are an important step for understanding contributing factors for deep convection in the Labrador Sea and their relationship with the Atlantic Meridional Overturning Circulation.

To access a copy of the report, visit:




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