Storm-Driven Mixing and Potential Impact on the Arctic Ocean

• Main Authors: Yang, Jiayan, Comiso, Josefino, Walsh, David, Krishfield, Richard, Honjo, Susumu
• Other Authors: NAVAL RESEARCH LAB STENNIS SPACE CENTER MS OCEANOGRAPHY DIV
• Format: Text
• Language: English
• Published: 2004
• Subjects: Meteorology; Physical and Dynamic Oceanography; Hydrology; Limnology and Potamology; Mechanics; *THERMODYNAMICS; *ICE MECHANICS; *STORMS; *HYDROGRAPHY; *MARINE METEOROLOGY; *ARCTIC OCEAN; REPRINTS; TEMPERATURE; OCEAN CURRENTS; OCEANOGRAPHIC DATA; WIND VELOCITY; BAROMETRIC PRESSURE; MIXED LAYER(MARINE); SALINITY; MARINE CLIMATOLOGY; STRATIFICATION; GEOSTROPHIC WIND; WIND STRESS; THERMOCLINES; BUOYS; MARINE GEOPHYSICS; SYNOPTIC METEOROLOGY; BERING STRAIT; FRAM STRAIT; SATELLITE IMAGERY; HALOCLINE; SEA ICE CONCENTRATION; ICE EXPORT; IOEB(ICE OCEAN ENVIRONMENTAL BUOYS); ARCTIC OSCILLATION; SEA LEVEL PRESSURE; *STORM-DRIVEN MIXING; METEOROLOGICAL BUOYS; ARCTIC MIXED LAYER; Arctic; Arctic Ocean; Bering Strait; Pacific; Beaufort Sea; Fram Strait; North Atlantic; Sea ice
• Online Access: http://www.dtic.mil/docs/citations/ADA423407; http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA423407

Observations of the ocean, atmosphere, and ice made by Ice-Ocean Environmental Buoys indicate that mixing events reaching the depth of the halocline have occurred in various regions in the Arctic Ocean. This analysis suggests that these mixing events were mechanically forced by intense storms moving across the buoy sites. In this study, the authors analyzed these mixing events in the context of storm developments that occurred in the Beaufort Sea and in the general area just north of Fram Strait, two areas with quite different hydrographic structures. The Beaufort Sea is strongly influenced by inflow of Pacific water through the Bering Strait, while the area north of Fram Strait is directly affected by the inflow of warm and salty North Atlantic water. These analyses of the basin-wide evolution of the surface pressure and geostrophic wind fields indicate that the characteristics of the storms could be very different. The buoy-observed mixing occurred only in the spring and winter seasons when the stratification was relatively weak. This indicates the importance of stratification, although the mixing itself was mechanically driven. The authors also analyze the distribution of storms, both the long-term climatology and the patterns for each year in the past 2 decades. The frequency of storms is also shown to be correlated (but not strongly) to Arctic Oscillation indices. This study indicates that the formation of new ice that leads to brine rejection is unlikely the mechanism that results in the type of mixing that could overturn the halocline. On the other hand, synoptic-scale storms can force mixing deep enough to the halocline and thermocline layers. Despite a very stable stratification associated with the Arctic halocline, the warm subsurface thermocline water is not always insulated from the mixed layer. (23 figures, 28 refs.) Pub. in the Journal of Geophysical Research, v109, pC04008 (18 pp.), 2004.