Observations of Ice-Ocean Momentum and Heat Fluxes at the SHEBA Ice-Camp

点击翻译按钮获取中文摘要

9701797 Pinkel This research project is a key component of a large, coordinated, multi-investigator program called SHEBA (Surface Heat Budget of the Arctic) Ocean. The SHEBA program will simultaneously measure, over an annual cycle, the various fluxes and properties of the atmosphere, ice pack, and upper ocean that determine the aggregate mass and energy budgets of Arctic sea ice. Its goal is improved understanding of how and to what extent, the ice covered Arctic Ocean affects climate variability in lower latitudes and in global climate models (GCMs). Towards that goal, two potentially important radiation/climate feedback processes have been singled out for study: Ice-Albedo Feedback and Cloud-Radiation Feedback. This proposal addresses an oceanographic component of SHEBA dealing with ice-albedo feedback mechanisms. Two specially constructed acoustic Doppler current profilers (ADCP)s will be deployed to investigate the roles of wind and ocean currents in moving ice from place to place. A Deep Profiling System consists of a 140 kHz, four beam coded pulse sonar. This will profile to 400 m with 3 m spatial resolution. It will provide an accurate picture of the Ekman layer, the deep mixed layer, meso and large scale flows. A second, five beam 560 kHz Flux Sonar deployed from the ice, will provide direct estimates of the turbulent momentum flux in the under-ice boundary layer. When coupled with co-located measurements of temperature and salinity, turbulent heat fluxes can be estimated as well. The intention is to run these two instruments for the full 12-13 month duration of the SHEBA camp. The combined set of measurements in SHEBA will allow refinement of climate models for the Arctic region. Those improved models will lead to better predictions of the climate and the permanence of the Arctic ice cap under a proposed global warming that could occur if atmospheric carbon dioxide levels are increased above present levels.