During the year-long SHEBA (Surface Heat Budget of the Arctic Ocean) experiment, we measured six of the components in the surface heat budget of Arctic sea ice at several sites and with various instruments. In this talk, we will review this SHEBA atmospheric surface flux program.
The focal point of our program was a 20-meter tower located at the main camp and instrumented with sonic anemometer/thermometers at five levels and with a fast-responding hygrometer at one level. These instruments yielded the latent heat flux and profiles of the momentum and sensible heat fluxes. Nearby were up-looking and down-looking pyranometers and pyrgeometers for measuring the radiation budget. Also near this main tower were a mini-sodar, several sensors that measured the crucial surface temperature, and a surface-layer scintillometer system that also measured the momentum and sensible heat fluxes. Distributed around the main camp at distances up to 5 km away were NCAR PAM (Portable Automated Mesonet) stations that duplicated, over other ice types, the radiation and momentum and sensible heat flux measurements at the main camp. All data were reported as hourly averages for the duration of the experiment.
Despite problems such as sensor riming, camp breakups, leads along the routes to the PAM stations, total darkness for two months, and vandalism by bears and foxes, data returns from both the in-camp and remote instruments are impressive. Although almost four months remain in the experiment, we have already collected at least two orders of magnitude more micrometeorological data than any previous experiment over sea ice. This talk will feature time series of the standard meteorological variables from the several sites, time series of heat fluxes, and flux comparisons from the several sites. We will also focus on the start of the 1998 ablation season, which began suddenly and dramatically in late May after several days of mist and drizzle