Dominic J. Salisbury

Warm-air advection, air mass transformation and fog causes rapid ice melt

Direct observations during intense warm-air advection over the East Siberian Sea reveal a period of rapid sea-ice melt. A semistationary, high-pressure system north of the Bering Strait forced northward advection of warm, moist air from the continent. Air-mass transformation over melting sea ice formed a strong, surface-based temperature inversion in which dense fog formed. This induced a positive net longwave radiation at the surface while reducing net solar radiation only marginally; the inversion also resulted in downward turbulent heat flux. The sum of these processes enhanced the surface energy flux by an average of similar to 15Wm(-2) for a week. Satellite images before and after the episode show sea-ice concentrations decreasing from > 90% to similar to 50% over a large area affected by the air-mass transformation. We argue that this rapid melt was triggered by the increased heat flux from the atmosphere due to the warm-air advection.

Global distribution and seasonal dependence of satellite-based whitecap fraction

We present the first study of global seasonal distributions of whitecap fraction, W, obtained from satellite-based radiometric observations. Satellite-based W incorporates variability from forcings other than wind speed and can capture differences in W in initial and late lifetime stages. The satellite-based Wis more uniform latitudinally than predictions from a widely used wind speed-dependent parameterization, W(U10), formulated from in situ observations, being on average higher than the W(U10) predictions at low latitudes and lower at middle and high latitudes. This difference provides an explanation for the consistent geographical biases in sea spray aerosol concentration found in a number of large-scale models. Satellite estimates of W would benefit air-sea interaction and remote sensing applications that use parameterizations in terms of W such as sea spray flux, gas transfer, and surface winds.

Atmospheric conditions during the Arctic Clouds in Summer Experiment (ACSE) : Contrasting open-water and sea-ice surfaces during melt and freeze-up seasons

The Arctic Clouds in Summer Experiment (ACSE) was conducted during summer and early autumn 2014, providing a detailed view of the seasonal transition from ice melt into freeze-up. Measurements were ...

Direct determination of the air-sea CO2 gas transfer velocity in Arctic sea ice regions

The Arctic Ocean is an important sink for atmospheric CO2. The impact of decreasing sea ice extent and expanding marginal ice zones on Arctic air-sea CO2 exchange depends on the rate of gas transfe ...