Arctic ice clouds and polluted air masses over

Interactive comment on “On the relationship between Arctic ice clouds and polluted air masses over the north slope of Alaska in April 2008” by C. Jouan et al

On the relationship between Arctic ice clouds and polluted air masses over the North Slope of Alaska in April 2008

Recently, two types of ice clouds (TICs) properties have been characterized using the Indirect and SemiDirect Aerosol Campaign (ISDAC) airborne measurements (Alaska, April 2008). TIC-2B were characterized by fewer (< 10 L−1) and larger (> 110 μm) ice crystals, and a larger ice supersaturation (> 15 %) compared to TIC-1/2A. It has been hypothesized that emissions of SO2 may reduce the ice nuclea...

Interannual Variations of Arctic Cloud Types in Relation to Sea Ice

Sea ice extent and thickness may be affected by cloud changes, and sea ice changes may in turn impart changes to cloud cover. Different types of clouds have different effects on sea ice. Visual cloud reports from land and ocean regions of the Arctic are analyzed here for interannual variations of total cloud cover and nine cloud types, and their relation to sea ice. Over the high Arctic, cloud ...

Suppression of Arctic Air Formation with Climate Warming: Investigation with a Two-Dimensional Cloud-Resolving Model

Arctic climate change inwinter is tightly linked to changes in the strength of surface temperature inversions, which occur frequently in the present climate as Arctic air masses form during polar night. Recent work proposed that, in a warmer climate, increasing low-cloud optical thickness of maritime air advected over highlatitude landmasses during polar night could suppress the formation of Ar...

Supersaturation, dehydration, and denitrification in Arctic cirrus

A polar cirrus case study is discussed with the help of a one-dimensional model with explicit aerosol and ice microphysics. It is demonstrated that continuous cooling of air in regions with small amounts of ice and slow ice deposition rates of water vapor drives significant in-cloud supersaturations over ice, with potentially important consequences for heterogeneous halogen activation. Radiativ...