The subject of the session will be the chemistry and the physics of short lived climate forcers (SLCF; black carbon, methane and ozone) in the Arctic atmosphere. The chemistry and physics of these species have been intensely studied at lower latitudes but in the Arctic their dynamics are still connected with large knowledge gaps and uncertainty due to the special Arctic conditions. Polar night represent one extreme condition with 24 hour darkness during polar winter leading to a very stratified troposphere and no photochemistry. Thereafter it is followed by another extreme situation with 24 hour-sunlight during polar summer. During this period special surface processes occur, where those related to halogen chemistry are most notable.
In the present session scientist are invited to submit their newest knowledge on SLCFs in the Arctic atmosphere.