Global Modelling of Arctic Sea-ice Cloud Feedback

The figure below shows a feedback loop, which may be important in the Arctic: rising temperatures will further decrease the sea ice extent. This may increase aerosol emissions from the ocean (sea salt, marine primary organic matter) and from ships (black carbon, organic carbon, sulphate). Some of these aerosols act as CCN and/or IN, and thus impact clouds. In addition, clouds are influenced by changes in specific humidity and temperature. Since both aerosols and clouds interact with radiation, they will feedback on Arctic temperatures.
We use the global climate model ECHAM6-HAM to analyse this feedback. The model is coupled to a mixed-layer ocean model to allow some interactions between the atmosphere and sea surface temperatures. In addition, enhanced future shipping activity related to transit shipping and to oil and gas production is considered.