The Impact of Black Carbon on Arctic Climate - Atmospheric Chemistry

7. Mechanisms <strong>of</strong> Arctic climate forcing by black carbon ................................................................... 45
7.1. Atmospheric forcing ................................................................................................................................................... 45
7.2. Indirect and semi-direct atmospheric forcing ................................................................................................... 48
7.3. Snow and ice forcing .................................................................................................................................................. 48
7.4. Dynamical influence on response to forcing ..................................................................................................... 49
7.5. Summary ......................................................................................................................................................................... 49
8. Linking sources to Arctic radiative forcing ................................................................................................ 50
8.1. Introduction to modeling studies conducted for this report ....................................................................... 50
8.2. Emissions used .............................................................................................................................................................. 51
8.3. Model description ........................................................................................................................................................ 52
8.4. Model results ................................................................................................................................................................. 52
8.4.1. Contribution to change in BC burden .............................................................................................................. 52
8.4.2. Contribution to RF in the Arctic ......................................................................................................................... 53
8.4.3. RF per unit emission ............................................................................................................................................ 56
8.4.4. RF by latitude <strong>of</strong> emissions ................................................................................................................................. 57
8.4.5. RF due to projected increases in global and Arctic shipping ...................................................................... 57
8.4.6. Relation between RF and temperature change .............................................................................................. 58
9. Summary findings on impacts <strong>of</strong> black carbon on Arctic climate and
relevance to mitigation actions ........................................................................................................................ 60
10. Information and science needs ....................................................................................................................... 61
10.1. Recommendations for improved characterization <strong>of</strong> spatial and vertical distribution <strong>of</strong>
BC and OC in the Arctic environment and deposition processes ............................................................ 61
10.2. Recommendations for emissions information ................................................................................................ 62
10.3. Recommendations for model development, evaluation and application ............................................ 62
References .............................................................................................................................................................................. 63
Abbreviations ....................................................................................................................................................................... 70
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