NOTE: Not all PDFs are available yet.

Monday Nov. 5th - State of Understanding

PPT - PDF - Trish Quinn (NOAA PMEL) Summary of our State of Understanding

PPT -PDF - Carl Egede Bøggild (University Center of Svalbard) Threatened Ice Sheet Integrity

PPT - PDF - Dorothy Koch (NASA GISS) GCM study comparing aerosol direct, indirect, and BC-albedo effects on Arctic climate

PPT - PDF - Surabi Menon (Lawrence Berkeley National Lab) Aerosol Indirect Forcing from the Climate Model Perspective

PPT - PDF -Tim Garrett (University of Utah) Associations between pollution and the effects of clouds on the Arctic LW and SW surface radiation balance

PPT - PDF -Christoph Ritter (Alfred Wegener Institute) Direct thermal radiative forcing of tropospheric aerosols

PPT - PDF - Gunnar Myhre (University of Oslo) Radiative forcing due to BC on snow and ice and the direct aerosol effect of BC in the Arctic

PPT - PDF - Mark Flanner (NCAR) Black Carbon – Snow Albedo: Mechanism and uncertainties in measurements and models

PDF - Drew Shindell (NASA GISS) The sensitivity of Arctic climate to regional forcings and emissions

- Discussion on State of Understanding

This first day of the workshop is designed to 1) describe how the forcing and temperature response by the short-lived pollutants currently are modeled and/or measured, 2) summarize the most up-to-date results concerning the impact of the short-lived pollutants on Arctic climate, and 3) outline new approaches and research directions required for successful mitigation strategies. Discussion topics include, but are not limited to:

• What modeling uncertainties are the largest and what measurements are needed to help reduce them? (See Table 1 of the ACP paper for relevant forcing agents and mechanisms.) This question applies to chemical transport models providing aerosol and gas phase distributions, climate models, and emission inventories.

• What is the best way to define the forcing and temperature response due to the short-lived pollutants in order to assess their relative climate impacts and identify “smoking guns”? For example, seasonal averages do not capture the response due to episodic, intense events; transient simulations do not allow for equilibration with the warming overlying atmosphere; Arctic-specific efficacy; fixed SST forcing…..The goal is to make Table 1 (or Figure 2) of the ACP paper an apples-apples comparison.

• What is the relative importance of local vs. extrapolar forcings due to short-lived pollutants in driving the surface temperature response within the Arctic?

• What mechanisms/feedbacks come into play due to the combination of forcings from all pollutants? What is the impact on the temperature response?

Tuesday Nov. 6th – Emerging Issues

PPT - PDF - Andreas Stohl (NILU) Boreal Forest Fires

PPT - PDF - Eric Williams (NOAA CSD) Arctic shipping activity

- Joseph McConnell (Desert Research Institute) Sources of BC that is deposited to snow

PPT - PDF - Tom Grenfell (University of Washington) Pan-Arctic black carbon snow sampling

PPT - PDF - Alex Kokhanovsky (University of Bremen) Observations of snow albedo and aerosol optical thickness from space

PDF - Drew Shindell (NASA GISS) Potential for mitigation of Arctic warming via ozone precursor emissions

PPT - PDF - Kathy Law (CNRS) Ozone reduction strategies

PPT - PDF - Kristin Rypdal (CICERO) BC Mitigation strategies

- Discussion on Emerging Issues

The second day of the workshop is designed to identify emerging factors that will influence the climate impact of short-lived pollutants near-term and in the more distant future. The goal is to take this new information, combine it with the background information and discussions from yesterday, and 1) develop strategies for optimizing IPY research on short-lived pollutants and Arctic climate and 2) begin developing mitigation strategies and recommendations for policy makers. Discussion topics include, but are not limited to:

• How are Arctic and sub-Artic sources expected to change with a warming of the Arctic (e.g., opening of waterways, disappearing permafrost, increase in frequency and intensity of boreal forest fires)? What will be the impacts on climate? What do these changes mean for successful mitigation strategies?

• What measurements are needed to identify sources (local and extra-polar) of Arctic aerosols?

• What does the importance of local vs. extra-polar forcing dictate about targets for emissions reductions? [Answer may depend on forcing agent].

• What strategies involving the short-lived pollutants are available to delay the onset of spring melt?

Wednesday, Nov. 7th – Recommendations for Policy Makers

Open Discussion Session

The goal of this discussion period is to finalize future research needs for the IPY time period and beyond, to provide continued synthesis of scientific understanding and to formalize recommendations for policy makers. The synthesis and recommendations will be presented and discussed at the policy meeting that will take place Nov. 7th and 8th.

Policymakers have posed the following series of questions. Our collective work will help inform the state of understanding and research needs at very least for questions 1 and 2.

1. What is the relative impact – climate forcing – of a specific Arctic pollutant?

2. What are the exact sources of that pollutant?

3. How can that pollutant be controlled?

4. What will those controls cost, and what will be the benefit for the Arctic climate?

A final exercise for the group will be to determine what disciplines need to be included (alternatively what disciplines were missing at this meeting) to get a full understanding of how short-term climate forcers could be impacting Arctic temperature and melting and to solicit suggestions for how best to bring together this expertise.