HTAP June 2008 WashDC

We are busy planning the Joint TF HTAP/ NAS / AC&C workshop here in Washington DC, 9-13 June. The first two days of this workshop are focused on providing input to a new U.S. National Academy of Sciences study on the significance of the international transport of air pollutants, cosponsored by EPA, NOAA, NASA, and NSF. The NAS panel is currently being formed and the workshop is expected to be their first public meeting. The very dense agenda for this part of the meeting is shaping up nicely.

The second half of the workshop, beginning on Wednesday morning, is focused on planning future analyses under AC&C and TF HTAP. The overall plan is to alternate between plenary sessions and smaller breakout sessions to cover the topics of interest. We have many issues to discuss and many areas of overlapping interest between AC&C and TF HTAP. Before we try to finalize a meeting agenda, I would like to get your feedback on how best to group the topics for discussion. Below (and in the attached Word document that you can mark up) I have suggested 7 sessions that address different sets of topics.

For each of the sessions, the objectives will be to:

• discuss what has been done to date
• discuss possible approaches for additional work
• identify next steps as concretely as possible
• identify individuals that will be responsible for moving the effort forward

There are probably many other ways of combining these topics and there may be issues that I have left out. I am interested to know:

• Have we covered the topics that we need to discuss? Is there something we have left out?
• Are the groupings reasonable?
• If you see your name listed, is this a role you would be willing to play?
• If you do not see your name listed, is there a role for which you would like to volunteer?
• Within each session, are there additional issues that should be discussed or individuals that should be invited to speak?
• Should equal time be allocated to these topics or are some going to need more time than others?
• Which discussions should not be scheduled at the same time (in parallel)? Does one logically follow another?

The 7 sessions I have suggested are as follows:

1. Multidecadal Hindcast

This session will focus on AC&C Activity 1: 20 yr Hindcast and will include discussions of what emissions and observations information will be needed. The session could include presentations on and discussion of the EDGAR-HTAP project, to develop an improved emissions inventory, and retrospective emissions work under AC&C/IPCC. The session could also discuss the NILU effort to develop a reference database of relevant surface observations for model evaluation. Possible speakers and discussion leaders:

• Jennifer Logan, Peter Hess, Martyn Chipperfield (AC&C Activity 1)
• John vanAardenne (EDGAR-HTAP and retrospective emissions work)
• Kjetil Torseth (NILU observations database)

2. Process and Tracer Simulations

This session would examine the results of the HTAP TP (passive tracer) experiments and the design of experiments for AC&C Activity 2: Upper Tropospheric Processes. The session could also consider the results of the comparison of the HTAP base simulations (SR1) with vertical profile observations. Needs for observational data can be discussed to inform the NILU database project. Possible speakers and discussion leaders:

• Jose Rodriguez, Joyce Penner, Celine Mari (AC&C Activity 2)
• Martin Schultz (HTAP TP experiment results)
• Jan Eiof Jonson (HTAP SR comparison to vertical profiles)

3. Aerosol Simulations and Cloud Processes

This session would focus on the most recent results from the HTAP and AEROCOM aerosol simulations and to discuss the design of the next phase of simulations. It would also provide an opportunity to discuss the plans for AC&C Activity 3: Cloud, Aerosol, Chemical Interactions. Possible speakers and discussion leaders:

• Thanos Nenes, Graham Feingold (AC&C Activity 3)
• Michael Schulz (AEROCOM and HTAP SR aerosols)

4. Event Simulations and Observational Campaigns

This session will focus on the design of the HTAP ES set of experiments looking at the ability of current models to simulate the events observed during the ICARTT campaign. It will also involve a discussion of the development of the NASA aircraft observations database. Given that these two efforts are underway but that few results are now available, we may also use this session to discuss how to take advantage of all of the work being done under POLARCAT and associated Arctic campaigns. Possible speakers and discussion leaders:

• Isabelle Bey (HTAP ES ICARTT analyses)
• Gao Chen (NASA aircraft observations database)
• Drew Shindell (HTAP SR results for Arctic)
• Andreas Stohl, Kathy Law (POLARCAT)

5. Impacts of Transport on Air Quality Objectives

This session would begin by discussing the analysis of the HTAP SR simulations with respect to the impacts on the achievement (or exceedance) of air quality objectives (ambient standards). The discussion will focus on the analyses and additional simulations that might be needed to better understand the impact of intercontinental transport on the achievement of air quality objectives. It could also include a discussion of the use of source apportionment techniques and relevant observational data, from long-term surface networks (including chemical speciation information), aircraft campaigns, and satellites, to better understand the relative role of local and regional sources as compared to intercontinental transport. This session may also be a place to discuss advances in adjoint modeling techniques. Possible speakers and discussion leaders:

• Arlene Fiore, Frank Dentener (HTAP SR results)
• Dan Jaffe (Use of observational evidence)?
• Daniel Jacob, Greg Carmichael (Adjoint techniques)?

6. Future Scenarios of Emissions and Climate Change

This session would include a discussion of AC&C Activity 4: Future scenarios: Sensitivities & Uncertainties, as well as other work developing future emission scenarios and examining the effect of climate change on transport pathways. The session would include a discussion of how to construct future emissions and climate scenarios for assessing intercontinental source-receptor relationships for purposes of the HTAP 2010 assessment. The session would include a discussion of Oliver Wild’s work looking at the linearity of HTAP SR results and the ability to project S/R relationships.

Note that for purposes of HTAP 2010, it may not be necessary to have internally consistent emissions-climate scenarios. It may be possible to separate the issues into future climate/meteorological conditions and future emissions inventories and have two separate discussions. Possible speakers and discussion leaders:

• Drew Shindell, Jean-Francois Lamarque (AC&C Activity 4)
• John vanAardenne, Markus Amann (other emissions scenarios work)
• Frank Dentener, Terry Keating, Bill Battye (HTAP Future Emission Scenarios)
• Oliver Wild (HTAP SR linearity tests)
• Peter Hess, Ruth Doherty, Daniel Jacob (Impacts of Climate on Transport)

7. Common Information Needs and Infrastructures

The first objective of this session is to summarize some of the common information (i.e., emissions data, observational data) and infrastructure needs (i.e., data servers, visualization tools, comparable documentation, communication mechanisms) associated with all of the activities discussed in the other sessions. The second objective is to develop a plan to meet these needs, building upon the existing emissions inventory efforts, observational databases, modeling data servers, visualization and analysis tools, and communication mechanisms (wikis, websites, and email lists). Possible speakers and discussion leaders:

• Martin Schultz (HTAP Juelich server, wiki)
• Kees Cuvelier (HemiTap Tool)
• Kjetil Torseth, Gao Chen (observational databases)
• John van Aardenne (emissions databases)
• Rudy Husar (interoperability approaches)