22 January, 2007NACP investigators’ meeting, Colorado Springs, CO NACP breakout group: Atmospheric Measurements and Analyses: Full notes Room: Cheyenne I Time: Monday, 3-5pm

22 January, 2007NACP investigators’ meeting, Colorado Springs, CO SUGGESTED TOPICS FOR DISCUSSION. Joe Berry: Analysis of NAcarbon requires global co2 info for boundary conditions. Carbon tracker is one possible source, but depends on input data for quality. Need global perspective to evaluate namerican data quality. Adam: transport model dependence as well. Britt Stephens: what data do we need and how to we access it? Pieter Tans: Fossil fuel quantification from air will be hard, but it is the biggest net flux. This is a focal point, at least initially, so that the rest can work well. – and it is important and the best known. Order of magnitude increase in 14C, halocarbon measurements, for example, would help. (See Miller poster.) Scott Denning – availability, QC, etc, of the entire range of atmospheric measurements that are available. Adam Hirsch – are there regions of the continent that need more observational density? Paul Wennberg - More free tropospheric CO2 data? How to prioritize observations? Scott Denning – atmospheric transport products to share? Models and model output to share? John Miller – what data centers do we have/do we need? Lin Huang – uncertainty characterization for measurements, fluxes.

22 January, 2007NACP investigators’ meeting, Colorado Springs, CO Optimization of observations Prioritizing the observational network is dependent on the questions being asked. –More species for fossil fuel characterization, e.g. –Can we define a process to guide our observational choices? First question – what is the atmospheric carbon budget over north america? What can we do already re: nacp science goals? What can’t we yet do, and what do we need to do to get there? NEON? Co, co2, maybe ch4, 13C, 18O, but no 14C. All short. Proposal: Put together a white paper on the benefits of trace gas measurements for distinguishing source/sinks? Second design question – location of measurements. Third design question – how to identify near vs. far field influence (far = e.g. outside of continent). Make carbon tracker happen to bring in other money. Obvious things that would be good: –Some emphasis on non-co2 tracers. Precisely what needs to be refined. –Build out of the tall tower network, continuity of existing atmospheric measurements. –More continuous co2 observations over the continent in the ABL. Complemented by flasks. (how many more?) –More free tropospheric co2 sampling. (how much more?) Optimal network design activities to be pursued. MCI is designed as a test bed to evaluate network design. Model/pseudodata activities. Potential experiments: –Lagrangian airmass tracking experiment? Use existing experiments of that sort? –Horizontal transects on aircraft at multiple levels. Focus on low level flights – ABL. –Commercial aircraft gas measurements? – particularly over oceans to get the ‘far field?’

22 January, 2007NACP investigators’ meeting, Colorado Springs, CO Potential experiments, continued. –Use COBRA 2003/2004 and INTEX transects that exist to evaluate this question. –Use ‘ring’ oversampling experiments to this end as well. –Urban intensive experiment? Merge with the interest in better characterizing fossil fuels, langrangian? – air quality experiments from NOAA Aeronomy – mine old data. Gurney project – Indianapolis – may happen shortly? Tap Dept of HomelandSec for interest in urban environment/transport there. (they know we mentioned them.) –Long distance air pollution transport studies should be tapped for transport understanding. –International polar year – starts March 2007 – nacp benefit from that work? (need someone knowledgeable to look into this?) –In general team with air quality experiments to save resources. OCO evaluation work with ground-based/airborne data? What exists for ongoing OCO evaluation. Current evaluation is based on FTS vs. OCO. Sufficient? Faster than annual data posting.

22 January, 2007NACP investigators’ meeting, Colorado Springs, CO Data centers/sharing needs. There is no thematic data center for atmospheric measurements. There is an NACP data policy for sharing measurements that requires sharing. Arlyn doesn’t want a second copy of data out so that versions can cause confusion if updates don’t happen readily. Different data sources, linked? But these can be hard to merge – different formats, etc. Carbon Tracker merges all data sets into one center? Eventual carbon reanalysis product? But different data sources (e.g. aircraft) have different intrinsic formats and are hard to standardize. Obvious agreement –Standardize formats as much as possible, and have a site to point to sources. Include flagging methods/standards in this. –Carbon tracker provides some more potential for synthesizing stationary data sources

22 January, 2007NACP investigators’ meeting, Colorado Springs, CO Data centers/sharing needs. model output. Back trajectory calculations from a defined set of towers – merge and compare back trajectories from various groups. Make them available for others to use and evaluate. Define a group to work towards sharing this. What other model output could be made available/shared/compared? Model input What common inputs can we pool/put in data centers? Reanalysis data – transport, weather data. We must be certain that we have this. Can we get ECMWF too? models Is this too hard? Work towards it. See climate modeling effort below. Do we need a thematic data center for the above? This is MAST-DC. We must talk with them about this. Identify sources that we need, and go to MAST-DC. Outcome-based evaluation – have a data center that allows a single PI to do ensemble transport analysis. History/example: Program for climate modeling diagnostics and intercomparison. Funded, ongoing program.

22 January, 2007NACP investigators’ meeting, Colorado Springs, CO Data centers/sharing needs. Mci should foster intercomparison of models mcimip Transport model tests.

22 January, 2007NACP investigators’ meeting, Colorado Springs, CO Community meeting/workshop activities to make this proceed. Trace gas measurement recommendation/white paper. Back trajectory/influence function comparison activity. Start with discussion and telecon. Go beyond basic transport, expand to get feedback from data users. E.g., what does MCI need? Similar comparison activities for other atmospheric transport/analysis tools. Meeting/discussion to decide who will host a co2/trace gas data center - virtual data center. MAST-DC discussion towards creating a common site to link to all tools/data needed for a typical top-down atmospheric analysis. ‘one stop shopping’ Optimal design studies – working group of investigators to decide how best to proceed. Must first define the question of interest. Start with namerican flux diagnosis. This will be iterative. There should be funding for this. Optimal human interaction design study – do we need annual NACP meetings? Periodic, but not necessarily annual? We should define purpose for the next meeting – gather results – feed in results. Include stakeholders. Interaction with stakeholder community should be initiated? Avoid having the political decisions be decoupled from science – initiate interaction.