The Ninth International GEIA Workshop was held at the University of Washington, Seattle, Washington (USA) 19-20 August 1998. It was held back-to-back with the Joint International Symposium on Global Atmospheric Chemistry (CACGP/IGAC 1998 Symposium), Seattle, Washington, 19-25 August 1998. The joint symposium comprised the Ninth Symposium of the IAMAS Commission on Atmospheric Chemistry and Global Pollution (CACGP) and the Fifth Scientific Conference on the International Global Atmospheric Chemistry Project (IGAC).
Much of the GEIA Workshop was devoted to presenting and discussing the proposed GEIA work plan for 1998-2000 and prioritizing the objectives. The workshop was attended by approximately 25 scientists.
The proposed GEIA work plan was outlined at the Eighth GEIA Workshop, which was held in Bilthoven in 1997. Draft documents describing a GEIA science plan, a data management plan and a business plan were prepared respectively by Jozef Pacyna, Paulette Middleton and Ann McMillan prior to the Seattle meeting. The main activity at the Seattle meeting was to review these plans and to agree on priorities for the next few years.
The GEIA Science Plan was presented by Carmen Benkovitz. There was consensus that the following items should receive the highest priority:
These priorities were established partly on the basis of surveys of users of the GEIA and the EDGAR data bases conducted by Paulette Middleton and Jos Olivier respectively. The results, based on approximately 60 responses, were reported by Jos Olivier. Users typically requested inventories for more compounds, uncertainty assessments, seasonal/monthly inventories and inventories for additional years.
One suggestion was to base uncertainty estimates on several independent estimates of the emissions of a single compound. Another suggestion was to try to derive these from comparisons of three-dimensional model calculations (including inverse modeling) and simultaneous atmospheric measurements of several gases. It was recognized that it is going to be difficult to provide realistic uncertainty estimates but that this is an important need.
From a modeling viewpoint, there is a need to have the inventories subdivided into the various sources of emissions (sectoral breakdown) as well as to estimate monthly or seasonal cycles in the emissions. This information allows improved interpretation of the measurements (e.g., particularly isotopic measurements) and testing of the estimated emissions. For fairly short-lived species such as CO, it is needed to calculate the species distributions in chemical models. Other related items of lower priority which were discussed included obtaining inventories on an even finer spatial distribution than on a 1 degree x 1 degree grid. Such a breakdown is not usually requested by global modelers but it could be useful for regional modelers (up to this time regional modelers have not had much interaction with GEIA). For political considerations, emission estimates for individual countries are needed; it was felt that this need could be met if software is applied to the 1 degree x 1 degree inventories, or alternatively if country breakdowns are provided as auxiliary data sets (as used for the preparation of the gridded inventories). Related data sets with country emissions may also be relevant for a number of scientific applications.
A need was recognized for inventories to be updated (from 1990 to 1995, for example). This was added to the priority list, but requests for historical or future emissions were regarded as having lower priority. Finally, there was a request that the GEIA data base also include models describing how natural emissions might respond to changes in temperature or soil moisture, for example. This information would be very valuable for climate change studies. Although there is nothing in this area in the current data base, this was recognized as an important community need.
The GEIA Data Management Plan was prepared and presented by Paulette Middleton. It was recognized that, in addition to the need to provide a critical mass of GEIA inventories, the essential feature of any data base is that it be of high quality. To ensure this, the following additional interactions between data base managers and users and providers were recommended:
Two significant changes in the inventory acceptance procedures were established: preliminary inventories can become part of the GEIA data base and the GEIA Web Site will provide pointers to non-GEIA inventories. The latter change can make the GEIA site more attractive as a starting point for searching international emission inventories and related data. It was recognized that GEIA will have less control on data quality with this change but it was noted that non-GEIA inventories would be clearly marked and would be clearly recognizable by their differences in format.
There was also discussion of additional data base services which GEIA could provide and for which there have been requests from the user community. These include
Most of these services cannot be provided with current funding. Therefore it was felt that connections with the data processing needs of other IGAC programs (as well as those of other international scientific programs) should be pursued with the hope that there may be data centers which are currently providing these sorts of services and which might welcome additional data bases. GEIA also will be seeking supplemental funds to carry out some of these important data services.
Finally, the GEIA data processing plan recognizes the need to support data base publicity efforts by assembling a GEIA presentation package.
The GEIA Business Plan was authored and presented by Ann McMillan. The Business Plan focuses on:
To make the data base as comprehensive as possible, a survey of inventory study groups was proposed. This survey would seek to determine some details about the inventory and its expected completion date and whether any additional resources or funding might be needed in order to complete the inventory. It would be primarily the responsibility of the Business Planning committee to assemble the GEIA publicity package. Additional interactions with the international community would be sought in order to obtain input from Asian scientists, for example, on the inventories and to attempt to identify possible sources of funding.
Finally, an updated GEIA work plan for 1998 to 2003 was presented by Jos Olivier. The timetable includes the completion of the three GEIA plans in 1998 and the addition of inventories of the identified highest priority gases next year. It was proposed that many more inventories and provision of the uncertainty estimates be completed in 2000. All GEIA inventories currently in progress are expected to be completed by 2003.
The GEIA and CACGP/IGAC meetings were followed by an IGAC Scientific Council Meeting which was attended by both GEIA co-conveners. In addition to reviewing the various IGAC sub-committee activities (and Dr. Brasseur expressing his pleasure at the recent activities of the GEIA organizing committee), there was a lengthy discussion of an IGAC integration and synthesis report. This report would summarize GEIA achievements and indicate future plans. One other discussion with particular relevance to GEIA concerned the archiving of the scientific results of IGAC activities (e.g., the emission inventories). It was felt that this topic was of interest to almost all IGAC activities and to other similar scientific organizations. As representative of GEIA, Dr. Olivier volunteered to represent IGAC on data center/archival issues and to investigate how world (or regional) data centers might support IGAC (and GEIA) activities.