Paris, France    18 June 2001

held back-to-back with the POET/IGAC workshop on
"Emissions of Chemical Species and Aerosols into the Atmosphere".

Agenda

Introduction

This was an unusually successful meeting because it was followed during the remainder of the week by a POET/IGAC workshop entitled “Emissions of Chemical Species and Aerosols into the Atmosphere”. The combination of meetings provided topical reviews on the status of emission inventories and considerable discussion regarding future directions for GEIA.

The GEIA meeting started with presentations regarding recent and upcoming changes to GEIA data bases and was followed by discussions on the future directions of GEIA.

Status of GEIA Inventories

NO_x/SO_x(A):     Benkovitz reported that a 1990 inventory is almost available. Unfortunately, it does not include Corinair data which has proved difficult to obtain. Individual source data (including height of emissions) was requested by several users; this would provide improved consistency between the NO_x/SO_x and CO/CO₂ emissions.

Ship emissions (A):      Corbett indicated that a 2^o x 2^o data base is already available and 1^o x 1^o data will be available in a few months. Consistent results for gases and particulates are included. Monthly gridded data for 1982-1993, based on fuel used in shipping, is being worked on.

VOC and CO (A):       Visschedijk is now in charge of these inventories, replacing Berdowski. CO has been completed for EDGAR and a 1995 inventory will be available shortly.

Black carbon (A):        It was stated that Liousse has produced the most recent data base for this compound and that it should be referenced at (linked to?) the GEIA site.

Primary particles: Benkovitz reported that a paper on sea salt emissions will be submitted shortly. A European inventory on emissions of primary particles already exists on the internet.

CFCs and HCFs (A): McCulloch reminded us that methyl chloroform and HCFC-22 are already available as a part of the reactive chlorine emission inventory and that the emissions of CFC-113 should have a distribution very similar to that of methyl chloroform. The CFC-11 distribution for 1995 should be available next year.

Heavy metals (A):  Data bases for mercury and persistent organic pollutants for the year 1995 should be available by the end of the year.

Supplementary data sets:  The following data sets were requested to be included in GEIA; a distribution for lightning, a climatological distribution of biomass burning (monthly), a dust distribution and a year 2000 global population distribution.

Other requests for inclusion in GEIA:  Algorithms for calculating emissions as a function of exogeneous factors; upper and lower bound estimates on inventories; more extensive radon emission estimates for testing 3D models.

Future Directions of GEIA; Cooperation with Modelers

The afternoon session was devoted to an informative discussion regarding future directions for GEIA. Two new initiatives were discussed at some length: viz. to interact more closely with modelers and to provide not only emission inventories but also general information on other existing emission-related data sets. In regard to the interaction with modelers, especially GIM, the principal suggestion was that GIM and GEIA hold workshops focused on common themes such as “Constraints on emissions based on satellite and in situ observations”.

GIM studies global distributions, global budgets and evaluations of trends over time. This is done by developing and implementation of chemical transport models and by model inter-comparison, e.g. of ozone, CO and NO_x; of SO₄⁼ and precursors; dynamic aerosol modeling. For comparison of the atmospheric transport of the models inventory of radon or SF₆ are very important.

Brasseur observed that GEIA has slowed down a bit the last years, but said there is now less need for a number of updates since the EDGAR datasets are available and widely use. He stressed the need of an overview of what information on emissions is presently available, globally as well as regionally. He noted that GIM was also a bit on hold, that a second round of inter-comparisons was needed and that the link with WRC should be strengthened. Presently, data on emissions are being estimated from field measurements (e.g. BIBEX), inverse modeling and, recently started, satellite data. Therefore, common workshops on emission constraints seem to be a logical new focus for GEIA activities.

Our response to the suggested broadened role for GEIA as an informational data center on emissions was to circulate a sign-up sheet to see if the community would be willing to participate in this task. Over 30 scientists signed up for providing information for the website; a similar number was interested in reviewing information proposed to add to the website. The objectives would be for the GEIA site to provide references to alternative emission inventories or (for national sources) scenarios with comments regarding the strengths or limitations of each and to incorporate data sets plus algorithms (e.g. emission factors) from which emissions could be derived. Many could provide information on NO_x and CH₄, whereas persons signed as reviewer showed a focus on NMVOC, CO, NO_x and aerosols.

Specific Proposals for an Expanded GEIA Site

Corbett suggested that GEIA could allow different emission datasets for one source or compound, like there are different models used in GIM, as long as the origins of the differences are clear. Different versions of an inventory should also be able to be tracked in time. It is important to highlight the trend in time across years. He suggested to periodically write review papers to invite the scientific community to bring in additional or updated information and propose priorities for modifications.

Galbally proposed that additional information brought by others, e.g. activity data or information on seasonality, should be considered as datasets for the GEIA website. GEIA should also provide opportunities for modeling emissions for policy purposes, i.e. provide both scientifically best inventories as well as official emission inventories. He suggested that GIM could be used as an evaluation tool for different emission datasets.

It was suggested that some inventories could be endorsed by GEIA as "best GEIA inventory" and that activities should be started to expand the present central GEIA website and to setup a webpage per compound with this kind of information. For inverse modeling it is very important to make available for national emissions a reference database with basic data, emission calculation functions and spatial correlations.

At the end of the POET workshop Brasseur emphasized this need for dynamic rather than static inventories through which variations on all time scales (diurnal to interannual to future) might be simulated. He also envisioned that the contents of the GEIA site might be broadened still further to include dry deposition information for example and information on combinations of feedbacks which could effect future emissions.

Conclusions of the Meeting

GEIA will:

• provide at the website references to alternative emission datasets with comments; (requires proposals from broader groups and a review of proposed additions);

• attempt to incorporate at the website underlying datasets from which the emissions were derived, viz. activity data, other data, calculation algorithms in case of national sources, and notably seasonal profiles;

• interact more closely with modelers and hold joint meetings with GIM and similar other modeling efforts and seek joint activities;

• provide clear definitions of what is included in the emissions datasets and where atmospheric modeling should start, e.g. primary emissions, extent of (natural) sinks included, dry depositions calculated by atmospheric models;

• attempt to provide trends in emissions:

  • historical trends;

  • seasonality;

  •  interannual changes in subsequent years;

  • (references to) key scenarios for future emissions available on grid, e.g. the IPCC scenarios;

  • more precise labeling of the reference year of the emission inventories. (requires proposals from broader groups and a review of proposed additions).

List of Participants

NAME	INSTITUTIONS	COUNTRY
Kazushi Aranami	Hokkaido University	Japan
Carmen Benkovitz	Brookhaven National Laboratory	USA
Simon Bently	CSIRO Atmospheric Research	Australia
Guy Brasseur	MPI Meteorologie	Germany
Knut Breivik	NILU (Norwegian Institute for Air Research)	Norway
Elaine Chapman	Pacific Northwest National Laboratory	USA
Bill Collins	Met. Office	UK
Emmanuel Cosme	.	France
Derek Cunnold	Georgia Tech.	USA
Stig Dalsyren	University of Oslo	Norway
Frank Dentener	JRC, Ispra	Italy
Gerd Folberth	LSCE	France
Ian Galbally	CSIRO Atmospheric Research	Australia
Claire Granier	CNRS Service d’Aeronomie	France
James J. Corbett	University of Delaware	USA
Svetlana Jagovkina	Suain Geophysical Obs.	Russia
Alexander Kallaur	Meteorological Service of Canada	Canada
Andrzej Klonecki	LSCE	France
Victor Lagun	Artic and Antarctic Research Institute	Russia
Archie McCullouch	University of Bristol	UK
Richard Memard	Meteorological Service of Canada	Canada
Paulette Middleton	RAND	USA
Pauline Midgley	EUREOTRAC	Germany
Jos Olivier	RIVM	Netherlands
Jose Palela	York U.	Canada
Bill Pennell	Pacific Northwest National Laboratory	USA
Jan Pieter Bloos	IMAU, Utrecht University	Netherlands
Nicola Rolfe	University of Cambridge	UK
Rainer Steinbrecher	IFU	Germany
Antoon Visschedijk	TNO-MEP	Netherlands