2416 December 2004
IGOS Atmospheric Chemistry Theme
Integrated Global Atmospheric Chemistry Observations (IGACO)
Implementation Up-date Dec 2004
2416 December 2004
Leonard Barrie
Atmospheric Research and Environment Programme
World Meteorological Organization
7 bis, avenue de la Paix, BP2300,CH-1211 Geneva, Switzerland
Email:
Jörg Langen
Earth Observation Science and Applications Department
ESA-ESTEC, POB 299, NL-2200AG Noordwijk, The Netherlands
Email:
2416 December 2004
On 27 May 2004, the IGOS-partners approved the Atmospheric Chemistry Theme Report assessing the past, present and future current state of global air composition observations, the requirements and priorities in the next 15 years for Integrated Global Atmospheric Chemistry Observations (IGACO) (see Figure 1). The IGACO report prepared by an expert international group convened by the World Meteorological Organization (WMO) and the European Space Agency (ESA) was reviewed independently by eminent scientists including two nobel prize winners. IGACO is a highly focused strategy for bringing together ground-based, aircraft and satellite observations of 13 chemical species in the atmosphere using atmospheric forecast models that assimilate not only meteorological observations but also chemical constituents. Socio-economic issues related to climate change, ozone depletion/ UV increase and air quality benefit by having such a system in place.
The IGACO report critically assesses, the requirements on accuracy/precision and spatial/temporal resolution, and the current state of modelling chemical cycles in forecast and climate models. It recommends specific steps to be taken in a phased approach over the next 15 years led by the WMO Global Atmosphere Watch (GAW) programme in cooperation with other key WMO programmes, the space agencies and the global air chemistry/meteorology/climate research community.
In June 2004, the IGACO approval by IGOS and suggestion for WMO lead in implementation was presented to the WMO Executive Council by the President of the WMO Commission on Atmospheric Science (CAS). Implementation involves utilizing the over-arching plan of IGACO to build the system through key collaborative initiatives supported regionally but having global implications. Maintenance of existing observations, addition of key missing observations and development of mechanisms that glue the system together are major but feasible challenges. IGACO is a framework through which atmospheric composition observations can be integrated using research and operational atmospheric models to contribute to the goals of IGOS-partners and the planned Global Earth Observations System of Systems.
A tentative organizational structure for the implementation that is currently under consideration brings specific bottom-up activities supported at the national, regional and international level together with top-down support at the highest level. Already major European, North American and Asian and southern hemispheric initiatives are being informed of IGACO and mutually beneficial activities explored.