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Joint TFHTAP and WMO Workshop on
Integrated Observations for Assessing Hemispheric Air Pollution

World Meteorological Organization Headquarters
7bis Avenue de la Paix
Geneva, Switzerland
24-26 January 2007


Atmospheric air chemistry observations play an important role not only in assessing the impacts of air pollution on human health, ecosystems, agriculture, weather and climate, but also in assessing quantitatively the contribution of one source region on another. In the last decade, it has become apparent that air pollution issues, once thought to be mainly regional in scope, are in fact hemispheric in nature. This is caused by the long-range transport of air pollution from continent to continent, over oceans (Pacific, Atlantic and Arctic), as well as across large landmasses such as Eurasia. A key application of observations is in the evaluation of chemical transport, weather and climate models used for understanding the contributions of sources when assessing policy options to mitigate negative impacts. Integrating observations from different observational platforms is a powerful and cost-effective way of achieving these goals.

The UNECE CLRTAP Task Force on Hemispheric Transport of Air Pollution (TF-HTAP) is joining with the Global Atmosphere Watch (GAW) programme of WMO to bring experts together to better coordinate observations and their applications. This is being organised in co-ordination with the Group on Earth Observations (GEO), as it contributes to the better definition of the Global Earth Observation System of Systems (GEOSS). The workshop follows two organized by the TF-HTAP held in 2006, on modelling and on emissions needed for such models. This workshop completes the picture by focussing on observational evidence of long-range transport and observations needed for model evaluation today and in the future. Representatives from many national and international co-operative observational programmes will be invited to participate and contribute. The agenda includes invited speakers, poster presentations and discussions.


  • To take stock of the current state of surface-based, aircraft and satellite observations relevant to: (i) hemispheric transport studies supporting the 2007 and 2009 assessments being conducted by the TF-HTAP under the UN-ECE LRTAP Convention, (ii) WMO weather, climate and environmental prediction applications and (iii) to the Societal Benefit Areas of GEO.
  • To determine the gaps inn observations for priority air pollutants, gaps in data management, and make recommendations on how to fill those gaps taking into account ongoing efforts under regional networks, GAW, IGACO, and the development of the GEOSS.
  • To identify ways to produce a common data base of observations suitable for evaluation of models and inventories for priority air pollutants, such as ozone and particulate matter and precursors thereof.
  • To recommend steps needed to create co-operative structures between regional observation networks and other sources of data.
  • To identify short-term and long-term effforts that will improve the information technology infrastructure for sharing relevant observational data and integrating observational data with modelling for purposes of evaluation and improved data assimilation for air quality forecasting.
  • To further encourage the particcipation of developing countries in long range air pollution observation systems


A joint workshop report will document in technical report series of the various programmes the recommendations of the working groups and short summaries of the presentations. This will support the 2007 Interim Assessment of the TF-HTAP, the 2008-2015 Strategic Plan for the WMO-GAW programme and the GEOSS 10-Year Implementation Plan.