1. SAG Precipitation Chemistry/Total Atmospheric Deposition Report for EPAC SSC Meeting 18-20 February, Geneva Rick Artz and Silvina Carou

2. Outline Accomplishments – Development of the Guidance Manual – Laboratory Intercomparison Study – Publication of a Global Assessment of Precipitation Chemistry and Deposition Future direction – Expanded focus – Sentinel sites – Collaboration with other SAGs/communities

3. Page 3 – January 22, 2014 Manual for the GAW Precipitation Chemistry Programme Provides guidelines, quality objectives and standard operating procedures for precipitation chemistry measurements. Strong resonance throughout the global community. Has led to upgraded operations, improved quality, requests for audits, and within-country network upgrades. Updated edition will be available in about a year. Content 1.Introduction 2.Siting 3.Field Protocols 4.Laboratory Operations 5.Data Management 6.Quality Control and Quality Assurance

4. By activating this tab, Lab Managers can log in with a User Name and Password. Conducted twice annually by the QA-SAC Americas Designed to track the performance of laboratories 51 studies have been completed Period of electronic record covers 1985 through present ~ 80 participating laboratories from around the world Results are made public via the data center website Provides a portal for data submission for participating laboratories GAW Laboratory Intercomparison Study

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6. A Global Assessment of Precipitation Chemistry and Deposition of Sulfur, Nitrogen, Sea Salt, Base Cations, Organic Acids, Acidity and pH, and Phosphorus Objective: To review and assess the state of the science of precipitation composition and deposition on global and regional scales. Key Science Questions: What are the global and regional spatial patterns of major ions in precipitation and wet, dry and wet+dry deposition? Has wet deposition of major ions changed since 2000 (and/or 1990)? What are the major gaps and uncertainties in our knowledge? R. Vet, R. Artz, S. Carou, M. Shaw, C.-U. Ro, W. Aas, A. Baker, V. Bowersox, F. Dentener, C. Galy-Lacaux, A. Hou, J. Pienaar, R. Gillett, M. C. Forti, S. Gromov, H. Hara, T. Khodzher, N. Mahowald, S. Nickovic, P. Rao, N. Reid

7. Global Assessment of Precipitation Chemistry and Deposition Approach Period: 2000 to 2007 with a focus on two 3-year averaging periods: 2000- 2002 and 2005-2007 Spatial Scales: Global and Regional (Africa, Asia, Oceania, Europe, North America, South America, Oceans) Method: Combined measurement and modelling results Data : measurements from > 470 regionally-representative non-urban sites from regional and national wet deposition monitoring networks ensemble mean model results from 39 global models from the HTAP 2001 Model Intercomparison Client Science Communities Atmospheric, biogeochemical, aquatic and terrestrial effects, critical loads, human health, nutrient cycling, chemical transport modelling.

9. Outline Accomplishments – Development of the Guidance Manual – Laboratory Intercomparison Study – Publication of a Global Assessment of Precipitation Chemistry and Deposition Future direction – Expanded focus – Sentinel sites – Collaboration with other SAGs/communities

10. Expanded Focus: Total Atmospheric Deposition

12. Establishment of sentinel sites “Strategic approach to monitoring is required for future improvements to estimating global deposition.” (Vet et al., 2014) Focus on increasing spatial coverage of long-term global deposition monitoring sites in key locations in under-represented regions. SAG-TAD will work with regional organizations and programmes (e.g., DEBITS) to seek funding and implement sentinel global sites.

13. Linkages with other SAGs and science activities Development of a robust method for estimating dry deposition requires collaboration with Aerosol and Reactive Gases SAGs. o Proposed one-day workshop at Acid Rain 2015. Future progress relies on measurement/model fusion techniques to produce global maps of total deposition. o SAG TAD will develop an action plan and identify collaborators from the modeling community.

14. Additional slides

15. Page 15 – January 22, 2014 SAG TAD Succession Plan RoleResponsibility Representing Chair Scientific understanding of deposition, international expert, strategic guidance/oversight, labor and funding resources to contribute, management capabilities. Global View Strategic and scientific goals of the SAG- PC including outreach, communication and linkages to other scientific communities and programs. WMO Secretariat Ex Officio member: link between WMO and the SAG WMO/GAW Programme World Data Centre for Precipitation Chemistry and QA SAC Ex Officio member: link between measurements, QA/QC, data archiving and data dissemination Illinois State Water Survey Major Monitoring Networks with Expertise, Funding, Personnel and Resources Ex Officio members: Expert advice on existing and new measurement methods (field, laboratory, QA/QC, data management) and results USA - NADP Canada – CAPMoN Europe - EMEP Asia - EANET / China Major International Science Programs Links to large international programs, provide advice and guidance to GAW from those programs, influence program scientists/projects to adopt GAW methods and standards DEBITS EMEP Science Experts - with Resources to assist in GAW activities Wet and Dry Deposition scientific expertise, advice, guidance and project execution Modeller – Global CTM advice, guidance and activity linking the CTM modelling community to the wet and dry measurement community Wet, dry and total deposition Global CTM Modelling Community Regions with Inadequate Monitoring Monitoring/scientific experts with influence and capability to implement monitoring programs in sparsely monitored areas South America Russia Expert ObserversNon-members: Observers and special project experts asked to collaborate on specific projects as needed Wet Deposition, Dry Deposition, Total Deposition, Metals, POPS, Mercury, Nutrients (P, N, C), Ecosystem Health/Critical Loads

16. Page 16 – January 22, 2014Page 16 – January 15, 2014 Status of major regional monitoring networks as contributors to GAW NetworkContributorFormal agreement National Atmospheric Deposition Program (NADP) Yes Clean Air Status and Trends Network (CASTNET)Yes Canadian Air and Precipitation Monitoring Network (CAPMoN) YesNo European Monitoring and Evaluation Program (EMEP) YesNo East Asia Network (EANET)No Deposition of Biogeochemically Trace Species (IGAC/DEBITS) NoIn progress Nitrogen Cycling network in South America (Nnet) NoFuture