WORKSHOP ON MEASUREMENT-MODEL FUSION for GLOBAL TOTAL ATMOSPHERIC DEPOSITION (MMF-TAD)

GLOBAL ATMOSPHERE WATCH SCIENTIFIC ADVISORY GROUP ON TOTAL ATMOSPHERIC DEPOSITION (SAG-TAD)

World Meteorological Organization,

Geneva, Switzerland

February 28 – March 2, 2017

Workshop Objectives:

To review the state-of-the-science and establish aGlobal Atmosphere Watch (GAW) project on Measurement-Model Fusion ofGlobal Total Atmospheric Deposition for the purpose of generatingglobal mapsof total atmospheric depositionand ambient gases and particle species.

Background

The Global Atmosphere Watch (GAW)Scientific Advisory Group for Total Atmospheric Deposition (SAG-TAD) has a mandate to produce global maps of total atmospheric deposition for a number of important atmospheric chemicals. The most suitable scientific approach for this activity is the emerging techniqueof measurement-model fusion for total atmospheric deposition (MMF-TAD). This technique requires global-scale measurements of atmospheric trace gases, particles, precipitation composition and precipitation depth, as well as predictions ofglobal/regional chemical transport models. The fusion of measurement and model results requires objective analysis and mapping techniquesthat are also applicable to the production of global maps of selected reactive gases, aerosols and wet and dry deposition.

MMF-TAD projects are currently being carried out in Sweden, the United States and Canada. The methodology employed by each country is different and not necessarily applicable on a global scale. To assess the feasibility and establish a path forward for a SAG-TAD project on global measurement-model fusion, a group of experts will be convened to discuss relevant MMF-TAD techniques and global measurements and modeling. These experts will include the Chairs or representatives of other Scientific Advisory Groups of the Global Atmosphere Watch.

The workshop will explore the feasibility and methodology of producing, on a routine retrospective basis, global maps of atmospheric gas and aerosol concentrations as well as wet, dry and total deposition. The purpose of the maps is to be used for research into biogeochemical cycles and ecosystem and human health effects.

Expected Outcomes

The expected outcomes of the Workshopwill be:

  • A review of the current state of global measurements (ground-based and satellite), chemical transport modelling (global and hemispheric), and measurement-model fusion/mapping techniques;
  • Key recommendations, conclusions and a project plan for moving forward on a GAW project on Global MMF-TAD;
  • Identification of MMF-TAD products (global maps) and timelines;
  • Identification of project participants, working groups and coordinators;
  • Coordination with major science and policy programmes interested in MMF maps.

Target Audience

Invited global experts in the fields of:

  • Measurement-model fusion for total atmospheric deposition, precipitation depth and ambient concentrations of reactive gases and aerosols
  • Global/regional measurements of wet, dry, total deposition
  • Global precipitation depth measurement, modeling and mapping
  • Global/regional measurements of reactive gases (ground-based and satellite-based)
  • Global/regional measurements of aerosols and aerosol species (ground-based and satellite-based)
  • Global/hemispheric chemical transport modeling.
  • Global science program/driver/client representativesfor nitrogen, critical loads, biodiversity and human health.

Representatives from:

  • GAW Scientific Advisory Groups on Aerosol, Reactive Gases and Modeling Applications, and relevant World Data Centers
  • International science and policy programmes with a need for global/regional maps of total atmospheric deposition, aerosol and gases

NOTIONAL AGENDA

WORKSHOP ON MEASUREMENT-MODEL FUSION FOR GLOBAL TOTAL ATMOSPHERIC DEPOSITION (MMF-TAD)

GLOBAL ATMOSPHERE WATCH SCIENTIFIC ADVISORY GROUP ON TOTAL ATMOSPHERIC DEPOSITION

World Meteorological Organization,

Geneva, Switzerland

February 28 – March 2, 2017

DAY 1: INTRODUCTION, BACKGROUND AND TECHNICAL SESSIONS ON MMF-TAD AND RELEVANT MEASUREMENTS

8:30Welcome and Introductions(WMO Secretariat)

8:40Workshop Context, Objectives and Expected Products

8:50Keynote Address 1. International Science and Policy Needs for Measurement-Model Fusion of Atmospheric Concentrations and Total Atmospheric Deposition

9:10 Keynote Address 2. Critical Loads/Levels and Biodiversity: Science and Policy Needs for Measurement-Model Fusion of Atmospheric Concentrations and Total Atmospheric Deposition

9:30 Keynote Address 3. Human Health Science and Policy Needs for Measurement-Model Fusion of Atmospheric Concentrations of Gases and Particles

9:50 - 1430Session 1: CurrentProjects on Measurement-Model Fusion for Total Atmospheric Deposition and Ambient Concentrations of Gases and Aerosol Species- National and Regional

Session 1will focus on descriptions of specific ongoing national and regionalmeasurement-model fusion projects for total atmospheric deposition and ambient aerosol and reactive gas concentrations for sulphur, nitrogen, base cations, ozone, and phosphorus. Speakers will present methods, results, problems, issues, uncertainties, concerns and future plans. A panel of speakers at the end of the session will discussoverarching topics.

9:50 1.1 United States - TDEP (Total Deposition) Project for S and N

10:10 -10:30 Break

10:301.2 Sweden - Total Deposition Mapping

10:501.3 Canada –The Canadian Atmospheric Deposition Analysis Generated by optimal Interpolation from Observations (ADAGIO) Project for Total Atmospheric Deposition

11:101.4 United Kingdom – Total Deposition Approaches in the United Kingdom

11:301.5 North America – Objective Analysis for Multi-Pollutant Surface Concentration Maps

11:50 -13:10 Lunch

13:10 1.6 Global Precipitation Depth from Measurements, Satellites and Measurement-Model-Satellite Fusion

13:30 1.7 Global/Continental Dry Deposition Using Satellite-Model Fusion

13:50 1.8 Recent Workshop Results Related to Satellite-Model Fusion

14:10 1.9 Chemical Data Assimilation: Lessons Applicable to Retrospective Measurement-Model Fusion

14:30 - 14:50 Panel Discussion: MMF Methods, Issues and Uncertainties

Discussion topics:

  • What are the advantages and disadvantages of the MMF methods used in the national efforts described above?
  • What are the major roadblocks, problems and uncertainties related to MMF on a global scale including precipitation depth, non-annual emission inventories, natural emissions, sparse data, model uncertainties and comparability, varying land use categories, dry deposition covariance, data storage and management?
  • Is there an objective analysis method that cancombine both non-urban (i.e., regional) and urban measurement and model results for MMF given their different spatial scales and site representativeness?

14:50 – 18:00Session 2: Available Ground-Level and Satellite-BasedMeasurements for Use in MMF-TAD

Session 2 will consist of overview presentations of existing and planned ground-based and satellite-based measurements of aerosols, reactive gases, wet, dry and total deposition related to sulfur, oxidized and reduced nitrogen,ozone, base cation species (and/or dust and sea salt) and phosphorus.Speakers will provide summaries of major measurement programs, monitoring networks and satellite sensors suitable for use in global measurement-model fusion projects and address related topics including measurement methods, data availability/access, problems, uncertainties and future outlook. A panel of speakers at the end of the session will discuss overarching topics.

14:502.1 Ground Level Measurements of RelevantReactive Gases in Large Non-Urban Monitoring Networks including GAW, Regional, and National Networks

15:10-15:30 Break

15:302.2 Ground Level Measurements of Relevant Aerosol Chemical Species in Large Scale Non-Urban Monitoring Networks Including GAW, Regional, National Networks

15:502.3 Ground Level Measurements of Reactive Gases andAerosol Chemical Species in Urban Monitoring Networks

16:102.4 Satellite Measurements of Relevant Reactive Gases,Aerosols and Aerosol Chemical Species

16:402.5 Global and Regional-Scale Measurements ofPrecipitation Chemistry and Wet Deposition

17:002.6 Regional-Scale Measurements of Precipitation Chemistry and Depositionin Asia/China

17:20–18:00Panel Discussion: Measurement Methods, Issues and Uncertainties

Discussion topics:

  • What chemicals can and should be addressed by MMF and in what order of priority?
  • For theidentified chemical species, are there additional measurement data available to supplement what was collected in the global precipitation chemistry and deposition assessment, especially in remote and sparsely monitored areas including the oceans?
  • How do satellite measurements of gases and particles compare with ground-level measurements? Is it feasible to use both in MMF? If so, what time resolution?
  • Are aerosol size distribution data available and, if not, how can particle dry deposition velocities be handled in MMF-TAD?
  • Are there special difficulties or uncertainties related to measurements over or near the oceans?

18:00Day 1 Wrap-Up
DAY 2: SCIENCE SESSION ON MODELLING RELATED TO MEASUREMENT-MODEL FUSION; WORKSHOP DISCUSSION SESSIONS

8:30-12:10Session 3: Chemical Transport and Deposition Modelling for Application to MMF-TAD

Session 3 will focus on overview presentations of global, hemispheric and regional chemical transport and deposition models for sulfur, nitrogen, ozone, phosphorus and base cation species (and dust and sea salt). Speakers will provide overviews of themodels, the species modeled, related model comparison studies, modeling uncertainties and future plans. A panel of speakers at the end of the session will discuss overarching topics.

3.1 Global, Hemispheric and Regional Modelling, Evaluation, and Comparabilityfor Use in MMF-TAD

8:303.1.1 An Overview of Global/Hemispheric Chemical Transport Models, Model Comparison Studies and Model-Evaluation Studies for Use in Global MMF-TAD

9:003.1.3 New Model Developments and InitiativesRelevanttoGlobal MMF-TAD (e.g., new models, new international projects, data assimilation, new ensemble schemes)

9:20 3.1.4 Global Modeling Activities

9:403.1.5 CMAQ in the USA and Elsewhere

10:003.1.6 Regional modeling for Europe

10:20 - 10:40 Break

10:403.1.7 Regional modeling for Asia

11:00 3.1.8 GESAMP Working Group 38 Atmosphere-Ocean Modeling (The Joint Group of Experts on the Scientific Aspects of Marine Environmental Protection)

11:203.1.8 Issues of Land Cover, Ecosystems and Feedback to Atmospheric Chemistry

11:40 – 12:10Panel Discussion: Modeling Requirements,Problems and Issues Related to MMF-TAD

Discussion topics:

  • What chemical species can be suitably modeled and applied to MMF-TAD?
  • Is model-to-model and model-to-measurement comparability sufficient for MMF? Are there specific models that should/should not be included in MMF?
  • What are potential modeling ensemble schemes for MMF-TAD?
  • How can model uncertainty be minimized/quantified?
  • How can dry deposition velocities/fluxes from the model(s) or the MMF product be validated?
  • What are the key issues related to modeling atmospheric atmospheric exchange/deposition mechanisms (e.g. bidirectional fluxes)?

12:10-13:30 Lunch

The discussion sessions on Day 2 will consist of a plenaryfollowed by two simultaneous breakout sessions. The objective of these sessions is to discuss the feasibility ofa global MMF-TAD project based on the questions listed below. The results of the discussion sessions will be included in the final workshop report and project plan.

13:30-14:30 Session 4. Plenary on Measurement-Model Fusion: Approaches, Objective Analysis Methods, Mapping, Management

This plenary will focus on feasibility and issues related to a global measurement-model fusion project. The plenary will highlight common issues and objectives for discussion in the two breakout sessions, thereby allowing the MMF experts to contribute to these sessions.

Q4.1Doesa measurement-model fusion project for atmospheric concentrations and total atmospheric depositionseem feasible on a global or hemispheric scale?

Q4.2What MMF-TAD paradigm and what optimal analysis and mapping method(s)could be used?

Q4.3Are there chemicals other than sulfur, nitrogen (oxidized and reduced) and ozone that should be included, and what are their relative priorities?

Q4.4What measurement and model input variables are needed and at what temporal and spatial scales?

Q4.5What practical issues and uncertainties would have to be overcome, e.g., data and model output management?

Q4.6What are the options for estimating and/or representing uncertainty?

14:30- 15:00 Break (then startthe breakout sessions)

15:00-17:00Session 5:Simultaneous Breakout Discussion Sessions

Two simultaneous breakout sessions will address and report on the questions that follow.

Breakout Group 1: Ground-Based and Satellite Measurements

Q5.1.1 How/where can the ground and satellite measurement data be obtained, screened, archived and managed in an efficient manner, including urban data?

Q5.1.2 What is the best path forward to obtain annual global precipitation depth fields for use in MMF-TAD?

Q5.1.3 What special measurement issues need to be addressed, e.g., spatial and temporal resolution, missing species, aerosol size distribution?

Q5.1.4 Are keynew sites, measurements, species, time frames, etc. needed and can their establishment be set in motion now?

Q5.1.5 Can we quantify measurement errors by species/location/instrument?

Breakout Group 2: Modeling

Q5.2.1What specific models or ensembles of models could be used for global MMF-TAD? What spatial resolution is possible for a global product?

Q5.2.2 How could model output be managed and accessed?

Q5.2.3If ensemblesof models are to be used, what ensemble scheme would be best/possible, or what criteria will be used to make that decision?

Q5.2.4What inputs to the models should be used, e.g., emission inventories, land use categories/schemes?

Q5.2.5How can the appropriate modeling agencies be engaged and theirmodel outputs obtained, archived and managed, e.g., through HTAP?

Q5.2.6Can/shouldfocused regional models (e.g., CMAQ, GEM-MACH, others) be usedto complement global or hemispheric models? If so, how?

17:00 – 17:15: Plenary

The Chairs/Rapporteurs of the Day 2 Breakout Sessions will raise any new ideas, issues, or considerations for discussion on Day 3.

DAY 3: WORKSHOP DISCUSSION SESSIONS CONTINUE

9:00 - 11:00Session 5B: Simultaneous Breakout Sessions Continue (with Break at 10:30)

Continue addressing the questions listed for the Breakout Sessions and any considerations raised in the plenary.

11:00 –16:30Session 6: Final Plenary

The final plenary will consist of presentations from the two Breakout Groups followed by a plenary discussion of the path forward (based plenary questions below).

11:00Breakout Group 1 Findings, Recommendations, and Path Forward

11:30Breakout Group 2 Findings, Recommendations, and Path Forward

12:00-13:15 Lunch

13:15Plenary discussion to address the following questions:

Q6.1 Is the Global MMF-TAD Project possible? Should we proceed with a Project Plan?

Q6.2 What are the needed and expected products/deliverables of the project and where would they be published/disseminated (e.g., what global gas, aerosol and deposition maps)? What are the time frames for delivery?

Q6.3 Assuming that such a project is possible, do we do start with a pilot project for a specific year (or set of years) before adopting a routine approach? What year(s)?

Q6.4 Who could lead and participate in the project, i.e., whatleaders/champions, coordinator(s), modelers, measurement groups, data management groups, objective analysis/mapping groups?

Q6.5 How canthe project be coordinated/carried out and in what time frame, e.g., where and how would the data and modeling output be archived, analyzed, mapped and managed?

Q6.6 What are the priority chemicals?

15:00- 15:30 Break

Q6.7 Can we create a Project Plan that includes the key tasks, major contributors and potential timelinesbroken down into the following sections:

  • Management and coordination
  • Measurements (ground and satellite)
  • Modeling
  • Objective analysis and mapping
  • Ongoing MMF-TAD development and research

Q6.8 What are the key recommendations for the measurement, modeling, and MMF communities to advance the Project (e.g., key new sites, new satellite measurements, new model algorithms)?

16:10 - 16:30Session 7: Final Comments and Close

16:10 7.1 Summary, Conclusionsand Expectations for the Workshop Report

A Workshop Report will be written to summarize the information in the Scientific and Discussion Sessions and document the path forward on the MMF-TAD Project.

16:30 7.2 Close of Workshop

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