1. ACC-VC Status and Issues – Continuity of Limb Sounding Richard Eckman NASA CEOS SIT-29 Meeting CNES, Toulouse, France 9 th -10 th April 2014

2. SIT-29 Meeting CNES, Toulouse, France 9 th -10 th April 2014 2 ACC Activity Status 3-Year Outcomes  Total ozone ECV validation & harmonization  Geostationary Air Quality constellation coordination  Multi-sensor volcanic eruption alert system  Greenhouse gas (GHG) constellation

3. SIT-29 Meeting CNES, Toulouse, France 9 th -10 th April 2014 3 ACC Activity Status Main Accomplishments ACC-9 workshop was held at EUMETSAT in Darmstadt, Germany, on 18-19 April 2013: ~30 participants from Europe, Asia, and North America  Total ozone ECV validation & harmonization: Common validation protocol set up for workshop Detailed consideration of US, European, and ground-based data sets: calibration and validation Combined long term space-based data set to be create Other satellite data sets (e.g., Chinese missions, infrared missions like IASI) discussed Telecons and in-person meeting held (at March 2014 OMI Science Team meeting) to plan next steps in preparation for ACC-10 meeting

4. SIT-29 Meeting CNES, Toulouse, France 9 th -10 th April 2014 4 ACC Activity Status Main Accomplishments (cont’d.)  Geostationary Air Quality constellation coordination Points of contact from each region have been named to participate on mutual mission science or advisory teams with a focus on common science and collaborative data products. CEOS/MACC-II International OSSE Workshop was held 22-24 October 2012 at ECMWF, shared expertise, discussed common approaches and experiments, defined initial collaboration to share high resolution global chemistry/aerosol nature runs

5. SIT-29 Meeting CNES, Toulouse, France 9 th -10 th April 2014 5 ACC Activity Status Main Accomplishments (cont’d.)  Multi-sensor volcanic eruption alert system Activities in Europe and North America to use space-based observations to monitor volcanic ash, enhance forecasts, and provide products to decision makers and industry were discussed With the successful conclusion of a workshop held in Dublin in March 2013, ACC meeting participants welcomed enhanced collaboration between the North American and European communities

6. SIT-29 Meeting CNES, Toulouse, France 9 th -10 th April 2014 6 ACC Activity Status Main Accomplishments (cont’d.)  Greenhouse gas (GHG) constellation Workshop noted activities in progress to further explore SCIAMACHY and GOSAT CH 4 and CO 2 measurements and to demonstrate their usefulness for retrieving information about regional sources and sinks. Attendees decided that it would be beneficial to follow the example of the ACC AQ Constellation and respond to CEOS CTF Report with an emphasis on algorithm improvements and uncertainty quantification.

7. SIT-29 Meeting CNES, Toulouse, France 9 th -10 th April 2014 7 ACC Near-Term Activities Future activities and milestones Total ozone measurement validation and harmonization 6/2014: Conduct ACC-10 workshop to complete total ozone validation activities and examine progress with harmonization project Geostationary AQ constellation coordination 9/2014: ACC to coordinate an SBA value assessment of air quality observations leveraging recent GCOS and GEO UIC efforts.

8. SIT-29 Meeting CNES, Toulouse, France 9 th -10 th April 2014 8 ACC Near-Term Activities Future activities and milestones Volcanic Ash Monitoring from Space 12/2014: Continue development of dispersion forecast models (global and regional) including data assimilation, inverse modelling, and ensemble techniques to generate a measure of the uncertainty of the forecast 6/2015: Develop an operational demonstration service for volcanic ash (and SO 2 ) monitoring and forecasting Greenhouse Gas Constellation coordination 6/2014: Begin implementation of near-term ACC objectives for GHG measurement coordination based on recommendations of CTF report

9. SIT-29 Meeting CNES, Toulouse, France 9 th -10 th April 2014 9 ACC Leadership Update/Next Meeting Participation/leadership update Co-Chairs working succession planning with ongoing outreach to ACC membership prior to next meeting Will be addressed at ACC-10 meeting Next Meeting ACC-10 planned for 4-5 June 2014, to be hosted by NOAA in College Park, Maryland

10. SIT-29 Meeting CNES, Toulouse, France 9 th -10 th April 2014 10 Continuity of Limb Sounding Atmospheric limb sounding gap (for information) ACC-9 workshop (4/2012) participants noted both the Earth Explorer 7 User Consultation Meeting which did not select the Premier mission concept and the earlier demise of Sciamachy (aboard Envisat). An ACC gap analysis (2008) noted a looming gap in limb sounding measurements necessary for high vertical resolution atmospheric composition measurements providing unique data for climate-chemistry interactions in the upper troposphere and stratosphere

11. SIT-29 Meeting CNES, Toulouse, France 9 th -10 th April 2014 11 Continuity of Limb Sounding (cont’d.) Atmospheric limb sounding gap A gap-filling mission to provide these needed measurements, important to both the atmospheric composition community and air quality decision support, would be desirable. Recent Development: NASA assigned responsibility for sustained measurements of solar irradiance, ozone profiles, and Earth radiation balance beginning in 2021 –OMPS-Limb integral with OMPS-Nadir planned for JPSS-2

12. SIT-29 Meeting CNES, Toulouse, France 9 th -10 th April 2014 12 Continuity of Limb Sounding (cont’d.) Atmospheric limb sounding gap (background) ACC-3 workshop report http://www.ceos.org/images/ACC/acc- 3%20report%20vsfinala.pdf ACC Gap Analysis http://www.ceos.org/images/PDFs/ACC/CEOS_ACC_Final_R eport_v2.pdf