1. AOPC-20 (2015)Atmos. Comp. JH Butler Atmospheric Composition Issues James H. Butler Global Monitoring Division, NOAA/ESRL Boulder, CO, USA WMO Global Atmosphere Watch, Geneva, CH AOPC-20, March 17-21, 2015

2. AOPC-20 (2015)Atmos. Comp. JH Butler Outline Ozone Aerosols Surface Radiation Greenhouse Gases 2

3. AOPC-20 (2015)Atmos. Comp. JH Butler Ozone Page 3

4. AOPC-20 (2015)Atmos. Comp. JH Butler Main ozone Issue(s) -- Reporting Reporting delays  Brewer total ozone data from 57 stations down to 28 in 2014  Dobson spectrophotometer measurements dropped from 47 to 37 stations in same interval  No SAOZ data have been archived in WOUDC since 2012  Data from 19 filter instruments down from 26 to 19 in 2012-2013  Data in 2014 exist but submissions delayed by 4-6 months Lost stations?  17 Brewer, 6 Dobson, and 6 filter instrument stations have not reported data since 2012. These are largely instruments from Canada. The reason for missing data needs further investigation. Page 4

5. AOPC-20 (2015)Atmos. Comp. JH Butler GAW Arctic Ozone Sites Reporting Over half of arctic sites have not updated data in the WMO/GAW WOUDC since 2002 Page 5

6. AOPC-20 (2015)Atmos. Comp. JH Butler NDACC Arctic Ozone Stations Reporting Several NDACC sites are not identified in the WMO/GAW WOUDC data base Page 6

7. AOPC-20 (2015)Atmos. Comp. JH Butler Canadian Arctic Ozone Sites Page 7 Only three sites are truly arctic Ten sites total

8. AOPC-20 (2015)Atmos. Comp. JH Butler Russian Arctic Ozone Sites Russian Stations in the Arctic  Blue = Brewer  Gray = SAOZ  Black = O 3 sonde Page 8 Arctic ozone depleted over 40% in 2011 when the vortex remained strong and cold until late March Because almost half the Arctic region is in Russian territory, it is essential that ozone observations continue in Russia

9. AOPC-20 (2015)Atmos. Comp. JH Butler Aerosols Page 9

10. AOPC-20 (2015)Atmos. Comp. JH Butler WMO/GAW Aerosol Measurements Page 10 SAG-Aerosol recommendation ​ Elaborate the "aerosol" ECV as "Including, but not restricted to”:  aerosol optical depth  light scattering and absorption coefficients  aerosol size distribution  vertical distributions of aerosol backscattering and extinction

11. AOPC-20 (2015)Atmos. Comp. JH Butler GCOS Aerosols: ECV (from AOPC XIX, 2014) The ECV called "Aerosol" is a very broad term that encompasses many actual aerosol variables SAG-Aerosol recommends that a further specification of the "Aerosol" ECV should include the variables in the table to the right Multiwavelength aerosol optical depth Particle mass concentration in two size fractions (fine, coarse) Vertical distribution of aerosol backscattering and extinction Mass concentration of major chemical components in particle-phase in two size fractions Multiwavelength light scattering and hemispheric back- scattering coefficient Cloud condensation nuclei number concentration at various super- saturations Multiwavelength light absorption coefficient Particle number concentration Particle number size distribution

12. AOPC-20 (2015)Atmos. Comp. JH Butler Aerosol Issues & Q’s WMO/GAW SAG-Aerosol Is there a formal process for a network to become an "official" GCOS network? Clarification of the status as official GCOS networks of the networks mentioned at these web sites:  http://gosic.org/content/gcos-atmospheric- composition-ecv-aerosols-properties http://gosic.org/content/gcos-atmospheric- composition-ecv-aerosols-properties  http://www.wmo.int/pages/prog/gcos/index.php?name =ObservingSystemsandData#composition http://www.wmo.int/pages/prog/gcos/index.php?name =ObservingSystemsandData#composition ​ What is the possibility of accepting AERONET as a GCOS comprehensive network, independent of GAW? ​ Page 12

13. AOPC-20 (2015)Atmos. Comp. JH Butler Surface Radiation Page 13

14. AOPC-20 (2015)Atmos. Comp. JH Butler BSRN 13th BSRN Scientific Review and Workshop was held at the Institute of Atmospheric Sciences and Climate in Bologna, Italy from 9-12 September, 2014.  39 oral presentations, 6 Working Group oral reports, and a poster session that included BSRN site status updates. BSRN Archive at WRMC  7825 station-month data sets from 58 stations collected in the WRMC by September 2014.  Recent years have seen a loss of a few sites, notably Manus and Nauru located in the equatorial western Pacific, but also newly planned sites and several newly proposed sites that will expand the global and climactic coverage.  BSRN data increasingly used in scientific research and publications. Page 14

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17. AOPC-20 (2015)Atmos. Comp. JH Butler Greenhouse Gases Page 17

18. AOPC-20 (2015)Atmos. Comp. JH Butler GHG Issues Marine Boundary Layer Reference for CO 2 and CH 4  GCOS Reference Networks? Should GCOS include ”minor” GHGs? National Metrology Institutes  BIPM/WMO Agreement “ensures” coordination  “Restlessness” among NMI’s in pursuing GHG emissions Constructing an Adequate Global Network  Filling Gaps  Validating and interpreting remotely sensed retrievals  Urban “domes” – do they need separate guidelines? Page 18

19. AOPC-20 (2015)Atmos. Comp. JH Butler Marine Boundary Layer Reference 25-40 sites All connected with the MBL Remote atmosphere Latitudinally representative Highest quality measurements Page 19

20. AOPC-20 (2015)Atmos. Comp. JH Butler MBL Products Global Averages Highest quality measurements Latitudinal representations Used in global models Information lags about one month Page 20

21. AOPC-20 (2015)Atmos. Comp. JH Butler Other MBL products Page 21 Global, gridded data sets Meridional Reference

22. AOPC-20 (2015)Atmos. Comp. JH Butler “Minor” GHGs Monitored mainly by two groups  AGAGE  NOAA High quality control Small number of sites Have a small, but measurable impact on radiative forcing Page 22

23. AOPC-20 (2015)Atmos. Comp. JH Butler Urban Domes 70% of world’s GHG emissions come from urban areas Today 5 of 10 live in urban areas Tomorrow (2050), 7 of 10 will live in urban areas Page 23