GAW Scientific Advisory Group for Ozone

M i n u t e s - Draft

of the meeting of the GAW Scientific Advisory Group for Ozone Toronto, September 09-10, 2002

Venue The meeting of SAG-O3 was held at the headquarters of the Meteorological Service of Canada (MSC), 4905 Dufferin Street, Toronto, Canada from 09 to 10 September, 2002

Participants The following SAG-O3 members attended the meeting (contact addresses see Appendix A): Bob Evans, NOAA/CMDL Dobson network Jack Fishman NASA Langley Tropospheric O3 and satellites Ed Hare MSC WOUDC Jim Kerr MSC Brewer network Jennifer Logan Harvard, University O3 modeling Mike Proffitt WMO Secretariat Capacity building Masanori Shitamichi JMA Head, O3 Layer Monit. Off., JMA Rich Stolarski NASA Goddard Satellite O3 measurements Karel Vanicek (Chair) CHMI/SOO-HK Training and information tools Pierre Viatte MeteoSwiss Payerne Ozone sondes

Program The program of the meeting was defined by the Agenda (see Appendix B). The individual topics of the meeting were discussed and recommendations defined as follows.

Opening − The meeting started by a welcome given by J. Kerr on behalf of MSC – the hosting institution − K. Vanicek, asked all SAG members to introduce themselves and chaired the meeting − The Agenda of the meeting was endorsed – see Appendix B − M. Proffitt presented a brief overview of the WMO-GAW ozone programme with a special aim to its key parts (QA/SACs, calibration centers, GAW/SIS) and to the recent outputs from the Ozone Research Managers Meeting, Geneva 2002

Total ozone observations – ground based B. Evans gave an outlook on the present state of the Dobson network: − The World Dobson Calibration Center (WDCC) continues its duties on maintenance of the Primary instrument D083 and guarantees transfer of the world calibration scale into the GAW network − The Regional Dobson Calibration Centers (RDCC) for Europe (Hohenpeissenberg- DWD) and for the Far East (Tsukuba-JMA) maintain regional reference instruments and organize regular intercomparisons. Results from these campaigns are published in WMO-GAW Reports.

1 − RDCC for South America (Buenos Aires) and Africa (Pretoria) have not been established definitely yet and they need a systematic support from WMO and WDCC.

M. Shitamichi presented a survey of activities performed by JMA on operation of RDCC in Tsukuba and the plan of the next intercomparison to be held in Tsukuba, 2003. He stressed that this campaign needs to be supported by WMO because of limited resources available at JMA. J. Kerr described the Brewer network of MSC and its function including the calibration system. This system is recommended to GAW as an example of a well-working and reliable regional Brewer network. The Brewer triad maintained by MSC is a stable World Brewer Standard and it represents the international Brewer calibration scale for total ozone observations. K. Vanicek presented a proposal for creation of a regional GAW Brewer calibration system for total ozone observations in the RA-VI region – Europe. The proposal was prepared on the request of the GAW Workshop of RA-VI, Riga, 2002 by K. Vanicek and E. Cuevas and it was presented at the Biennial Brewer Workshop, Toronto, 2002. M. Proffitt recommended to use this Brewer calibration system also for calibrations of Brewer instruments from developing countries when the system is implemented and its function verified. K. Vanicek introduced an external paper prepared and submitted to SAG by J. Staehelin at al. “Comparison of Total Ozone Measurements of Dobson and Brewer spectrophotometers and Recommended Transfer Functions”. The paper gives a strong evidences for needs of investigation relations between Dobson and Brewer data series from collocated stations and documentation of calibration histories of Brewer instruments in the GAWQ network which are calibrated by private companies out of the GAW QA system. E. Hare The present situation in the Russian filter instruments network is not clear. About a half of the network still deposit data to WOUDC but no fresh information about the current state of the network is known from the metadata base. The situation needs to be investigated. Remark: Before these Minutes have been finalized a Report on the current state of the Russian filter instrument network was prepared by A. Shalamiansky and delivered via V. Fioletov to the Chairman of SAG-O3. The Report is attached in the Appendix C.

Recommendations:

1. WMO GAW should seek support for Dobson calibrations in developing countries. Otherwise calibrations in developing countries will fall behind schedule.

2. A plan must be made to augment and extend the existing system of calibration and maintenance of Brewer instruments, which is presently being performed by private companies. An evaluation of the history and efficiency of the existing Dobson calibration system, which is operated through cooperation between the individual users and WMO- GAW oversight, would be useful in forming this plan.

3. Calibration histories of the Dobson, Brewer and FSU filter instruments should be incorporated in to the WOUDC as assistance to the data users.

4. Creation of a regional Brewer calibration system in the RA-VI Region operated under the GAW Programme is recommended for long-term maintenance of the Brewer network and for continuity of high accuracy of total ozone observations in the region.

5. Stations with long time records of Dobson data that are considering changing to Brewer instruments should continue to report the Dobson data. If the reporting instrument is to be hanged, the changeover process must be consistent with the recommendations in

2 “Comparison of total ozone measurements of Dobson and Brewer Spectrophotometers and recommended transfer functions” (Staehelin, et al) to avoid discontinuities in the data record. 6. The SAGO3 chairman is directed to contact the manager of the Regional calibration center for filter instruments at MGO in St. Petersburg to investigate the current status of the network.

Vertical profiles P. Viatte presented a brief survey of the latest results reached on ozone balloon sounding program of GAW, mainly on preparation of the Standard Operation Procedures (SOPs). He also pointed out a great contribution of the World Calibration Center for Ozone Sondes at FC Juelich and laboratory campaigns JOSIE 1996-2000 M. Proffitt informed the SAG members about organization and goals of the “BESOS 2003” campaign. This mission is to play an important role in validation of the preliminary SOPs defined in 2001. E. Hare informed that the vertical profiles measured under the SHADOZ project have been already deposited into WOUDC. J. Logan, R. Stolarski, P. Viatte asked for a better description of the re-evaluated Dobson Umkehr data set and the 1999 algorithm used. They pointed out that Dobson and \Brewer Umkehr observations significantly contribute to understanding of ozone changes in mid and upper stratosphere. M. Shitamichi presented the current Lidar and microwave program in JMA M. Proffitt and E. Hare stressed a need for deposition of Lidar and microwave profiles into WOUDC.

Recommendations: 7. Standard operating procedures for the preparation of ECC ozonesondes must be finalized as soon as possible after the comprehensive intercomparison of ozonesondes flown on a single balloon planed for 2003. Additional investigations should be performed to define standard operating procedures for the processing of the data.

8. To guarantee long-term stability of the ozone time series QA of the manufacturing of ozonesondes should be performed on a regular basis by the WCCOS.

9. Continuing Umkehr measurements presently made and expansion to new stations by both Dobson and Brewer instruments should be encouraged.

10. The evaluation of the 1999 algorithm should be completed and a decision made as to whether or not to replace the 1992 algorithm now in use in the WOUDC. Evaluation of the three-wavelength Umkehr measurements made at many stations should be done to identify any possible additional information

11. Measurements of ozone currently being made using LIDAR and Microwave techniques should continue without interruption, and new measurement programmes should be established where local infrastructure and support are sufficient for long term observation series

Tropospheric ozone J. Fishman presented details on the “Tropospheric Ozone Project” (GTOP) and its science plan defined in 2001

3 M. Shitamichi informed about the present state of the WDCSO as a part of World Data Center for Greenhouse Gasses at JMA and about facilities available for access of contributors. M. Proffitt informed that the Regional Calibration Center for Surface Ozone for South America has been established in Buenos Aires and instruments from this region can be calibrated at this facility. J. Fishman presented a description of the GLOBE project and its goals for education of the population on ozone related problems.

Recommendations: 12. Instruments from South America should be calibrated at the newly established GAW Regional Calibration Centre for surface ozone and data routinely reported to WDCGG at JMA.

13. The WMO should work in collaboration with the International Global Atmospheric Chemistry Project of the Global Troposphere Ozone Project by providing the necessary infrastructure to enhance ozonesonde measurement capabilities.

14. The WMO should embrace programs that educate the public about the importance of ozone as an environmental issue. Specifically, the Global Learning through Observations to Better the Environment (GLOBE) project should continue to be supported.

The World Ozone and UV Data Center WOUDC E. Hare informed that: − The WOUDC has now released an updated web site with tools for obtaining information about data sets. The number of stations submitting data to the WOUDC can be extracted using a new catalogue form − The present inventory of the data deposited in WOUDC is as follows:

Data Category No. of Stations Earliest Date Latest Date

Ozonesonde (Level 1) 108 1962-02-19 2002-06-06 Surface Ozone (Level 1) 16 1973-03-14 1995-10-31 Total Ozone (Level 1) 260 1926-07-23 2002-05-31 UmkeherN14 (Level 1) 63 1951-10-21 2002-04-29 UmkeherN14 (Level 2) 57 1951-10-21 2002-04-29

− Calibration and inter-comparison data from all ground-based instruments (Brewer, Dobson, Filter) should be made available from the Internet or deposited at WOUDC site − The number of stations that have submitted Dobson Umkehr data for the years 1999, 2000 and 2001 are 21, 20 and 17 respectively. − The new software for processing Dobson Umkehr data created under the REVUE project should be presented and the re-evaluated data set submitted to the WOUDC data base − The WOUDC has successfully build good data submission relationships with the NASA-SHADOZ and NASA-GTE (TRACE projects) databases for the release and archiving of these ozonesonde data sets into the WOUDC. The WOUDC has re- formatted the SHADOZ and GTE data in the standard extCSV format. The NDSC and WOUDC are presently working on the details of data submission of the NDSC data sets to the WOUDC and the creation of this data submission pathway is expected soon.

4 − At present, the WOUDC is still working on a lidar standard format for submission to the WOUDC. The WOUDC anticipates getting the NDSC lidar data, but this is still to be formalized. There are two Canadian stations that have submitted data. There are no microwave data housed at the WOUDC. − There are no stations depositing surface data to the WOUDC − The WOUDC has converted its entire inventory of all ozone (and UV) data sets into the extCSV format, except for the lidar data. The WOUDC still accepts data in the old WODC 80-column format, but there are converter programs available to translate 80- column to extCSV and vice versa − Data should be submitted to the WOUDC in a timely manner (i.e. within 6-12 months.), more processed Brewer Umkehr data including all type of Level 0 data (via the Brewer Data Management System or BDMS) − Activities should continue to evolve the data center and to meet the needs of the ozone community by using new web search and visualization tools such as the new data in archive catalogue form − Building up relationships with data originators should continue. Measured data, data of inter-comparisons of all agencies and data categories submissions should be sent directly to the WOUDC by the data originator. If this is not possible, then third party data submission should always link back to the actual data originator. This includes also metadata and “meta-information” such as calibration histories, logbook notes and scientific sponsorship statements or SSS (see note). These documents can be posted at the WOUDC ftp site. Note: The SSS is presently in use within the UV community as recommended by the SAG_UV. − The file format standard for data submission to the WOUDC is the Extended Comma Separated Values (ExtCSV). The use of other organizations formats will be coordinated by the WOUDC. Presently, the WOUDC accepts NASA-Ames 2160 formatted files.

Recommendations: 15. The WMO should continue to encourage the submission of data to the WOUDC in timely manner including more Level 0, data from both Dobson and Brewer networks, especially more processed Brewer Umkehr data Along with the traditional data files, related metadata and calibration data ( inter-comparison records, calibration histories, logbook notes and scientific sponsorship statement) should be submitted, and also be available from the WOUDC web and ftp sites. In this regard, the WMO-GAW through the WOUDC should continue to build relationships with data originators. Data submissions should be sent directly to the WOUDC by the data originator. If this is not possible, then third party data submission should always link back to the actual data originator.

16. WOUDC should continue improving the data center to meet the growing needs of the ozone community. For this new web search and visualization tools and ExtCSV format for data submission implemented by WOUDC will be used. The use of other organizations formats will be coordinated by the WOUDC

Satellite ozone observations R. Stolarski emphasized a need for a long-term co-operation between ground-based and satellite teams on maintenance of calibration systems and validation of total ozone observations. This is an important aspect for assessment of quality of measurements and consistency of long-term data series for trend analyses. Building up an integrated ground- based and satellite observation system remains a chief task for the future.

5 M. Proffitt and K. Vanicek stated that a better co-operation is needed between ozone monitoring projects of ESA and the GAW programme. They suggested to invite an expert familiar with and involved in ESA´s ozone missions to become a member of SAG-Ozone. E. Hare pointed out an important role of satellite data for assessment of quality of ozone observations at GAW stations recorded in WOUDC

Recommendations: 17. GAW should emphasize the importance of the long-term ground-based system in maintaining the calibration of the present and future satellite systems. It should specifically seek support for the inter-calibration of network of instruments from the satellite validation programs.

18. It is recommended that GAW begins to take steps to incorporate satellite data at station locations into the WOUDC data base

Ozone modeling J. Logan informed about the latest progress in modeling of stratospheric and tropospheric ozone and needs for input data. She stressed that future improvements in modeling require a better knowledge of ozone profiles from regions outside north mid and high latitudes. Extension of ozone sounding network is therefore highly desirable in these regions. Projects like SHADOZ campaign can serve as an efficient mechanism for implementation of new ozone sonde stations.

Recommendations: 19. New ozonesonde stations are needed in the northern tropics and subtropics (West Africa, continental Asia, the Middle East, Central America, and the Pacific) to explain discrepancies among global tropospheric chemistry models and the satellite derived data. . 20. Contribution of measurements from the ozonesonde stations in the SHADOZ network to the GAW Programme should continue, with expansion desirable.

Capacity building M. Proffitt gave a summary of the recent activities of WMO/ENV on building of capacities for the ozone segment of the GAW programme in developing countries. The main resources are need mainly for implementation of the Dobson calibration centers in South America and Africa and for establishment new ozone sounding stations in the equatorial belt and SH. An important role of twin co-operations between institutions from developed and developing countries was pointed out. These partnerships should be expanded under the GAW programme. K. Vanicek informed about the training programme for Dobson operators from developing countries performed at SOO Hradec Kralove, Czech Republic under the sponsorship of CHMI and WMO. This programme is to be continued and it should be extended also for Brewer operators in the future.

Recommendations: 21. The twinning cooperation and training support for GAW ozone stations in developing countries should be continued and expanded as the situations warrants. The past experiences with these activities have shown valuable results

6 End of the meeting All suggestions prepared under all particular topics have been summarized (see below) as a draft for the final review and endorsement to be done by the end of October 2002. It was suggested to hold the next SAG-Ozone meeting in Prague, Czech Republic in the beginning of October 2003 (Monday-Tuesday) under the sponsorship of the Czech Hydrometeorological Institute. K. Vanicek and M. Proffitt thanked the SAG members for attendance and closed the meeting.

7 Appendix A

Members of the Scientific Advisory Group for Ozone of GAW

January, 2002

Dobson observations Mr. Bob Evans DOC/NOAA/ERL/CMDL 325 Broadway, R/E/CG1 Brewer observations Boulder, CO. 80303 Dr Jim Kerr USA Meteorological Service of Canada Tel.: 303 497 6679 4905 Dufferin Street Fax: 303 497 5590 Downsview, Ontario M3H 5T4 e-mail: [email protected] Canada Tel.: 416 739 4626 Fax: 416 739 4281 Satellite obs. -tropospheric ozone e-mail: [email protected] Dr Jack Fishman NASA Langley Research Centre Mail Stop 401A Modelling Hampton, VA 23681-2199, Dr. Jennifer Logan USA Harvard, University, 108 Pierce Hall Tel.: 757 864 2720 29 Oxford Street Fax: 757 864 6381 Cambridge, MA02138 e-mail: [email protected] USA Tel: +1-617-495-4582 Fax: +1-617-495-9837 Surface ozone measurements/S.H. GAW e-mail: [email protected] Dr Ian E. Galbally CSIRO, Div. Atmospheric Research Private Bag No. 1 Secretariat WMO, Capacity Building Aspendale, Victoria 3195 Dr Michael H. Proffitt Australia WMO/AREP Environment Division Tel.: 61 3 9239 4613 7 bis Avenue de la Paix Fax: 61 3 9239 4444 1211 Geneva 2 e-mail: [email protected] Switzerland Tel: +41-22-730 8235 Fax: 4+1-22-730 8049 WOUDC e-mail: [email protected] Mr Edward Hare Meteorological Service of Canada 4905 Dufferin Street Instrumentation/Met Service North York, Ontario,M3H 5T4 Mr. Masanori Shitamichi Canada Head, Ozone Layer Monitoring Office, Tel.: 416 739 4635 Japan Meteorological Agency Fax: 416 739 4281 1-3-4, Otemachi, Chiyoda-ku, Tokyo e-mail: [email protected] 100-8122, Japan

8 Tel +81-3-3287-3439 Fax +81-3-3211-4640 e-mail [email protected]

Satellite ozone measurements Dr. Rich Stolarski NASA Goddard Space Flight Center Mail Code 916 Greenbelt, MD, 20771 USA Tel +1-301-6145982 Fax +1-301-6145903 e-mai: [email protected]

Ozone stations in developing countries Dr. Karel Vanicek - Chairman Czech Hydrometeorological Institute Solar and Ozone Observatory Hvezdarna 456, 500 08 Hradec Kralove 8 Czech Republic Tel: 420 49 526 0352 Fax: 420 49 526 4127 e-mail:[email protected]

Ozone sondes Dr Pierre Viatte Meteo Swiss Station Aérologique, Les Invuardes CH-1530 Payerne Switzerland Tel.: 41 26 662 62 57 Fax: 41 26 662 62 12 e-mail:[email protected]

9 Appendix B A g e n d a

of the

Meeting of the Scientific Advisory Group on Ozone Toronto, September 9-10, 2002

September 09

09:00 Opening the Meeting 09:10 Welcome by a representative of MSC 09:20 A brief overview of the WMO GAW Ozone Programme

09:35 GAWSIS and the new GAW webpage

09:45 Total ozone observations Topics for possible discussion − Dobson intercomparisons and calibration activities − Brewer intercomparisons and calibration activities − Proposal for a Regional Brewer Calibration Center of RA-VI − Report on Dobson and Brewer intercomparisons – J. Staehelin´s paper − Maintaining the Russian filter instruments network − A Dobson software package and its implementation in the GAW network − Prepare draft of recommendations

14:00 Vertical profiles Topics for possible discussion − Definition and implementation of SOPs − BESOS 2002 (Balloon Experiment on Standards for Ozone Sondes) − Cooperation with SHADOZ − Expansion of ozonesonde observations − Re-evaluated Umkehr profiles − Expansion of Umkehr observations − Expansion of Lidar and microwave observations − Prepare draft of recommendations

16:30 Tropospheric and surface ozone Topics for possible discussion − Regional Calibration. Center (Buenos Aires) − Updating of the WMO Report No.97 − Transfer of WDCSO into WDCGG − Global Tropospheric Ozone Project (GTOP) − Global Learning through Observations to Better the Env. Program

10 September 10

09:00 Surface ozone Continue discussions of tropospheric and surface ozone Prepare draft of recommendations

09:30 The World Ozone and UV Data Center of WMO Topics for possible discussion − Implementation of extCSV codes − Inventory of stations depositing data into WOUDC − Deposition of NDSC and SHADOZ data into WOUDC − New ftp tools for data transfer to and from WOUDC − Cooperation of WOUDC with satellite data centres − A possible GAW World Ozone Data Evaluation Centre (WODEC)? − Prepare draft of recommendations

10:45 Satellite ozone observations Topics for possible discussion - The integrated satellite and ground based ozone monitoring system (WMO Report No.140) - TOMS-GOME-GAW - Suggestion for location of new GAW ozone stations (column and sonde) - Development of technologies for satellite monitoring of tropospheric ozone - Umkehr versus satellite observations - Prepare draft of recommendations

11:45 Ozone modeling Topics for possible discussion Status of workshop on needs of modeling community for ozone data − Prepare draft of recommendations

14:00 Capacity building in developing countries and continue ozone modeling Topics for possible discussion − Suggestion for new twin-co-operations (Portugal-Capverde Islands) − Know-how transfer meetings with scientists from developing countries − GAW training programme for Dobson operators − Prepare draft of recommendations

15:15 Finalize and adopt recommendations for the Secretariat of WMO

17:00 End of the Meeting

11 Appendix C

The M-124 Ozonometers Network Arcady Shalamiansky Main Geophysical Observatory (MGO), St. Petersburg, Russia, October 2002

Instruments:

The Russian network for observing total column ozone consists of 28 stations within Russia and 2(3) Antarctic stations, which are equipped with filter ozonometers, model M-124. These same instruments were used at stations in Bulgaria (3 stations), Cuba (2), Georgia (1), Latvia (1), Lithuania (1), Kazakhstan (5 ), Tajikistan (1), Turkmenistan (2), Ukraine (4) and Vietnam (3). This report and schedule refers only to those stations, which are calibrated with assistance from the MGO with some degree of regularity.

The M-124 ozonometer uses two filters to measure the total ozone amount. The filter spectral intervals have their maximum at 302 and 326 nm each with a half-width of about 20 nm. With time, the filters could be affected by solarization and this could be the cause of observed systematic errors.

Total ozone is retrieved from direct sun measurements at zenith angles of 20-70 and from blue or cloud zenith measurements at zenith angles of 20- 85 which allows for ozone measurements at northern latitude stations, under practically all weather conditions.

All of the M-124 ozonometers are calibrated against the Dobson spectrophotometer No.108, which is regularly compared with the WMO standard. Intercomparisons in Boulder (1988), Hradec Králové (1993), Kalavrita (1997) and Hohenpaissenberg (2001) showed that the measurement-scale drift of the Dobson No.108 did not exceed 1.0 %.

Data quality control methodology

The possibility of the filter characteristic degradation determines the special features of the station equipment and the measurement procedure. In particular, it is necessary to carry out the regular control of a measurement scale. Russian ozone stations are equipped with three ozonometers: one dedicated to continuous operation, one spare and a reserve that is sent to the MGO for calibration.

The measurement procedure consists of the mandatory blue or cloud zenith measurements and the direct sun measurements (when sun is clear and the zenith angle is less than 70). Tables of observation results are sent from the stations to the MGO every month.

The MGO control of measurement quality is based on: 1) the calibration of M-124 ozonometers against the standard every two years; 2) the monthly comparison of two ozonometers, with which any station is equipped. 3) the comparison of direct sun and zenith measurements (the difference can not exceed 1- 3 %); 4) the routine control over the measurements for revealing the "-dependence" which indicates change of instrument spectral characteristics

The MGO analysis is being performed to minimise the systematical errors, which are accounts for about 90 % of the total error. At the Russian network stations, the error of a single direct sun and zenith ozone measurement by the M-124 ozonometer is no more than 5 %. After the MGO control and correction procedure, the measurement error could be reduced to 3 %.

12 Real-time data.

The MGO also receives real-time data each day by telegram and/or e-mail. These data are then plotted on a chart to compare with satellite ozone measurements (NASA TOMS instrument) and with 300 mb geopotential charts (as well as 200 mb geopotential and 30 mb temperature charts). There comparisons are intended to determine main features of total ozone distribution and to find rough (technical) errors in the real-time data.

Telegram real-time data can be used for the WOUDC real-time ozone maps, but are not suitable for the data submission to the WOUDC.

Ozone data for a publication

The MGO strongly recommends that the WOUDC users use only the MGO quality controlled data. As a minimum requirement, the data should at least be accompanied by comments (qualified or not qualified). It is standard practice for the MGO to submit only qualified data to the WOUDC.

At present, the MGO presents the qualified data only from Russia and Kazakhstan instruments.

Since 1973, the MGO have performed the control of the filter ozonometers (models M-83 and M-124) data for the former USSR ozone network. The MGO also recommends that the WOUDC users do not use any M-83 data prior to 1973 because of large systematic errors.

State of the M-124 ozonometers network (as of 2002)

The M-124 ozonometers have been in operation for more than 17 years. Each ozonometer requires regular maintenance and repair. With assistance from the WMO, a number of M-124 instruments have been upgraded. Such upgrades include the installation of an inner power supply block, block of thermostabilization and a complete set of new optical filters.

Filter updating is a challenge for the MGO now because Russian industry does not manufacture inexpensive optical glasses anymore.

Up to the year 2002, the MGO upgraded two thirds of the Russian ozonometers.

The instruments located in Lithuania (1 station) and Vietnam (4) were upgraded and calibrated at the MGO in 2002. Also in 2002, two ozonemeters were prepared for Cuba.

The Bulgarian ozonometers were calibrated in 2000.

The Ukraine (3) and Kazakhstan (4) ozonometers were partially upgraded and then calibrated in 1999.

The Latvian ozonometer was calibrated in 1997.

The Georgia, Turkmenistan and Tajikistan instruments have not been calibrated since 1995-96.