Report on the WCRP/JSC Meeting, Tokyo, Japan, 13-17 March, 2000

Marie-Lise Chanin and Marvin Geller (SPARC Co-Chairs)

The co-chairs of the SPARC Scientific Steering Group (SSG), Marie-Lise Chanin and Marvin Geller, attended the 21^st session of the Joint Steering Committee for the World Climate Research Programme in Tokyo, held during March 13-18, 2000. Drs. Chanin and Geller made a joint presentation that reviewed the progress of SPARC during the past year as reported in the SPARC Newsletter N° 14, and indicated some new directions that are being considered. The presentation closely followed the SPARC thematics according to the following outline.

Stratospheric Indicators of Climate Change

• Stratospheric Temperature Trends
• Vertical profile of Ozone Trends
• Upper Troposphere/Lower Stratosphere (UT/LS) Water Vapour Climatology and Trends

Stratospheric Processes and Their Relation to Climate

• Dynamics and Transport in the UT/LS
• Chemistry and Microphysics in the UT/LS
• Gravity Wave Processes and their Parameterization

Modeling Stratospheric Effects on Climate

• Climate-Middle Atmospheric Modeling: GRIPS
• Stratospheric Reference Climatology
• Stratospheric Aspects of Climate Forcing
• Dynamical Coupling of the Stratosphere and Troposphere

Other Scientific Issues

• Data Assimilation
• Solar Forcing and Climate Variability
• Monitoring Stratospheric Change

Other Topics

• Review of Overall SPARC Strategy and Status of Implementation
• Cooperation with Other International Programmes
• Planning for the 2^nd SPARC General Assembly
• SPARC Data Centre
• SPARC Office

The discussion on each of these topics closely reflected the Report on the Seventh Meeting of the SPARC SSG that was presented in SPARC Newsletter No. 14. The JSC felt that the SPARC project was progressing quite well, but did present some advice on various topics. These included the following.

Data Assimilation

The JSC urged that the SPARC efforts in data assimilation should be closely coordinated with those of WGNE (the Working Group on Numerical Experimentation).

Stratospheric Aerosols

The JSC felt that consideration should be given to pursuing this aerosol effort as a joint SPARC-IGAC-GEWEX activity. IGAC should be involved given the importance of aerosol chemistry, and GEWEX because of the aerosol impact on radiation and also its role in cloud nucleation.

Next Phase of SPARC

The JSC indicated that it considered SPARC’s efforts so far to be very successful, but that it was timely to consider its future. When asked about when SPARC might consider its efforts complete, Drs. Geller and Chanin indicated not until the role of the stratosphere is properly integrated into the other WCRP projects, will it be time to end SPARC.

Solar Forcing and Climate Variability

The JSC agreed that it is desirable to pursue studies of Upper Atmosphere Trends and Solar Influences on Climate jointly with SCOSTEP. It was also felt that GEWEX should undertake studies of how the occurrence of clouds might depend on solar activity.

Data Activities

The JSC indicated that it was desirable that SPARC and GEWEX link their data bases to one another.