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Report on the 23^rd Session of the Joint Scientific Committee (JSC) for the World Climate Research Programme (WCRP)

Reading, United Kingdom, March 17-21, 2003

Alan O’Neill, Data Assimilation Research Centre, Reading, UK (alan@met.reading.ac.uk)

The JSC of the World Climate Research Programme held its 23^rd annual meeting during 17-21 March at the University of Reading, UK. The co-chairs of SPARC, A. O’Neill and A.R. Ravishankara, attended on behalf of SPARC. The meeting was an especially important one for SPARC to air its views, since the scientific direction and structure of WCRP was being considered. The meeting considered a major new effort on the prediction and predictability of seasonal to inter-decadal climate variations, reaffirming WCRP’s original aims: to determine to what extent climate can be predicted; and to determine the extent of man’s influence on climate. It was also proposed the JSC should investigate the feasibility of a Global Climate Experiment. Specifically, the idea for a decade long observational programme was proposed to exploit to the full all the new satellite instruments that are, or soon will be, available.

SPARC’s new scientific themes fit in very well with the proposed evolution of WCRP. They recognise the need for a closely integrated effort with other projects in WCRP. A. O’Neill opened SPARC’s presentation to the JSC by emphasising the science-oriented nature of SPARC’s activities, and the responsiveness of SPARC to the needs of international bodies such as WMO/UNEP and the IPCC. He noted that recent achievements included the completion of a SPARC reference climatology (led by W. Randel), and strong participation in the WMO/UNEP Ozone Assessment 2002.

He then outlined SPARC’s future themes: stratospheric chemistry and climate; detection and attribution of past stratospheric changes; and stratosphere-troposphere coupling. These scientific themes are underpinned by targeted supporting activities: model development, process studies and data. Working groups are being established to advance these themes. The SPARC Data Center will continue to be an important resource for the community, linking in with the developing activities of the SPARC Data Assimilation Working Group. A. O’Neill expressed the sadness felt by the SPARC community about the tragic death of P. Udelhofen, who had done so much to place the SPARC Data Center on a secure footing.

He noted that the SPARC Office provided essential support for the project, and mentioned that discussions are under way to relocate the Office when the long-standing support provided by CNRS ends in spring 2004.

His presentation continued with a summary of the links between SPARC and other WCRP projects. Existing links with WGNE (e.g. on data assimilation) and WGCM (e.g. on coupled chemistry-climate modelling) are being strengthened, and closer links are needed with CLIVAR (e.g. on predictability), GEWEX (on water vapour, the hydrological cycle and radiation), ACSYS/CliC (on studies of polar regions) and WGSIP (on seasonal and inter-annual prediction).

SPARC is playing an active role in strengthening these links. A. O’Neill noted that the SPARC 3_^rd General Assembly in 2004, Victoria (BC), Canada, was located, and will be structured, to encourage participation of the wider climate community.

A.R. Ravishankara delivered the second part of the SPARC presentation to the JSC, focusing on the new theme of chemistry-climate interactions, and a joint venture in this area with the IGBP Global Atmospheric Chemistry (IGAC) project. The list of topics that would benefit from such a collaboration is large, including: the role of aerosols and clouds in chemistry and climate, the role of convection in controlling UT/LS water and chemical constituents, and the extent and role of stratosphere-troposphere exchange in controlling the abundances of ozone and other species in UT/LS region. A.R. Ravishankara noted the success of a current SPARC-IGAC collaboration on laboratory data, which led to a peer-reviewed paper. He mentioned that a joint SPARC-IGAC workshop was planned in April 2003, at Giens, France, to further define the programme, and that the main recommendations of this workshop would be presented at the joint meeting of the AGU and EGS in Nice later in the month.

The SPARC presentations were very well received by the JSC. The JSC approved the new formulation of SPARC and its science goals. It welcomed the ongoing efforts in the joint IGBP/WCRP atmospheric chemistry-climate initiative, and supported the planned efforts in this direction, including the joint SPARC/IGAC workshop in April 2003. The JSC further recommended that its members help identify financial support for the SPARC 3^rd General Assembly (1-6 August,2004 Victoria, Canada).