S P A R C Stratospheric Processes And their Role in Climate A project of the World Climate Research Programme Home Initiatives Organisation Publications Meetings Acronyms and Abbreviations Useful Links

Preface

The SPARC (Stratospheric Processes and Their Role in Climate) research project was established in 1992 under the auspices of the WCRP (World Climate Research Programme). At that time, it was recognised that the stratosphere plays an important role in the climate system and that the effect of anthropogenic emissions could modify this role. While a great deal of research was being carried out internationally and nationally on the stratosphere, especially on stratospheric ozone, there were several important research areas that were not receiving sufficient attention, notably those concerning the role of the stratosphere in climate. It is the intention of SPARC to stimulate research in those areas that require its attention.

SPARC interacts with the WCRP projects concerned with different aspects of the climate system, such as CLIVAR and GEWEX, as the expert group on the atmosphere in the vicinity of the tropopause and above.

Some of the research interests of SPARC overlap with those of the IGAC (International Global Atmospheric Chemistry) project of the IGBP (International Geosphere-Biosphere Programme). The focus on these issues is not quite the same since IGAC is mainly concerned with tropospheric chemistry and its interactions with the biosphere whereas SPARC seeks to understand the role of chemistry in the depletion of the ozone layer, which impacts the climate system. There has been much co-operation between the two programmes on developing our understanding of the chemistry and aerosols in the upper troposphere and lower stratosphere.

The scientific issues of concern to the SPARC project and its initial objectives were outlined in 1993 by the WCRP and published in the WCRP-83 document. Four research foci were identified for SPARC, as follows:

SPARC has initiated research in all of these areas except UV radiation, where it strongly interacts with the WMO-GAW, who is currently responsible for monitoring trends in UV at the earth’s surface.

In this initial Implementation Plan for SPARC it has been felt necessary to review briefly once again the scientific issues of concern to SPARC since much has occurred since the WCRP-83 document. Understanding on many issues concerning the stratosphere and its role in climate has evolved considerably. The current state of Implementation of the project will be described, and future plans drawn. Since understanding in most of the areas of concern to SPARC is still evolving, not all of the SPARC initiatives are at the same level of maturity. Some have accomplished a great deal already, while others are still in their planning stages. This is reflected in the heterogeneous structure of the document.

The organisation of this implementation plan reflects the current readjustment to the first three foci identified in document WCRP-83. The SPARC research topics have been classified into the three following categories: "Stratospheric Indicators of Climate Change", described in chapter 1; "Stratospheric Processes and Their Relation to Climate" in chapter 2; "Modelling Stratospheric Effects on Climate" in chapter 3.