Description / Table of Contents:
This scientific assessment has been carried out by the WCRP project on Stratospheric Processes
and their Role in Climate (SPARC). The objective of the report is to critically review
measurements of water vapour in the stratosphere and upper troposphere, in order to consolidate
our knowledge and understanding of the distribution of water vapour and its variability on time
scales ranging from the seasonal to the long-term inter-annual.
Considering the fundamental role of water vapour in climate, and the scarcity of information
concerning its distribution, variability and long-term evolution, the need for such an assessment
was recognised by the SPARC Scientific Steering Group. The lack of knowledge on water
vapour also leads to a large uncertainty in the prediction of climate change. One of the
objectives of the assessment was therefore to support the Third IPCC Assessment Report on
Climate Change due to be published in 2001.
Great effort has been made to prepare the best data sets possible, to retrieve historical data sets,
and to make them all available to the assessment team. This report contains an extensive
description of the measurements and their associated uncertainties, an assessment of data
quality based on comparison studies of the various data sets, and a description of the
understanding of the distribution and variability of water vapour in the stratosphere and upper
troposphere which ensues from the data. Finally, recommendations are made to ensure that the
difficulties met during this work are overcome in order that the remaining uncertainties in our
knowledge and understanding can be resolved. The preceding summary also appears in SPARC
Newsletter number 16 (January 2001).
The outline of the assessment was determined during an international workshop held at NCAR,
Boulder, Colorado, USA, 26-28 August 1998. The drafts of the chapters were prepared in the
following year and a number of new data sets were produced. The first draft report was
examined by an international panel of reviewers both by mail peer review and at a meeting in
Paris, France in January 2000. During the review meeting the responses to the mail review
comments were proposed by the authors and discussed by the participants. This rigorous review
greatly improved the report, the contribution of the reviewers being significant. A second draft
report was reviewed by mail review in August 2000.
The success in producing the Report is the result of the intensive work and enthusiastic cooperation
of a large number of scientists world-wide who have worked towards improving the
quality of the measurements and our understanding of the observations. The work of the
contributors and reviewers was generously supported by many organisations and agencies
including WMO, WCRP, SPARC, DG Research of the European Commission, NASA, NOAA,
NCAR, CNRS, CNES, Forschungszentrum Jülich, Imperial College and other national research
programmes and institutions.
We take this opportunity to express our gratitude to all the scientists (authors, contributors and
reviewers) who helped in the preparation of this assessment and to the SPARC scientific
steering group who have been supportive since its inception. Our special gratitude is due to the
lead authors of the chapters. Particular thanks must be given to: Petra Udelhofen at the SPARC
Data Center for setting up the data archive, Sam Oltmans who organised the workshop at
NCAR, Boulder, Colorado; Computational Physics Inc., for hosting the workshop in
Washington D.C.; François Dulac from the CNES for hosting the review meeting in Paris, and
Céline Phillips for her co-editorship. We also thank Marie-Christine Gaucher at the SPARC
office for her help in the organisation of the review meeting in Paris and in the final editing of the report and Catherine Michaut at the SPARC office for her help in editing the second peerreview
draft and the final draft of the report.
Online-Ressource (XVIII, 312 Seiten)