Keywords:
stratosphere
;
ozone
;
aerosol
Description / Table of Contents:
Assessments of stratospheric ozone have been conducted for nearly two decades and have
evolved from describing ozone morphology to estimating ozone trends, and then to attribution
of those trends. Stratospheric aerosol has only been integrated in assessments in the context
of their effects on ozone chemistry and has not been critically evaluated itself. As a result,
the Assessment of Stratospheric Aerosol Properties (ASAP) has been carried out by the
WCRP project on Stratospheric Process and their Role in Climate (SPARC). The objective
of this report is to present a systematic analysis of the state of knowledge of stratospheric
aerosols including their precursors. It includes an examination of precursor concentrations
and trends, measurements of stratospheric aerosol properties, trends in those properties, and
modeling of aerosol formation, transport, and distribution in both background and volcanic
conditions. The scope of this report is extensive; however, some aspects of stratospheric
aerosol science have been deliberately excluded. For instance, we have not attempted to include
an examination of polar stratospheric clouds (PSCs) or other clouds (such as cirrus
clouds) occurring at or above the tropopause except in as much as they influence aerosol observations.
Polar stratospheric clouds are the subject of a separate SPARC activity. We have
produced a gap-free aerosol data base for use beyond this report. This required some new
analysis that has not previously appeared in the technical literature. Similarly, the trend
analysis required the development of a new analysis technique that is the subject of an article
published in the Journal of Geophysical Research. New work is clearly identified in the present
report.
ASAP began with a general kick-off meeting in November 2001 at CNES in Paris, France.
There were also three chapter lead meetings in Nice, France (April 2003), in Frankfurt, Germany
(July 2003) and in Lexington, Massachusetts, USA (January 2004). The final report is
the result of concerted effort by scientists world-wide who continue to work toward understanding
the measurements and processes controlling stratospheric aerosol. Their work was
supported by their host institutions and funding agencies that include the WCRP and the
SPARC Office (in Paris and Toronto), as well as Atmospheric and Environmental Research,
Inc., NASA, the Universities of Frankfurt and Wyoming, and ETH Zurich. An initial overview
of ASAP appeared in the SPARC Newsletter No. 23 in July 2004.
Pages:
Online-Ressource (XXIV, 322 Seiten)
URL:
http://www.sparc-climate.org/publications/sparc-reports/sparc-report-no4/
Language:
English
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