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Objectives

To determine

the predictability of climate

the effect of human activities on climate

WCRP

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TOGA 1985-1994

GEWEX 1988

WOCE 1990-2002

SPARC 1992

ACSYS 1994–2003

CLIVAR 1995

WGNEWGCM

, CliC 2000

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Aim of SPARC

• To bring stratospheric expertise to bear on scientific issues concerned with climate processes and climate prediction;

• for the benefit of– WCRP – WMO/UNEP Ozone Assessment– IPCC– Space Agencies

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Current SPARC Themes• Stratospheric Indicators of Climate Change

– Trends in T, O3 and H2O in UTLS

• Stratospheric Process and their Relation to Climate – UTLS – gravity wave process + parametrisation

• Modelling stratospheric effects on climate– GCM Reality Intercomparison Project (GRIPS) – reference climatology

• Special projects (e.g.)– aerosol assessment – data assimilation

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Recent Deliverables

• "Stratospheric temperature trends: observations and model simulations" (paper by STTA group, awarded the WMO Norbert Gerbier-MUMM Award, 2003).

• Stratospheric reference climatology

• WMO/UNEP Ozone Assessment 2002– Chap. 4 Global Ozone: past and future.

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Stratospheric Chemistry

and Climate

Stratosphere-Troposphere coupling

Detection and Attribution of Past Stratospheric Changes

Model

Development

Process

StudiesData

Future Themes

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Stratospheric Chemistryand Climate

• How will stratospheric ozone and other constituents evolve?

• How will changes in stratospheric composition affect climate?

• What are the links between changes in stratospheric ozone, UV radiation and tropospheric chemistry?

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Detection and Attribution of Past Stratospheric Changes

• What are the past changes and variations in the stratosphere?

• How well can we explain past changes in terms of natural and anthropogenic effects.

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1979-1994

2 uncertainty

Compiled using radiosonde, satellite and analysed data sets

Mean vertical profile of annual & decadal temperature trend at 45oN.

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Stratosphere-Troposphere Coupling

• What is the role of dynamical and radiative coupling with the stratosphere in extended range tropospheric weather forecasting?

• What is the role of dynamical and radiative coupling in determining long-term trends in tropospheric climate?

• By what mechanisms do the stratosphere and troposphere act as a coupled system?

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Future Deliverables• Temperature Trend Assessment Report. • Aerosol Assessment Report.• Review on AO/NAO for strat-trop system.• Review of gravity-wave parameterisations

(after Chapman conference 2003). • Review of scientific issues in chemistry-climate.• Ozone: coherent review on GCM/CTM. predictions of

mid-latitude O3 anticipating next WMO/UNEP requirement.

• IPCC

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SPARC General Assembly 1-6 August 2004

• Victoria, Canada

• Co-chairs of Programme Committee:– A.R. Ravishankara & T. Shepherd

• Chair of LOC: N. McFarlane

• Web site http://sparc.seos.uvic.ca (to be launched in few weeks time)