Transcript No Slide Title - global change SysTem for Analysis, Research

AF07: Climate Change Scenarios
Project Objectives
Climate change scenario information at spatial and temporal scales appropriate
to the vulnerabilities of Africa.
Emphasis on development of multi-institutional capacity within Africa in the use
and application of regional climate models (RCMs), empirical downscaling, and
analysis of the climate system processes.
Distributed team
Host Institution:
University of Cape Town
Bruce Hewitson
Mark Tadross (project coordinator)
Ernest Afiesiemama
Suman Jain
Joseph Intsiful
Abdoulaye Sarr
Brad Garangara
Hannes Rautenbach
Ruwani Walawege
Chris Jack
William Gutowski
Robert Crane,
Richard Jones
South Africa
South Africa
Nigeria
Zambia
Ghana
Senegal
Zimbabwe
South Africa
South Africa
South Africa
Iowa State University
Penn State University
Hadley Center, UK
GCM Skill: Average precipitation anomaly (mm/day) for DJF
6 GCMs, A2 scenario, 2070-2099 – 1970-1999
GCM Skill: Grid cells where 4 out of 6 models agree on the
sign of the change
RCM or empirical downscaling
translates (in principle) from
GCM to user requirements
User requirement
“Pan equatorial” RCM
domain
Southern Africa RCM domain
 = significant progress
Project activities
GCM Simulations

Assess skill & uncertainty
GCM-based regional scenarios
User Needs
AIACC projects
Other?

Observational Data
Quality Control

Formatting
Dissemination
Common GCM / Observational data sets for participants usage
Availibility via internet and CD- ROM
Regional Climate Model Simulations
Control simulations with reanalysis
()
Skill & uncertainty
GCM boundary forcing
Long-term for sub-continental
Short-term high resolution foci

Empirical downscaling
Downscaling from reanalysis data
()
Skill & uncertainty
Downscaling of GCM simulation data
Initial downscaling of ppt and T
Integration and Analysis
Project progress and status
a) Input to Norwich regional scenario workshop: recommendation that
Africa AIACC-projects emphasize sensitivity studies
b) DDC GCM monthly data collated, subset, with support graphics and
software – initial CD for distribution
c) Historical station data partly collated – initial CD distributed
d) GCM data appropriate for downscaling acquired (high temporal
resolution), and initial assessment of model performance completed
(see later talk)
e) New empirical downscaling methodology developed
f)
RCM tests with MM5 (perturbation and sensitivity to land surface)
g) RCM (MM5) climatology for southern Africa domain complete
h) PRECIS training workshop completed – climatology still to be
assessed
Perturbation simulations:
Experiment: 20% change in land
surface albedo (within natural
variability), can generate a
temperature anomaly of 1°C
Perturbation simulations:
Experiment: Desiccation of
soil moisture – temperature
increases up to 4°C
Next steps:
Continued validation of GCMs and assessment of skill.
Evaluation of GCMs in terms of characteristics for RCM forcing
Empirical downscaling of GCM data.
Climatology simulation with MM5 RCM pan-equatorial domain
Initial climate change simulations with MM5
Climatology simulation with PRECIS
Data product time Frames:
2002/3 : Dissemination of GCM + observational data
2003
: GCM skill assessment and uncertainty envelope
2003/4 : Empirical downscaling products
2004
: RCM-based products
Continuous Assessment: Questions of Integration and Analysis
Inter-GCM comparison – spread as function of GCM and SRES scenario
Downscaling comparison – Inter-RCM comparison / RCM vs Empirical downscaling
Downscaling skill – Stationarity, representation of control climate, convergence?
Confidence levels and uncertainty of regional scenarios
Tailoring of results to user needs
Journal papers / workshops and training / inter-institutional visits / internships