1. The CCAM multi-scale variable-resolution modelling system at CSIR
Francois Engelbrecht, Willem Landman and Mary-Jane Bopape CSIR Natural Resources and the Environment Climate Studies, Modelling and Environmental Health

2. Climate Modelling at the CSIR NRE
NWP and RCM capacity build around the conformal-cubic atmospheric model (CCAM) of the CSIRO
A cube-based global model; semi-Lagrangian semi-implicit solution of the primitive equations
Includes a wide range of physical parameterizations
Developed by the CSIRO Marine and Atmospheric Research (McGregor, 2005)
Runs in quasi-uniform or in stretched grid mode
Multi-scale climate modelling.
Quasi- uniform C48 grid with resolution about 210 km
© CSIR

3. Regional climate modelling and NWP over Africa using CCAM
CCAM applied in stretched-grid mode
Modest stretching provides a resolution of about 50 km over southern Africa; decreases to about 4 degrees in the far-field
Options for spectral nudging, gridpoint nudging or no nudging from the host model (atmospheric fields)
C64 stretched-grid with resolution about 50 km over southern Africa
© CSIR

4. CSIR seamless forecasting system CSIR CCAM 7-day forecast
Testing the CCAM code used for projections of future climate change through short-range and seasonal forecasts leads to model development and increased confidence climate change projections
Routine CCAM short-range weather forecasts over Africa (7-days ahead, 50 km resolution)
Higher-resolution forecasts are produced over smaller domains (downscaling) - False Bay example:
CSIR CCAM 7-day forecast
Engelbrecht et al. (2011) Water SA; Landman et al. (2012) Water SA.

5. Forecast error as a function of integration time
Average Absolute Error 500 hPa geopotential height: January 2005
Potgieter (2006), UP
© CSIR

6. Forecast error as a function of integration time
Average Absolute Error 500 hPa geopotential height: January 2005
Potgieter (2006), UP
© CSIR

7. Forecast error as a function of integration time
Average Absolute Error 500 hPa geopotential height: January 2005
Potgieter (2006), UP
© CSIR

8. UM CCAM Rainfall Bias ONDJFM 2007/8 Rainfall Bias ONDJFM 2007/8
Landman et al. (2012) Water SA UM
CCAM
Rainfall Bias ONDJFM 2007/8
Rainfall Bias ONDJFM 2007/8

9. Brier Skill Score ONDJFM 2007/8
Landman et al. (2012) Water SA UM
CCAM
Brier Skill Score ONDJFM 2007/8
Brier Skill Score ONDJFM 2007/8

10. Brier Skill Score ONDJFM 2007/8
Landman et al. (2012) Water SA UM
CCAM
Brier Skill Score ONDJFM 2007/8
Brier Skill Score ONDJFM 2007/8

11. Seasonal forecast operational approach (SARVA, GFCSA)
Atmospheric ICs
NCEP/GFS
Boundary Conditions
Model Output Statistics

12. Verification of seasonal forecasts: CCAM and CGCMs
Spearman’s rank correlation between observed and downscaled DJF seasonal rainfall totals. The correlations were calculated over the period from 1979/80 to 2004/05
CCAM simulation skill (ROC) over north-eastern interior
Latest system based on CCAM-CABLE with 27 levels in the vertical
Engelbrecht et al. (2011) Water SA; Landman and Beraki (2012) IJC
Winsemius et al. (2014) HESS in press

13. Emission Scenarios and Representative Concentration Pathways
CSIRO: Martin Dix

14. CRUTEMP3v linear temperature trend 1961-2010 (°C per century)
Strong warming has occurred over the western+central parts of southern Africa
Warming more moderate along the coastal areas

15. Simulated trends for 1961-2010 are shown (°C per century)
A strict test of the seamless forecasting system: simulation of temperature trends over southern Africa
Simulated trends for are shown (°C per century)
© CSIR

16. Taylor diagram: Verification of simulated linear trends in annual average temperatures over southern Africa
The six ensemble members produced very different simulations of the trends in annual average temperatures over southern Africa
The simulation of trends in regional climate provides a stringent test to regional climate models
© CSIR

17. CSIR-CSIRO collaboration
CCAM-CABLE projections of future climate change (CORDEX)
CSIR-CSIRO collaboration
RCP4.5
RCP8.5

18. Time-slabs annual rainfall anomalies (mm) – based on six CCAM A2 SRES scenarios
Most ensemble members project southern Africa to become generally drier under climate change
Most ensemble members project East Africa to become generally wetter under climate change
A robust signal of drying is projected for the southwestern Cape of SA.
Engelbrecht et al. (2009), IJC
Engelbrecht et al. (2011), Water SA
Engelbrecht et al. (2012), IJC
© CSIR

19. Climate Change, climate dynamics and extreme weather events over southern Africa
MSG IR image
© CSIR

20. Climate Change and Tropical Cyclones+Lows
Model simulated (top) and observed (bottom) tropical cyclone track climatology over southern Africa – for the period
Malherbe et al. (2013), Climate Dynamics
© CSIR

21. Climate Change and Tropical Cyclones+Lows
Model projected change in tropical cyclone and tropical low frequencies over the southwestern IO and southern Africa, for relative to
Malherbe et al. (2013) Climate Dynamics
© CSIR

22. Projecting latitudinal shifts in the westerlies in response to enhanced anthropogenic forcing: the enhanced greenhouse effect and (recovering) depleted stratospheric ozone
Projected changes in mean winds and storm tracks are relevant to Southern Ocean dynamics, bio-chemistry and carbon cycle
Simulated 1000 hPa u-winds ( ) for January and projected changes ( vs ). A2 scenario with full radiative forcing
Latest research explores the effects of stratospheric ozone depletion and cooling on southern African rainfall at inter-annual time-scales – implications for predictability at the seasonal time- scale
© CSIR

23. CSIR-NRE has capacity in numerical model development
Simulations of nonhydrostatic mountain waves
Scorer parameter =S ~ N/U = 0.001
1/S ~ a = 2000 m
Propagation of waves on the lee side of the mountain
Janjic et al. (2001)
Engelbrecht et al. (2007) SAJS

24. 2K radiative cooling in troposphere
Non-hydrostatic atmospheric dynamics and cloud microphysics scheme development – consistent with atmospheric component of the new coupled model (MW equations)
NH tests inform the development of larger-scale convection parameterizations within the coupled model
Thunderstorms forced with observed large scale forcing – T, qv, SST, surface p, zonal wind
2K radiative cooling in troposphere
Model is able to capture suppressed and deep convection periods.
Simulations – convection triggered by 2K perturbation with different micro-physics
Engelbrecht et al. (2006) SAJS
Bopape et al. (2013) APJAS
Bopape et al. (2014) SAJS in press
Tozuka et al. (2013) Climate Dynamics

25. Development of a new cube-based Earth System Model in Africa (CSIR-CSIRO-JAMSTEC collaboration)
Based on cube-based global atmospheric and land-surface models of CSIRO and a cube-based global ocean model of JAMSTEC (equi-angular gnomonic-cubic grid)
Coupling of ocean and atmosphere components performed at CSIR
Seasonal forecasting
Projections of future climate change (CMIP6)
Simulations of Southern Hemisphere climate dynamics;
Simulations of the carbon cycle of the Southern Ocean and southern African landmass
Paleo-climate simulations