1. COMMISSION FOR ATMOSPHERC SCIENCES (CAS) ATMOSPHERIC RESEARCH AND ENVIRONMENT PROGRAMME (AREP)
Report on Activities of the
Commission for Atmospheric Sciences (CAS) and
Atmospheric Research and Environment Programme (AREP)
in Support of the WMO DPM Programme
Dr. Michel Béland, President of CAS
Dr. Len Barrie, Director, AREP
Dr. Slobodan Nickovic, Scientific Officer, ARREP
WMO DPM Programme Coordination Meeting, 4-6 December, Geneva

2. CAS Mandate Support of research in atmospheric science to:
Reduce and mitigate natural disasters,
Protect the environment,
Enhance understanding and response to environmental change
through the Global Atmospheric Watch (GAW) and World Weather Research Programme (WWRP-THORPEX)
WMO DPM Programme Coordination Meeting, 4-6 December, Geneva

3. CAS COMPONENTS:
WMO DPM Programme Coordination Meeting, 4-6 December, Geneva

4. CAS: WWRP-THORPEX Goals – to improve forecasting of
High-impact weather (tropical storms, monsoons)
Clouds and precipitation
Chemical Weather
Sand and dust storms
WMO DPM Programme Coordination Meeting, 4-6 December, Geneva

5. Warning on extreme-weather related hazards
Deliverables
Warning on extreme-weather related hazards
Improvement of forecast skill
Designing strategy for interactive forecasting and observation
Data assimilation for satellite and in situ data
Testing the effectiveness of a global ensemble forecasting system
Status
Early implementation stage; timeline:
Responsible
OPAG-WWRP
Crosscutting cooperation
CBS, CIMO, CCI, All RA’s
WMO DPM Programme Coordination Meeting, 4-6 December, Geneva

6. Global Interactive Forecast System based on THORPEX INTERACTIVE GLOBAL GRAND ENSEMBLE (TIGGE)
Ensembles of global forecasts conducted by three Centres (CMA, ECMWF & NCAR)
Distributed archives providing regional products
Research will address dynamical and physical process operating on various scales that contribute to errors in high-impact forecasts. Studies of Rossby wave excitation and subsequent dispersion will consider: i) the skill of forecast systems in predicting Rossby wave amplitudes, ray-paths and group velocities; ii) the initiation of wave -trains by tropical convection, extratropical cyclones and large -scale topography; iii) the initiation of tropical convection by Rossby wave-trains propagating from extratropics into the tropics; iv) the influence of physical processes, both parametrised and explicit, on the prediction of Rossby waves and their dispersion. Coherent structures, such as discrete anomalies of PV, and the extratropical transition of tropical cyclones, will be investigated. Assessments will be made of the role of global teleconnections, e.g., tropical-extratropical interaction, including the factors involved in their initiation and predictability.
THORPEX will assess the intra-seasonal and inter-annual variability in the climatology of forecast error, ensemble spread and the distribution of observationally sensitive regions. This includes determining the dependence of these climatological variabilities on flow regimes, such as: i) zonal or blocked states, and ii) phases of prominent phenomena and major teleconnections, e.g., MJO, PNA, ENSO and NAO. The impacts of such flow regimes and their variability on Rossby wave propagation, dispersion and predictability will be investigated. The skill of EPS forecasts will vary depending on the meteorological situation. For example, the skill in predicting extratropical cyclones in the Pacific sector may differ substantially depending on the phase of ENSO (e.g., Shapiro et al 2000). This is referred to as regime-dependent evaluation of forecast skill. THORPEX aims to fully explore the analysis of this regime dependence, as this will provide substantial input to improve EPS design.
Key questions concern what are the limitations of predictability and what determines these limitations. THORPEX aims to address these issues, including an assessment of the various limitations of predictability appropriate to defined forecast attributes, and through this assessment explore new forecasting strategies to reduce these limitations. Improved methods of generating ensembles will be used to investigate potential predictability, under the perfect model assumption, utilizing state-of-the -art operational forecast models to assess the potential for further improvements in predictive skill.
a) Quantify the contributions of initial condition and model uncertainty to forecast errors: Developing interactive forecast systems depend critically on having accurate estimates of the sources of forecast error attributable to initial condition uncertainty and forecast-model uncertainty. Research will quantify the influence of all sources of forecast error and their associated mechanisms for growth, on different space and time scales and for different variables and different meteorological phenomena. This includes the uncertainty associated with numerical schemes and physical parameterizations. Improved estimates of the relative contribution of the various sources of forecast error growth will lead to improved probabilistic forecasts and products.
b) Investigate the relative effects of small and large-scale initial-condition uncertainty:
Forecast errors can grow rapidly upscale from initial uncertainties in the small-scale motions. However, the analysis and forecast uncertainty is dominated by the slower -growing, but far more energetic, larger-scale motions. THORPEX will address the relative roles of these two sources of initial uncertainty in limiting forecast skill. This will provide guidance for the design of improved observation systems and observing strategies, i.e., should observations be targeted in localized regions of rapid forecast error growth, or is the reduction of initial uncertainty at the larger scales preferable through dispersing finite observation resources over broader areas?
c) Develop improved ensemble -prediction systems: Improved ensemble perturbations are required to accurately represent uncertainty in all aspects of the initial state, including land and ocean surface conditions. Advanced methods must be developed to account for the effect of un-parameterized, unresolved phenomena on the resolved scales in ensemble forecast systems. Formulations are required to include uncertainties in forecast model formulation, including numerical errors and parameterization errors, in forecast ensembles (these may include investigations of multi-model and multi-parameter ensemble prediction methods, as well as stochastic parameterizations). Prior research has indicated that there may be some useful additional ensemble spread contributed by multi-model or multi-parameterization ensembles. However, these techniques are mostly ad-hoc, and it is not clear if their benefit is from the variety of forecast models or the variety of initial conditions provided by different forecast systems. Additional research will determine the potential applications of multimodel ensembles.
The parameterisation schemes in present-day forecast models were designed to give the best possible single forecast and not an ensemble. This is a fundamental problem, since many of these schemes (e.g., those representing turbulent diffusion by unresolved sub-grid processes or convective instabilities) have a stabilizing effect on the resolved larger scales, even though the process acts as a forcing in nature. Hence, another presumably more desirable approach involves developing parameterisations that are stochastic, i.e., time tendencies in the models that include a random component.
d) Development of Grand Ensemble Prediction System:
Determine the degree of intra-seasonal predictive skill: Studies suggest that there is predictive skill in forecasting weekly averages several weeks ahead. Much of this skill can be achieved by simple linear, stochastically-forced inverse models of the extratropical circulation and tropical heating variations derived from their observed simultaneous and lagcorrelation statistics. Such models have been shown to be competitive with operational forecast models at 2-3 week forecast ranges. Results from using these inverse models show that extratropical weekly averages are predictable only about two weeks ahead if the influence of tropical heating is ignored, but might be predictable as far as six weeks ahead, in some locations, if that influence were properly taken into account. This suggests that 2-3 week forecast skill could be improved by including predictions of the evolution of sea -surface temperature anomalies. Further research will address how much of the predictability in the linear inverse model is associated with growing singular vectors of the empirically-determined system propagator. Research is also required to determine whether such singular vectors could be used for targeting of observations in climatologically critical regions to improve forecasts with lead times of up to two weeks. Reconfiguration of regional observing systems will require longer lead-times than for localized targeting for short-range forecast applications.
WMO DPM Programme Coordination Meeting, 4-6 December, Geneva

7. WMO Sand and Dust Storm Warning System
WWRP/GAW Sand and Dust Storm (SDS) Project was established in September 2004
The Development of a Regional Sand and Dust Storm Early Warning System in East Asia was presented at the Third International Early Warning Conference, Bonn, Germany, March 2006
A new proposal on WMO Sand and Dust Storm (SDS) Warning System extending the scope to two other regions has been accepted at the Scientific Steering Committee meeting for SDS Project (November 2006 Shanghai, China)
PROJECT OBJECTIVE:
To establish a WMO-coordinated global network of SDS forecasting centers delivering products useful to a wide range of users for reducing the impacts of SDS
WMO DPM Programme Coordination Meeting, 4-6 December, Geneva

8. A WMO survey in 2006: more than 40 Member States expressed interest to participate in SDS project

9. Designated three Regional WMO SDS Warning System (SDSWS) Centres:
Deliverables
Designated three Regional WMO SDS Warning System (SDSWS) Centres:
Spain (for the Europe/Africa/Middle East region)
China (for the Eastern Asia region)
Canada (for the Southern America region)
Research operational SDS forecasts provided by eight organizations within the above three regions
Establishing a WMO SDSWS portal to support the above activities
Established an expert group for SDSWS implementation
Proposed an Secretariat-based group in support of SDSWS activities and cross-cutting issues
WMO/GEO Expert Meeting on International Sand and Dust Storm Warning System” to be organized in Barcelona, Spain in November 2007;
WMO DPM Programme Coordination Meeting, 4-6 December, Geneva

10. ACADEMIA WHO CAS CBS CAeM CAgM
Status
Implementation; Timeline:
Responsible
OPAG-WWRP, OPAG-EPAC
Crosscutting aspects
All affected regions: RA I, II, IV, V, VI,
NHMSs (Spain, Japan, China, Korea, Canada);
Academia: U of Arizona, Barcelona
Users, modellers, observation community
ACADEMIA
WHO
Developments
Health
CAS
CBS
CAeM
CAgM
Data exchange
Agriculture
Aviation
WMO DPM Programme Coordination Meeting, 4-6 December, Geneva

11. 13 April 2002 Napoli Raman Lidar
WMO DPM Programme Coordination Meeting, 4-6 December, Geneva

12. Dust impacts health
Valley Fever endemic regions
WMO DPM Programme Coordination Meeting, 4-6 December, Geneva

13. Improved accuracy of high impact weather forecasts
CAS: Tropical Meteorology Research - Monsoon variability, tropical cyclone forecasting, tropical limited area modeling
Deliverables
Improved accuracy of high impact weather forecasts
Training workshops on monsoon, tropical cyclone and application based on NWP
Status
Implementation; Timeline:
Responsible
OPAG-WWRP
Crosscutting cooperation
WCRP, All RA I, II, IV, V, ICSU
WMO DPM Programme Coordination Meeting, 4-6 December, Geneva

14. CAS: GAW Programme
Deliverables
Improving environmental security by implementing of the Integrated Global Atmospheric Composition Observation (IGACO) strategy
Scientific assessments in support of environmental policy
Coordinating global measurements of atmospheric chemical variables
Routine monitoring of air pollution and sand/dust storms
Responsible
OPAG-EPAC
Status
Ongoing programme, Timeline:
Crosscutting cooperation
IGACO, NHMSs
WMO DPM Programme Coordination Meeting, 4-6 December, Geneva

15. Global Aerosol Optical Depth
Ozone and Aerosols - Essential Multi-Hazard Climate and Weather Variables
Beijing Roof CMA March
DUST
POLLUTION
FIRES
OZONE HOLE & UV
A best estimate of the global distribution of annual average tropospheric aerosol optical depth (AOD) compiled by combining data from six satellites (operating for limited periods between 1979 and 2004). Observations for a region were selected using ground- based AOD observations as guidance ( courtesy of S. Kinne MPI, Hamburg, Germany
Global Aerosol Optical Depth

16. Acquisition of advanced equipment and software
AREP: Development of an Advanced Tropical Cyclone Early Warning System for the Philippines
Deliverables
Education and training of local personnel on NWP, interpretation of RS observations, risk management
Acquisition of advanced equipment and software
Transfer of technology to other countries in the region (in the second phase after 2009)
Status
Work Plan development stage; Timeline:
Responsible
OPAG-WWRP
Crosscutting cooperation
CBS, RA V and II, NHMS of Philippines, Australia, Japan, USA, Japan MRI, US NCAR, US National Hurricane Center
WMO DPM Programme Coordination Meeting, 4-6 December, Geneva

17. AREP (THORPEX): Health and Climate Partnership for Africa Deliverables
Reviewing social impacts of timely warnings of epidemics
Education and training both meteorological and medical community
Improved understanding of relationship between environmental conditions and health outcomes
Downscaling of seasonal forecasts to a particular regions interest
Status
Work Plan development; Timeline:
Responsible
OPAG-WWRP
Crosscutting cooperation
WCP, WCRP, RAF;
WHO, CERMES, ACMAD, AGRHYMET, ECMWF, NOAA, U of Liverpool, Liverpool School of Tropical Medicine, US EPA
WMO DPM Programme Coordination Meeting, 4-6 December, Geneva

18. AREP: Weather Modification Activities Deliverables
WM research projects in different member States for precipitation enhancement and hail suppression
Status
Ongoing activities in Member States
Responsible
OPAG-WWRP
Crosscutting cooperation No
WMO DPM Programme Coordination Meeting, 4-6 December, Geneva

19. Backup slides
WMO DPM Programme Coordination Meeting, 4-6 December, Geneva