1. © Crown copyright Met Office WGNE activities and future directions Andy Brown and Jean-Noël Thépaut (WGNE co-chairs)

2. © Crown copyright Met Office Role of WGNE Working Group on Numerical Experimentation Jointly established by the WCRP and the WMO Commission for Atmospheric Sciences (CAS) Responsibility of fostering the development of atmospheric circulation models for use in weather prediction and climate studies on all time scales and diagnosing and resolving shortcomings. A distillation of the Terms of Reference….. Advice, liaison Co-ordinated experiments Workshops, publications, meetings

3. © Crown copyright Met Office Co-ordinated projects and experiments Transpose-AMIP - testing climate models in weather mode Cloudy-radiance - comparing methods used in data assimilation Grey-zone - representation of cold-air outbreaks at different resolutions Verification NWP performance (eg TCs, precipitation) Polar (CBS-style; ConcordIASI intercomparison) PPP Climate metrics Issues with verification against own analysis MJO / Boreal Summer Intraseasonal Oscillation intercomparisons (with MJO-TF) Importance of aerosols for weather and climate - assessing the level of complexity required Comparison of model momentum budgets - how do they differ? What is right?

4. MJO Task Force Joined WGNE ~1.5 years ago Continues to make progress towards its overall goal to facilitate improvements of the MJO in weather and climate models. 6 current subprojects: 1.Process-oriented diagnostics/metrics for MJO simulation 2.Boreal summer monsoon ISV monitoring and forecast metrics 3.Assessment of CMIP5 model capability to simulate realistic intraseasonal variability 4.MJO TF + GASS Multi-Model Diabatic Processes Experiment 5.MJO air-sea interaction 6.The MJO and the Maritime Continent (with S2S). All is, and will continue to be, completely aligned with S2S

5. WGNE DRAG-project, torque inter-comparison Step0-24 January 2012 Thanks to: Ayrton Zadra subgrid orography

6. WGNE DRAG-project, torque inter-comparison Step0-24 January 2012 Boundary layer Thanks to: Ayrton Zadra

7. WGNE DRAG-project, torque inter-comparison Step0-24 January 2012 Boundary layer + subgrid orography Thanks to: Ayrton Zadra

8. ECMWF – 8© European Centre for Medium-Range Weather Forecasts AEROSOL impact on NWP

9. ECMWF – 9© European Centre for Medium-Range Weather Forecasts 3 cases: Egyptian dust storm – 18 April 2012 Air pollution event, Beijing – 14 January 2013 Biomass burning over South America

10. ECMWF – 10© European Centre for Medium-Range Weather Forecasts

11. ECMWF – 11© European Centre for Medium-Range Weather Forecasts

12. ECMWF – 12© European Centre for Medium-Range Weather Forecasts Impact of aerosols direct effect on minimum temperatures Taking into account the direct effect brings warmer night-time temperatures over land, by up to 4 degrees Near-perfect collocation with AOD patterns For most stations in desertic area, it reduces a cold bias at night Creates a local heat low Generates stronger local wind Lifts more aerosols (in agreement with observations) With direct effect

13. WGNE Greyzone project The Grey Zone Project aims to systematically explore convective transport and cloud processes in weather and climate models at various resolutions, ranging from high resolution turbulent resolving scales all the way to coarse resolutions that require full parameterized descriptions of these processes. By exploring the behaviour of these models with and without convective parameterizations through the so-called grey zone the project aims to answer:  What are the relative contributions of the parameterized versus the resolved contributions to the convective transport?  How well do models operate in the grey zone without an explicit convection parameterization?  How well do models operate in the grey zone with a convection parameterization?  How should scale-aware convection parameterizations behave in the grey zone? The Grey Zone project aims to apply this methodology on a number of different types of moist convective systems. The type of moist convection considered here is a cold air outbreak. 3 components – Global (MPI led), LAM (MetOffice led), LES (TUD led) LAM contributors so far: NCAR, NOAA, CHMI, CNRS, UKMO, [coming soon JMA, EnvCan]

14. UM No convection WRF No convection 1km2km4km8km16km MODIS LW Workshop Dec 1-3 MPI, Hamburg

15. © Crown copyright Met Office 4th WGNE Workshop on Systematic Errors in Weather and Climate Models Met Office, Exeter, UK. 15th- 19th April 2013 Weather and climate Nature and causes of errors Use of diagnostic techniques, observations, process models and simplified experiments to understand errors http://www.metoffice.gov.uk/conference/wgne2013

16. © Crown copyright Met Office Future directions Short-range weather prediction Changing focus – cloud, rain, surface temperature (not Z500!) Increased emphasis on high resolution – especially convection permitting Grey-zone project Appropriate metrics for high resolution models (with JWGVR) and routine use of them Link to climate downscaling? 25km 1.5km

17. © Crown copyright Met Office Future directions Earth system prediction Weather models coupled to ocean, composition, air quality, hydrology, ice..... Bringing together communities (GODAE coupling workshop; systematic errors meeting) Importance of aerosol for NWP: review and test cases TRANSPOSE-CMIP? Time evolution of coupled model SST errors

18. © Crown copyright Met Office Future directions “Traditional model evaluation and development” Still important – and importance under-recognized Champion (with partners) e.g. Conferences Specific projects to engage community and tackle key issues

19. © Crown copyright Met Office Future directions Continue to look cross-timescale – weather and climate (and air quality/chemistry) communities together Need to keep championing the importance of model development Maintain strong links to many other groups and projects e.g. WWRP, DAOS, GASS, PPP, subseasonal-seasonal, HIW, EUMETCHEM, WGCM, SPARC, WMAC, GODAE, WCRP Grand Challenges...... Maintaining an active portfolio of projects and workshops and conferences

20. ECMWF – 20© European Centre for Medium-Range Weather Forecasts Future directions: short-term focus and immediate actions Comparison of model momentum budgets – Consolidate results, engage with more participants, expand to climate (SPARC) Importance of aerosols for weather and climate – Expand cases, refine protocols, expand beyond NWP angle, etc. Links to EUMETCHEM Support to S2S – Systematic error workshop, special focus on teleconnections Support to PPP (PCPI) – Verification (quality of (re-)analyses), observational system design, etc. Support to HIW Support to CMIP – High resolution time slice intercomparisons

21. © Crown copyright Met Office Questions?

22. Aerosols project Progress with 3 case studies Develop links to EUMETCHEM Workshop Broader role in air quality? Grey-zone, drag projects – good progress; discussing next steps Verification – link TC work to proposed RDP; further work on verification against analyses High resolution climate – planning systematic study as part of CMIP6 Future systematic errors workshop – link to S2S/teleconnections Future membership changes Role of CAS in influencing funding agencies? © Crown copyright Met Office WGNE 29, Melbourne 10-13 March 2014