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WG-MWFR activities Jeanette Onvlee Chair WWRP/WG-MWFR

WG-MWFR activities Jeanette Onvlee Chair WWRP/WG-MWFR. Outline: Scientific issues WG-MWFR Activities Liaisons with other groups. Scientific issues considered. Mesoscale data assimilation : What analysis setup is most appropriate for mesoscale/nowcasting?

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WG-MWFR activities Jeanette Onvlee Chair WWRP/WG-MWFR

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  1. WG-MWFR activities Jeanette Onvlee Chair WWRP/WG-MWFR WGNR meeting, 8-10 February 2011

  2. Outline: • Scientific issues • WG-MWFR Activities • Liaisons with other groups WGNR meeting, 8-10 February 2011

  3. Scientific issues considered • Mesoscale data assimilation: • What analysis setup is most appropriate for mesoscale/nowcasting? • How best to analyze moist processes, with minimal spinup? • How to add small scale information while retaining the strengths of the larger scale nesting analysis? • What is best way to use radar, cloud, hydrometeor information? • Convection and complex topography: • Grey zone for convection/turbulence: how to handle in models? • How to best represent steep orography? • Surface modelling • Initiation and modelling of new, more realistic components (e.g. snow, urban) • High-quality high-resolution physiographic data • Predictability and probabilistic forecasting • What influences predictability on convection-permitting scales, and how to describe it? • Towards convection-permitting ensembles: practical methods, cross-fertilization of ensemble and DA techniques? • Underlying all: suitable verification and validation methods WGNR meeting, 8-10 February 2011

  4. Activities • Focus on 0.5-5km grid size models, mostly extratropics so far • Push mesoscale weather research questions in several fora • Help set up / involvement in RDP’s/FDP’s • Just started activities on: • “Grey zone” studies in context of WGNE • Promote worldwide standards for mesoscale verification, routine quality assessment and exchange (together with JWGV) • Inventory of available mesoscale training material, gaps therein • Liaisons with other WMO WG (e.g. Thorpex/TIGGE-LAM, WWRP/NWC, JWGV, WGNE, …) • WMO symposia, dedicated workshops on specific topics WGNR meeting, 8-10 February 2011

  5. Past, present and possible future RDP’s and FDP’s • MAP-DPHASE: Demonstration of Probabilistic Hydrological and Atmospheric Simulation of flood Events in the Alpine region (finished 2009) • COPS: Convective Orographic Precipitation Study. Intense observation campaign in Rhine Valley area, subsequent process and predictability studies, and assimilation experiments (finishing) • Beijing 2008 RDP: development, improvement, intercomparison and demonstration of LAM EPS systems (finished 2009) • Sochi 2014: RDP/FDP on high-resolution nowcasting and NWP support of Sochi Winter Olympic Games activities (in preparation) • HYMEX programme (HYdrology in Mediterranean EXperiment): long-term observation and modelling campaign aimed at studying all aspects of the hydrological cycle in the Mediterranean (WG-MWFR involvement in preparation). WGNR meeting, 8-10 February 2011

  6. D-PHASE:Demonstration of Probabilistic Hydrological and Atmospheric Simulation of flood Events in the Alpine regionDistributed real-time end-to-end forecasting system D P Medium range H A Short range S Now-casting E WGNR meeting, 8-10 February 2011

  7. Beijing 2008 RDP • Aim: develop, intercompare and demonstrate LAMEPS systems at synoptic and convection-permitting scales • 7 EPS systems involved in Tier 1 • Only few experiments on convection-permitting scale • During Games: • Delivery of EPS products and services, contacts with forecasters • Subsequently: • Verification • Continued improvements in all EPS systems and calibration techniques • Case studies • User assessment WGNR meeting, 8-10 February 2011

  8. WGNR meeting, 8-10 February 2011

  9. COPS RDP • Summer 2007: massive observation campaign • Subsequent analysis of IOP results: • Process studies on the convective life cycle, focussing on selected IOP cases • Research on new observation types: validation, intercomparison and joint interpretation, representativity studies, sensor synergy • Model validation studies (clouds, microphysics) • Tests of advanced data assimilation systems, development of observation operators, observation impact studies • Verification techniques and impact assessment of convective-permitting models • Joint COPS/D-PHASE Database collected, now generally available through DKRZ/Hamburg WGNR meeting, 8-10 February 2011

  10. Sochi 2014 • Aim: combined RDP/FDP on nowcasting/mesoscale modelling, as meteorological support of Sochi 2014 Winter Games. • Winter nowcasting/short-range forecasting in complex terrain • High resolution prediction of wind speed and wind gust, visibility, fog, precipitation intensity and time (including downscaled surface systems and fog models) • Assimilation and verification based on remote sensing data • Emphasis on more extensive use of remote sensing data for nowcasting, regional data assimilation, and forecast/nowcast validation • Capacity building for regional forecsters • Status: in preparation. Kickoff meeting with intended participants: March 2011. Exact scope of activities to be decided then. WGNR meeting, 8-10 February 2011

  11. Grey zone (1): the problem • Extratropics: convection partially resolved from hor resolutions of ~5km to ~ several 100m. Tropics: partially resolved convection appears to occur at coarser resolutions • Similar grey zone for turbulence appears to become important at resolutions of ~2km and less. • In this partially resolved range: neither the assumption of fully parametrized nor that of fully resolved convection/turbulence works quite well • Strategies for dealing with grey zone: switch off convection parametrization at some resolution (most models), or gradual shut-down of parametrized deep convection. • The first strategy is not well applicable to global models in the future. • Particularly problematic: initial, not-yet-organized stages of deep convection. Models often show far too active growth. Neither strategy has yet been able to deal with this very well. • Very great sensitivity of convective behaviour observed to details of physics-dynamics interaction, diffusion, microphysics, domain size, … • Apparent need for inherent 3D-treatment of parametrizations, and inclusion of stochasticity in initial stages WGNR meeting, 8-10 February 2011

  12. Grey zone (2): proposed studies • Request WGNE: WGNE, WG-MWFR, GCSS to set up idealized experimentation, to gain better understanding • Use experimentation and model intercomparison framework as developed successfully by GCSS. • Run several LES systems at several 100m resolution as “truth”, make model simulations at stepwise progressively coarser resolutions throughout grey zone range, for different models. 1- and 3D- analysis of outcome. • Presently working on setting up basic experimental framework for a “simple” extratropical case of cold air outbreak over sea, in 2011-2012 • Intention: Later extend this framework and modelling community to other cases, including e.g. deep convection in tropics. WGNR meeting, 8-10 February 2011

  13. Mesoscale verification • Unlike global models, no commonly accepted “gold standards” to assess and intercompare meteorological quality of mesoscale models • Lack of overlap in domains => little or no exchange in objective verification results. • Still, model improvement is clearly stimulated by a better understanding of the relative strengths and weaknesses of different models, and by some “friendly competition” • New spatial or object-oriented verification methods required for mesoscale models, in particular for precipitation (some new standards for this are being pushed by JWGV) and clouds (no standards defined by JWGV yet). • 2010: WG-MWFR and JWGV started cooperation, aiming to define useful basic set of quality measures and verification methods to “push” for mesoscale models, and to promote routine verification and exchange of verification results between models worldwide WGNR meeting, 8-10 February 2011

  14. Training material Recently started activity: • Make inventory of available training material on mesoscale modelling for forecasters and users • Idem for training activities and capacity building by the various mesoscale modelling groups • Aims: • provide descriptions and links to existing material and promote its use • identify gaps and try to fill them WGNR meeting, 8-10 February 2011

  15. Liaisons with other WG’s • JWGV • Verification/validation crucial in all MWFR activities; Sophisticated (spatial) techniques for non-standard parameters (clouds, microphysics) • Attempt to jointly define/promote quality measures for / routine monitoring and intercomparison of mesoscale models • Joint meetings,irregular email contacts on ideas for new approaches • TIGGE-LAM • Development, use and improvement of LAM EPS systems worldwide • Participation of WG-MWFR members in TIGGE-LAM meetings • Africa ensemble-forecasting initiatives • WGNE • Grey zone experimentation • NWC • Joint interest in development/characterization of new observation types • Joint activity on use of NWP as tool in support of nowcasting, to start off with workshop • Cross-attendance at WG meetings attempted WGNR meeting, 8-10 February 2011

  16. Use of mesoscale NWP in support of nowcasting • Nowcasting tools: • Purely observation-based (e.g. radar extrapolation) • NWP used indirectly as input in dedicated nowcasting applications • Increasing push for more direct use of high-resolution NWP in some form of RUC mode. But what are its limitations? Workshop aim: • Strengthen interaction between NWP and NWC communities • Confront present and future prospects of NWP for NWC with challenges of NWC, come up with recommendations on way forward (how to optimize NWP in support of NWC, and how/when to best use it (or not)) • ~30 participants (invitation only). 27-29 June 2010, Boulder. • JSC support already given in principle, invitation awaiting their final approval WGNR meeting, 8-10 February 2011

  17. Proposed setup of workshop • First two days: Presentations • Challenges of typical NWC applications, and user needs • Present use of NWP used either directly or indirectly in support of NWC: What are known capabilities and limitations. • Future prospects and their expected impact: new types of observations; innovations in mesoscale analysis and model treatment of e.g. severe convection, and fog; inclusion of uncertainty information in NWC; developments in spatialization / downscaling techniques; etc. • Third day: Working groups to explore the way forward on several topics, e.g.: • How to optimize NWP itself for high accuracy/detail in the 0-6h range? Which nowcasting needs could be better met in the future through dedicated changes in either the quality or use of NWP models? • When to use NWP directly, when better indirect? • Define/organize experimentation aimed at performance assessment and intercomparison of alternative nowcasting methods, including NWP-based ones. Plenary wrapup meeting to consider and finalize WG recommendations WGNR meeting, 8-10 February 2011

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