EUROPEAN REGIONAL ACTIVITIES (Submitted by European Institutions through the IPO)

Transcription

1 WORLD METEOROLOGICAL ORGANIZATION COMMISSION FOR ATMOSPHERIC SCIENCES INTERNATIONAL CORE STEERING COMMITTEE FOR THORPEX Eighth Session DWD, Offenbach (2 4 November 2009) CAS/ICSC-8/DOC5.3 (27 X.2008) Item: Introduction EUROPEAN REGIONAL ACTIVITIES (Submitted by European Institutions through the IPO) A meeting took place in WMO (Geneva) on 5 August 2009 to discuss European THORPEX activities, organisational arrangements and the status of the European THORPEX Plan. Early on in the meeting it became clear that the main need was to improve communications and information about European THORPEX-related research. There was a lot going on but this was not widely known or appreciated. A formal European Committee was not regarded as essential and for the time being it was felt that it should be put into abeyance. Instead, regular European Workshops, providing a forum for reporting on progress and plans, will be organised by a Meetings Committee and are planned to take place about every 2 years. The first meeting will be held in the University of Karlsruhe and the Chair of the Meetings Committee will be Sarah Jones who will in practice be regarded as the European Chair for THORPEX until the first of this Workshop. The meeting also agreed that the formal publication of a European Plan was useful evidence of co-ordination of THORPEX research across Europe and could help in bids for funding and it was agreed to publish the plan to the THORPEX Web Site by December European activities This following, whilst probably not exhaustive, provides a summary of the main European THORPEX activities. 2.1 Campaigns T-PARC European involvement in *T-PARC* included the DLR coordination of the Falcon mission consisting of 95 flight hours of the DLR Falcon (funded by the DLR, NSF, JMA, Forschungszentrum Karlsruhe, KMA, Environment Canada, and EUCOS) instrumented with drop-sondes and wind and water vapour lidars, CNES (France) support of the drift-sonde system, the customisation of the Data Targeting System for Summer and Winter T-PARC by ECMWF, and additional E-AMDAR data for summer and winter T-PARC (provided by EUCOS, funded by Forschungszentrum Karlsruhe and NOAA). German Ph.D. students participated in the operation centres in Monterey and Japan, which was a valuable training for these young scientists. Customised forecast products were provided by ECMWF and the Met Office. The drop-sonde, Doppler wind lidar and DIAL water vapour lidar data from the DLR Falcon is now part of the T-PARC data archive. The impact of the dropsonde data on tropical cyclone track forecasts and on the mid-latitude flow has been investigated by the DLR in collaboration with ECMWF. It was discovered that ECMWF has been using partly erroneous drop-sonde time stamps. A reanalysis with corrected dropsonde timing led to clearly improved typhoon track forecasts and as a consequence the operational procedure for drop-sonde time stamps was corrected in June Results of data denial experiments show a mean reduction of the typhoon track forecast errors at days 3-5, a reduction of the forecast errors over the Pacific at days 3-5 and of the northern hemisphere forecast at days Sensitivity studies revealed that in particular observations in the vicinity of the storm taken before recurvature are beneficial. Experiments assimilating airborne lidar data are ongoing.

2 CAS/ICSC-8/Doc.5.3, p. 2 The extra-tropical transition (ET) cases are being investigated at the Karlsruhe Institute of Technology. An initial analysis of the ET of Typhoon Jangmi combining COSMO modelling, observational analysis and PV inversion indicates the importance of the interaction of the tropical cyclone circulation with a baroclinic zone near Japan and the subsequent development of a new potential vorticity tower for the extra-tropical transition. The representation of this evolution varied between different forecasts leading to uncertainty in forecasts of the subsequent extra-tropical cyclogenesis. The ET of Jangmi is being compared to that of Typhoon Sinlaku in collaboration with the Naval Postgraduate School and NCAR. Future ET studies will include analysis of TIGGE data and data denial experiments at ECMWF. More details on T-PARC may be found in CAS/ICSC-8/DOC4.1 T-PARC and TCS08. IPY The European participation in IPY is considered a success and interesting results should soon emerge in the literature. The outcome from Greenland Flow Distortion Experiment (GFDex) will be published in a special issue of the RMETS Quarterly Journal. Attention within European is now turning to ensuring an IPY legacy. T-NAWDEX The THORPEX-North Atlantic Waveguide and Downstream Impact Experiment (T- NAWDEX) was proposed by the THORPEX working group Predictability and Dynamical Processes for the European THORPEX Science Plan. The first planning meeting for T- NAWDEX took place in Erding, Germany on 19 and 20 February Since that meeting it has become clear that T-NAWDEX will not be able to take place before 2012 and may well be delayed to There are many issues which remain to be resolved. A UK Pilot Project, involving four planning flights, for T-NAWDEX using FAAM aircraft may help resolve some of these. Importantly, a good science case is needed with more focus on processes, their representation in models and consequences forecast impact was probably essential. A concise science Plan is expected by the end of More details on T-NAWDEX may be found in CAS/ICSC-8/DOC4.2. HyMeX HyMeX (HYdrological cycle in the Mediterranean EXperiment) aims at a better understanding and quantification of the hydrological cycle and related processes in the Mediterranean, with emphasis on high-impact weather events, inter-annual to decadal variability of the Mediterranean coupled system, and associated trends in the context of global change. The Mediterranean region features a nearly closed sea surrounded by urbanized littorals and mountains from which numerous rivers originate. This results in a lot of interactions and feedback between oceanic, atmospheric, and hydrological processes which are perturbed by anthropogenic activities and play a predominant role in the regional climate and ecosystems. The Mediterranean climate is also influenced by both sub-tropical and mid-latitude climate dynamics and is therefore very sensitive to global climate change. Extreme weather events (heavy precipitation and flash-flooding, strong winds and large swell, droughts, etc) regularly affect the Mediterranean region causing heavy damages and human loss. The ability to predict such dramatic events remains weak because of the contribution of very fine-scale processes and their non-linear interactions with the larger scale processes. The HyMeX programme aims to:

3 CAS/ICSC-8/Doc.5.3, p. 3 improve our understanding of the water cycle, with emphasis on extreme events, by monitoring and modelling the Mediterranean atmosphere-land-ocean coupled system, its variability from the event to the seasonal and interannual scales, and its characteristics over one decade ( ) in the context of global change assess the social and economic vulnerability to extreme events and adaptation capacity The multidisciplinary research and the database developed within HyMeX should contribute to: improve observational and modelling systems, especially for coupled systems, better predict extreme events simulate the long-term water-cycle more accurately provide guidelines for adaptation measures, especially in the context of global change More details on HyMeX may be found in CAS/ICSC-8/DOC Institutional and National activities ECMWF The ECMWF has a wide-ranging programme of research of direct relevance to THORPEX including: Basic predictability studies using models and re-analyses Data-targeting Ensemble prediction utility of multi-model ensembles, flood forecasting etc Tropical convection The ECMWF has a major involvement in TIGGE through its contribution to the archives and its maintenance of the TIGGE archive and elements of the international websites. There are more than 500 registered TIGGE users, however this may well be an underestimate of the usage, European Users, for example, access the ECMWF archives directly and bypass the Public TIGGE interface. ECMWF have also supported IPY (especially GFDEx). The ECMWF Data Targeting System (DTS) proved to be a very powerful tool in T-PARC and was widely used in PREVIEW. The latter ran for one year and recently a list of events had been compiled. Analysis may offer more clues on the situations when targeting could offer some benefit. ECMWF also provided global forecast output for the YOTC data base and is now willing to extend it into 2010 and also typhoon tracks for T-PARC (in real-time) France Research on the cyclogenesis The French research community, including Météo-France, is carrying out research on the nature, structure, life-cycle, precursors, etc of cyclogenesis, the dynamics of the cyclone track: mainly for North-Atlantic and Mediterranean cyclones, but also for tropical cyclones. Specific projects include: Examination of the tropical to extra-tropical transitions of North-Atlantic cyclones, in relation to the impact of various observing systems (PDP, DAOS, preparation of T-NAWDEX) Impact of cloudy infra-red observations from satellites on Mediterranean lows; use of satellite data to validate the simulation of Mediterranean storms approaching from the Atlantic (PDP, DAOS, MEDEX, preparation of HYMEX)

4 CAS/ICSC-8/Doc.5.3, p. 4 Impact of cloudy/rainy microwave radiances on tropical cyclones, in the Indian Ocean, near La Réunion (PDP, DAOS, preparation of SWICE campaign and of Megha-Tropiques launch). Impact of the West-African improved radiosonde network during the AMMA campaign in order to improve the understanding of African weather features (monsoon, generation of tropical cyclones) and in order to optimise the operational conventional observation network; link with other studies or OSEs (e.g.: impact and use of microwave radiances over land) (PDP, DAOS, continuation of AMMA) Ensemble and probabilistic forecasting Meteo France is carrying out research on and development of global Ensemble Prediction System and Data Assimilation Systems. The ensemble prediction system, PEARP, is based on ARPEGE. The Ensemble Data Assimilation is based on ARPEGE with 3D-VAR assimilation (rather than on the 4D-VAR used in deterministic version of ARPEGE). PEARP has been operational since 2004, and is now contributing to the TIGGE data base. A French National Research (ANR) project (PREVASSEMBLE - use of ensembles in meteorology) is seeking to address three questions Rôle of model error in ensembles (PDP, TIGGE) Flow-dependent structure functions in assimilation systems and assimilation ensembles (DAOS, TIGGE) Non-linearities and particle filters (PDP) Campaigns, adaptive networks, data targeting Here specific THORPEX-related projects are: (i) (ii) (iii) CONCORDIASI Validation of IASI near the Antarctica station CONCORDIA; there plans to enhance the radiosonde network and employ driftsondes/dropsondes to provide targeted observations; data impact studies will be carried out using highresolution forecast systems Data Targeting System (DTS) tests in an operational context, similar to those carried out in 2008 under the banner EUCOS/Preview, for EUCOS/Medex (DAOS, MEDEX) Preparation of targeting strategies for HYMEX Special Observing Periods (SOP) and T-NAWDEX (DAOS, HYMEX, T-NAWDEX) Germany A number of German institutions have a major involvement in T-NAWDEX - see above. Other, interests included the PANDOWAE, IPY, Summer and Winter T-PARC. PANDOWAE The research group PANDOWAE, funded by the German research council (DFG), is now in its second year. The institutions involved are the Karlsruhe Institute of Technology, DLR Oberpfaffenhofen, ETH Zürich, Leibniz Institute of Atmospheric Physics at the University of Rostock, University of Mainz, and the University of Munich. The project supports four postdoctoral scientists and seven Ph.D. students working in three research areas. They are quantifying processes involved in the development of Rossby wave trains and the methods used to identify them, investigating the impact of moist processes on predictability, and conducting investigations into adaptive observations and ensembles. Operational weather forecast models of DWD (GME and COSMO) and ECMWF IFS (including data assimilation and EPS) are used in an academic setting and diagnostic tools developed and applied to

5 CAS/ICSC-8/Doc.5.3, p. 5 quantify the factors influencing the evolution of weather systems and their predictability. The PANDOWAE group is involved in utilising the data from the T-PARC campaign and from TIGGE. An overview of PANDOWAE was presented at the TTISS along with 9 individual papers with initial results from the project. A close collaboration takes place with a DFG funded project analysing wind and water vapour lidar data during E-TReC/COPS and another DFG project applying TIGGE data to investigate upper-level extratropical distubances extending into low latitudes. More information is available from Work on the E-TReC work is still underway at DLR and the data are also being used in process studies. Analysis of important PREVIEW cases was expected. Similarly T-PARC targeting studies are expected particularly on the extra-tropical transition component of T- PARC Switzerland The ETH interests include planning and modelling for T-NAWDEX. Good links are maintained with Meteo-Swiss on meso-scale weather research and on short-range to the medium-range hydrological predictions UK The UK Met Office is running a regular experimental medium-range ensemble forecast system, known as MOGREPS-15 as a major part of its contribution to TIGGE. A significant increase in the resolution of MOGREPS-15, from a 90km grid to 60km and 38 levels to 70, is planned for the beginning of By combining forecasts from MOGREPS-15 with ensemble forecasts from ECMWF and NCEP, we have demonstrated that the use of multimodel ensembles can lead to significant improvement in forecasts of surface air temperature, although the benefit is only marginal for forecasts of sea-level pressure and 500 hpa geopotential height. In the future, it is planned to investigate multi-model ensemble forecasts of precipitation. This will also contribute to the development of the planned Global Interactive Forecast System (GIFS). The initial emphasis of GIFS is on the development of products to improve forecasts of tropical cyclones and rainfall. The Universities of Reading and Leeds have a major interest in research on and applications of the TIGGE data base, including for example, tracking extra-tropical cyclones, blocking, extreme seasons, jets. Using ensemble forecasts, Met Office THORPEX research has led to the development of weather impact models to help provide warnings of the risks of strong winds. In particular, a model has been developed to forecast the risk of vehicles overturning in high winds. The Met Office has contributed to investigations of the benefits of targeted observations. Sensitive area predictions produced using the ETKF technique have been made available via the PREVIEW data targeting system hosted by ECMWF, and have been used in an extended trail of observation targeting over the N. Atlantic as well as for the Pacific during the T-PARC campaign. For the ConcordIASI project now planned for 2010 it is hoped that the British Antarctic Survey will launch additional radiosondes from its bases in Halley and possible Rothera at the same time as the dropsonde deployments. They should provide a valuable resource for assessing other observation types (e.g. polar Atmospheric Motion Vectorss) in a data sparse region. An announcement of Opportunity is being prepared by the National Environmental Research Council (NERC) on Storm Risk Mitigation Through Improved Prediction and Impact

6 CAS/ICSC-8/Doc.5.3, p. 6 Modelling. An Expert Group is being assembled that will define the specifications for a Research Programme. Approximately 5M was available over 5 years. About 50% would be devoted to improving ability to predict hazardous mid-latitude weather (0-48h forecasts). The rest on how climate change may affect mid-latitude storms and modelling vulnerability to storms (river catchments and coastal defence).