THORPEX Activities 1 Sue Gray and John Methven University of Reading

THORPEX mission statement THORPEX (The Observing System Research and Predictability Experiment) A 10-year research and development programme to accelerate improvements in the accuracy of 1-day to 2-week high-impact weather forecasts and the utilisation of weather products for the benefit of society, the economy and the environment.

WORLD WEATHER RESEARCH PROGRAMME Research focused on improving forecast skill for high-impact weather and benefiting member states through advancing the utilization of weather products and promoting the application of new techniques. THORPEX (The Observing System Research and Predictability Experiment) A 10-year research and development programme to accelerate improvements in the accuracy of 1-day to 2-week high-impact weather forecasts and the utilzation of weather products for the benefit of society, the economy and the environment. Working Group on Mesoscale Weather Forecasting Research Promotes, organizes and/or endorses end-to-end weather research and development projects (RDPs) including efforts to advance the understanding of weather processes, improve forecasting techniques and increase the utility of forecast information with an emphasis on high- impact weather. Working Group on Tropical Meteorology Research Identifies and supports the research initiatives of NMHSs in tropical countries, generally including collaboration with groups in universities or research institutes, which are likely to lead to social and economic benefits, particularly in the prevention of disasters during severe weather associated with tropical cyclone and monsoon rainfall anomalies. Working Group on Nowcasting Promotes and aids the implementation of nowcasting in the WWRP framework and within NMSs and among their end-users, including the potential use of numerical modelling and assimilation of very high resolution data. Joint Working Group on Verification Facilitates the development and application of improved diagnostic verification methods to assess and enable improvement of the quality of weather forecasts, including forecasts from numerical weather and climate models. Working Group on Societal and Economic Applications Advances the science of the social and economic application of weather-related information and services and reviews and assists in the development and promotion of societal and economic-related demonstration projects. Contact: THORPEX programme Working Group on Mesoscale Weather Forecasting Research Working Group on Tropical Meteorology Research Working Group on Nowcasting Working Group on Societal and Economic Applications Joint Working Group on Verification World Weather Research Programme Sand and Dust Storm Warning and Assessment System Joint Working Group on Numerical Experimentation (WGNE) -- physcal processes Expert Team on Weather Modification

IPO/ICSC/EC Regional Committees Africa Asia Europe North America Southern Hemisphere Predictability and Dynamical Processes Working Group PDP WG Data Assimilationand Observing Strategies Working Group DAOS WG Global Interactive Forecasting System – THORPEX Interactive Grand Global Ensemble Working Group GIFS-TIGGE WG THORPEX Organisational Structure With links to the WWRP SERA and the Verification WGs

Predictability and Dynamical Processes working group: PDP WG 8 interest groups 1.The role of Rossby wave dynamics in predictability 2.The large scale response of the atmosphere to organized tropical convection (e.g. MJO) 3.Predictability of tropical cyclones and of their ET 4.The impact of ET on the downstream mid-latitude predictability 5.Ensemble prediction 6.Atmospheric blocking, low-frequency variability and their role in predictability 7.The impact of moist processes on dynamical processes and predictability in the extra-tropics 8.AMMA and further aspects of tropical-extratropical interactions

Data Assimilation and Observing Strategies working group: DAOS WG 1.Impact of observations Guidance for observation campaigns and the configuration of the Global Observing system Assessment of the value of targeted observations Evaluation of observation impact with different systems 2.Improving the use of satellite data Use of sensitivity information to do adaptive data selection

1.THORPEX Interactive Grand Global Ensemble (TIGGE) Collating operational ensemble forecasts from 10 global forecasting centres 2.Develop the concept of a Global Interactive Forecasting System (GIFS). 3.Enhance international collaboration on ensemble prediction for high impact weather. Collaboration between operational centres and universities 4.Develop theory and practice of multi-model ensembles. 5.Develop products based on TIGGE GIFS-TIGGE WG

New projects WMO commission for atmospheric sciences (CAS) is proposing new THORPEX projects on Polar prediction research to improve understanding of the impact of polar processes on polar weather, the assimilation of data in polar regions and the prediction of high impact weather over polar regions (links to IPY- THORPEX) Seasonal to sub-seasonal prediction

(NCAS-weather meeting February 2009)9 Major THORPEX Field Campaigns ATReC 2003: observations targeted in sensitive regions GFDex 2007: investigation of the role that Greenland plays in distorting atmospheric flow over and around it: affecting local and remote weather systems ETReC 2007/COPS: multi-scale observation of convective events IPY-THORPEX 2008: high-impact weather in the Arctic region T-PARC 2008: dynamics and predictability in subtropical and midlatitude Pacific regions YOTC : ‘year’ of tropical convection. Global prediction, integrated observations and research (attribution, modelling and theoretical studies. T-NAWDEX-PILOT 2009: dynamics and predictability on the North Atlantic Waveguide DIAMET 2011/2012:

THORPEX activity in Europe European plan has been distinguished by its absence but does now exist! Research consortium has been funded in Germany (PANDOWAE) In UK, the Met Office and ECMWF are part of TIGGE and clearly have interests in the THORPEX aims but Universities have been slow to be involved. THORPEX-UK start-up meeting was held in Oct THORPEX European regional meeting May 2011 GEOWOW: GEOSS Interoperability for weather, ocean and water. Enhave accessibility of TIGGE. EUROSIP: multi-model seasonal forecasting system consisting of three independent coupled systems: ECMWF, Met Office and Météo-France; all integrated in a common framework. PREVASSEMBLE: Ensemble methods for prediction and data assimilation. Aim to ensemble methods and to develop their use both for data assimilation and numerical prediction. LMD/ Météo- France

P redictability AN d D ynamics O f W eather Systems in the A tlantic- E uropean Sector PANDOWAE Severe Convection European Windstorms Mediterranean Cyclones Tropical Cyclones DFG funded Research Group PANDOWAE : 4 Million Euros Motivated but not constrained by operational needs. Collaboration with EUCOS, DWD, ECMWF, Meteo-France

PANDOWAE projects The impact of extratropical transition on downstrem predictability The dynamics and predictability of Mediterranean cyclones leading to high impact weather Role of diabatic processes in the dynamics and predictability of extratropical cyclones Sensitivity of severe weather over Europe to upstream wavetrains and related processes Variability and extremes of poleward breaking Rossby waves over the North Atlantic-European region Large-scale and local control of severe weather: Towards adaptive ensemble forecasting Adaptive observing strategies for active airborne remote sensing instruments New projects on blocking, Rossby wave guide and projects moving towards the subseasonal scale

THORPEX- North Atlantic Waveguide and Downstream Impact Experiment. Status as of June 2011 Has been proposed by the THORPEX working group Predictability and Dynamical Processes for the European THORPEX Science Plan. Andreas Dörnbrack, Andreas Schäfler, Ulrich Corsmeier, Heini Wernli DLR Oberpfaffenhofen, ETH Zürich, Karlsruhe Institute of Technology (KIT) Its overarching scientific goal is to investigate in detail the physical processes that are primarily responsible for degradation in 1-7 day forecast skill in global prediction systems and of their representation in NWP models. T-NAWDEX

T-NAWDEX will have - experimental (international field experiment) and -theoretical/diagnostic/modelling research components which investigate the different phases of wave guide disturbances: 1.Triggering of wave guide disturbances by different dynamical processes 2.Downstream evolution of the disturbances along the wave guide 3.Downstream impact of wave guide disturbances over Europe and North Africa Funded national activities exist in the UK & Germany/Switzerland: DIAMET and PANDOWAE

Current experimental status German HALO research aircraft is not accessible for our community in the next years for different reasons... Institute of Atmospheric Physics (IPA) arranged to keep the DLR FALCON research aircraft for the next years - opens the possibility to conduct field campaigns with THORPEX focus interest at IPA, ETH Zürich and KIT triggered initiative to deploy FALCON in collaboration with DIAMET and/or HYMEX in 2012: "T-NAWDEX-Falcon" scientific focus on water vapour transport and on cloud processes within weather systems involving condensation of water vapour and latent heat release and fluxes in the atmospheric boundary layer Instrumentation: 1.water vapour lidar not available any more for the FALCON, wind lidar could be installed 2.most probably: in-situ sensors to observe thermodynamic properties of the air and turbulent quantities plus dropsondes 3.check the possibility of a tracer experiment for warm conveyor belts

Future experimental plans explore possibilities to access in-situ instruments and DLR resources for conducting a THORPEX field campaign (including a tracer experiment) in September-November 2012 (mid July 2011) common project meeting involving KIT, ETH and DLR and interested external partners from DIAMET and HYMEX (autumn 2011) science plan EUFAR (European facility for airborne research) proposals for additional flight hours (interest by Univ Vienna and Croatian colleagues) fine-tuning with DIAMET and HYMEX T-NAWDEX: discussion with US partners ongoing. A cross- Atlantic T-NAWDEX experiment could occur in 2014 since the US and Canada are now interested.

T-NAWDEX pilot ●Developed as a pilot study for T-NAWDEX (THORPEX- North Atlantic Waveguide and Downstream Impact Experiment) which has been proposed by the THORPEX working group Predictability and Dynamical Processes for the European THORPEX Science Plan. ●Brief project with flight-time only funded (Lead PI: Ian Renfrew). ●3 flights in November 2009 trying out flight plans to identify influence of diabatic processes on mesoscale structure within growing cyclones. 1. 3/11/09: intense cold front case 2. 13/11/09: attempted two flights ahead and behind frontal cyclone, crossing WCB both times to infer Δ . First flight crossed intense warm front and WCB dropping sondes. Forced to abandon second flight due to malfunction /11/09: Box within marine BL either side of cold front plus transect across WCB behind. PV source/sink analysis has also been performed for this case. 17

DIAMET DIAbatic influences on Mesoscale structures in ExTratropical storms ●Consortium led by Geraint Vaughan (NCAS-weather director) with Methven, Parker and Renfrew as other lead PIs + Met Office partners. Response to NERC Natural Hazards theme action call. ●Overarching theme is the role of diabatic processes in generating mesoscale PV and moisture anomalies in cyclones, and the consequences of those anomalies for weather forecasts. ●Three-pronged approach: a)Determining influence of diabatic processes on mesoscale structure (PV tracers partitioned by process) b)Improving parameterisation of convection (in cyclone environment), air- sea fluxes and microphysics. c)Using feature-tracking within the Met Office ensemble prediction system to quantify the predictability of mesoscale features and the dependence of the skill of weather forecasts (precipitation and winds) on mesoscale features. 18

WP A: Mesoscale structure and diabatic effects ●New streams of Doppler radar data from Met Office Radar group and data assimilation for convection-resolving model (JCMM) ●Nested Met Office operational forecasts at varying resolution (currently 40km global, 12km LAM, 1.5km UK) ●Hindcasts at varying resolution using tracers to partition the effects of model processes on heating and PV (directly following on from the work presented here). 19  Two flight campaigns with U.K. FAAM (Facility for Airborne Atmospheric Measurement) aircraft spanning: Autumn 2011: 3 month period of opportunity with 2 week Intensive Observing Period. Late summer 2012: 2 month period   possible link with T-NAWDEX/ HYMEX campaigns?

WP B: Parameterisation of key processes 1.Detailed examination of convection parameterisation using the PV tracer diagnostic adapted to decompose the moisture field into contributions from different parameteriation schemes:  Can existing parameterisation be adapted to treat elevated convection?  Choice of closure timescale for embedded convection  Decomposition of bulk mass flux detrainment 2.Quantify contribution of surface and boundary layer fluxes to mesoscale PV anomalies and storm evolution 3.Measure microphysical properties and use them to derive latent heating estimates and improve parameterisations. 20

WP C: Predictability and DA for high resolution forecasts 1.Quantify forecast statistics for objectively identified mesoscale features in the Met Office ensemble prediction system (MOGREPS).  Measure distances between forecasts in terms of feature tracks; characterise dependence of precipitation forecast skill stratified by mesoscale feature type. 2.Use short-range convection-resolving ensemble, perturbing parameterisations (with and without stochastic terms) to disentangle model error from initial condition error. 3.Use ensemble forecasts to assess the nature of balance between variables at high resolution and influence on forecast error statistics. 21 Hewson and Titley, 2010

The end Thank you for your attention 22