TEMPEST: Testing and Evaluating Model Predictions of European Storms

‘What’s past is prologue; what to come, in yours and my discharge.’ Act 2, Scene 1, The Tempest

Aims of the meeting 1. Review and discuss the science plan for TEMPEST Overview Len Shaffrey WP1 Kevin Hodges WP2 Tim Woollings WP3 Tim Palmer PhD studentships 2. A non-exhaustive overview of related UK research Presentations from related projects Help with project planning 3. Overview of the Storm Risk Mitigation (SRM) programme DIAMET (NWP) and DEMON (Impacts) SRM Programme communication, management and integration

People and Institutions NCAS, ReadingMet Dept, Reading Len Shaffrey Brian Hoskins Dave BrayshawHelen Dacre Mike BlackburnTim Woollings NCEO, Reading Exeter University Kevin Hodges Renato Vitolo David Stephenson Oxford University Tim PalmerMet Office (Partner) Ruth McDonald ECMWF (Partner)Simon Brown tbc Reading – Giuseppe Zappa, Ben Harvey, Matt Hawcroft Oxford – Andrew Dawson Exeter – Phil Sansom

Overview and Objectives Q1. How will climate change affect the generation and evolution of extra-tropical cyclones? How large are these effects compared to natural variability? WP1 Provide the first systematic assessment of the predictions of intense extratropical cyclones in the CMIP5 models using established and innovative analysis methodologies. Q2. Which physical processes are most important, and which predicted changes are most robust? WP2 Perform an integrated set of sensitivity experiments that will quantify the impact of key processes in driving changes in the North Atlantic and European storm track. Q3. How important are the features and processes that climate models poorly represent due to their limited resolution? WP3 Investigate the impact of climate change on intense extratropical cyclones, and their upscale effects, in very high-resolution global atmospheric model experiments capable of capturing mesoscale structures. WP4 Develop an integrated research community to tackle the questions surrounding the impact of climate change on extratropical cyclones and engage the wider scientific community and external stakeholders.

Overview and Objectives Q1. How will climate change affect the generation and evolution of extra-tropical cyclones? How large are these effects compared to natural variability? WP1 Provide the first systematic assessment of the predictions of intense extratropical cyclones in the CMIP5 models using established and innovative analysis methodologies. Q2. Which physical processes are most important, and which predicted changes are most robust? WP2 Perform an integrated set of sensitivity experiments that will quantify the impact of key processes in driving changes in the North Atlantic and European storm track. Q3. How important are the features and processes that climate models poorly represent due to their limited resolution? WP3 Investigate the impact of climate change on intense extratropical cyclones, and their upscale effects, in very high-resolution global atmospheric model experiments capable of capturing mesoscale structures. WP4 Develop an integrated research community to tackle the questions surrounding the impact of climate change on extratropical cyclones and engage the wider scientific community and external stakeholders.

TEMPEST Project Structure WP3 Impact of Resolution Lead Palmer PDRA at Oxford WP3 Impact of Resolution Lead Palmer PDRA at Oxford WP1 Assessing Storms Lead Hodges PDRA at Reading WP1 Assessing Storms Lead Hodges PDRA at Reading WP2 Quantifying Processes Lead Shaffrey PDRA at Reading WP2 Quantifying Processes Lead Shaffrey PDRA at Reading WP4 Integration and pull- through Lead Shaffrey Student Statistical Modelling of Trends Exeter Student Latent Heat Release in Storms Reading Project meetings every six months First meeting in Reading as a kick-off workshop; invite key stakeholders Final meeting in London to disseminate TEMPEST outcomes Total staff request: 3 PDRAs, 2 project studentships

TEMPEST Project Status WP3 Impact of Resolution Lead Palmer Andrew Dawson WP3 Impact of Resolution Lead Palmer Andrew Dawson WP1 Assessing Storms Lead Hodges Giuseppe Zappa WP1 Assessing Storms Lead Hodges Giuseppe Zappa WP2 Quantifying Processes Lead Shaffrey Ben Harvey WP2 Quantifying Processes Lead Shaffrey Ben Harvey WP4 Integration and pull- through Lead Shaffrey Student Statistical Modelling of Trends Exeter Phil Sansom Student Latent Heat Release in Storms Reading Matt Hawcroft All research positions have been filled Reading University posts have started Oxford and Exeter posts to start at end of Feb Kick-off meeting at Reading University, 8 th Feb Cross representation from DIAMET, DEMON and the SMT

Storm Risk Mitigation Programme In addition to TEMPEST, an Impacts and a NWP project were also funded by the NERC Storm Risk Mitigation programme NWP - DIAMET (PI: Geraint Vaughan, Manchester) Manchester, Leeds, Reading, East Anglia, Met Office 1.The generation of mesoscale PV anomalies 2.Physical processes and improving model parameterisations 3.Predictability Impacts - DEMON (PI: Paul Bates, Bristol) Bristol, Reading, Kings College 1. Downscaling and uncertainty propagation 2. Data assimilation and remote sensing 3. Extreme storm surge and fluvial modelling 4. Hydraulic modelling Storm Risk Mitigation Science Management Team (CEH and BGS) Annual meetings, programme communication and management, data management etc...

Project Studentships Statistical Estimation and Understanding of Trends in Extreme Extratropical Cyclones: Phil Sansom (R. Vitolo, D.B. Stephenson - University of Exeter, R.E. McDonald - Met Office) Understanding trends in extra-tropical cyclones from: Reanalyses (e.g. NCEP, ERA-40 and ERA-interim) Climate models (e.g. CMIP5 and HadCM3 perturbed physics ensemble) Time trends analysed using Poisson regression and extreme value models Evaluating latent heat release in extratropical cyclones from high-resolution climate models, remote sensing and global reanalyses: Matt Hawcroft (L. Shaffrey, K. Hodges, H. Dacre - University of Reading) Evaluate latent heat release in high-resolution climate models against a range of remote sensing data and global reanalyses. Storm compositing will be applied to: HiGEM climate model output ERA-Interim global reanalysis data Remote sensing data (ISCCP: International Satellite Cloud Climatology Project and TRMM: Tropical Rainfall Measurement Mission, which measures rainfall up to latitudes of 50N).

TEMPEST Summary and Key Outcomes First systematic assessment of how intense extratropical cyclones are predicted to change in the CMIP5 climate models An integrated set of sensitivity experiments with the Met Office Unified Model, which will lead to improved understanding of the spread in climate model projections Analysis of the impact of climate change on intense extratropical cyclones in very high-resolution global atmospheric model experiments capable of capturing mesoscale structures Guidance and advice for the climate impacts assessment community and policy-makers regarding the trustworthiness of climate predictions Developing an integrated research community and wider impacts

Morning discussion Points for discussion: WP1 Implementation of feature tracking across CMIP5 WP2 Priorities: 1. SST 2. Arctic sea ice? WP3 Practicalities (where will data be stored and/or analysed?)

Afternoon discussion Briefly outline: SRM programme management and governance SRM programme communication and integration Collaboration outside of Storm Risk (e.g. CWC, AXA projects…) Points for discussion: Internal communication – mailing list and project website, is this enough? Collaboration a) within SRM and b) outside of SRM Interaction with stakeholders (DECC, DEFRA, EA, Met Office, ECMWF, Insurance industry, General public) Next meeting

SRM Programme Governance Programme Executive Board (PEB) The Storm Risk Mitigation Programme will be managed by NERC Swindon Office in conjunction with the Changing Water Cycle Programme. Programme Advisory Group (PAG) A Programme Advisory Group (PAG) will advise the PEB on the delivery of the Storm Risk Mitigation Programme. (Dennis Peach, Dave Burridge, Sean Longfield, Ian Townend) Science Management Team (SMT) The SMT will be responsible for the day-to-day management and coordination of the SRM and CWC programmes. (Graham Leeks, Daren Gooddy, Lucy Bell, Ann Stokes)

SRM Programme Communication Programme Website Annual SRM programme meetings First meeting - October 2011 Later meetings jointly with CWC? Researcher only meetings SRM mailing lists are also being set up

SRM Programme Integration Small amount of funding available to integrate SRM activities Case Studies and PV Tracers in a climate model? Extratropical cyclone case studies Potential Vorticity diabatic tracer diagnostics Proposed work to link: DIAMET, TEMPEST and DEMON with cyclone case studies DIAMET and TEMPEST with PV diabatic tracer diagnostics

18 Vertical section Note the sharpness and depth of the tropopause fold in the LAM PV source/sink analysis will indicate that these features are a result of diabatic modification Trough structure Courtesy of Jeffrey Chagnon 40km 12km

Diabatic processes affecting fold/trough structure 19 Conv Micro + Conv BlyrHtg Micro Conv Micro + Conv + BlyrHtg LW + Conv LW Tripole structure along fold sharpens gradient Negative anomaly at tropopause level ahead of the trough due mainly to two processes: LW cooling Convective heating Nonconservative PV (Total – Adv only) Courtesy of Jeffrey Chagnon

20 Vertical section What would these plots look like in a climate model? Trough structure Courtesy of Jeffrey Chagnon 40km 12km

Suggested work plan 1. Compare PV tracer diagnostics in simulations of cyclone case studies using NWP to climate resolutions Run cyclone case studies with the HiGEM climate model with the PV diabatic tracer diagnostic (HiGEM ~100km resolution) Compare with case studies being run in DIAMET (DIAMET cases, T- NAWDEX, 20 th Oct 2008, 20 th July 2007?) Lots of observations for the DIAMET case studies to evaluate models Output could be utilised by DEMON 2. Develop extratropical cyclone composites of PV tracer structure from the HiGEM climate model Carry through the understanding gained from the case studies to multi- decadal integrations of HiGEM Composite PV tracer structure for ‘intense’ storm What is an ‘intense’ storm – opportunity for dialogue with DEMON

Afternoon discussion Briefly outline: SRM programme management and governance SRM programme communication and integration Collaboration outside of Storm Risk (e.g. CWC, AXA projects…) Points for discussion: Internal communication – mailing list and project website, is this enough? Collaboration a) within SRM and b) outside of SRM Interaction with stakeholders (DECC, DEFRA, EA, Met Office, ECMWF, Insurance industry, General public) Next meeting

TEMPEST Project Communication Project Website tempest.nerc.ac.uk Six monthly project meetings Alternating locations (Reading, Exeter, Oxford) Researcher visits to other institutions TEMPEST mailing list

TEMPEST links Related Activities Transpose AMIP – running CMIP5 climate models in NWP forecast mode AXA Research Project : Assessing model uncertainties in climate projections of severe European windstorms (Peter Knippertz, Leeds) AXA Research Project: European windstorms in a Changing Climate (David Stephenson, Exeter and Ruth McDonald, Met Office) EU PREDEX: Predictability of Extreme Events (Renato Vitolo, Exeter) Lizzie Froude’s work on error growth in TIGGE forecasts at ESSC, Reading PhD projects at Reading (A. Champion, R. Lee, T. Philp, H. De Leeuw) and at Grantham (E. Thompson) CWC projects – PAGODA (P.L. Vidale) and Hydrological Extremes (A. Wade) EQUIP project (A. Challinor, Leeds)

TEMPEST links Wider Impacts National (LWEC, JWCRP) and international (CMIP5, AR5) programmes Operational centres and model development (Met Office, ECMWF) Government departments (DEFRA, DECC) and NGOs (Environment Agency) Insurance and reinsurance industries (Willis Research Network)

Afternoon discussion Briefly outline: SRM programme management and governance SRM programme communication and integration Collaboration outside of Storm Risk (e.g. CWC, AXA projects…) Points for discussion: Internal communication – mailing list and project website, is this enough? Collaboration a) within SRM and b) outside of SRM Interaction with stakeholders (DECC, DEFRA, EA, Met Office, ECMWF, Insurance industry, General public) Next meeting

Changes in extratropical extremes of daily MSLP in the SRESA1B CMIP3 scenarios (Lambert and Fyfe, 2006) WP1 Assessing Changes in Storms Q1. How will climate change affect the generation and evolution of extra- tropical cyclones? How large are these effects compared to natural variability? Previous analyses have only been performed on a subset of climate models, using different methodologies and sometimes using only daily output. Red: changes in intense events Blue: changes in total events

WP1 Providing the first systematic assessment of climate model predictions of intense extratropical cyclones from the CMIP5 models Opportunity: Six-hourly model output will be archived as part of CMIP5 – apply objective feature tracking algorithm to the CMIP5 models WP1 Assessing Changes in Storms ERA-40 – DJF Track density ERA-40 Winter tracks from a regional climate model

WP2 Quantifying Key Processes Increase in the upper tropospheric temperature contrast Decreased lower tropospheric temperature contrast due to Arctic warming Changes in North Atlantic SSTs associated with the slowdown of the Atlantic Meridional Overturning Circulation Stationary wave changes associated with changes in tropical precipitation The land-sea contrast in surface warming Increased moisture content in a warmer climate Ensemble mean surface temperature differences for minus in the AR4 models Q2. Which physical processes are most important, and which predicted changes are most robust? The spread in CMIP3 projections for North Atlantic and European climate is large

WP2 Quantifying Key Processes WP2 Quantifying the key processes driving changes in intense extratropical cyclones Opportunity: Perform an integrated series of sensitivity experiments with the Unified Model to develop a deeper understanding of how these processes give rise to the large spread in the CMIP3 climate model projections Zonal mean sensitivity experiments: Upper tropospheric and lower tropospheric temperature contrast North Atlantic and European sensitivity experiments: Arctic ice extent, Atlantic SST, Land-sea contrast, Stationary waves from changes in tropical precipitation

Q3. How important are the features and processes that climate models poorly represent due to their limited resolution? WP3 Determining how increased resolution may improve climate predictions of extra-tropical cyclones Opportunity: ECMWF IFS climate runs at T159 (125km), T511 (40km), T1279 (20km) and T2047 (10km) resolution with present day and future climate forcings WP3 Impact of Resolution HiGEM – DJF 925hPa wind and mslp composites ERA-40 Propogation ERA-40 – DJF 925hPa wind and mslp composites

WP4 Integration and Pull-through Links to the Storm Risk NWP deliverable Scope to use results from DIAMET to investigate storm processes in extratropical cyclones in climate models: Run NWP forecasts with the TEMPEST models for the DIAMET case studies PV diagnostics, diabatic processes and storm structure Analysis of systematic error growth in ECMWF forecasts (Thomas Jung) Comparison of tracking methodologies Remote sensing? (Latent heat release studentship at Reading) Links to the Storm Risk Impacts deliverable What output from climate models are most robust? What constitutes an ‘intense’ storm (e.g. redo tracking for slow-moving storms that produce intense rainfall in one location)?

WP4 Integration and Pull-through Wider Impacts National (LWEC, JWCRP) and international (CMIP5, AR5) programmes Operational centres and model development (Met Office, ECMWF) Government departments (DEFRA, DECC) and NGOs (Environment Agency) Insurance and reinsurance industries (Willis Research Network) Related Activities Transpose AMIP – running CMIP5 climate models in NWP forecast mode AXA Research Project : Assessing model uncertainties in climate projections of severe European windstorms (Peter Knippertz, Leeds) AXA Research Project: European windstorms in a Changing Climate (David Stephenson, Exeter and Ruth McDonald, Met Office) EU PREDEX: Predictability of Extreme Events (Renato Vitolo, Exeter) Lizzie Froude’s work on error growth in TIGGE forecasts at ESSC, Reading PhD projects at Reading (A. Champion, R. Lee, T. Philp, H. De Leeuw) and at Grantham (E. Thompson)

TEMPEST Summary and Key Outcomes First systematic assessment of how intense extratropical cyclones are predicted to change in the CMIP5 climate models An integrated set of sensitivity experiments with the Met Office Unified Model, which will lead to improved understanding of the spread in climate model projections Analysis of the impact of climate change on intense extratropical cyclones in very high-resolution global atmospheric model experiments capable of capturing mesoscale structures Guidance and advice for the climate impacts assessment community and policy-makers regarding the trustworthiness of climate predictions Developing an integrated research community and wider impacts

Project Timeframe Q4Q1Q2Q3Q4Q1Q2Q3Q4Q1Q2Q3 WP1.1 Assessing track statistics from CMIP5 ms WP1.2 Assessing composite structures from CMIP5 ms WP1.3 Natural variability of ETC activity from historical datasets ms WP2.1 Sensitivity of N Atl to upper tropospheric temp contrastms WP2.2 Quantify regional processes driving changes in N Atl storm trackms WP2.3 Synthesis of the sensitivity experiment resultsms WP3.1 Evaluating extra-tropical cyclone statistics in the ECMWF modelms WP3.2 Assess the ETC climate change response in the ECMWF modelms WP3.3 Assessing the upscale response of resolving mesoscale featuresms WP4.1 Developing an integrated research community ms WP4.2 Links to the Numerical Weather Prediction Deliverablems WP4.3 Links to the Impacts Deliverablems WP4.4 Pull-through to the operational centres ms WP4.5 Outreach to external stakeholders ms Project communication and co-ordination Project Meetings Final workshop NERC OPM returns

U850; AR4 models (A2) – (20 th Century runs); Lorenz and DeWeaver, 2007 Poleward shift of the jet

Laine et al 2009 There are some very different responses in the North Atlantic These could be due to different local SST changes Differences in the North Atlantic