Home » Research & Impact » Natural Hazard & Risk » Tropical Cyclones

Tropical Cyclones

Tropical Cyclones (also known as hurricanes or typhoons) represent the single largest cause of natural catastrophe risk to exposed populations and insurance and reinsurance markets in developed and developing countries. Assessing global tropical cyclone risk in current and future climate is a core activity of the WRN.

Tropical cyclone risk combines the destructive force of tropical cyclones with growing concentration of population and assets in coastal zones. Additional concern is the potential impact of climate change on distribution, frequency and intensity of tropical storms on exposed regions across the world. Developing greater confidence and control over tropical cyclone risk is a major focus for the Willis Research Network involving many of the world's leading experts and research infrastructures.

Tropical Cyclone Research

Exploring History.

Economic losses are driven by the risk of tropical cyclones making landfall. A major priority of the WRN is a continued analysis of the historical storms with the benefit of new records, improved statistical techniques for evaluating extreme distributions and a greater understanding of the global processes that influence tropical cyclone variability.

Global Climate Models.

We are reaching the limits of what historical records alone can tell us about tropical cyclone risk. Detailed historic records are only available for the last 30 to 40 years and therefore not sufficient to estimate low-probability events, tail risks and extremes. The WRN is at the centre of employing the outputs of a new generation of high resolution climate models which have the power to model realistically the distribution and intensities of current climate tropical cyclones on a regional and global scale. New opportunities arise from the convergence of low-resolution global climate models and dynamic high-resolution weather models, as well as global-scale variable grid climate models. With these resources we are at the beginning of a new era in our assessment of global and local patterns of tropical cyclone activity opening major possibilities for catastrophe risk protection and management.

Seasonal and Multi-Year Forecasting.

The improvements of global climate and numerical weather modelling systems as well as advances in quality-controlled historic ‘Best Track’ data sets enables meteorological and research agencies to develop hybrid forecast systems. These forecast models build on regional high-resolution climate models and statistical relationships with climate variables. The lead-times of operational weather forecasting extends from of around fourteen days to long-term forecasting with a scope of months or even several seasons ahead. The potential of developing a statistically robust forecast of annual tropical cyclone risk relative to reference-level regional norms offers an important improvement in our ability to manage risk and allocate capital to regions with greatest need.

Hazard Modelling.

Potential tropical cyclone damage is triggered by wind, storm surge and/or extreme precipitation. The effect of wind is described by a footprint of cumulated maximum windspeeds observed during the storm. The footprint depends on the strength and extend of the rotational windfield as well as on the track and forward speed of the storm. Regional damages from flood and/or storm surge can differ from regions affected by wind and are usually modelled independently from the wind hazard. The treatment of these components within tropical cyclone models has a significant influence on expected losses. Within the WRN resources are combined to fully understand the complete damageability of tropical cyclones using new methods and indices to translate cyclone characteristics into effective estimates of destructive potential.

Understanding Exposure and Vulnerability.

The impact of tropical cyclones is driven by their interactions with the built environment, systems, networks and populations. Our understanding of exposure and vulnerability is insufficient in most developed and developing regions so that enhancing the quality of exposure data is a major priority for disaster risk reduction in communities at local and global scales. Facilities within the WRN also test buildings against cyclone wind and flood forces.

Economics, Insurance, Finance & Public Policy.

Developing sustainable solutions for tropical cyclone risk presents major challenges for administrations and insurance systems throughout the world. The research network combines the strength of its physical modelling with an extensive understanding of WRN's members institutions at the forefront of the economics, financing and public policy around tropical cyclone risk. This coupled with Willis role as a global insurance and reinsurance broker provides a comprehensive range of knowledge required to confront these challenges.

Latest on Tropical Cyclones

  • High resolution global climate modelling; the UPSCALE project, a large simulation campaign

    Date: Jan 17, 2014 | Type: Paper | Journal: Geoscientific Model Development | Ext. Link: Click Here ›

    Pillar: Natural Hazard & Risk
    Hub: Tropical Cyclones

    Authors: M. S. Mizielinski, M. J. Roberts, P. L. Vidale, R. Schiemann, M.-E. Demory, J. Strachan, et al.
    Fields: Hurricanes, Tropical cyclones, Climate change, Climate models, Coupled models

    Summary: The UPSCALE (UK on PRACE: weather-resolving Simulations of Climate for globAL Environmental risk) project constructed and ran an ensemble of HadGEM3 (Hadley centre Global Environment Model 3) atmosphere-only global climate simulations over the period 1985–2011, at resolutions of N512 (25 km), N216 (60 km) and N96 (130 km) as used in current global weather forecasting, seasonal prediction and climate modelling respectively. Alongside these present climate simulations a parallel ensemble looking at extremes of future climate was run, using a time-slice methodology to consider conditions at the end of this century.

    Read More about this publication ›

    Improved evaporative flux partitioning and carbon flux in the land surface model JULES: Impact on the simulation of land surface processes in temperate Europe

    Date: Jan 17, 2014 | Type: Paper | Journal: Agricultural and Forest Meteorology | Ext. Link: Click Here ›

    Pillar: Natural Hazard & Risk
    Hub: Tropical Cyclones

    Authors: Catherine Van den Hoof, Pier Luigi Vidale, Anne Verhoef, Caroline Vincke
    Fields: Eddy fluxes measurements; Europe; Evaporative flux partitioning; Land surface model; 2003 heat wave

    Summary: The primary role of land surface models embedded in climate models is to partition surface available energy into upwards, radiative, sensible and latent heat fluxes. Partitioning of evapotranspiration, ET, is of fundamental importance: as a major component of the total surface latent heat flux, ET affects the simulated surface water balance, and related energy balance, and consequently the feedbacks with the atmosphere. In this context it is also crucial to credibly represent the CO2 exchange between ecosystems and their environment. In this study, JULES, the land surface model used in UK weather and climate models, has been evaluated for temperate Europe. Compared to eddy covariance flux measurements, the CO2 uptake by the ecosystem is underestimated and the ET overestimated

    Read More about this publication ›

    The sensitivity of the tropical circulation and Maritime Continent precipitation to climate model resolution

    Date: Dec 31, 2013 | Type: Paper | Journal: Climate Dynamics | Ext. Link: Click Here ›

    Pillar: Natural Hazard & Risk
    Hub: Tropical Cyclones

    Authors: R. Schiemann, M.-E. Demory, M. S. Mizielinski, M. J. Roberts, L. C. Shaffrey, J. Strachan, P. L. Vidale
    Fields: Precipitation Climate model bias Resolution GCM Boundary conditions Maritime Continent Walker circulation Coastal tiling

    Summary: The dependence of the annual mean tropical precipitation on horizontal resolution is investigated in the atmospheric version of the Hadley Centre General Environment Model. Reducing the grid spacing from about 350 km to about 110 km improves the precipitation distribution in most of the tropics. In particular, characteristic dry biases over South and Southeast Asia including the Maritime Continent as well as wet biases over the western tropical oceans are reduced. The annual-mean precipitation bias is reduced by about one third over the Maritime Continent and the neighbouring ocean basins associated with it via the Walker circulation.

    Read More about this publication ›

    Determining tropical cyclone inland flooding loss on a large scale through a new flood peak ratio-based methodology

    Date: Dec 20, 2013 | Type: Paper | Attachment: Download File ›
    Journal: Environmental Research Letters | Ext. Link: Click Here ›

    Pillar: Natural Hazard & Risk
    Hub: Tropical Cyclones

    Authors: Jeffrey Czajkowski, Gabriele Villarini, Erwann Michel-Kerjan and James A Smith
    Fields:

    Summary: In recent years, the United States has been severely affected by numerous tropical cyclones (TCs) which have caused massive damages. While media attention mainly focuses on coastal losses from storm surge, these TCs have inflicted significant devastation inland as well. Yet, little is known about the relationship between TC-related inland flooding and economic losses.

    Read More about this publication ›

    Response of Tropical Cyclones to Idealized Climate Change Experiments in a Global High-Resolution Coupled General Circulation Model

    Date: Oct 31, 2013 | Type: Paper | Journal: Journal of Science | Ext. Link: Click Here ›

    Pillar: Natural Hazard & Risk
    Hub: Tropical Cyclones

    Authors: Bell, Ray, Jane Strachan, Pier Luigi Vidale, Kevin Hodges, Malcolm Roberts
    Fields: Hurricanes, Tropical cyclones, Climate change, Climate models, Coupled models

    Summary: The authors present an assessment of how tropical cyclone activity might change owing to the influence of increased atmospheric carbon dioxide concentrations, using the U.K. High-Resolution Global Environment Model (HiGEM) with N144 resolution (~90 km in the atmosphere and ~40 km in the ocean).

    Read More about this publication ›

    As the Wind Blows? Understanding Hurricane Damages at the Local Level Through a Case Study Analysis

    Date: Oct 25, 2013 | Type: Paper | Journal: American Meteorological Society | Ext. Link: Click Here ›

    Pillar: Natural Hazard & Risk
    Hub: Tropical Cyclones

    Authors: James Done and Jeff Czajkowski.
    Fields:

    Summary: An understanding of the potential drivers of local scale hurricane losses is developed through a case study analysis. Two recent Category Three US landfalling hurricanes (Ivan in 2004 and Dennis in 2005) are analyzed that, although similar in terms of maximum wind speed at their proximate coastal landfall locations, caused vastly different loss amounts.

    Read More about this publication ›

    Importance of oceanic resolution and mean state on the extra-tropical response to El Niño in a matrix of coupled models

    Date: Sep 30, 2013 | Type: Paper | Journal: Climate Dynamics | Ext. Link: Click Here ›

    Pillar: Natural Hazard & Risk
    Hub: Tropical Cyclones

    Authors: Andrew Dawson, Adrian J. Matthews, David P. Stevens, Malcolm J. Roberts, Pier Luigi Vidale
    Fields: North Pacific Extra-tropical SST ENSO GCM Basic state

    Summary: The extra-tropical response to El Niño in configurations of a coupled model with increased horizontal resolution in the oceanic component is shown to be more realistic than in configurations with a low resolution oceanic component. This general conclusion is independent of the atmospheric resolution.

    Read More about this publication ›

    The role of horizontal resolution in simulating drivers of the global hydrological cycle

    Date: Sep 30, 2013 | Type: Paper | Journal: Climate Dynamics | Ext. Link: Click Here ›

    Pillar: Natural Hazard & Risk
    Hub: Tropical Cyclones

    Authors: Marie-Estelle Demory, Pier Luigi Vidale, Malcolm J. Roberts, Paul Berrisford, Jane Strachan, Reinhard Schiemann, Matthew S. Mizielinski
    Fields: Hydrological cycle Atmospheric moisture transport Precipitation Moisture recycling GCM Horizontal resolution

    Summary: The role of atmospheric general circulation model (AGCM) horizontal resolution in representing the global energy budget and hydrological cycle is assessed, with the aim of improving the understanding of model uncertainties in simulating the hydrological cycle.

    Read More about this publication ›

    Investigating global tropical cyclone activity with a hierarchy of AGCMs: the role of model resolution

    Date: May 17, 2013 | Type: Paper | Journal: Journal of Climate, 26 (1). pp. 133-152 | Ext. Link: Click Here ›

    Pillar: Natural Hazard & Risk
    Hub: Tropical Cyclones

    Authors: Strachan, J., Vidale, P. L., Hodges, K., Roberts, M. and Demory, M.-E
    Fields:

    Summary: The ability to run General Circulation Models (GCMs) at ever-higher horizontal resolutions has meant that tropical cyclone simulations are increasingly credible. A hierarchy of atmosphere-only GCMs, based on the Hadley Centre Global Environmental Model (HadGEM1), with horizontal resolution increasing from approximately 270km to 60km (at 50N), is used to systematically investigate the impact of spatial resolution on the simulation of global tropical cyclone activity, independent of model formulation.

    Read More about this publication ›

    What Can Models Tell us About Tropical Cyclones?

    Date: Apr 04, 2013 | Type: Paper | Attachment: Download File ›

    Pillar: Natural Hazard & Risk
    Hub: Tropical Cyclones

    Authors: Dr. James Done and Dr. Greg Holland
    Fields:

    Summary: Global Climate Model (GCM)-based Tropical Cyclone (TC) data hold considerable promise as an adjunct to the historical TC record. Multiple GCM simulations commonly extend for over one hundred years thereby substantially complementing the shorter observational record

    Read More about this publication ›

    Recent intense hurricane response to global climate change

    Date: Mar 19, 2013 | Type: Paper | Journal: Climate Dynamics | Ext. Link: Click Here ›

    Pillar: Natural Hazard & Risk
    Hub: Tropical Cyclones

    Authors: Greg Holland, Cindy L. Bruyère
    Fields:

    Summary: Recent community consensus has concluded that it is likely that the frequency of intense hurricanes will increase with future anthropogenic climate change. IPCC (2007) also concluded that the current ‘warming of the climate system is unequivocal’. Yet IPCC (2012) concluded that ‘There is low confidence in any observed long-term increases in tropical cyclone activity’, based largely on potential errors in the observed data. Here we investigate this apparent anomaly and find that there has been an increase in the proportion of intense hurricanes relative to all hurricanes, and that is strongly related to an Anthropogenic Climate Change Index (ACCI).

    Post-Sandy: Recovering, Repairing and Rebuilding

    Date: Jan 29, 2013 | Type: Paper | Ext. Link: Click Here ›

    Pillar: Natural Hazard & Risk
    Hub: Tropical Cyclones

    Authors: IBHS
    Fields:

    Summary: Insurance Institute for Business and Home Safety (IBHS), a WRN partner released three new papers focusing on building codes in New York and New Jersey; guidance for repairing and rebuilding residential and commercial structures post-Sandy; and business protection lessons learned from Sandy. These papers contain valuable information related to building codes in New York and New Jersey and highlights the importance of building mitigation measures to wind and flood.

    Read More about this publication ›

    Atmospheric blocking in a high resolution climate model: influences of mean state, orography and eddy forcing

    Date: Jan 28, 2013 | Type: Paper | Journal: Atmospheric Science Letters | Ext. Link: Click Here ›

    Pillar: Natural Hazard & Risk
    Hub: Tropical Cyclones

    Authors: Julie Berckmans, Tim Woollings, Marie-Estelle Demory, Pier-Luigi Vidale and Malcolm Roberts
    Fields: atmospheric blocking;high resolution;orography;mean state;transient eddies

    Summary: An underestimate of atmospheric blocking occurrence is a well-known limitation of many climate models. This article presents an analysis of Northern Hemisphere winter blocking in an atmospheric model with increased horizontal resolution. European blocking frequency increases with model resolution, and this results from an improvement in the atmospheric patterns of variability as well as a simple improvement in the mean state. There is some evidence that the transient eddy momentum forcing of European blocks is increased at high resolution, which could account for this.

    Read More about this publication ›

    WRN Bulletin: Hurricane Sandy Damage Survey Report

    Date: Dec 10, 2012 | Type: Paper | Attachment: Download File ›

    Pillar: Natural Hazard & Risk
    Hub: Tropical Cyclones

    Authors: Dr. Habil. Michael Kunz & Prasad Gunturi
    Fields:

    Summary: Sandy was a storm system with special meteorological characteristics causing widespread damage from the Caribbean to the U.S. East Coast. At the U.S. coast, especially in New York, New Jersey and Pennsylvania, Sandy resulted in a relatively high death toll compared to historic events. Critical infrastructure failures (electricity, transportation) are expected to lead to a high amount of indirect damages.

    CEDIM FDA-Report on Hurricane Sandy Sandy 22-30 October

    Date: Nov 08, 2012 | Type: Paper | Attachment: Download File ›

    Pillar: Natural Hazard & Risk
    Hub: Tropical Cyclones

    Authors: Chris Kilsby and Jim Hall. Bernhard Mühr. Michael Kunz, Tina Kunz -Plapp, James Daniell, Bijan Khazai, Marjorie Vannieuwenhuyse, Tina Comes, Florian Elmer, Kai Schröter, Adrian Leyser, Christian Lucas, Joachim Fohringer, Thomas Münzberg, Werner Trieselmann, Jochen Zschau
    Fields:

    Summary: Hurricane Sandy was a storm system with special meteorlogical characteristics. It caused widespread damage from the Caribbean to the U.S. East Coast.

    Read More about this publication ›

    Assessing Tropical Cyclone Damage

    Date: Nov 01, 2012 | Type: Article | Attachment: Download File ›

    Pillar: Natural Hazard & Risk
    Hub: Tropical Cyclones

    Authors: James Done, Jeffrey Czajkowski
    Fields: Atmospheric

    Summary: This study provides new insights into the drivers of hurricane losses that have implications for existing approaches to hurricane loss modeling.

    Read More about this publication ›

    Impact of North Atlantic Oscillation on European Windstorms

    Date: Oct 31, 2012 | Type: Paper | Attachment: Download File ›

    Pillar: Natural Hazard & Risk
    Hub: Tropical Cyclones

    Authors: Prof David B. Stephenson; Dr. Leon Hermanson; Dr Angelika Werner
    Fields:

    Summary: A two page paper looking at the impact of North Atlantic Oscillation on European Windstorms

    Counting the coming storms

    Date: Aug 30, 2012 | Type: Paper | Attachment: Download File ›

    Pillar: Natural Hazard & Risk
    Hub: Tropical Cyclones

    Authors: Ed Hawkins and Pier Luigi Vidale
    Fields:

    Summary: Tropical Atlantic storms impact the lives of many thousands of people each year. A study describes how different future anthropogenic emission pathways may change the frequency of these storms.

    Investigating Global Tropical Cyclone Activity with a Hierarchy of AGCMs: The Role of Model Resolution

    Date: Aug 01, 2012 | Type: Paper | Journal: Journal of Climate | Ext. Link: Click Here ›

    Pillar: Natural Hazard & Risk
    Hub: Tropical Cyclones

    Authors: J. Strachan, P.L. Vidale, K.I. Hodges, MJ Roberts, and M.E. Demory,
    Fields:

    Summary: Tropical cyclones are among the most destructive environmental hazards, with intense, landfalling storms leading to significant socioeconomic impacts. Tropical cyclones account for four of the five most costly insurance losses from natural disasters over the period 1950 to 2009 (Munich Re, 2010), with U S. hurricanes responsible for the highest natural catastrophe insurance losses. It is therefore essential that risk assessment takes into account our best understanding of how the naturally and anthropogenically varying climate system modulates storm behaviour

    Read More about this publication ›

    WRN Bulletin - Tropical Cyclone Seasonal Forecast

    Date: May 15, 2012 | Type: Article | Attachment: Download File ›

    Pillar: Natural Hazard & Risk
    Hub: Tropical Cyclones

    Authors: David Brayshaw, Angelika Werner
    Fields:

    Summary: A 2-page summary on the current state of Tropical Cyclone Seasonal Forecasting: methods and sources...

About WRN

As economic, social and environmental uncertainties increase, institutions and populations seek greater resilience to support sustainable growth. Science and insurance lay at the heart of understanding, managing and sharing these risks, building more secure futures at local and global scales.

The Willis Research Network (WRN) operates across the full spectrum of risk from natural catastrophe, to legal liability, financial and security issues linked across driving themes: Resilience, Security & Sustainable Growth; Managing Extremes; Insurance & Risk Management and Mastering the Modelled World.

All Members and activities are united by a common aim: improving resilience by integrating first class science into operational and financial decision-making across public and private institutions.

Latest News

Extending Terrorism Insurance Program Could Save Federal Government Money After Future Attacks
Apr 11, 2014 | read more ›

Senate Bill to Extend TRIA: Positive, but no Guarantee
Apr 11, 2014 | read more ›

Forecasting, Flood & Fortitude: Slides available
Mar 25, 2014 | read more ›

Seasonal Forecast Summary Update
Mar 24, 2014 | read more ›

RAND Study: TRIA Expiration Could “Affect U.S. National Resilience”
Mar 14, 2014 | read more ›

Newsletter

Fast Facts

  • The WRN was formed in September 2006 to support leading academic research into extreme events, with a specific focus on responding to the challenges faced by businesses, insurers and governments
  • The WRN's membership spans the globe, counting more than 50 world-class universities, scientific research organisations and public policy institutions
  • Collectively, our members have published more than 100 papers in leading scientific journals
  • Nearly all of the WRN's research is freely available to the public and can be downloaded on our website

Copyright © 2012 Willis Group Holdings

Site Map | Terms & Conditions | Privacy Policy | Accessibility | RSS