Can Climate Models Capture the Structure of Extratropical Cyclones

Abstract Composites of wind speeds, equivalent potential temperature, mean sea level pressure, vertical velocity, and relative humidity have been produced for the 100 most intense extratropical cyclones in the Northern Hemisphere winter for the 40-yr ECMWF Re-Analysis (ERA-40) and the high resolution global environment model (HiGEM). Features of conceptual models of cyclone structure—the warm conveyor belt, cold conveyor belt, and dry intrusion—have been identified in the composites from ERA-40 and compared to HiGEM. Such features can be identified in the composite fields despite the smoothing that occurs in the compositing process. The surface features and the three-dimensional structure of the cyclones in HiGEM compare very well with those from ERA-40. The warm conveyor belt is identified in the temperature and wind fields as a mass of warm air undergoing moist isentropic uplift and is very similar in ERA-40 and HiGEM. The rate of ascent is lower in HiGEM, associated with a shallower slope of the moist ...

[1]  Gill Martin,et al.  The Physical Properties of the Atmosphere in the New Hadley Centre Global Environmental Model (HadGEM1). Part II: Aspects of Variability and Regional Climate , 2006 .

[2]  Heini Wernli,et al.  A 15-Year Climatology of Warm Conveyor Belts , 2004 .

[3]  Damian R. Wilson,et al.  A microphysically based precipitation scheme for the UK meteorological office unified model , 1999 .

[4]  Thomas Jung,et al.  Sensitivity of extratropical cyclone characteristics to horizontal resolution in the ECMWF model , 2006 .

[5]  Luca Bonaventura,et al.  The atmospheric general circulation model ECHAM 5. PART I: Model description , 2003 .

[6]  R. Neale,et al.  Midlatitude Cyclone Compositing to Constrain Climate Model Behavior Using Satellite Observations , 2008 .

[7]  Kevin I. Hodges,et al.  A General Method for Tracking Analysis and Its Application to Meteorological Data , 1994 .

[8]  R. Blender,et al.  Cyclone Tracking in Different Spatial and Temporal Resolutions , 2000 .

[9]  Kevin I. Hodges,et al.  Adaptive Constraints for Feature Tracking , 1999 .

[10]  Kevin I. Hodges,et al.  Feature Tracking on the Unit Sphere , 1995 .

[11]  Lennart Bengtsson,et al.  How may tropical cyclones change in a warmer climate? , 2007 .

[12]  Explosive east coast cyclogenesis over the west-central North Atlantic Ocean - A composite study derived from ECMWF operational analyses , 1989 .

[13]  D. Schultz.  Reexamining the Cold Conveyor Belt , 2001 .

[14]  B. Hoskins,et al.  New perspectives on the Northern Hemisphere winter storm tracks , 2002 .

[15]  Toby N. Carlson,et al.  Airflow Through Midlatitude Cyclones and the Comma Cloud Pattern , 1980 .

[16]  D. Randall,et al.  Climate models and their evaluation , 2007 .

[17]  H. Dacre,et al.  The Spatial Distribution and Evolution Characteristics of North Atlantic Cyclones , 2009 .

[18]  M. Bauer,et al.  Composite Analysis of Winter Cyclones in a GCM: Influence on Climatological Humidity , 2006 .

[19]  Simon Wilson,et al.  U.K. HiGEM: The New U.K. High-Resolution Global Environment Model― Model Description and Basic Evaluation , 2009 .

[20]  B. Hoskins,et al.  A Comparison of Recent Reanalysis Datasets Using Objective Feature Tracking: Storm Tracks and Tropical Easterly Waves , 2003 .

[21]  Peter Clark,et al.  The sting at the end of the tail: Model diagnostics of fine‐scale three‐dimensional structure of the cloud head , 2005 .

[22]  K. Browning,et al.  Structure of a frontal cyclone , 1994 .

[23]  A. Sterl,et al.  The ERA‐40 re‐analysis , 2005 .

[24]  Chung‐Chieh Wang,et al.  A composite study of explosive cyclogenesis in different sectors of the North atlantic. Part I: Cyclone structure and evolution , 2001 .

[25]  Lennart Bengtsson,et al.  Will Extratropical Storms Intensify in a Warmer Climate , 2009 .

[26]  T. Hewson,et al.  A classification of FASTEX cyclones using a height‐attributable quasi‐geostrophic vertical‐motion diagnostic , 2002 .

[27]  M. Latif,et al.  Cyclone life cycle characteristics over the Northern Hemisphere in coupled GCMs , 2008 .

[28]  P. Field,et al.  Precipitation and Cloud Structure in Midlatitude Cyclones , 2007 .

[29]  M. Sinclair.  An Objective Cyclone Climatology for the Southern Hemisphere , 1994 .

[30]  K. Browning.  The dry intrusion perspective of extra‐tropical cyclone development , 1997 .

[31]  M. Shapiro,et al.  Fronts, Jet Streams and the Tropopause , 1990 .

[32]  T. W. Harrold.  Mechanisms influencing the distribution of precipitation within baroclinic disturbances , 1973 .

[33]  M. Shapiro,et al.  The Life Cycle of an Extratropical Marine Cyclone. Part I: Frontal-Cyclone Evolution and Thermodynamic Air-Sea Interaction , 1993 .

[34]  Michel Crucifix,et al.  The new hadley centre climate model (HadGEM1) : Evaluation of coupled simulations , 2006 .