Breaking Waves at the Tropopause in the Wintertime Northern Hemisphere: Climatological Analyses of the Orientation and the Theoretical LC1/2 Classification

Abstract Breaking waves on the tropopause are viewed as potential vorticity (PV) streamers on middle-world isentropic levels. A Northern Hemisphere winter climatology of the streamers’ spatial distribution and meridional orientation is derived from the 40-yr ECMWF Re-Analysis (ERA-40) dataset, and used to assess the nature and frequency of occurrence of breaking synoptic-scale waves. The streamers are grouped into two classes related to the so-called cyclonic (LC2) and anticyclonic (LC1) patterns, and the ambient wind strength and wind shear is also noted. It is shown that the occurrence of cyclonic and anticyclonic PV streamers exhibits a distinct spatial variability in the horizontal and the vertical. The majority of cyclonic PV streamers are found on lower isentropic levels that intersect the tropopause at more poleward latitudes, whereas anticyclonic streamers predominate at higher elevations in the subtropics. An analysis of the streamer patterns for the two phases of the North Atlantic Oscillation (...

[1]  H. Wernli,et al.  Heavy precipitation on the alpine southside: An upper‐level precursor , 1998 .

[2]  B. Hoskins,et al.  Barotropic Influences on the Growth and Decay of Nonlinear Baroclinic Waves , 1980 .

[3]  X. Zou,et al.  The Role of Wave Breaking, Linear Instability, and PV Transports in Model Block Onset * , 1998 .

[4]  W. Randel,et al.  Deep convective influence on the Asian summer monsoon anticyclone and associated tracer variability observed with Atmospheric Infrared Sounder (AIRS) , 2006 .

[5]  H. Davies.  Theories of Frontogenesis , 1999 .

[6]  Jeffrey S. Whitaker,et al.  A Linear Theory of Extratropical Synoptic Eddy Statistics , 1998 .

[7]  D. Lüthi,et al.  The effect of barotropic shear on upper-level induced cyclogenesis : Semigeostrophic and primitive equation numerical simulations , 1998 .

[8]  Huw C. Davies,et al.  Forced Waves on a Zonally Aligned Jet Stream , 2004 .

[9]  I. Orlanski.  Bifurcation in Eddy Life Cycles: Implications for Storm Track Variability , 2003 .

[10]  H. V. D. Dool,et al.  Asymmetric Impact of Tropical SST Anomalies on Atmospheric Internal Variability over the North Pacific , 1997 .

[11]  C. Schwierz,et al.  Surface Cyclones in the ERA-40 Dataset (1958–2001). Part I: Novel Identification Method and Global Climatology , 2006 .

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

[13]  H. Wernli,et al.  Stratosphere–Troposphere Exchange and Its Relation to Potential Vorticity Streamers and Cutoffs near the Extratropical Tropopause , 2007 .

[14]  D. Hartmann,et al.  Response of Baroclinic Life Cycles to Barotropic Shear , 1998 .

[15]  K. Swanson.  Stationary Wave Accumulation and the Generation of Low-Frequency Variability on Zonally Varying Flows , 2000 .

[16]  Huw C. Davies,et al.  Episodes of alpine heavy precipitation with an overlying elongated stratospheric intrusion: a climatology , 2006 .

[17]  T. Palmer,et al.  Breaking planetary waves in the stratosphere , 1983, Nature.

[18]  C. Schär,et al.  The Palette of Fronts and Cyclones within a Baroclinic Wave Development , 1991 .

[19]  Kevin E. Trenberth,et al.  Progress during TOGA in understanding and modeling global teleconnections associated with tropical sea surface temperatures , 1998 .

[20]  Christian Franzke,et al.  Is the North Atlantic Oscillation a Breaking Wave , 2004 .

[21]  B. Hoskins,et al.  The Life Cycles of Some Nonlinear Baroclinic Waves , 1978 .

[22]  John M. Wallace,et al.  Planetary-Scale Atmospheric Phenomena Associated with the Southern Oscillation , 1981 .

[23]  M. Hitchman,et al.  A Climatology of Rossby Wave Breaking along the Subtropical Tropopause , 1999 .

[24]  B. Hoskins,et al.  On the use and significance of isentropic potential vorticity maps , 2007 .

[25]  J. Bjerknes.  ATMOSPHERIC TELECONNECTIONS FROM THE EQUATORIAL PACIFIC1 , 1969 .

[26]  J. G. Esler,et al.  Baroclinic Wave Breaking and the Internal Variability of the Tropospheric Circulation , 1999 .

[27]  C. Appenzeller,et al.  Fragmentation of stratospheric intrusions , 1996 .

[28]  Sukyoung Lee,et al.  The Dynamical Relationship between Subtropical and Eddy-Driven Jets. , 2003 .

[29]  C. Appenzeller,et al.  Structure of stratospheric intrusions into the troposphere , 1992, Nature.

[30]  P. Kushner,et al.  Dynamics of Barotropic Storm Tracks , 1997 .

[31]  D. Hartmann.  A PV view of zonal flow vacillation , 1995 .

[32]  Michael Sprenger,et al.  Identification and ERA-15 Climatology of Potential Vorticity Streamers and Cutoffs near the Extratropical Tropopause , 2007 .

[33]  N. Harnik,et al.  The Effects of Variations in Jet Width on the Growth of Baroclinic Waves: Implications for Midwinter Pacific Storm Track Variability , 2004 .

[34]  F. Sanders.  Life History of Mobile Troughs in the Upper Westerlies , 1988 .

[35]  Sukyoung Lee,et al.  Synoptic View of the North Atlantic Oscillation , 2004 .

[36]  A. Simmons.  Numerical Simulations of Cyclone Life Cycles , 1999 .

[37]  S. Feldstein.  The dynamics of NAO teleconnection pattern growth and decay , 2003 .

[38]  N. Bond,et al.  The influence of the 1997–99 El Niňo Southern Oscillation on extratropical baroclinic life cycles over the eastern North Pacific , 2001 .

[39]  X. Zou,et al.  A Planetary-Scale to Mesoscale Perspective of the Life Cycles of Extratropical Cyclones: The Bridge between Theory and Observations , 1999 .

[40]  S. Yoden,et al.  Zonal Flow Vacillation and Bimodality of Baroclinic Eddy Life Cycles in a Simple Global Circulation Model , 1997 .

[41]  B. Hoskins,et al.  Two paradigms of baroclinic‐wave life‐cycle behaviour , 1993 .

[42]  L. Polvani,et al.  The effect of lower stratospheric shear on baroclinic instability , 2007 .

[43]  D. Waugh,et al.  Rossby Wave Breaking in the Southern Hemisphere Wintertime Upper Troposphere , 2003 .

[44]  S. Garner,et al.  The Role of Momentum Fluxes in Shaping the Life Cycle of a Baroclinic Wave , 1997 .

[45]  K. Swanson.  Dynamical Aspects of Extratropical Tropospheric Low-Frequency Variability , 2002 .