TITLE

Low-Level Convergence Lines over Northeastern Australia. Part II: Southerly Disturbances

AUTHOR(S)
Smith, Roger K.; Reeder, Michael J.; May, Peter; Richter, Harald
PUB. DATE
November 2006
SOURCE
Monthly Weather Review;Nov2006, Vol. 134 Issue 11, p3109
SOURCE TYPE
Academic Journal
DOC. TYPE
Article
ABSTRACT
Observations of northward-moving borelike convergence lines over the southern part of the Gulf of Carpentaria region of northern Australia are described. Eleven such disturbances were documented during the 45-day period of the 2002 Gulf Lines Experiment. Of these, six were classified as major and five as minor, depending on their coherence throughout the region. The mean synoptic conditions leading to the two types of events were found to differ. The data for the events provide further insight into the structure and origin of borelike disturbances in the region. Two of the major events, those of 28–29 September and 9 October, are particularly noteworthy. The first of these had a clear double-change structure at all surface stations in the southeastern gulf region with an undular borelike wave preceding and separating from an airmass change in the form of a dryline. It is probably one of the best documented cases of its type. The second, which was documented in unprecedented detail by an instrumented research aircraft, consisted of three separate disturbances: one moving from the southeast, one from the south, and one from the northeast, all of which collided over the gulf. It is believed that the aircraft measurements are the first of their kind anywhere in the world. The aircraft made two long low-level transects through the disturbances and a higher-level transect where they were colliding. Various soundings were also made. The aircraft data showed clearly the undular borelike nature of the southeasterly disturbance. Measured vertical velocities in the waves were as high as 3 m s-1 at a mean altitude of about 230 m. Vertical velocities as high as 5 m s-1 were measured in the region of the collision at an altitude of about 1 km. The longevity of the bores is not explained by the vertical structure of the Scorer parameter, which indicates a leaky waveguide.
ACCESSION #
23580174

 

Related Articles

  • Formation of reversed lee flow over the north-eastern Adriatic during bora. Prtenjak, Maja Telišman; Belušić, Danijel // Geofizika;2009, Vol. 26 Issue 2, p145 

    In-situ measurements indicate the existence of reversed near-surface airflow over the north-eastern Adriatic during the bora wind. Here we examine its structure and evolution by means of a numerical simulation. The studied phenomenon developed during typical summer frontal bora that is...

  • Air-sea interactions in the Adriatic basin: simulations of Bora and Sirocco wind events. Ferrarese, S.; Cassardo, C.; Elmi, A.; Genovese, R.; Longhetto, A.; Manfrin, M.; Richiardone, R. // Geofizika;2009, Vol. 26 Issue 2, p157 

    Two simulations of the response of Adriatic Sea to severe wind performed by an atmosphere-ocean coupled model and the comparisons with observed data and modelled fields published in literature are presented. The model RAMS-DieCAST was applied to simulate the variations of sea currents and...

  • A High-Resolution Modeling Study of the 24 May 2002 Dryline Case during IHOP. Part I: Numerical Simulation and General Evolution of the Dryline and Convection. Xue, Ming; Martin, William J. // Monthly Weather Review;Jan2006, Vol. 134 Issue 1, p149 

    Results from a high-resolution numerical simulation of the 24 May 2002 dryline convective initiation (CI) case are presented. The simulation uses a 400 km × 700 km domain with a 1-km horizontal resolution grid nested inside a 3-km domain and starts from an assimilated initial condition at...

  • Dryline on 19 June 2002 during IHOP. Part I: Airborne Doppler and LEANDRE II Analyses of the Thin Line Structure and Convection Initiation. Murphey, Hanne V.; Wakimoto, Roger M.; Flamant, Cyrille; Kingsmill, David E. // Monthly Weather Review;Jan2006, Vol. 134 Issue 1, p406 

    The evolution and finescale structure of a dryline that initiated a line of thunderstorms is presented. Both the along-line variability and mean vertical structure were examined using data collected by an airborne Doppler radar and a water vapor differential absorption lidar (DIAL). The...

  • Summary of Convective Storm Initiation and Evolution during IHOP: Observational and Modeling Perspective. Wilson, James W.; Roberts, Rita D. // Monthly Weather Review;Jan2006, Vol. 134 Issue 1, p23 

    The data-rich International H2O Project (IHOP_2002) experiment is used to study convective storm initiation and subsequent evolution for all days of the experiment. Initiation episodes were almost evenly divided between those triggered along surface-based convergence lines and elevated...

  • Observations of the 11 June Dryline during IHOP_2002—A Null Case for Convection Initiation. Huaqing Cai; Wen-Chau Lee; Weckwerth, Tammy M.; Flamant, Cyrille; Murphey, Hanne V. // Monthly Weather Review;Jan2006, Vol. 134 Issue 1, p336 

    The detailed analysis of the three-dimensional structure of a dryline observed over the Oklahoma panhandle during the International H2O Project (IHOP_2002) on 11 June 2002 is presented. High-resolution observations obtained from the National Center for Atmospheric Research Electra Doppler Radar...

  • Waiting for the bore. Bennett, Penelope // Contemporary Review;Nov96, Vol. 269 Issue 1570, p257 

    Describes the author's experiences with bores, a tidal wave created by the moon that rides up certain rivers. Sound of a bore, travelling up river; Booking by bore watchers of their river-facing rooms well in advance; Author's third encounter with bores.

  • Oasis in the desert.  // Australian Geographic;Sep/Oct2013, Issue 116, p130 

    A photograph of Purni Bore in the Great Artesian Basin in South Australia.

  • COASTAL PHOTOGRAPH BY HUBERT CHANSON.  // Journal of Coastal Research;Jan2009, Vol. 25 Issue 1, p155 

    A photograph of a tidal bore taken on April 7, 2004 in the Sélune River, Baie du Mont Saint Michel, France, is presented, along with a brief description of its size.

Share

Read the Article

Courtesy of THE LIBRARY OF VIRGINIA

Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics