The Boundary Layer Winds in Hurricanes Danielle (1998) and Isabel (2003)

Schwendike, Juliane; Kepert, Jeffrey D.
August 2008
Monthly Weather Review;Aug2008, Vol. 136 Issue 8, p3168
Academic Journal
This paper describes the boundary layer wind structure and dynamics of Hurricanes Danielle (1998) and Isabel (2003), based on the analysis of high-resolution global positioning system dropwindsonde data and simulation of the flow by a three-dimensional boundary layer model produced by Kepert and Wang. The observations show that the hurricane boundary layer has a complex three-dimensional structure with large variability over small distances. The analysis emphasizes three aspects: the degree of gradient-wind balance, the radially varying depth of the boundary layer, and the strength of the near-surface wind speed relative to that at a higher level. Each aspect is compared both with results obtained in a simulation of the individual storm by Kepert and Wang’s model and with theoretical predictions. The observations show that the boundary layer depth decreases toward the center of the storm, consistent with theoretical arguments. The strongest azimuthal winds occur near the top of, but still within, the frictional inflow layer. These strong azimuthal winds are marginally supergradient in Hurricane Danielle but strongly so in Hurricane Isabel, where the imbalance amounts to approximately 10 m s-1 near the radius of maximum winds and is statistically significantly nonzero. This layer of supergradient flow is surmounted by a layer of outflow, in which the flow returns to gradient balance. The maximum storm-relative azimuthal wind occurs in the left front of Hurricane Danielle, and the strongest inflow is located in the right front. These asymmetries rotate anticyclonically with height, but there is also a clear wavenumber-2 asymmetry superimposed, which shows less rotation with height and is possibly forced by environmental factors associated with the storm’s impending recurvature. In Hurricane Isabel, the azimuthal wind maximum is located in the left rear and the inflow maximum in the left front, with neither showing much tendency to vary in azimuth with height. The ratio of the near-surface wind speed to that farther aloft increases toward the storm center for both storms. The largest values are located near the radius of maximum wind, and in general higher values are found on the left of the storm’s track than on the right. Simulations of the two storms with the boundary layer model are able to explain several of these factors; they also show some ability to reproduce individual dropsonde wind observed profiles. Important is that the model predicts weakly supergradient flow in Danielle and strongly supergradient flow in Isabel, in excellent agreement with the observational analysis. Based on these simulations, physical arguments, and earlier studies, the authors conclude that the differences between these storms in this respect result from their differing radial profiles of gradient wind and argue that the occurrence of supergradient flow in the upper boundary layer of individual hurricanes should be readily predictable.


Related Articles

  • Transcritical Flows in the Coastal Marine Atmospheric Boundary Layer. Rogerson, A. M. // Journal of the Atmospheric Sciences;8/15/99, Vol. 56 Issue 16, p2761 

    Provides information on a study which computed numerical solutions of shallow water flow to model the summertime atmospheric boundary layer off the United States West Coast. Model formulation and numerical approach; Description of steady-state base flows; Interaction between coastal-trapped...

  • Evaluating Large-Eddy Simulations Using Volume Imaging Lidar Data. Mayor, Shane D.; Tripoli, Gregory J.; Eloranta, Edwin W. // Monthly Weather Review;Jul2003, Vol. 131 Issue 7, p1428 

    The authors apply data analysis techniques that demonstrate the power of using volume imaging lidar observations to evaluate several aspects of large-eddy simulations (LESs). They present observations and simulations of an intense and spatially evolving convective boundary layer on 13 January...

  • Unsteady Thermally Driven Flows on Gentle Slopes. Hunt, J.C.R; H.J.S. Fernando; Princevac, M. // Journal of the Atmospheric Sciences;9/1/2003, Vol. 60 Issue 17, p2169 

    The theoretical and laboratory studies on mean velocity and temperature fields of an unsteady atmospheric boundary layer on sloping surfaces reported here were motivated by recent field observations on thermally driven circulation in very wide valleys in the presence of negligible synoptic...

  • Le maintien du tourbillon des ondes planétaires stationnaires. Dugas, Bernard; Derome, Jacques // Atmosphere -- Ocean (Canadian Meteorological & Oceanographic Soc;Mar1987, Vol. 25 Issue 1, p60 

    The January 1979 FGGE data are used to investigate the dynamics of the stationary planetary waves. The different terms of the time-averaged vorticity equation are evaluated and compared. The zonal variance of the main terms reaches relative maxima in three distinct regions: the north side of the...

  • Erratum: ‘‘Application of the dynamic subgrid-scale model to axisymmetric transitional boundary layer at high speed’’ [Phys. Fluids 6, 1299 (1994)]. El-Hady, Nabil M.; Zang, Thomas A.; Piomelli, Ugo // Physics of Fluids;Jul94, Vol. 6 Issue 7, p2551 

    Presents a correction to the article 'Application of the dynamic subgrid-scale model to axissymmetric transitional boundary layer at high speed', by Nabil M. El-Hady, Thomas A. Zang, Ugo Piomelli, published in 1994 issue of the journal 'Phys. Fluids.'

  • The Influence of Idealized Heterogeneity on Wet and Dry Planetary Boundary Layers Coupled to the Land Surface. Patton, Edward G.; Sullivan, Peter P.; Chin-Hoh Moeng // Journal of the Atmospheric Sciences;7/1/2005, Vol. 62 Issue 7, p2078 

    This manuscript describes numerical experiments investigating the influence of 2–30-km striplike heterogeneity on wet and dry convective boundary layers coupled to the land surface. The striplike heterogeneity is shown to dramatically alter the structure of the convective boundary layer...

  • Airborne measurements of HCl from the marine boundary layer to the lower stratosphere over the North Pacific Ocean during INTEX-B. Kim, S.; Huey, L. G.; Stickel, R. E.; Pierce, R. B.; Chen, G.; Avery, M. A.; Dibb, J. E.; Diskin, G. S.; Sachse, G. W.; McNaughton, C. S.; Clarke, A. D.; Anderson2, B. E.; Blake, D. R. // Atmospheric Chemistry & Physics Discussions;2008, Vol. 8 Issue 1, p3563 

    Gas phase HCl was measured from the marine boundary layer (MBL) to the lower stratosphere from the NASA DC-8 during five science flights (41 h) of the Intercontinental Chemical Transport Experiment-Phase B (INTEX-B) field campaign. In the upper troposphere/lower stratosphere (UT/LS, 8-12 km) HCl...

  • Spatial spectra and characteristic horizontal scales of temperature and velocity fluctuations in the convective boundary layer of the atmosphere. Glazunov, A.; Dymnikov, V. // Izvestiya, Atmospheric & Oceanic Physics;Jan2013, Vol. 49 Issue 1, p33 

    Using a high-resolution LES numerical model, we calculated the turbulent thermal convection for high ratios of horizontal and vertical sizes of the computational domain (26: 26: 1). The natural analog of the simulated process is a planetary boundary layer (PBL) of the atmosphere growing with...

  • Concentration Fluctuation Measurements in a Plume Dispersing Through a Regular Array of Obstacles. Yee, Eugene; Biltoft, Christopher A. // Boundary-Layer Meteorology;Jun2004, Vol. 111 Issue 3, p363 

    We describe a comprehensive study of the statistical characteristics of concentration fluctuations in a neutrally buoyant tracer plume dispersing through a large array of building-like obstacles, each of which measured 12.2 m × 2.42 m × 2.54 m. The plumes were released both upwind and...


Read the Article


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

Try another library?
Sign out of this library

Other Topics