Initiation and Propagation of an Atmospheric Bore in a Numerical Forecast Model: A Comparison with Observations

Simon R. Osborne Met Office, Exeter, United Kingdom

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Alan Lapworth Met Office, Exeter, United Kingdom

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Abstract

In the autumn of 2016, an undular atmospheric bore passed over southern England. Observations at surface sites as the bore passed gave phase speeds of up to 30 m s−1, surface pressure rises of over 1.5 hPa, and abrupt wind direction changes of 90°, followed by slower changes of a further 180°. Use was made of this event, rarely observed in the United Kingdom, to compare surface and satellite observations of the bore with output from the operational Met Office limited-area 1.5-km numerical weather model and to investigate the bore initiation mechanism within the model. Although the model had timing errors of over an hour and orientation errors of the bore, the bore propagation was simulated fairly well, giving similar bore phase speeds and decay times. There was also a reasonable correlation between surface and satellite observations and the model. One significant difference was the longer bore wavelength in the model simulation.

For information regarding reuse of this content and general copyright information, consult the AMS Copyright Policy (www.ametsoc.org/PUBSReuseLicenses).

Corresponding author: Simon R. Osborne, simon.osborne@metoffice.gov.uk

Abstract

In the autumn of 2016, an undular atmospheric bore passed over southern England. Observations at surface sites as the bore passed gave phase speeds of up to 30 m s−1, surface pressure rises of over 1.5 hPa, and abrupt wind direction changes of 90°, followed by slower changes of a further 180°. Use was made of this event, rarely observed in the United Kingdom, to compare surface and satellite observations of the bore with output from the operational Met Office limited-area 1.5-km numerical weather model and to investigate the bore initiation mechanism within the model. Although the model had timing errors of over an hour and orientation errors of the bore, the bore propagation was simulated fairly well, giving similar bore phase speeds and decay times. There was also a reasonable correlation between surface and satellite observations and the model. One significant difference was the longer bore wavelength in the model simulation.

For information regarding reuse of this content and general copyright information, consult the AMS Copyright Policy (www.ametsoc.org/PUBSReuseLicenses).

Corresponding author: Simon R. Osborne, simon.osborne@metoffice.gov.uk
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  • Clarke, R. H., R. K. Smith, and D. G. Reid, 1981: The morning glory of the Gulf of Carpentaria: An atmospheric undular bore. Mon. Wea. Rev., 109, 17261750, doi:10.1175/1520-0493(1981)109<1726:TMGOTG>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Engel, C. B., T. P. Lane, M. J. Reeder, and M. Rezny, 2013: The meteorology of Black Saturday. Quart. J. Roy. Meteor. Soc., 139, 585533, doi:10.1002/qj.1986.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Gregory, D., J. Shutts, and J. R. Mitchell, 1998: A new gravity-wave scheme incorporating anisotropic orography and low-level wave breaking: Impact upon the climate of the UK Meteorological Office Unified Model. Quart. J. Roy. Meteor. Soc., 124, 463493, doi:10.1002/qj.49712454606.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Hallworth, M. A., A. J. Hogg, and H. E. Huppert, 1998: Effects of external flow on compositional and particle gravity currents. J. Fluid Mech., 359, 109142, doi:10.1017/S0022112097008409.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • King, J. C., W. M. Connolley, and S. H. Derbyshire, 2001: Sensitivity of modelled Antarctic climate to surface and boundary-layer flux parameterizations. Quart. J. Roy. Meteor. Soc., 127, 779794, doi:10.1002/qj.49712757304.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Klemp, J. B., R. Rotunno, and W. C. Skamarock, 1997: On the propagation of internal bores. J. Fluid Mech., 331, 81106, doi:10.1017/S0022112096003710.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Knupp, K. R., 2006: Observational analysis of a gust front to bore to solitary wave transition within an evolving nocturnal boundary layer. J. Atmos. Sci., 63, 20162035, doi:10.1175/JAS3731.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Koch, S. E., P. B. Dorian, R. Ferrare, S. H. Melfi, W. C. Skillman, and D. Whiteman, 1991: Structure of an internal bore and dissipating gravity current as revealed by Raman lidar. Mon. Wea. Rev., 119, 857887, doi:10.1175/1520-0493(1991)119<0857:SOAIBA>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Koch, S. E., M. Pagowski, J. W. Wilson, F. Fabry, C. Flamant, W. Feltz, G. Schwemmer, and B. Geerts, 2005: The structure and dynamics of atmospheric bores and solitons as determined from remote sensing and modeling experiments during IHOP. 11th Conf. on Mesoscale Processes, Albuquerque, NM, Amer. Meteor. Soc., JP6J.4, https://ams.confex.com/ams/pdfpapers/97033.pdf.

  • Lock, A. P., A. R. Brown, M. R. Bush, G. M. Martin, and R. N. B. Smith, 2000: A new boundary layer mixing scheme. Part I: Scheme description and single-column model tests. Mon. Wea. Rev., 128, 31873199, doi:10.1175/1520-0493(2000)128<3187:ANBLMS>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Lutzak, P. A., 2013: A proposal for analyzing and forecasting lower-atmospheric undular bores in the western Gulf of Mexico region. Wea. Forecasting, 28, 5576, doi:10.1175/WAF-D-12-00051.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Martin, E. R., and R. H. Johnson, 2008: An observational and modeling study of an atmospheric internal bore during NAME 2004. Mon. Wea. Rev., 136, 41504167, doi:10.1175/2008MWR2486.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Nudelman, I., R. K. Smith, and M. J. Reeder, 2010: A climatology of pressure jumps around the Gulf of Carpentaria. Aust. Meteor. Oceanogr. J., 60, 91101.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Osborne, S. R., S. J. Abel, I. A. Boutle, and F. Marenco, 2014: Evolution of stratocumulus over land: Comparison of ground and aircraft observations with numerical weather prediction simulations. Bound.-Layer Meteor., 153, 165193, doi:10.1007/s10546-014-9944-0.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Rottman, J. W., and J. E. Simpson, 1989: The formation of internal bores in the atmosphere: A laboratory model. Quart. J. Roy. Meteor. Soc., 115, 941963, doi:10.1002/qj.49711548809.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Scorer, R. S., 1949: Theory of waves in the lee of mountains. Quart. J. Roy. Meteor. Soc., 75, 4156, doi:10.1002/qj.49707532308.

  • Smith, R. K., and M. J. Reeder, 2014: A review of research on the dry season mesoscale meteorology of northern Australia. Aust. Meteor. Oceanogr. J., 64, S9S43.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Smith, R. N. B., 1990: A scheme for predicting layer cloud and their water content in a general circulation model. Quart. J. Roy. Meteor. Soc., 116, 435460, doi:10.1002/qj.49711649210.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Tang, Y., H. W. Lean, and J. Bornemann, 2013: The benefits of the Met Office variable resolution NWP model for forecasting convection. Meteor. Appl., 20, 417426, doi:10.1002/met.1300.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Vosper, S. B., A. R. Brown, and S. Webster, 2016: Orographic drag on islands in the NWP mountain grey zone. Quart. J. Roy. Meteor. Soc., 142, 31283137, doi:10.1002/qj.2894.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Walters, D. N., and Coauthors, 2014: The Met Office Unified Model global atmosphere 4.0 and JULES global land 4.0 configurations. Geosci. Model Dev., 7, 361386, doi:10.5194/gmd-7-361-2014.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Webster, S., A. R. Brown, D. R. Cameron, and C. P. Jones, 2003: Improvements to the representation of orography in the Met Office unified model. Quart. J. Roy. Meteor. Soc., 129, 19892010, doi:10.1256/qj.02.133.

    • Crossref
    • Search Google Scholar
    • Export Citation
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