• Alpert, P., , and H. Shafir, 1989: Meso-γ-scale distribution of orographic precipitation: Numerical study and comparison with precipitation derived from radar measurements. J. Appl. Meteor., 28, 11051117.

    • Search Google Scholar
    • Export Citation
  • Anders, A. M., , G. H. Roe, , B. Hallet, , D. R. Montgomery, , N. J. Finnegan, , and J. Putkonen, 2006: Spatial patterns of precipitation and topography in the Himalaya. Tectonics, Climate, and Landscape Evolution, S. D. Willett et al., Eds., Geological Society of America, 39–53.

    • Search Google Scholar
    • Export Citation
  • Barros, A. P., , and D. P. Lettenmaier, 1993: Dynamic modeling of the spatial distribution of precipitation in remote mountainous areas. Mon. Wea. Rev., 121, 11951214.

    • Search Google Scholar
    • Export Citation
  • Barstad, I., , and R. B. Smith, 2005: Evaluation of an orographic precipitation model. J. Hydrometeor., 6, 8599.

  • Barstad, I., , and S. Grønås, 2006: Dynamical structures for southwesterly airflow over southern Norway: The role of dissipation. Tellus, 58A, 218.

    • Search Google Scholar
    • Export Citation
  • Barstad, I., , W. W. Grabowski, , and P. K. Smolarkiewicz, 2007: Characteristics of large-scale orographic precipitation: Evaluation of linear model in idealized problems. J. Hydrol., 340, 7890.

    • Search Google Scholar
    • Export Citation
  • Caroletti, G. N., , and I. Barstad, 2010: An assessment of future extreme precipitation in western Norway using a linear model. Hydrol. Earth Syst. Sci., 14, 23292341.

    • Search Google Scholar
    • Export Citation
  • Collier, C. G., 1975: A representation of the effects of topography on surface rainfall within moving baroclinic disturbance. Quart. J. Roy. Meteor. Soc., 101, 407422.

    • Search Google Scholar
    • Export Citation
  • Crochet, P., , T. Jóhannesson, , T. Jonsson, , O. Sigurðsson, , H. Björnsson, , F. Pálsson, , and I. Barstad, 2007: Estimating the spatial distribution of precipitation in Iceland using a linear model of orographic precipitation. J. Hydrometeor., 8, 12851306.

    • Search Google Scholar
    • Export Citation
  • Eliassen, A., , and E. Palm, 1960: On the transfer of energy in stationary mountain waves. Geofys. Publ., 22, 123.

  • Jaedicke, C., and Coauthors, 2008: Spatial and temporal variations of Norwegian geohazards in a changing climate, the GeoExtreme Project. Nat. Hazards Earth Syst. Sci., 8, 893904.

    • Search Google Scholar
    • Export Citation
  • Jiang, Q., , and R. B. Smith, 2003: Cloud timescales and orographic precipitation. J. Atmos. Sci., 60, 15431559.

  • Kunz, M., , and C. Kottmeier, 2006: Orographic enhancement of precipitation over low mountain ranges. Part I: Model formulation and idealized simulations. J. Appl. Meteor. Climatol., 45, 10251040.

    • Search Google Scholar
    • Export Citation
  • Lundquist, J. D., , J. R. Minder, , P. J. Neiman, , and E. Sukovich, 2010: Relationships between barrier jet heights, orographic precipitation gradients, and streamflow in the northern Sierra Nevada. J. Hydrometeor., 11, 11411156.

    • Search Google Scholar
    • Export Citation
  • Minder, J. R., 2010: The sensitivity of mountain snowpack accumulation to climate warming. J. Climate, 23, 26342650.

  • Rhea, J. O., 1978: Orographic precipitation model for hydrometeorological use. Ph.D. thesis, Colorado State University, 198 pp.

  • Roe, G. H., 2005: Orographic precipitation. Annu. Rev. Earth Planet. Sci., 33, 645671.

  • Sawyer, J. S., 1956: The physical and dynamical problem of orographic rain. Weather, 11, 375381.

  • Schuler, T. V., , P. Crochet, , R. Hock, , M. Jackson, , I. Barstad, , and T. Jóhannesson, 2008: Distribution of snow accumulation on Svartisen ice cap, Norway, assessed by a model of orographic precipitation. Hydrol. Proc., 22, 39984008.

    • Search Google Scholar
    • Export Citation
  • Sinclair, M. R., 1994: A diagnostic model for estimating orographic precipitation. J. Appl. Meteor., 33, 11631175.

  • Smith, R. B., 1979: The influence of mountains on the atmosphere. Adv. Geophys., 21, 87230.

  • Smith, R. B., 2001: Stratified flow over topography. Environmental Stratified Flows, R. Grimshaw, Ed., Kluwer Academic, 119–159.

  • Smith, R. B., 2003: A linear time-delay model of orographic precipitation. J. Hydrol., 282, 29.

  • Smith, R. B., 2006: Progress on the theory of orographic precipitation. Tectonics, Climate, and Landscape Evolution, S. D. Willett et al., Eds., Geological Society of America, 1–16.

    • Search Google Scholar
    • Export Citation
  • Smith, R. B., 2007: Interacting mountain waves and boundary layers. J. Atmos. Sci., 64, 594607.

  • Smith, R. B., , and I. Barstad, 2004: A linear theory of orographic precipitation. J. Atmos. Sci., 61, 13771391.

  • Smith, R. B., , and J. P. Evans, 2007: Orographic precipitation and water vapor fractionation over the southern Andes. J. Hydrometeor., 8, 319.

    • Search Google Scholar
    • Export Citation
  • Smith, R. B., , I. Barstad, , and L. Bonneau, 2005: Orographic precipitation and Oregon’s climate transition. J. Atmos. Sci., 62, 177191.

    • Search Google Scholar
    • Export Citation
  • Smith, R. B., , P. Schafer, , D. J. Kirshbaum, , and E. Regina, 2009: Orographic precipitation in the tropics: Experiments in Dominica. J. Atmos. Sci., 66, 16981716.

    • Search Google Scholar
    • Export Citation
  • White, A. B., , D. J. Gottas, , E. T. Strem, , F. M. Ralph, , and P. J. Neiman, 2002: An automated brightband height detection algorithm for use with Doppler radar spectral moments. J. Atmos. Oceanic Technol., 19, 687697.

    • Search Google Scholar
    • Export Citation
  • White, A. B., , P. J. Neiman, , F. M. Ralph, , D. E. Kingsmill, , and P. O. G. Persson, 2003: Coastal orographic rainfall processes observed by radar during the California Land-Falling Jets Experiment. J. Hydrometeor., 4, 264282.

    • Search Google Scholar
    • Export Citation
  • Yuter, S. E., , and R. A. Houze, 2003: Microphysical modes of precipitation growth determined by S-band vertically pointing radar in orographic precipitation during MAP. Quart. J. Roy. Meteor. Soc., 129B, 455476.

    • Search Google Scholar
    • Export Citation
All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 84 84 6
PDF Downloads 69 69 2

An Extension of Smith’s Linear Theory of Orographic Precipitation: Introduction of Vertical Layers

View More View Less
  • 1 Uni Bjerknes Centre, Uni Research, and Bjerknes Centre for Climate Research, Bergen, Norway
  • | 2 University of Innsbruck, Innsbruck, Austria
© Get Permissions
Restricted access

Abstract

This paper proposes an extension of a linear theory of orographic precipitation (OP). In the original theory, cloud water is produced by forced lifting over mountains, moderated by airflow dynamics. Controlled by a time delay τc, the cloud water converts into hydrometeors, which drift and fall out as precipitation. This drift is controlled by another time delay τf. The new extension proposed here introduces vertical layers, limited to two in this study. In this way, a more realistic vertical structure is permitted. Wind and stability may change with height and different microphysical properties may be assigned to the layers. For instance, a long fallout delay in the upper layer may represent snow that, after falling through a melting layer, turns into rain that has a short delay in the lower model layer. The sensitivity to microphysical delay and wind speed has been addressed for various interface heights separating the two layers. This layered approach allows adjustment of the water vapor influx and truncation of dry descent above a crest line, which, in the context of the existing linear theory, otherwise could cancel cloud water in lower layers. The introduction of layers requires more information in the vertical, but this may be derived, to some extent, from surface information.

Bjerknes Centre for Climate Research Paper 371.

Corresponding author address: Idar Barstad, Uni-Bjerknes, Allegt.70, NO-5007 Bergen, Norway. E-mail: idar.barstad@uni.no

Abstract

This paper proposes an extension of a linear theory of orographic precipitation (OP). In the original theory, cloud water is produced by forced lifting over mountains, moderated by airflow dynamics. Controlled by a time delay τc, the cloud water converts into hydrometeors, which drift and fall out as precipitation. This drift is controlled by another time delay τf. The new extension proposed here introduces vertical layers, limited to two in this study. In this way, a more realistic vertical structure is permitted. Wind and stability may change with height and different microphysical properties may be assigned to the layers. For instance, a long fallout delay in the upper layer may represent snow that, after falling through a melting layer, turns into rain that has a short delay in the lower model layer. The sensitivity to microphysical delay and wind speed has been addressed for various interface heights separating the two layers. This layered approach allows adjustment of the water vapor influx and truncation of dry descent above a crest line, which, in the context of the existing linear theory, otherwise could cancel cloud water in lower layers. The introduction of layers requires more information in the vertical, but this may be derived, to some extent, from surface information.

Bjerknes Centre for Climate Research Paper 371.

Corresponding author address: Idar Barstad, Uni-Bjerknes, Allegt.70, NO-5007 Bergen, Norway. E-mail: idar.barstad@uni.no
Save