Stable Boundary Layer in Complex Terrain. Part II: Geometrical and Sheltering Effects on Mixing

Luiz E. Medeiros Atmospheric Sciences Research Center, University at Albany, State University of New York, Albany, New York

Search for other papers by Luiz E. Medeiros in
Current site
Google Scholar
PubMed
Close
and
David R. Fitzjarrald Atmospheric Sciences Research Center, University at Albany, State University of New York, Albany, New York

Search for other papers by David R. Fitzjarrald in
Current site
Google Scholar
PubMed
Close
Restricted access

Abstract

The authors examine how terrain texture and topography influence nocturnal mixing rates. Local topographic curvature and site sheltering exhibit systematic influences on nocturnal heat and momentum fluxes and the near-surface potential temperature distribution. This influence is particularly evident in hilly terrain with patchy forested areas, typical of eastern North America and many other regions. Exposure to local obstacles, quantified using Fujita’s “transmission factor,” has its maximum influence on mixing during strong winds (>5 m s−1), whereas the effects of local terrain curvature dominate under weaker winds. Such complementary dominance conditions currently limit direct comparison of the two effects. Even with a limited network of 10 stations, it is clear that preferred regions for mixing can be identified in advance given knowledge of land cover and topography. When designing a network of surface stations to be deployed in heterogeneous terrain, one should consider site curvature, slope, and exposure in addition to spatial coverage.

Current affiliation: Universidade Federal de Santa Maria, Santa Maria, Brazil.

Corresponding author address: Luiz E. Medeiros, Departamento de Física, Universidade de Federal de Santa Maria, Av. Roraima 1000, Santa Maria RS 97105-900, Brazil. E-mail: ducamobi@gmail.com

Abstract

The authors examine how terrain texture and topography influence nocturnal mixing rates. Local topographic curvature and site sheltering exhibit systematic influences on nocturnal heat and momentum fluxes and the near-surface potential temperature distribution. This influence is particularly evident in hilly terrain with patchy forested areas, typical of eastern North America and many other regions. Exposure to local obstacles, quantified using Fujita’s “transmission factor,” has its maximum influence on mixing during strong winds (>5 m s−1), whereas the effects of local terrain curvature dominate under weaker winds. Such complementary dominance conditions currently limit direct comparison of the two effects. Even with a limited network of 10 stations, it is clear that preferred regions for mixing can be identified in advance given knowledge of land cover and topography. When designing a network of surface stations to be deployed in heterogeneous terrain, one should consider site curvature, slope, and exposure in addition to spatial coverage.

Current affiliation: Universidade Federal de Santa Maria, Santa Maria, Brazil.

Corresponding author address: Luiz E. Medeiros, Departamento de Física, Universidade de Federal de Santa Maria, Av. Roraima 1000, Santa Maria RS 97105-900, Brazil. E-mail: ducamobi@gmail.com
Save
  • Acevedo, O. C., and D. R. Fitzjarrald, 2001: The early evening transition: Temporal and spatial variability. J. Atmos. Sci., 58, 26502667, doi:10.1175/1520-0469(2001)058<2650:TEESLT>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Acevedo, O. C., and D. R. Fitzjarrald, 2003: In the core of the night—Effects of intermittent mixing on a horizontally heterogeneous surface. Bound.-Layer Meteor., 106, 133, doi:10.1023/A:1020824109575.

    • Search Google Scholar
    • Export Citation
  • Acevedo, O. C., F. D. Costa, and G. A. Degrazia, 2012: The coupling state of an idealized stable boundary layer. Bound.-Layer Meteor., 145, 211228, doi:10.1007/s10546-011-9676-3.

    • Search Google Scholar
    • Export Citation
  • Anderson, J. R., E. E. Hardy, J. T. Roach, and R. E. Witmer, 1976: A land use classification system for use with remote sensor data. U.S. Geological Survey Professional Paper 964 (a revision of the land use classification system as presented in U.S. Geological Survey Circular 671), 41 pp. [Available online at http://landcover.usgs.gov/pdf/anderson.pdf.]

  • Banta, R. M., L. Mahrt, D. Vickers, J. Sun, B. B. Balsley, Y. Pichugina, and E. J. Williams, 2007: The very stable boundary layer on nights with weak low-level jets. J. Atmos. Sci., 64, 30683090, doi:10.1175/JAS4002.1.

    • Search Google Scholar
    • Export Citation
  • Bosveld, F. C., and Coauthors, 2014: The third GABLS intercomparison case for evaluation studies of boundary-layer models. Part B: Results and process understanding. Bound.-Layer Meteor., 152, 157187, doi:10.1007/s10546-014-9919-1.

    • Search Google Scholar
    • Export Citation
  • Clements, C. B., C. D. Whiteman, and J. D. Horel, 2003: Cold-air-pool structure and evolution in a mountain basin, Peter Sinks, Utah. J. Appl. Meteor., 42, 752768, doi:10.1175/1520-0450(2003)042<0752:CSAEIA>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Costa, F. D., O. C. Acevedo, J. Mombach, and G. A. Degrazia, 2011: A simplified model for intermittent turbulence in the nocturnal boundary layer. J. Atmos. Sci., 68, 17141729, doi:10.1175/2011JAS3655.1.

    • Search Google Scholar
    • Export Citation
  • Einaudi, F., and J. J. Finnigan, 1993: Wave–turbulence dynamics in the stably stratified boundary layer. J. Atmos. Sci., 50, 18411864, doi:10.1175/1520-0469(1993)050<1841:WTDITS>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Fernando, H. J. S., and J. C. Weil, 2010: Whither the stable boundary layer? Bull. Amer. Meteor. Soc., 91, 14751484, doi:10.1175/2010BAMS2770.1.

    • Search Google Scholar
    • Export Citation
  • Finnigan, J. J., F. Einaudi, and D. Fua, 1984: The interaction between an internal gravity wave and turbulence in the stably-stratified nocturnal boundary layer. J. Atmos. Sci., 41, 24092436, doi:10.1175/1520-0469(1984)041<2409:TIBAIG>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Fujita, T. T., and R. M. Wakimoto, 1982: Effects of miso- and mesoscale obstructions on PAM winds obtained during the project NIMROD. J. Appl. Meteor., 21, 840858, doi:10.1175/1520-0450(1982)021<0840:EOMAMO>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Garratt, J. R., 1992: The Atmospheric Boundary Layer. Cambridge University Press, 316 pp.

  • Grachev, A. A., E. L. Andreas, C. W. Fairall, P. S. Guest, and P. O. G. Persson, 2013: The critical Richardson number and limits of applicability of local similarity theory in the stable boundary layer. Bound.-Layer Meteor., 147, 5182, doi:10.1007/s10546-012-9771-0.

    • Search Google Scholar
    • Export Citation
  • Gustavsson, T., M. Karlsson, J. Bogren, and S. Lindqvsit, 1998: Development of temperature patterns during clear nights. J. Appl. Meteor., 37, 559571, doi:10.1175/1520-0450(1998)037<0559:DOTPDC>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Holtslag, A. A. M., and Coauthors, 2013: Stable atmospheric boundary layers and diurnal cycles: Challenges for weather and climate models. Bull. Amer. Meteor. Soc., 94, 16911706, doi:10.1175/BAMS-D-11-00187.1.

    • Search Google Scholar
    • Export Citation
  • Hurst, M. D., S. M. Mudd, R. Walcott, M. Attal, and K. Yoo, 2012: Using hilltop curvature to derive the spatial distribution of erosion rates. J. Geophys. Res., 117, F02017, doi:10.1029/2011JF002057.

    • Search Google Scholar
    • Export Citation
  • Knupp, K. R., J. Walters, and E. W. McCaul, 2000: Doppler profiler observations of Hurricane Georges at landfall. Geophys. Res. Lett., 27, 33613364, doi:10.1029/1999GL011260.

    • Search Google Scholar
    • Export Citation
  • LeMone, M. A., R. L. Grossman, and M. W. Rotach, 2003: Horizontal variability of 2-m temperature at night during CASES-97. J. Atmos. Sci., 60, 24312449, doi:10.1175/1520-0469(2003)060<2431:HVOMTA>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Louis, J. F., 1979: A parametric model of vertical eddy fluxes in the atmosphere. Bound.-Layer Meteor., 17, 187202, doi:10.1007/BF00117978.

    • Search Google Scholar
    • Export Citation
  • Mahrt, L., 2014: Stably stratified atmospheric boundary layers. Annu. Rev. Fluid Mech., 46, 2345, doi:10.1146/annurev-fluid-010313-141354.

    • Search Google Scholar
    • Export Citation
  • Mahrt, L., J. Sun, W. Blumen, T. Delany, and S. Oncley, 1998: Nocturnal boundary-layer regimes. Bound.-Layer Meteor., 88, 255278, doi:10.1023/A:1001171313493.

    • Search Google Scholar
    • Export Citation
  • Mahrt, L., D. Vickers, R. Nakamura, M. R. Soler, J. Sun, S. Burns, and D. H. Lenschow, 2001: Shallow drainage flows. Bound.-Layer Meteor., 101, 243260, doi:10.1023/A:1019273314378.

    • Search Google Scholar
    • Export Citation
  • Mahrt, L., S. Richardson, D. Stauffer, and N. Seaman, 2014a: Nocturnal wind-directional shear in complex terrain. Quart. J. Roy. Meteor. Soc., doi:10.1002/qj.2369, in press.

    • Search Google Scholar
    • Export Citation
  • Mahrt, L., J. Sun, S. P. Oncley, and T. W. Horst, 2014b: Transient cold air drainage down a shallow valley. J. Atmos. Sci., 71, 25342544, doi:10.1175/JAS-D-14-0010.1.

    • Search Google Scholar
    • Export Citation
  • Maki, M., T. Harimaya, and K. Kikuchi, 1986: Heat budget studies on nocturnal cooling in a basin. J. Meteor. Soc. Japan, 64, 727741.

  • McNider, R. T., D. E. England, M. J. Friedman, and X. Shi, 1995: Predictability of the atmospheric boundary layer. J. Atmos. Sci., 52, 16021614, doi:10.1175/1520-0469(1995)052<1602:POTSAB>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Medeiros, L. E., 2011: Origin and maintenance of the stable boundary layer in a patchy landscape. Ph.D. thesis, University at Albany, State University of New York, 191 pp. [Available online at ftp://boojum.asrc.cestm.albany.edu/pub/Medeiros_PhD/Medeiros_Phd_UAlbany-2011.pdf.]

  • Medeiros, L. E., and D. R. Fitzjarrald, 2014: Stable boundary layer in complex terrain. Part I: Linking fluxes and intermittency to an average stability index. J. Appl. Meteor. Climatol., 53, 21962215, doi:10.1175/JAMC-D-13-0345.1.

    • Search Google Scholar
    • Export Citation
  • Miller, N. E., and R. Stoll, 2013: Surface heterogeneity effects on regional-scale fluxes in the stable boundary layer: Aerodynamic roughness length transitions. Bound.-Layer Meteor., 149, 277301, doi:10.1007/s10546-013-9839-5.

    • Search Google Scholar
    • Export Citation
  • Moore, I. D., R. B. Grayson, and A. R. Ladson, 1991: Digital terrain modelling: A review of hydrological, geomorphological, and biological applications. Hydrol. Processes, 5, 330, doi:10.1002/hyp.3360050103.

    • Search Google Scholar
    • Export Citation
  • Nappo, C. J., 1991: Sporadic breakdowns of stability in the PBL over simple and complex terrain. Bound.-Layer Meteor., 54, 6987, doi:10.1007/BF00119413.

    • Search Google Scholar
    • Export Citation
  • Oncley, S. P., S. Semmer, T. W. Horst, J. Militzer, G. Maclean, K. Knudson, C. Golubieski, and L. L. Dong, 2010: CentNet—A deployable 100-station network for surface exchange research. Preprints, 15th Symp. on Meteorological Observation and Instrumentation, Atlanta, GA, Amer. Meteor. Soc., 1721. [Available online at https://ams.confex.com/ams/90annual/techprogram/paper_165855.htm.]

  • Poulos, G. S., and Coauthors, 2002: CASES-99: A comprehensive investigation of the stable nocturnal boundary layer. Bull. Amer. Meteor. Soc., 83, 555581, doi:10.1175/1520-0477(2002)083<0555:CACIOT>2.3.CO;2.

    • Search Google Scholar
    • Export Citation
  • Price, J. D., and Coauthors, 2011: COLPEX: Field and numerical studies over a region of small hills. Bull. Amer. Meteor. Soc., 92, 16361650, doi:10.1175/2011BAMS3032.1.

    • Search Google Scholar
    • Export Citation
  • Roache, P. J., 1976: Computational Fluid Dynamics. Hermosa, 446 pp.

  • Rosenberg, N. J., B. L. Blad, and S. B. Verma, 1983: Microclimate: The Biological Environment. John Wiley and Sons, 495 pp.

  • Salmond, J. A., and I. G. McKendry, 2002: Secondary ozone maxima in very stable nocturnal layer: Observations from the Lower Fraser Valley, BC. Atmos. Environ., 36, 57715782, doi:10.1016/S1352-2310(02)00698-2.

    • Search Google Scholar
    • Export Citation
  • Sandu, I., A. Beljaars, P. Bechtold, T. Mauritsen, and G. Balsamo, 2013: Why is it so difficult to represent stably stratified conditions in numerical weather prediction (NWP) models? J. Adv. Model. Earth Syst., 5, 117133, doi:10.1002/jame.20013.

    • Search Google Scholar
    • Export Citation
  • Staebler, R. M., and D. R. Fitzjarrald, 2004: Observing subcanopy CO2 advection. Agric. For. Meteor., 122, 139156, doi:10.1016/j.agrformet.2003.09.011.

    • Search Google Scholar
    • Export Citation
  • Staebler, R. M., and D. R. Fitzjarrald, 2005: Measuring canopy structure and the kinematics of subcanopy flows in two forests. J. Appl. Meteor., 44, 11611179, doi:10.1175/JAM2265.1.

    • Search Google Scholar
    • Export Citation
  • Stull, R. B., 1988: An Introduction to Boundary Layer Meteorology. Kluwer Academic, 666 pp.

  • Sun, J., and Coauthors, 2002: Intermittent turbulence associated with density currents passage in the stable boundary layer. Bound.-Layer Meteor., 105, 199219, doi:10.1023/A:1019969131774.

    • Search Google Scholar
    • Export Citation
  • Sun, J., and Coauthors, 2004: Atmospheric disturbances that generate intermittent turbulence in nocturnal boundary layers. Bound.-Layer Meteor., 110, 255279, doi:10.1023/A:1026097926169.

    • Search Google Scholar
    • Export Citation
  • Van de Wiel, B. J. H., R. J. Ronda, A. F. Moene, H. A. R. De Bruin, and A. A. M. Holtslag, 2002: Intermittent turbulence and oscillations in the stable boundary layer over land. Part I: A bulk model. J. Atmos. Sci., 59, 942958, doi:10.1175/1520-0469(2002)059<0942:ITAOIT>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Van de Wiel, B. J. H., A. F. Moene, O. K. Hartogensis, H. A. R. De Bruin, and A. A. M. Holtslag, 2003: Intermittent turbulence in the stable boundary layer over land. Part III: A classification for observations during CASES-99. J. Atmos. Sci., 60, 25092522, doi:10.1175/1520-0469(2003)060<2509:ITITSB>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Van de Wiel, B. J. H., A. F. Moene, and H. J. J. Jonker, 2012a: The cessation of continuous turbulence as precursor of the very stable nocturnal boundary layer. J. Atmos. Sci., 69, 30973115, doi:10.1175/JAS-D-12-064.1.

    • Search Google Scholar
    • Export Citation
  • Van de Wiel, B. J. H., A. F. Moene, H. J. J. Jonker, P. Baas, S. Basu, J. M. M. Donda, J. Sun, and A. A. M. Holtslag, 2012b: The minimum wind speed for sustainable turbulence in the nocturnal boundary layer. J. Atmos. Sci., 69, 31163127, doi:10.1175/JAS-D-12-0107.1.

    • Search Google Scholar
    • Export Citation
  • Wieringa, J., 1976: An objective exposure correction method for average wind speeds measured at sheltered location. Quart. J. Roy. Meteor. Soc., 102, 241253, doi:10.1002/qj.49710243119.

    • Search Google Scholar
    • Export Citation
All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 314 52 3
PDF Downloads 226 40 4