• \
    Start Submission Become a Reviewer

    Reading: Non-stationary drainage flows and motions in the cold pool

    Download

     A- A+
    Alt. Display

    Original Research Papers

    Non-stationary drainage flows and motions in the cold pool

    Authors:

    L. Mahrt ,

    COAS, Oregon State University, Corvallis, OR 97331, US
    X close

    Scott Richardson,

    Department of Meteorology, Pennsylvania State University, University Park, PA 16802, US
    X close

    Nelson Seaman,

    Department of Meteorology, Pennsylvania State University, University Park, PA 16802, US
    X close

    David Stauffer

    Department of Meteorology, Pennsylvania State University, University Park, PA 16802, US
    X close

    Abstract

    The initial formation of drainage flows and subsequent interaction with the cold pool are examined by contrasting winds measured with 2-sonic anemometers at three stations along a gentle slope for a 45-d observational period in late summer and early fall. On clear nights with weak winds, the station at the bottom of the slope experiences downslope flow only at the beginning of the evening, which quickly yields to light winds of variable direction after formation of a cold pool on the valley floor. A second station, several hundred metres up the slope, experiences drainage flow in the first part of the evening, which diminishes and yields to light and variable winds in the middle of the night as the influence of the cold pool deepens and engulfs the station. Drainage flow continues throughout the night at the third station located still farther up the slope and above the cold pool throughout the night. The interplay between the drainage flow, large-scale flow and submeso motions leads to frequent large shifts of wind direction. The character of the wind-direction variability differs substantially between the three stations. Large remaining uncertainties are noted.

    How to Cite: Mahrt, L., Richardson, S., Seaman, N. and Stauffer, D., 2010. Non-stationary drainage flows and motions in the cold pool. Tellus A: Dynamic Meteorology and Oceanography, 62(5), pp.698–705. DOI: http://doi.org/10.1111/j.1600-0870.2010.00473.x
    1
    Views
    30
    Citations
      Published on 01 Jan 2010
    Peer Reviewed
     CC BY 4.0
     Accepted on 24 Jun 2010            Submitted on 25 Jan 2010

    References

    1. Acevedo , O. C. and Fitzjarrald , D. R . 2001 . The early evening surface-layer transition: temporal and spatial variability. J. Atmos. Sc i . 58 , 2650 – 2667 .  

    2. Anquetin , S. , Guilbaud , C. and Chollet , J. P . 1998 . The formation and destruction of inversion layers within a deep valley . J. Appl. Meteorol . 37 , 1547 – 1560 .  

    3. Aubinet , M . 2008 . Eddy covariance CO2 flux measurements in the nocturnal conditions: an analysis problem . Ecol. Appl . 18 , 1368 – 1378 .  

    4. Blumen , W . 1984 . An observational study of instability and turbulence in nighttime drainage winds . Boundary-Layer Meteorol . 28 , 245 – 269 .  

    5. Blumen , W. , Grossman , R. and Piper , M . 1999 . Analysis of heat budget, dissipation and frontogenesis in a shallow density current . Boundary-Layer Meteorol . 91 , 281 – 306 .  

    6. Bodine , D. , Klein , R , Arms , S. and Shapiro , A . 2009 . Variability of surface air temperature over gently sloped terrain . J. Appl. Meteorol . 48 , 1117 – 1141 .  

    7. Caughey , S. J. , Wyngaard , J. C. and Kaimal , J. C . 1979 . Turbulence in the evolving stable boundary layer. J. Atmos. Sc i . 36 , 1041 – 1052 .  

    8. Clements , C. B. , Whiteman , C. D. and Horel , J. D . 2003 . Cold-air-pool structure and evolution in a mountain basin: Peter Sinks, Utah . J. Appl. Meteorol . 42 , 752 – 768 .  

    9. Cuxart , J. , Jiménez , M. A. and Martínez , D . 2007 . Nocturnal mesobeta basin and katabatic flows on a midlatitude island. Mon . Wea. Re v . 135 , 918 – 932 .  

    10. Davies , B. M. and Thomson , D. J . 1999 . Comparisons of some parameterizations of wind direction variability with observations . Atmos. Environ . 33 , 4909 – 4917 .  

    11. de Aratijo , A. , Krúijt , B. , Antonio , A. , Nobre , A. , Dolman , J. and co-authors. 2008. Nocturnal accumulation of CO2 underneath a tropical forest canopy along a topographical gradient. Ecol. Appl . 18 , 1406 – 1419 .  

    12. de Wekker , S. and Whiteman , C. D . 2006 . The time scale of nocturnal boundary layer cooling in valleys and basins and over plains . J. Appl. Meteorol. Clim . 45 , 813 – 820 .  

    13. Doran , J. C. and Horst , T. W . 1981 . Velocity and temperature oscillations in drainage winds . J. Appl. Meteorol . 20 , 360 – 364 .  

    14. Edwards , J. M. , Beare , R. J. and Lapworth , A. J . 2006 . Simulation of the observed evening transition and nocturnal boundary layers: single-column modelling . Quart. J. Roy. Meteorol. Soc . 132 , 61 – 80 .  

    15. Grant , J. L. M . 1997 . An observational study of the evening transition boundary-layer . Quart. J. Roy. Meteorol. Soc . 123 , 657 – 677 .  

    16. Grisogono , B. and Oerlemans , J . 2001 . Katabatic flow: analytic solution for gradually varying eddy diffusivities. J. Atmos. Sc i . 58 , 3349 – 3354 .  

    17. Heywood , G. S. P . 1933 . Katabatic winds in a valley . Quart. J. Roy. Meteorol. Soc . 59 , 43 – 57 .  

    18. Holden , J. J. , Derbyshire , S. H. and Belcher , S. E . 2000 . Tethered balloon obser vations of the nocturnal stable boundary layer in a valley . Boundary-Layer Meteorol . 97 , 1 – 24 .  

    19. LeMone , M. A. , Kyoko , I. , Grossman , R. and Rotach , M . 2003 . Horizontal variability of 2-m temperature at night during CASES-97. J. Atmos. Sc i . 60 , 2431 – 2450 .  

    20. Mahrt , L . 1982 . Momentum balance of gravity flows. J. Atmos. Sc i . 39 , 2701 – 2711 .  

    21. Mahrt , L . 2008 . Mesoscale wind direction shifts in the stable boundary-layer . Tellus 60A , 700 – 705 .  

    22. Mahrt , L. and Larsen , S . 1990 . Relation of slope winds to the ambient flow over gentle terrain . Boundary-Layer Meteorol . 53 , 93 – 102 .  

    23. Mahrt , L. , Vickers , D. , Nakamura , R. , Sun , J. , Burns , S. and co-authors . 2001 . Shallow drainage and gully flows. Boundary-Layer Meteorol . 101 , 243 – 260 .  

    24. Monti , P. , Fernando , H. J. S. , Chan , W. C. , Princevac , M. , Kowalewski , T. A. and co-authors. 2002. Observations of flow and turbulence in the nocturnal boundary layer over a slope. J. Atmos. Sci . 59 , 2513 – 2534 .  

    25. Nakamura , R. and Mahrt , L . 2005 . Air temperature measurement errors in naturally ventilated radiation shields . J. Atmos. Oceanic Tech . 22 , 1046 – 1058 .  

    26. Neff , W. and King , C . 1989 . The accumulation and pooling of drainage flows in a large basin . J. Appl. Meteorol . 28 , 518 – 529 .  

    27. Orlanski , I . 1975 . A rational subdivision of scales for atmospheric processes . Bull. Am. Meteorol. Soc . 56 , 527 – 530 .  

    28. Papadopoulos , K. H. and Helmis , C. G . 1999 . Evening and morning transition of Katabatic flows . Boundary-Layer Meteorol . 92 , 195 – 227 .  

    29. Poulos , G. , Bossert , J. , McKee , T. and Pielke, R. Sr . 2007 . The interaction of lcatabatic flow and mountain waves. Part H: case study analysis and conceptual model. J. Atmos. Sc i . 64 , 1875 – 1879 .  

    30. Shapiro , A. , Klein , P. , Arms , S. , Bodine , D. and Carney , M . 2009 . The Lake Thunderbird Micronet Project . Bull. Amer Meteorol. Soc . 90 , 811 – 823 .  

    31. Stone , G. and Hoard , D . 1989 . Low-frequency velocity and temperature fluctuations in katabatic valley flows . J. Appl. Meteorol . 28 , 477 – 488 .  

    32. Sun , J. , Burns , S. P. , Lenschow , D. H. , Banta , R. , Newsom , R. and co-authors . 2002 . Intermittent turbulence associated with a density current passage in the stable boundary layer. Boundary-Layer Meteorol . 105 , 199 – 219 .  

    33. Sun , J. , Burns , S. , Delany , A. , Oncley , S. , Turnipseed , A. and co-authors . 2007 . CO 2 transport over complex terrain. Agric. For Meteorol . 145 , 1 – 21 .  

    34. Vosper , S. B. and Brown , A. R . 2008 . Numerical simulations of sheltering in valleys: the formation of nighttime cold-air pools . Boundary-Layer Meteorol . 27 , 429 – 448 .  

    35. Whiteman , C. D . 2000 . Mountain Meteorology . Oxford University Press , 355 pp .  

    36. Whiteman , C. D. , Bian , X. and Zhong , S . 1999 . Wintertime evolution of the temperature inversion in the Colorado Plateau Basin . J. Appl. Meteorol . 38 , 1103 – 1117 .  

    37. Whiteman , C. D. , Hubbe , J. and Shaw , W . 2000 . Evaluation of an in-expensive temperature data logger for meteorological applications . J. Atmos. Oceanic Tech . 17 , 77 – 81 .  

    38. Whiteman , C. D. , Thong , S. , Shaw , W. , Hubbe , J. and Bian , X . 2001 . Cold Pools in the Columbia Basin . Wea. Forecast 16 , 432 – 447 .  

    39. Whiteman , C. D. and Thong , S . 2008 . Downslope flows on a low-angle slope and their interactions with valley inversions. Part I: observations . J. Appl. Meteorol. Clim . 47 , 2023 – 2038 .  

    40. Yao , W. and Thong , S . 2009 . Nocturnal temperature inversions in a small, enclosed basin and their relationship to ambient atmospheric conditions . Meteorol. Atmos. Phys . 103 , 195 – 210 .  

    41. Yoshino , M. M . 1984 . Thermal belt and cold air drainage on the mountain slope and cold air lake in the basin at quiet clear night . Geophys. J . 8 , 235 – 250 .  

    Jump to Discussions Related content
    comments powered by Disqus