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Decomposition of Spatial Structure of Nocturnal Flow over Gentle Terrain

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Abstract

A network of sonic anemometers was deployed over gentle terrain in north-eastern Colorado, USA to observe and characterize local nocturnal circulations. Our study focuses on a small valley about 270 m wide and 12 m deep with a down-valley slope of 2–3 %. The measurements include 19 stations with sonic anemometers at 1 m and a 20-m tower that includes six sonic anemometers in the lowest 5 m. Shallow cold pools and drainage down the valley develop for weak ambient flow and relatively clear skies. However, transient modes constantly modulate or intermittently eliminate the cold pool, which makes extraction and analysis of the horizontal structure of the cold pool difficult with traditional analysis methods. Singular value decomposition successfully isolates the effects of large-scale flow from local down-valley cold-air drainage within the cold pool in spite of the intermittent nature of this local flow. Shortcomings of the method are noted.

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References

  • Aubinet M, Heinesch B, Yernaux M (2003) Horizontal and vertical CO\(_2\) advection in a sloping forest. Boundary-Layer Meteorol 108:397–417

    Article  Google Scholar 

  • Blumen W (1984) An observational study of instability and turbulence in nighttime drainage winds. Boundary-Layer Meteorol 28:245–269

    Article  Google Scholar 

  • Bodine D, Klein P, Arms S, Shapiro A (2009) Variability of surface air temperature over gently sloped terrain. J Appl Meteorol 48:1117–1141

    Article  Google Scholar 

  • Doran J, Horst T (1981) Velocity and temperature oscillations in drainage winds. J Appl Meteorol 20:360–364

    Article  Google Scholar 

  • Farr T, Rosen P, Caro E, Crippen R, Duren R, Hensley S, Kobrick M, Paller M, Rodriguez E, Roth L, Seal D, Shaffer S, Shimada J, Umland J, Werner M, Oskin M, Burbank D, Alsdorf D (2007) The shuttle radar topography mission. Rev Geophys 45:RG2004

  • Fernando M, Chan W, Princevac M, Kowalewski T, Pardyjak E (2002) Observations of flow and turbulence in the nocturnal boundary layer over a slope. J Atmos Sci 59:2513–2534

    Article  Google Scholar 

  • Grisogono B, Oerlemans J (2001) Katabatic flow: analytical solution for slowly varying eddy diffusivities. J Atmos Sci 58:3349–3354

    Article  Google Scholar 

  • Haiden T, Whiteman C (2005) Katabatic flow mechanisms on a low-angle slope. J Appl Meteorol 44:113–126

    Article  Google Scholar 

  • Hannachi A, Jolliffe I, Stephenson D (2007) Empirical orthogonal functions and related techniques in atmospheric science: a review. Int J Climatol 27:1119–1152

    Article  Google Scholar 

  • Helmis C (1996) Some aspects of the variation with time of katabatic flow over a simple slope. Q J R Meteorol Soc 122:595–610

    Article  Google Scholar 

  • Heywood G (1933) Katabatic winds in a valley. Q J R Meteorol Soc 59:43–57

    Google Scholar 

  • Leith C (1973) The standard error of time-averaged estimates of climatic means. J Appl Meteorol 12:1066–1069

    Article  Google Scholar 

  • Mahrt L, Heald R (2015) Marginal cold pools. J Appl Meteorol Climatol 54:339–351

    Article  Google Scholar 

  • Mahrt L, Vickers D, Nakamura R, Sun J, Burns S, Lenschow D, Soler M (2001) Shallow drainage and gully flows. Boundary-Layer Meteorol 101:243–260

    Article  Google Scholar 

  • Mahrt L, Thomas C, Richardson R, Seaman N, Stauffer D, Zeeman M (2013) Non-stationary generation of weak turbulence for very stable and weak-wind conditions. Boundary-Layer Meteorol 177:179–199

    Article  Google Scholar 

  • McNider R, England D, Friedman M, Shi X (1995) Predictability of the stable atmospheric boundary layer. J Atmos Sci 52:1602–1614

    Article  Google Scholar 

  • North G, Bell T, Cahalan R, Moeng F (1982) Sampling errors in the estimation of empirical orthogonal functions. Mon Weather Rev 110:699–706

    Article  Google Scholar 

  • Oerlemans J, Grisogono B (2002) Glacier winds and parameterisation of the related surface heat fluxes. Tellus 54A:440–452

    Article  Google Scholar 

  • Parmhed O, Oerlemans J, Grisogono B (1993) Describing surface fluxes in katabatic flow on Breidamerkurj Akull, Iceland. Q J R Meteorol Soc 130:1137–1151

    Article  Google Scholar 

  • Sheridan P, Vosper S, Brown A (2013) Characterisation of cold pools observed in narrow valleys and dependence on external conditions. Q J R Meteorol Soc 140:715–728

    Article  Google Scholar 

  • Smeets C, Duynkerke P, Vugts H (1998) Turbulence characteristics of the stable boundary layer over a mid-latitude glacier, part 1: a combination of katabatic and large scale forcing conditions. Boundary-Layer Meteorol 87:117–145

    Article  Google Scholar 

  • Vosper S, Hughes J, Lock A, Sheridan P, Ross A, Jemmett-Smith B, Brown A (2013) Cold-pool formation in narrow valleys. Q J R Meteorol Soc 127:429–448

    Google Scholar 

  • Yoshino M (1975) Climate in a small area. University of Tokyo Press, Tokyo, 549 pp

Download references

Acknowledgments

We gratefully acknowledge the helpful detailed comments of the reviewers. This project was supported by NSF Grant AGS-1115011. The SCP measurements were provided by the Integrated Surface Flux System of the Earth Observing Laboratory of the National Center for Atmospheric Research.

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  1. NorthWest Research Associates, Redmond, WA, USA

    Andrew Geiss & Larry Mahrt

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  1. Andrew Geiss
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  2. Larry Mahrt
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Correspondence to Andrew Geiss.

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Geiss, A., Mahrt, L. Decomposition of Spatial Structure of Nocturnal Flow over Gentle Terrain. Boundary-Layer Meteorol 156, 337–347 (2015). https://doi.org/10.1007/s10546-015-0043-7

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