Diagnostic Downscaling of Large-Scale Wind Fields to Compute Local-Scale Trajectories

Andreas Stohl Institute of Meteorology and Physics, University for Agricultural Sciences, Vienna, Austria

Search for other papers by Andreas Stohl in
Current site
Google Scholar
PubMed
Close
,
Kathrin Baumann Central Institute for Meteorology and Geodynamics, Vienna, Austria

Search for other papers by Kathrin Baumann in
Current site
Google Scholar
PubMed
Close
,
Gerhard Wotawa Institute of Meteorology and Physics, University for Agricultural Sciences, Vienna, Austria

Search for other papers by Gerhard Wotawa in
Current site
Google Scholar
PubMed
Close
,
Matthias Langer Central Institute for Meteorology and Geodynamics, Vienna, Austria

Search for other papers by Matthias Langer in
Current site
Google Scholar
PubMed
Close
,
Bruno Neininger MetAir AG, Illnau, Switzerland

Search for other papers by Bruno Neininger in
Current site
Google Scholar
PubMed
Close
,
Martin Piringer Central Institute for Meteorology and Geodynamics, Vienna, Austria

Search for other papers by Martin Piringer in
Current site
Google Scholar
PubMed
Close
, and
Herbert Formayer Institute of Meteorology and Physics, University for Agricultural Sciences, Vienna, Austria

Search for other papers by Herbert Formayer in
Current site
Google Scholar
PubMed
Close
Restricted access

Abstract

This paper describes a simple method, based on routine meteorological data, to produce high-resolution wind analyses throughout the planetary boundary layer (PBL). It is a new way to interpolate wind measurements. According to this method, high-frequency information from surface wind measurements is extrapolated to greater heights by assuming that the vertical shear of the horizontal wind, that is, the differential vertical wind profile, is horizontally more homogeneous than the wind profile itself. Under this assumption, it is sufficient to combine high-resolution surface wind measurements with low-resolution vertical profiles of differential winds—for which high-resolution measurements usually do not exist—to yield high-resolution wind analyses throughout the PBL. The method can thus be viewed as a diagnostic downscaling of large-scale wind fields. Downscaling works best during daytime within a homogeneous air mass and in flat terrain. A validation against sodar wind measurements demonstrates that downscaling actually improves large-scale wind fields. A comparison of trajectories calculated from large-scale wind fields, from downscaled wind fields, and from wind fields produced by a conventional diagnostic wind field model, with daytime constant level balloon flights, again shows that the downscaled wind fields are most accurate.

Corresponding author address: Dr. Andreas Stohl, Institute of Meteorology and Geophysics, University of Vienna, Hohe Warte 38, A-1190 Vienna, Austria.

Abstract

This paper describes a simple method, based on routine meteorological data, to produce high-resolution wind analyses throughout the planetary boundary layer (PBL). It is a new way to interpolate wind measurements. According to this method, high-frequency information from surface wind measurements is extrapolated to greater heights by assuming that the vertical shear of the horizontal wind, that is, the differential vertical wind profile, is horizontally more homogeneous than the wind profile itself. Under this assumption, it is sufficient to combine high-resolution surface wind measurements with low-resolution vertical profiles of differential winds—for which high-resolution measurements usually do not exist—to yield high-resolution wind analyses throughout the PBL. The method can thus be viewed as a diagnostic downscaling of large-scale wind fields. Downscaling works best during daytime within a homogeneous air mass and in flat terrain. A validation against sodar wind measurements demonstrates that downscaling actually improves large-scale wind fields. A comparison of trajectories calculated from large-scale wind fields, from downscaled wind fields, and from wind fields produced by a conventional diagnostic wind field model, with daytime constant level balloon flights, again shows that the downscaled wind fields are most accurate.

Corresponding author address: Dr. Andreas Stohl, Institute of Meteorology and Geophysics, University of Vienna, Hohe Warte 38, A-1190 Vienna, Austria.

Save
  • Angell, J. K., and D. H. Pack, 1960: Analysis of some preliminary low-level constant level balloon (tetroon) flights. Mon. Wea. Rev.,88, 235–248.

  • ——, ——, L. Machta, C. R. Dickson, and W. H. Hoecker, 1972: Three-dimensional airtrajectories determined from tetroon flights in the planetary boundary layer of the Los Angeles basin. J. Appl. Meteor.,11, 451–471.

  • Baumann, K. M., and A. Stohl, 1997: Validation of a long-range trajectory model using gas balloon tracks from the Gordon Bennett Cup 95. J. Appl. Meteor.,36, 711–720.

  • ——, M. Langer, and A. Stohl, 1996: Hot-air balloon tracks used to analyze air flow in alpine valleys. Proc. 24th Conf. on Alpine Meteorology, Bled, Slovenia, Hydrometeorological Institute of Slovenia, 60–66.

  • Beljaars, A. C. M., and A. K. Betts, 1992: Validation of the boundary layer representation in the ECMWF model. Seminar Proc. Validation of Models Over Europe, Vol II, Reading, U.K., ECMWF, 159–195.

  • Breaker, L. C., W. H. Gemmill, and D. S. Crosby, 1994: The application of a technique for vector correlation to problems in meteorology and oceanography. J. Appl. Meteor.,33, 1354–1365.

  • Bridger, A. F. C., A. J. Becker, F. I. Ludwig, and R. M. Endlich, 1994: Evaluation of the WOCSS wind analysis scheme for the San Francisco Bay area. J. Appl. Meteor.,33, 1210–1218.

  • Brocchini, M., M. Wurtele, G. Umgiesser, and S. Zecchetto, 1995: Calculation of a mass-consistent two-dimensional wind field with divergence control. J. Appl. Meteor.,34, 2543–2555.

  • Connell, B. H., and D. R. Miller, 1995: An interpretation of radiosonde errors in the atmospheric boundary layer. J. Appl. Meteor.,34, 1070–1081.

  • Crosby, D. S., L. C. Breaker, and W. H. Gemmill, 1993: A proposed definition for vector correlation in geophysics: Theory and application. J. Atmos. Oceanic Technol.,10, 355–367.

  • Daley, R., 1991: Atmospheric Data Analysis. Cambridge University Press.

  • ECMWF, 1989: Research Manual 2. ECMWF Forecast Model—Adiabatic Part. 2d ed. European Centre for Medium-Range Weather Forecasts.

  • Goodin, W. R., G. McRae, and J. H. Seinfeld, 1979: A comparison of interpolation methods for sparse data: Application to wind and concentration fields. J. Appl. Meteor.,18, 761–771.

  • ——, ——, and ——, 1980: An objective analysis technique for constructing three-dimensional urban-scale wind fields. J. Appl. Meteor.,19, 98–108.

  • Graber, W. K., and W. Portmann, 1993: Modeling wind fields over complex terrain by super-position of scale-related processes and its application to the Alpine air mass exchange. Meteor. Z.,N.F. 2, 153–166.

  • Hanna, S. R., and J. C. Chang, 1992: Representativeness of wind measurements on a mesoscale grid with station separations of 312 m to 10 km. Bound.-Layer Meteor.,60, 309–324.

  • Jakobs, H. J., H. Feldmann, H. Hass, and M. Memmesheimer, 1995: The use of nested models for air pollution studies: An application of the EURAD model to a SANA episode. J. Appl. Meteor.,34, 1301–1319.

  • Kahl, J. D., and P. J. Samson, 1986: Uncertainty in trajectory calculations due to low resolution meteorological data. J. Climate Appl. Meteor.,25, 1816–1831.

  • ——, and ——, 1988a: Trajectory sensitivity to rawinsonde data resolution. Atmos. Environ.,22, 1291–1299.

  • ——, and ——, 1988b:Uncertainty in estimating boundary-layer transport during highly convective conditions. J. Appl. Meteor.,27, 1024–1035.

  • Knudsen, B. M., and G. D. Carver, 1994: Accuracy of the isentropic trajectories calculated for the EASOE campaign. Geophys. Res. Lett.,21, 1199–1202.

  • Koracin, D., and R. Berkowicz, 1988: Nocturnal boundary-layer height: Observations by acoustic sounders and predictions in terms of surface-layer parameters. Bound.-Layer Meteor.,43, 65–83.

  • Kunz, R., and N. Moussiopoulos, 1995: Simulation of the wind field in Athens using refined boundary conditions. Atmos. Environ.,29, 3375–3391.

  • Ludwig, F. L., J. M. Livingston, and R. M. Endlich, 1991: Use of mass conservation and critical dividing streamline concepts for efficient objective analzsis of wind fields in complex terrain. J. Appl. Meteor.,30, 1490–1499.

  • Mathur, R., and L. K. Peters, 1990: Adjustment of wind fields for application in air pollution modeling. Atmos. Environ.,24A, 1095–1106.

  • McQueen, J. T., R. R. Draxler, and G. D. Rolph, 1995: Influence of grid size and terrain resolution on wind field predictions from an operational mesoscale model. J. Appl. Meteor.,34, 2166–2181.

  • MetAir, 1996: Schlussbericht Schwebeballonflüge und Berechnungen zu Mischungsschichten für das Pannonische Ozonprojekt (POP)—Kampagne 1995. Rep. to the Austrian Environmental Protection Agency, 197 pp. [Available from Umweltbundesamt, Spittelaner Lande 5, 1090 Vienna, Austria.].

  • Moussiopoulos, N., and T. Flassak, 1986: Two vectorized algorithms for the effective calculation of mass-consistent flow fields. J. Climate Appl. Meteor.,25, 847–857.

  • Neininger, B., 1988: Quasi-Langrange’sche Turbulenzmessung mit Schwebeballonen in der Planetaren Grenzschicht. Lenticularis AG, Opfikon, Switzerland.

  • Palomino, I., and F. Martin, 1995: A simple method for spatial interpolation of the wind in complex terrain. J. Appl. Meteor.,34, 1678–1693.

  • Pechinger, U., K. v.d. Emde, M. Langer, and C. Streissler, 1994: Immissionsabschätzung bei Nuklearunfällen. Rep. of the Central Institute of Meteorology and Geodynamics to the Austrian Ministry of Health and Sports, 149 pp. [Available from Central Institute of Meteorology and Geodynamics, Hohe Warte 38, A-1190 Vienna, Austria.].

  • Peters, L. K., and Coauthors, 1995: The current state and future direction of Eulerian models in simulating the tropospheric chemistry and transport of trace species: A review. Atmos. Environ.,29, 189–222.

  • Petterssen, S., 1940: Weather Analysis and Forecasting. McGraw-Hill.

  • Piringer, M., 1994: Selected results of a sodar intercomparison experiment. Meteor. Z.,N.F. 3, 132–137.

  • ——, 1996: Data availability of commercial sodars depending on meteorological conditions. Preprints, Eighth Symp. on Acoustic Remote Sensing, Russian Academy of Science, Moscow, Russia, 27–31.

  • ——, M. Jaritz, E. Petz, M. Langer, and B. Pospisil, 1995: Vertikalprofilstudie Wien—Untersuchung sommerlicher Ozonepisoden in Wien anhand der Vertikalstruktur der planetaren Grenzschicht. Rep. to MA22, 225 pp. [Available from Central Institute of Meteorology and Geodynamics, Hohe Warte 38, A-1190 Vienna, Austria.].

  • Press, W.H., S. A. Teukolsky, W. T. Vetterling, and B. P. Flannery, 1992: Numerical Recipes in FORTRAN. The Art of Scientific Computing. 2d ed. Cambridge University, 963 pp.

  • Reisinger, L. M., and S. F. Mueller, 1983: Comparisons of tetroon and computed trajectories. J. Climate Appl. Meteor.,22, 664–672.

  • Richner, H., and T. Griesser, 1993: Air motion from potential temperature analysis on a meso-β-scale over complex terrain during POLLUMET 1990 and 1991. Meteor. Z.,N.F. 2, 145–152.

  • Ross, D. G., I. N. Smith, P. C. Manins, and D. G. Fox, 1988: Diagnostic wind field modeling for complex terrain: Model development and testing. J. Appl. Meteor.,27, 785–796.

  • Schlünzen, K. H., 1994: Mesoscale modelling in complex terrain—An overview on the German nonhydrostatic models. Beitr. Phys. Atmos.,67, 243–253.

  • Scire, J., E. Insley, and R. Yamartino, 1990: Model Formulation and User’s Guide for the CALMET Meteorological Model. Rep. A025-1. [Available from the State of California Air Resources Board, 1131 S Street, Sacramento, CA 95812.].

  • Seibel, C., and K. Maßmeyer, 1995: Berechnung von Windfeldern über Nordrhein-Westfalen mit einem massenkonsistenten Windfeldmodell. Staub Reinhalt. Luft,55, 205–210.

  • Sherman, C. A., 1978: A mass-consistent model for wind fields over complex terrain. J. Appl. Meteor.,17, 312–319.

  • Stocker, R. A., R. A. Pielke, A. J. Verdon, and J. T. Snow, 1990: Characteristics of plume releases as depicted by balloon launchings and model simulations. J. Appl. Meteor.,29, 53–62.

  • Stohl, A., and G. Wotawa, 1995: A method for computing single trajectories representing boundary layer transport. Atmos. Environ.,29, 3235–3239.

  • ——, ——, P. Seibert, and H. Kromp-Kolb, 1995: Interpolation errors in wind fields as a function of spatial and temporal resolution and their impact on different types of kinematic trajectories. J. Appl. Meteor.,34, 2149–2165.

  • Strimaitis, D. G., G. E. Moore, and S. G. Douglas, 1991: Analysis of tracer data collected during the SCCCAMP 1985 intensive measurement periods. J. Appl. Meteor.,30, 674–705.

  • Stull, R. B., 1988: An Introduction to Boundary Layer Meteorology. Kluwer Academic Publishers, 666 pp.

  • Talagrand, O., and P. Courtier, 1987: Variational assimilation of meteorological observations with the adjoint vorticity equation. I: Theory. Quart. J. Roy. Meteor. Soc.,113, 1311–1328.

  • Zou, X., I. M. Navon, and F. X. Ledimet, 1992: An optimal nudging data assimilation scheme using parameter estimation. Quart. J. Roy. Meteor. Soc.,118, 1163–1186.

All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 506 210 20
PDF Downloads 121 39 3