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The impact of weak synoptic forcing on the valley-wind circulation in the Alpine Inn Valley

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Abstract

This paper investigates the impact of weak synoptic-scale forcing on the thermally induced valley-wind circulation in the Alpine Inn Valley and one of its largest tributaries, the Wipp Valley. To this end, high-resolution numerical simulations with realistic topography but idealized large-scale atmospheric conditions are performed. The large-scale flow has a speed increasing linearly from 5 m s−1 at sea level to 12.5 m s−1 at tropopause level, but its direction is varied between each experiment. For reference, an experiment without large-scale winds is conducted as well. The results indicate that the sensitivity to ambient flow forcing differs substantially between the Inn Valley and the Wipp Valley. The valley-wind circulation of the Inn Valley is found to be fairly robust against weak ambient forcing, changing by a much smaller amount than the along-valley component of the imposed large-scale flow. The valley wind tends to be intensified (weakened) when the ambient flow is aligned with (opposite to) the local valley orientation. However, the flow response is complicated by larger-scale interactions of the ambient flow with the Alpine massif. Most notably, northerly and northwesterly flow is deflected around the Alps, leading to the formation of a low-level jet along the northern edge of the Alps which in turn affects the valley-wind circulation in the lower Inn Valley. For the Wipp Valley, which is oriented approximately normal to the Alpine crest line and constitutes a deep gap in the Alpine crest, two distinctly different flow regimes are found depending on whether the large-scale flow has a significant southerly component or not. In the absence of a southerly flow component, the valley-wind circulation is similarly robust against ambient forcing as in the Inn Valley, with a fairly weak response of the local wind speeds. However, southerly ambient flow tends to force continuous downvalley (southerly) wind in the Wipp Valley. The flow dynamics can then be described as a pressure-driven gap flow during the day and as a mixture between katabatic flow and gap flow during the night. The responsible pressure forcing arises from the larger-scale interaction of the ambient flow with the Alpine massif, with southerly flow causing lifting on the southern side of the Alps and subsidence in the north.

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References

  • Armi L, Mayr GJ (2007) Continuously stratified flows across an Alpine crest with a pass: shallow and deep föhn. Q J R Meteorol Soc 133:459–477

    Article  Google Scholar 

  • Dreiseitl E, Feichter H, Pichler H, Steinacker R, Vergeiner I (1980) Windregimes an der Gabelung zweier Alpentäler. (Wind regimes at the intersection of two Alpine valleys). Arch Met Geoph Biokl B 28:257–275

    Article  Google Scholar 

  • Eckman RM (1998) Observations and numerical simulations of winds within a broad forested valley. J Appl Meteor 37:206–219

    Article  Google Scholar 

  • Flamant C, Drobinski P, Nance L, Banta R, Darby L, Dusek J, Hardesty M, Pelon J, Richard E (2002) Gap flow in an Alpine valley during a shallow south föhn event: observations, numerical simulations and hydraulic analogue. Q J R Meteorol Soc 128:1173–1210

    Article  Google Scholar 

  • Föst F (2006) Eine objektive Föhnklimatologie für das Wipp- und Inntal (An objective foehn climatology for the Wipp and Inn Valley). Diploma thesis, University of Innsbruck, Austria, 153 pp

  • Freytag C (1985) MERKUR-results: aspects of the temperature fields and the energy budget in a large Alpine valley during mountain and valley wind. Contr Atmos Phys 58:458–476

    Google Scholar 

  • Freytag C, Hennemuth B (1983) MERKUR. Mesoskaliges Experiment im Raum Kufstein–Rosenheim (Mesoscale experiment in the region Kufstein–Rosenheim). Wiss Mitt Meteorol Inst Univ München, vol 48, 132 pp

  • Garnier BJ, Ohmura A (1968) A method of calculating the direct shortwave radiation income of slopes. J Appl Meteor 7:796–800

    Article  Google Scholar 

  • Gohm A, Mayr GJ (2004) Hydraulic aspects of foehn winds in an Alpine valley. Q J R Meteorol Soc 131:449–480

    Article  Google Scholar 

  • Grell GA, Dudhia J, Stauffer DR (1995) A description of the fifth-generation Penn State/NCAR mesoscale model (MM5). NCAR Tech Note NCAR/TN-398+STR, 122 pp

  • Groß G, Wippermann F (1987) Channeling and countercurrent in the upper Rhine Valley: Numerical simulations. J Clima Appl Meteor 26:1293–1304

    Article  Google Scholar 

  • Kalthoff N, Vogel B (1992) Counter-current and channelling effect under stable stratification in the area of Karlsruhe. Theor Appl Climatol 45:113–126

    Article  Google Scholar 

  • Kossmann M, Sturman AP (2003) Pressure-driven channeling effects in bent valleys. J Appl Meteor 42:151–158

    Article  Google Scholar 

  • Klemp JB, Durran DR (1983) An upper boundary condition permitting internal gravity wave radiation in numerical mesoscale models. Mon Wea Rev 111:430–444

    Article  Google Scholar 

  • Lugauer M, Winkler P (2005) Thermal circulation in South Bavaria climatology and synoptic aspects. Met Z 14:15–30

    Article  Google Scholar 

  • Mlawer EJ, Taubman SJ, Brown PD, Iacono MJ, Clough SA (1997) Radiative transfer for inhomogeneous atmosphere: RRTM, a validated correlated-k model for the longwave. J Geophys Res 102:16663–16682

    Article  Google Scholar 

  • Müller H, Reiter R, Sládkovič R (1984) Die vertikale Windstruktur beim Merkur-Schwerpunkt “tagesperiodische Windsysteme” aufgrund von aerologischen Messungen im Inntal und im Rosenheimer Becken (On the vertical wind structure of the diurnal wind system within the Inn Valley and the adjacent plain: results of aerological soundings during the field experiment Merkur). Arch Met Geoph Biokl B 33:359–372

    Google Scholar 

  • Olafsson H, Bougeault P (1997) The effect of rotation and surface friction on orographic drag. J Atmos Sci 54:193–210

    Article  Google Scholar 

  • Pamperin H, Stilke G (1985) Nächtliche Grenzschicht und LLJ im Alpenvorland nahe dem Inntalausgang (Nocturnal boundary layer and LLJ in the pre-alpine region near the outlet of the Inn Valley). Meteor Rundsch 38:145–156

    Google Scholar 

  • Reisner J, Rasmussen RM, Bruintjes RT (1998) Explicit forecasting of supercooled liquid water in winter storms using the MM5 mesoscale model. Q J R Meteorol Soc 124:1071–1107

    Article  Google Scholar 

  • Rucker M (2003) Observational and numerical study of daytime flows in an Alpine valley. PhD dissertation, The University of British Columbia, 164 pp

  • Schär C, Leuenberger D, Fuhrer O, Lüthi D, Girard C (2002) A new terrain-following vertical coordinate for atmospheric prediction models. Mon Wea Rev 130:2459–2480

    Article  Google Scholar 

  • Seibert P (1990) South foehn studies since the ALPEX experiment. Meteorol Atmos Phys 43:91–103

    Article  Google Scholar 

  • Shafran PC, Seaman NL, Gayno GA (2000) Evaluation of numerical predictions of boundary layer structure during the Lake Michigan Ozone Study (LMOS). J Appl Meteorol 39:412–426

    Article  Google Scholar 

  • Steinacker R (1984) Area-height distribution of a valley and its relation to the valley wind. Contr Atmos Phys 57:64–71

    Google Scholar 

  • Vergeiner J (2004) South foehn studies and a new foehn classification scheme in the Wipp and Inn Valley. PhD thesis, University of Innsbruck, Austria, 105 pp

  • Weber RO, Kaufmann P (1998) Relationship of synoptic winds and complex terrain flows during the MISTRAL field experiment. J Appl Meteor 37:1486–1496

    Article  Google Scholar 

  • Weigel AP, Rotach MW (2004) Flow structure and turbulence characteristics of the daytime atmosphere in a steep and narrow Alpine valley. Q J R Meteorol Soc 130:2605–2627

    Article  Google Scholar 

  • Whiteman CD (1990) Observations of thermally developed wind systems in mountainous terrain. Met Monogr Am Met Soc 23:5–42

    Google Scholar 

  • Whiteman CD, Doran JC (1993) The relationship between overlying synoptic-scale flows and winds within a valley. J Appl Meteor 32:1669–1682

    Article  Google Scholar 

  • Wippermann F, Groß G (1981) On the construction of orographically influenced wind roses for given distributions of the large-scale wind. Beitr Phys Atmos 54:492–501

    Google Scholar 

  • Zängl G (2002a) Stratified flow over a mountain with a gap. Linear theory and numerical simulations. Q J R Meteorol Soc 128:927–949

    Google Scholar 

  • Zängl G (2002b) An improved method for computing horizontal diffusion in a sigma-coordinate model and its application to simulations over mountainous topography. Mon Wea Rev 130:1423–1432

    Article  Google Scholar 

  • Zängl G (2002c) Idealized numerical simulations of shallow föhn. Q J R Meteorol Soc 128:431–450

    Article  Google Scholar 

  • Zängl G (2003a) A generalized sigma coordinate system for the MM5. Mon Wea Rev 131:2875–2884

    Article  Google Scholar 

  • Zängl G (2003b) Deep and shallow south foehn in the region of Innsbruck: typical features and semi-idealized numerical simulations. Meteorol Atmos Phys 83:237–261

    Google Scholar 

  • Zängl G (2004) A reexamination of the valley wind system in the Alpine Inn Valley with numerical simulations. Meteorol Atmos Phys 87:241–256

    Article  Google Scholar 

  • Zängl G (2005) Large-scale-flow interactions with the Alps and their impact on the low-level temperature field in the northern foreland. Met Z 14:379–386

    Article  Google Scholar 

  • Zängl G, Egger J, Wirth V (2001) Diurnal winds in the Himalayan Kali Gandaki Valley. Part II: Modeling. Mon Wea Rev 129:1062–1080

    Article  Google Scholar 

Download references

Acknowledgments

The author wants to thank the Remote Sensing Centre (DFD) of DLR Oberpfaffenhofen for providing the high-resolution orography data. This work was sponsored by the German Science Foundation (DFG) under grant ZA 268/6-1.

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  1. Deutscher Wetterdienst, Frankfurter Straße 135, 63067, Offenbach, Germany

    Günther Zängl

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  1. Günther Zängl
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Zängl, G. The impact of weak synoptic forcing on the valley-wind circulation in the Alpine Inn Valley. Meteorol Atmos Phys 105, 37–53 (2009). https://doi.org/10.1007/s00703-009-0030-y

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