Abstract
We investigate the mesoscale dynamics of the mistral through the wind profiler observations of the MAP (autumn 1999) and ESCOMPTE (summer 2001) field campaigns. We show that the mistral wind field can dramatically change on a time scale less than 3 hours. Transitions from a deep to a shallow mistral are often observed at any season when the lower layers are stable. The variability, mainly attributed in summer to the mistral/land–sea breeze interactions on a 10-km scale, is highlighted by observations from the wind profiler network set up during ESCOMPTE. The interpretations of the dynamical mistral structure are performed through comparisons with existing basic theories. The linear theory of R. B. Smith [Advances in Geophysics, Vol. 31, 1989, Academic Press, 1–41] and the shallow water theory [Schär, C. and Smith, R. B.: 1993a, J. Atmos. Sci. 50, 1373–1400] give some complementary explanations for the deep-to-shallow transition especially for the MAP mistral event. The wave breaking process induces a low-level jet (LLJ) downstream of the Alps that degenerates into a mountain wake, which in turn provokes the cessation of the mistral downstream of the Alps. Both theories indicate that the flow splits around the Alps and results in a persistent LLJ at the exit of the Rhône valley. The LLJ is strengthened by the channelling effect of the Rhône valley that is more efficient for north-easterly than northerly upstream winds despite the north–south valley axis. Summer moderate and weak mistral episodes are influenced by land–sea breezes and convection over land that induce a very complex interaction that cannot be accurately described by the previous theories.
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References
U. Aebischer C. Schär (1998) ArticleTitle‘Low-level Potential Vorticity and Cyclogenesis to the Lee of the Alps’ J. Atmos. Sci 55 186–207
R. Bleck C. Mattocks (1984) ArticleTitle‘A Preliminary Analysis of the Role of the Potential Vorticity in Alpine Lee Cyclogenesis’ Contrib. Atmos. Phys 57 357–368
Blondin, C. and Bret, B.: 1986, ‘Numerical Study of the Mistral with a Mesoscale Model’, in preprint Scientific results of the Alpine experiment (ALPEX), GARP Publication Series, WMO/TD, pp. 549–563.
Bordreuil, C., Barbia, A., and Comte, P.: 1973, ‘Vent du Nord Ouest à Marseille de 1882 à 1970’, Monographie 88 de la Météorologie nationale.
P. Bougeault P. Binder A. Buzzi R. Dirks R. Houze J. Kuettner R. Smith R Steinacker H. Volkert (2001) ArticleTitle‘The MAP Special Observing Period’ Bull. Amer. Meteorol. Soc 82 433–462
A. Buzzi A. Speranza (1986) ArticleTitle‘A Theory of Deep Cyclogenesis in the Lee of the Alps. Part I: Modifications of Baroclinic Instability by Localized Topography’ J. Atmos. Sci 42 1521–1535
A. Buzzi A. Tibaldi (1978) ArticleTitle‘Cyclogenesis in the Lee of the Alps: A Case Study’ Quart. J. Roy. Meteorol. Soc 104 271–287
Corsmeier, U., Behrendt, R., Drobinski, P., and Kottmeier, C.: 2004, ‘The Mistral and its Effect on Air Pollution Transport and Vertical Mixing’, Atmos. Res., in press.
B. Cros P. Durand H. Cachier P. Drobinski E. Fréjafon C. Kottmeier P. E. Perros V. H. Peuch J. L. Ponche D. Robin F. Sa G. Toupance H. Wortham (2004) ArticleTitle‘The ESCOMPTE Program: An Overview’ Atmos. Res 69 241–279
P. Drobinski J Dusek C Flamant (2001a) ArticleTitle‘Diagnostics of Hydraulic Jump and Gap Flow in Stratified Flows over Topography’ Boundary-Layer Meteorol 98 475–495
P. Drobinski C Flamant J Dusek PH Flamant J Pelon (2001b) ArticleTitle‘Observational Evidence and Modelling of an Internal Hydraulic Jump at the Atmospheric Boundary-layer Top during a Tramontane Event’ Boundary-Layer Meteorol 98 497–515
D. Durran (1986) ArticleTitle‘Another Look at Downslope Windstorms. Part I: The Development of Analogs to Supercritical Flow in an Infinitely Deep Continuously Stratified Fluid’ J. Atmos. Sci 93 2527–2543
J. Egger (1972) ArticleTitle‘Numerical Experiments on the Cyclogenesis in the Gulf of Genoa’ Contrib. Atmos. Phys 45 320–346
J. Egger (1988) ArticleTitle‘Alpine Lee Cyclogenesis: Verification of Theories’ J. Atmos. Sci 45 2187–2203
C. Flamant (2003) ArticleTitle‘Alpine lee Cyclogenesis Influence on Air–Sea Heat Exchanges and Marine Atmospheric Boundary Layer Thermodynamics over the Western Mediterranean during a Tramontane/Mistral Event’ J. Geophys. Res. 108(C3) 8057
M. Georgelin E. Richard (1996) ArticleTitle‘Numerical Simulation of Flow Diversion around the Pyrenees: A Tramontana Case Study’ Mon. Wea. Rev 124 687–700
K. P. Hoinka M. Hagen H. Volkert D. Heimann (1990) ArticleTitle‘On the Influence of the Alps on a Cold Front’ Tellus 42A 140–164
K. P. Hoinka E. Richard G. Poberaj R. Busen J. L. Caccia A. Fix H. Mannsetein (2003) ArticleTitle‘Analysis of a Potential Vorticity Streamer Crossing the Alps during MAP IOP-15 on 6 November 1999’ Quart. J. Roy. Meteorol. Soc 129, 588 609–632
Q. Jiang R. B. Smith J. D. Doyle (2003) ArticleTitle‘The Nature of the Mistral: Observations and Modelling of Two MAP Events’ Quart. J. Roy. Meteorol. Soc 129 857–876
R. R. Long (1953) ArticleTitle‘Some Aspects of the Flow of Stratified Fluids: I. A Theoretical Investigation’ Tellus 5 42–58 Occurrence Handle10.1111/j.2153-3490.1953.tb01035.x
Mayençon, R.: 1982, Météorologie Pratique, Editions Maritimes D’Outre-Mer, 336 pp.
C. Millot (1979) ArticleTitle‘Wind Induced Upwellings in the Gulf of Lions’, Oceanol Acta 2 261–274
Orieux, A. and Pouget, E.: 1984, ‘Le mistral: Contribution à l’étude de ses aspects synoptiques et régionaux’, Monographie 5 de la Météorologie nationale.
P. Pettré (1982) ArticleTitle‘On the Problem of Violent Valley Winds’ J. Atmos. Sci 39 542–554
M. Rhein (1995) ArticleTitle‘Deep Water Formation in the Western Mediterranean’ J. Geophys. Res 10 IssueIDC4 6943–6959
C. Schär R. B. Smith (1993) ArticleTitle‘Shallow-Water Flow Past Isolated Topography. Part I: Vorticity Production and Wave Formation’ J. Atmos. Sci 50 1373–1400
R. B. Smith (1985) ArticleTitle‘On Severe Downslope Winds’ J. Atmos. Sci 42, 23 2597–2603
Smith, R. B.:1989, ‘Hydrostatic flow over Mountains’, Advances in Geophysics, Vol. 31, Academic Press, 1–41.
P. K. Smolarkievicz R. Rotunno (1989) ArticleTitle‘Low Froude Number Flow Past Three Dimensional Obstacles. Part I: Baroclinically Generated Lee Vortices’ J. Atmos. Sci 46 1154–1164
M. Sprenger C. Schär (2001) ArticleTitle‘Rotational Aspects of Stratified Gap Flows and Shallow Foehn’ Quart. J. Roy. Meteorol. Soc 127 161–188
A. Tafferner J. Egger (1990) ArticleTitle‘Test of Theories of Lee Cyclogenesis: ALPEX Cases’ J. Atmos. Sci 47 2417–2428
J. E. Wrathall (1985) ArticleTitle‘The Mistral and Forest Fires in Provence-Côte d’Azur-South France’ Weather 40 119–124
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Guenard, V., Drobinski, P., Caccia, JL. et al. An Observational Study of the Mesoscale Mistral Dynamics. Boundary-Layer Meteorol 115, 263–288 (2005). https://doi.org/10.1007/s10546-004-3406-z
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DOI: https://doi.org/10.1007/s10546-004-3406-z