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Meccanica

, Volume 31, Issue 1, pp 15–25 | Cite as

Stochastic modeling of the thermally induced atmospheric flow at mesoscale

  • Jingfeng Wang
  • Rafael L. Bras
  • Elfatih A. B. Eltahir
Article
  • 22 Downloads

Abstract

This paper presents a three-dimensional stochastic linear model of the atmospheric flow induced by the variability of heat flux over land surface. The primitive equations relating perturbation terms of wind field, geopotential and buoyancy are formulated as a system of stochastic partial differential equations and solved analytically. The solution is based on spectral representations of the homogeneous random fields. The flow intensity is found to be proportional to the standard deviation of the heat flux into the atmosphere. The intensity of the vertical motion becomes more sensitive to the differential heating with a larger length scale as altitude goes higher. Stability and synoptic wind inhibit the development of the flow. The proposed theory improves the understanding of the role that heterogeneous land surface plays in atmospheric circulations at the mesoscale.

Key words

Surface heating Mesoscale flow Stochastic approach Hydrometeorology 

Sommario

Questo lavoro presenta un modello stocastico lineare del moto atmosferico tridimensionale indotto dalla variabilità del flusso di calore sulla superficie del terreno. Le equazioni primitive che legano i termini perturbativi del campo di vento, del geopotenziale e del parametro di galleggiamento sono formulate come un sistema di equazioni stocastiche alle derivate parziali che vengono risolte analiticamente. Tale soluzione è basata su rappresentazioni spettrali di campi aleatori omogenei. L'intensità del moto risulta essere proporzionale alla deviazione standard del flusso di calore diretto verso l'atmosfera. L'intensità del moto in direzione verticale appare più sensibile al riscaldamento differenziale, con scale spaziali più grandi al crescere dell' altitudine. La stabilità ed il flusso sinottico tendono ad inibire lo sviluppo del moto. La teoria qui proposta migliora la comprensione del ruolo che la superficie eterogenea del terreno gioca nella circolazione atmosferica alla meso-scala.

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Copyright information

© Kluwer Academic Publishers 1996

Authors and Affiliations

  • Jingfeng Wang
    • 1
  • Rafael L. Bras
    • 1
  • Elfatih A. B. Eltahir
    • 1
  1. 1.Department of Civil and Environmental EngineeringMassachusetts Institute of TechnologyCambridgeUSA

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