Implementation of a new urban energy budget scheme in the MetUM. Part I: Description and idealized simulations

Authors

  • A. Porson,

    Corresponding author
    1. Department of Meteorology, University of Reading, UK
    • Met Office, FitzRoy Road, Exeter EX1 3PB, UK.
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  • P. A. Clark,

    1. Joint Centre for Mesoscale Meteorology, Met Office, Reading, UK
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    • The contributions of P. A. Clark and M. J. Best were written in the course of their employment at the Met Office, UK, and are published with the permission of the Controller of HMSO and the Queen's Printer for Scotland.

  • I. N. Harman,

    1. CSIRO Marine and Atmospheric Research, Canberra, Australia
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  • M. J. Best,

    1. Joint Centre for Hydrometeorological Research, Met Office, Wallingford, UK
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    • The contributions of P. A. Clark and M. J. Best were written in the course of their employment at the Met Office, UK, and are published with the permission of the Controller of HMSO and the Queen's Printer for Scotland.

  • S. E. Belcher

    1. Department of Meteorology, University of Reading, UK
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Abstract

This paper describes the formulation of a new urban scheme, MORUSES (Met Office–Reading Urban Surface Exchange Scheme) for use in the Met Office Unified Model. The implementation of the new scheme ensures that (1) the new scheme offers more flexibility in the parametrization of the building properties, and hence provides a more realistic representation of the fluxes; (2) the bulk outputs are in satisfactory agreement with previous observational studies; and (3) the impact of the new scheme on the energy balance fluxes is similar to the impact of the current urban scheme when set up to mimic it. As well as having a better physical basis, MORUSES also gains in flexibility in applications and adaptations to different urban materials as well as urban planning. The new scheme represents the urban area as a composition of two tiles, a canyon and a roof, using a simple 2D geometry. Sensitivity analysis to canyon geometry and thickness of the roof canopy emphasizes the gain in flexibility captured by the new scheme. Copyright © 2010 Royal Meteorological Society and Crown Copyright

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