Extended Abstract (184K)11.11
Evaluation of the Town Energy Balance (TEB) scheme with direct measurements from dry districts in two cities
Valéry Masson, Meteo-France/CNRM, Toulouse, France; and C. S. B. Grimmond and T. R. Oke
The Town Energy Balance (TEB) model of Masson (2000) simulates turbulent fluxes for urban areas. It is forced with atmospheric data and radiation recorded above roof-level, and incorporates detailed representations of the urban surface (canyon geometry) to simulate energy balances for walls, roads and roofs. Here we present an evaluation of TEB using directly measured surface temperatures and local-scale energy balance and radiation fluxes for two "simple" urban sites: a downtown area within the historic core of Mexico City (stone buildings 5-6 stories in height), and a light industrial site in Vancouver, Canada (flat-roofed, single-story warehouses). At both sites, vegetation cover is < 5%, which permits direct evaluation of TEB in the absence of a coupled vegetation scheme. TEB is run and evaluated for 14 days in Vancouver (August 1992) and 6 days in Mexico City (December 1993).
Following small modifications to TEB, notably to the aerodynamic resistance formulations, the model is shown to perform well overall. In Mexico City, with deep urban canyons and stone walls almost two thirds of the net radiation is partitioned into storage heat flux (?QS) during the day, and this maintains large heat releases and an upward turbulent sensible heat flux at night. TEB simulates all of these features well. At both sites TEB correctly simulates the net radiation (Q*), surface temperatures and the partitioning between the turbulent and storage heat fluxes. The composite wall temperature simulated by TEB is very close to the average of the four measured wall temperatures. A sensitivity analysis of model parameters shows TEB is fairly robust. For the conditions considered here, TEB is most sensitive to roof characteristics and incoming solar radiation.
Session 11, Urban canopy layer: models
Thursday, 23 May 2002, 8:00 AM-1:30 PM
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