特別講演会(2) in東工大のご案内
イスラエル気鋭の都市気象研究者David Pearlmutter 博士の学会参加のための来日を機に、
下記のような特別講演会を企画致しました。興味のある方は是非、ご参加下さい。屋外スケ
ールモデル実験による都市の熱収支解析(イスラエル版)の話題を提供して頂きます。時間は
たっぷりありますので技術的なことも根ほり葉ほり聞けると思います。
日時 2005年9月30日(金)15:00〜
場所 東京工業大学 石川台4号館地下B04会議室
(アクセス http://www.cv.titech.ac.jp/~kandalab/)
講師 David Pearlmutter (Ben-Gurion University of the Negev)
題目 Open-air modeling of urban canopy and boundary-layer climate
参加 無料
要旨
The thermal behavior of an urban surface is crucial to understand, but
it is difficult to predict using
conventional measurement or modeling approaches. In this study, an integrated
method is proposed
for evaluating urban energy exchanges with an open-air scale model of a building–street canyon surface
array. The technique, which potentially combines the flexibility of modeling
with the reliability of empirical
observation under natural turbulence and radiative loading, is tested in hot, arid summer conditions to
gauge its ability for reproducing surface–atmosphere energy fluxes that are representative of diurnal
patterns in actual urban settings. After identifying the inertial sublayer,
which is created above the scaled
roughness array at a point near its downwind edge, roughness parameters
utilized in the calculation of
turbulent sensible heat flux are determined for two different array configurations of varying frontal area
density and compared with existing data from field studies and morphometric models. For each geometric
configuration, the relative sharing of radiant energy between storage and
turbulent fluxes is compared
with published findings obtained by conventional methods, as is the diurnal pattern of each component flux.
Roughness parameters that are obtained conform to the expected ranges,
as do daytime and overall daily
fluxes and flux ratios. Overall, radiation absorption and heat storage
are higher in the array with deeper
canyons, and in both arrays the share of sensible heat channeled into the atmosphere is both higher in
magnitude and later in reaching its peak intensity than that which is stored
within the scaled urban fabric.
This thermal time lag, when evaluated by fitting data to a published model
for parameterizing heat storage
from net radiation, shows a high correlation with hysteresis behavior in actual
cities.