标量粗糙度对地气交换的影响

Influence of Scalar Roughness Lengths on the Biosphere-Atmosphere Transfer

为提高地－气间感热和潜热通量的精度，利用Ｇａｒｒａｔｔ的公式将标量粗糙度Ｚ０Ｔ和Ｚ０ｑ引入ＢＡＴＳ，对六种不同的植被作对比试验。结果表明：标量粗糙度Ｚ０Ｔ和Ｚ０ｑ均远远小于动量粗糙度Ｚ０，约相差３～１０个数量级不等。晴天状况下，农作物区Ｚ０／Ｚ０Ｔ，最小，约１０3,阔叶林最大，达１０１０；雨天状况下，各种植被间标量粗糙度的差异减小了。计算的地表温度、感热通量、潜热通量较原ＢＡＴＳ的更为合理。

In order to improve the computed precision of sensible heat flux and latent heat flux between the biosphere and the atmosphere, six experiments have been done for six different vegetationtype experiments by using Garratt equation that computes scalar roughness length ZoT and Z_0q inBATS. The results show that f (l) The scalar roughness length Z_oT and Z_oq, is much smaller thanroughness length Z_o with an order-of-magnitude of Z_o / Z_oT of from 3 to 10. (2) On the sunny day,the value of Z_o / Z_oT is the smallest on the crop with a value of about 10~3, it is largest on the deciduousbroad leaf tree with a value of about 10_10, on the rainy day, the difference of scalar roughness lengths inall kinds of vegetation became small. (3) The calculated land surface temperature, sensible heat flux andlatent heat flux is more reasonable than those in unchanged BATS.