鄱阳湖地区零平面位移及动力粗糙度的计算

利用2013年7月1日至2014年6月30日鄱阳湖东岸70 m铁塔涡动相关观测资料，应用Martano方法和TVM（Temperature Variance Method）方法分别计算了该地地表零平面位移d和粗糙度z₀，通过代回Monin-Obukhov相似性理论的风廓线关系计算摩擦速度，以验证与实测摩擦速度的一致性。速度和温度标准差的归一化拟合线分别与Panosky等和Tillman给出的曲线趋势一致，表明该站观测数据总体满足近地层相似性。Martano方法计算结果随季节变化较大，春夏季的粗糙度是秋冬季的6.3倍；陆面方向零平面位移和粗糙度分别为来自湖面的2倍和10倍；Martano方法比TVM方法对季节和方向的敏感性更强。Martano方法计算得到零平面位移和粗糙度对摩擦速度造成了约9.9%的高估；而TVM方法对摩擦速度造成了约32.8%的高估；Martano方法计算的摩擦速度和观测值的一致性更好。

Calculation of zero plane displacement and dynamic roughness length in Poyang lake area

Based on the eddy correlation observation data of the 70-m tower on the east bank of Poyang lake from July 1, 2013 to June 30, 2014, the surface zero plane displacement and roughness length were calculated with the Martano method and TVM method (Temperature Variance Method). The friction velocity calculated by substituting the wind profile relation based on Monin-Obukhov similarity theory was compared with the observation for verifying their consistency. The results show that the normalized fitted curves of velocity and temperature standard deviations show a similar trend with the theoretical curves given by Panosky et al. and Tillman. The results calculated with the Martano method vary greatly with the season, and the roughness in spring and summer is 6.3 times larger than that in autumn and winter. The zero plane displacement and roughness for land surface are 2 times and 10 times larger than those for lake surface, respectively. Martano method is more sensitive to the season and direction relative to the TVM method. The friction velocity estimated with the Martano method causes about 9.9% overestimation for the friction velocity, while that with the TVM method results in an overestimation of about 32.8%. On the whole, it can be seen that the friction velocity calculated by the Martano method is better consistent with the observed value.