摘要
采用 1998年青藏高原当雄地区的实测资料 ,研究高原边界层的高度及其日变化 ,结果表明高原上的边界层高度比平原地区通常出现的值要大得多 .主要是由于青藏高原地处内陆 ,气温强烈的日变化引起大气层结日变化加大所致 .同时 ,利用通量廓线法计算了表征湍流动量通量的特征U 、表征湍流热量通量的特征量T 以及总体输送系数CD,HH°结果高原的CD值明显比平原地区的大 .
Because of existance of Qinghai Tibet Plateau, the conditions of the atmospheric circulation in the whole East Asia and even in the whole world are tremendously affected. Nowadays, it has been realized that Qinghai?Tibet Plateau acts as the heat resource in summer, whereas, in winter, as the cold resource except its southeastern part. The construction of the boundary layer in Qinghai?Tibet Plateau is one of the principal issues that scientists are interested today. The height of the boundary layer and its diurnal variation have been studied by using the Qinghai?Tibet Plateau scientific experimental information in Dangxiong in 1998. The results showed the height of the boundary layer in the plateau (1.6 km to 2.5 km )is higher than that of the plain (often varied from 1.0 km to 1.5 km). The reason possibly is that Qinghai?Tibet Plateau is located inland and that its diurnal variation of the atmospheric temperature is so violent that the atmospheric stratification becomes stronger. In contrast to Jiangxi and other plain areas, the diurnal variation of temperature in Dangxiong is apparently higher. Moreover, the maximum balance of temperature between the soil and the air in Dangxiong is 8 ℃ higher than that in Jiangxi. At the same time, the important parameter, U *, T *, (characterizing the turbulent momentum flux and sensible heat flux), the turbulent drag coefficient C D and the bulk transport coefficient of heat flux C H, are calculated by the method of the flux?profile. The result shows C D in the Plateau is stronger than that in the plain area such as Wangara, even if they have the same roughness Z 0. From these studies, it can be further confirmed that, in Qinghai?Tibet Plateau, the turbulent exchange in the ground layer is strong, the diurnal variation of temperature is large and the height of the boundary layer is high. All of these are significant character istics of Qinghai?Tibet Plateau. But it is also emphasized that in Qinghai?Tibet Plateau, the geology condition is arduous, the climate is violent and the observation is so difficult that the data and the information are very limited. All of thess will further affect the development of the research.
出处
《南京大学学报（自然科学版）》
CAS
CSCD
北大核心
2001年第3期348-357,共10页
Journal of Nanjing University（Natural Science）
关键词
边界层高度
磨擦速度
湍流热量通量
特征量
总体输送系数
青藏高原
大气边界层
boundary layer height, frictional velocity, characteristic temperature, turbulent sensible heat flux, turbulent drag coefficient
