Comparative Analysis of Surface- layer Micrometeorological Characteristics in the Surrounding Area on the Southeast Edge of Tibetan Plateau

By using the field observational data in Wenjiang and Dali site on the southeast edge of Tibetan Plateau in January and July of 2008 which represent winter and summer season respectively, some micrometeorological characteristics are preliminarily analyzed and compared. The main results are as follows: (1) Wind speed both in two sites rises up as height increasing, but in the layer of 4- 10 m it decreases with height increasing in the daytime in Wenjiang site. As to frequency distribution of wind direction, northeast wind is dominant in winter and northwest / south wind in summer in Wenjiang site; the main direction in Dali site is southeast / southwest wind in winter and east / southeast wind in summer. Temperature inversion and humidity inversion phenomena in the surface layer are remarkable both in two sites. (2) In the same season, atmospheric counter radiation and surface longwave radiation in Wenjiang site are bigger than those in Dali site, but solar radiation is smaller. Surface longwave radiation is bigger than atmospheric counter radiation in Wenjiang site in the whole day, while in Dali site, it shows the same trend in the daytime and the opposite trend in the nighttime. (3) Sensible heat flux in Wenjiang site is bigger than that in Dali site in winter and smaller in summer, but latent heat flux is smaller than that in Dali site both in winter and summer. Latent heat flux is higher than sensible heat flux both in two sites and diurnal average of latent heat flux is above zero all the day in Dali site. Soil heat flux in Wenjiang site is smaller than that in Dali site and has phase delay with depth increasing.