中文摘要：

利用2007年珠穆朗玛峰（珠峰）北侧地区定日站一日两次的实测探空资料， 分析了珠峰地区的气温、 湿度、 风速、 风向在垂直方向上的结构特征， 分析了逐日和空间尺度（20 m垂直分辨率）上的平均变化特征并解释了其可能原因。同时， 根据对流层顶的定义计算了不同对流层顶出现的高度。结果表明, 在垂直方向上， 气温常在18 km高度的时候降到最低。珠峰地区夏季风速小、 风向以东南风为主， 而在其他季节风速偏大、 风向以西风为主。相对湿度在低海拔的地方全年均存在逆湿现象， 水汽混合比值高值中心也出现在夏季近地面到8 km范围， 这与该地区降水高值中心时空高度相吻合。第一对流层顶全年可见， 夏季以单对流层顶为主， 冬季以多对流层顶结构居多。第一和第二对流层顶的高度均与该对流层顶的温度成反比， 而第三对流层顶几乎不随高度变化， 因此， 推断该稳定层结为平流层大气。这些发现为深入理解该地区对流层和平流层物质、 能量交换以及区域气候变化提供了重要参考数据。

英文摘要：

The spatio-temporal variation of several meteorological elements at Dingri station of the north slope of Mount Qomolangma were investigated across the board in the vertical, in terms of temperature, wind speed, and humidity. The data applied in this study included one year （2007） worth of twice-per-day radiosonde sounding data （08：00 and 20：00, Beijing time）. The height of various tropopause types was calculated according to tropopause criteria developed by the World Meteorological Organization （WMO）. Particularly, good appreciation of climatic features in this region was obtained： The temperature dropped down to the lowest at 18 km above sea level. Compared with the relatively lower wind speed in summer and the prevailing northeasterly, the wind speed in other seasons was much greater and the dominant wind direction changed to westerly. In addition, there was a humidity inversion at lower atmosphere layer all year round, whereas water vapor mixing ratio was relatively higher in summertime from surface to 8 km above sea level, consistent with the well-known precipitation peak in this region. Furthermore, the first tropopause can be seen all year round and single tropopause appeared in summer and multi-tropopause took majority in winter. The first tropopause and the second tropopause varied inversely with temperature at the first tropopause, whereas the third tropopause kept constant with varying temperature, which was possibly due to the fact that the third tropopause was located in the stratosphere.