Abstract:

Ground - based meteorological observation is essential for understanding the relationship between alp ine glacier and climate change, especially in remote regionswhere in - situmeasurements are extremely limited. Themeteorological factors, including air temperature, wind speed and direction, atmospheric water content, were measured over the accumulation area on the East Rongbuk Glacier, Mt. Qomolangma ( theMt. Everest) at elevation of 6 560 m. Measurements were conducted using an automatic weather station (AWS) fromMay 1 to July 22, 2005 ( sp ring - summer period) and from October 2, 2007 to January 19, 2008 ( autumn - winter period). The variational trend of air temperature and atmospheric water contentwere nearly similar at both the measurement site and Dingri meteorological station by analyzing the observations, and this result testifies the rationality of the observed data on the extremely difficult conditions. Mean monthly air temperature ranged from - 11. 3 ℃ inMay to - 3. 4 ℃ in July, 2005 and from - 11. 3 ℃ in October,2007 to - 19. 0 ℃ in January, 2008 at the AWS site on the East Rongbuk Glacier in theMt. Qomolangma region. Near - surface the
mixing ratio of water vapour increased from 1. 4 g/kg inMay to 5. 4 g/kg in July of 2005 after onset of the Indianmonsoon, while it decreased very slowly from 1. 4 g/kg in October of 2007 to 0. 5 g/kg in January of 2008 when the westerlieswas dominated in the region.Surface wind characteristics were strongly controlled by two major synop tic circulation regimes: the Indian monsoon regime in summer and the westerlies in winter. At the AWS site on the East Rongbuk Glacier, north or northwestwinds p revailed and mean monthlywind speed ranged from 7. 1 m / s in October, 2007 to 14. 2 m / s in January, 2008 with the extreme value up to 35 m / s. South or southeast winds p redominated after the onset of the southwesterly Indian monsoon with relatively low wind speed in summer, ranging from 6. 9 ms- 1 inMay to 2. 2 m s- 1 in July, 2005.

Key words: Mt. Qomolangma, glacier, meteorological characteristic

摘要：

在极端高海拔地区获取定点的气象观测资料对于研究山地冰川与气候变化的关系极为重要。2005年5月1日～7月22日(春末夏初)和2007年10月2日～2008年1月19日(秋冬)在珠峰地区海拔6 560 m的东绒布冰川积累区进行了包括气温、湿度、风向风速和气压在内的气象要素观测。对观测资料的分析表明,气温和湿度与附近较低海拔定日气象站的变化趋势基本一致,证明了在极端环境下获得的气象观测资料的合理性。春末夏初月平均气温从5月的- 11. 3 ℃上升到7月的- 3. 4℃,秋冬季月平均气温则从10月的- 11. 3 ℃下降到次年1月的- 19. 0 ℃。在春末夏初受印度季风影响,湿度呈持续增加趋势,月平均湿度混合比从5月的1. 4 g/ kg增加到7月的5. 4 g/kg;而在西风环流控制下的秋冬季湿度呈缓慢降低,月平均湿度混合比从10月的1. 4 g/kg降低到次年1月的0. 5/kg。春末夏初主要以阴天为主,秋冬季则是晴天占据主导地位。西风环流控制时东绒布冰川盛行西北风,风速较大,极端最大风速可达35 m / s。而受印度季风影响时东绒布冰川以南风为主,风速相对较小。
　

关键词: 珠穆朗玛峰, 冰川, 气象特征