Precipitation is a key process in the hydrologic cycle. However, accurate precipitation data are scarce in high mountainous areas, mainly restricted by complex topography, solid precipitation and sparse recording stations. In order to evaluate the quality of precipitation measurement, this study conducted a comparison campaign of precipitation measurements with the PWS100 laser sensor and the Geonor T-200B rain gauge for an entire year from 30 April 2018 to 1 May 2019 at an elevation of 3835 m in a nival glacial zone in eastern Tianshan, Central Asia. The results show that the daily precipitation values recorded by Geonor T-200B and PWS100 are well correlated and the annual precipitation amounts recorded by the two instruments differ by 7%, indicating good capabilities of both instruments in solid precipitation measurement. However, the amount of precipitation measured by Geonor T-200B was 36 mm lower in June to August and 120 mm higher in the remaining months compared with the values measured by PWS100. Our study indicated that Geonor T-200B is more efficient than PWS100 in terms of catching solid precipitation measurements. According to the PWS100 data, the experiment site was dominated by solid precipitation particles, accounting for 60% of total precipitation particles. Based on the precipitation particle and in-situ air temperature measurements, a set of temperature thresholds were established to discriminate rain, sleet and snow. The threshold temperature of rainfall and snowfall is −1.5 and 8 °C, respectively. When air temperature ranges from −1.5 to 8 °C, sleet occurs, meanwhile the ratio of rain to snow depends on air temperature.

中文翻译：

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利用PWS100激光传感器和Geonor T-200B雨量计在中亚东天山雪地冰川区进行的降水测量比较

降水是水文循环中的关键过程。但是，在高山地区，准确的降水数据很少，主要是受复杂的地形，固体降水和稀疏记录站的限制。为了评估降水测量的质量，本研究从2018年4月30日至2019年5月1日，在3835 m的高度上，使用PWS100激光传感器和Geonor T-200B雨量计进行了降水测量的比较活动在中亚天山东部的一个新生冰河带中。结果表明，Georor T-200B和PWS100记录的日降水量具有良好的相关性，两种仪器记录的年降水量相差7％，表明这两种仪器在固体降水测量中均具有良好的能力。然而，与PWS100测得的值相比，Geonor T-200B测得的降水量在6月至8月减少了36毫米，而其余月份则增加了120毫米。我们的研究表明，在捕获固体降水量方面，Georor T-200B比PWS100更有效。根据PWS100的数据，实验地点以固体沉淀颗粒为主，占总沉淀颗粒的60％。根据降水颗粒和原位空气温度测量结果，建立了一套温度阈值来区分雨，雨夹雪和雪。降雨和降雪的阈值温度分别为-1.5和8°C。当气温在-1.5至8°C之间时，会出现雨夹雪，而雨雪的比例取决于气温。