Parsivel激光雨滴谱仪观测较强降水的可行性分析和建议

为了研究OTT-Parsivel激光雨滴谱仪(简称Parsivel)在较强降水观测中应用的可行性,用南京地区2012年6—7月份4个典型的降水个例,对Parsivel和SL3-1翻斗式雨量计(简称雨量计)的累积降水量、降水强度观测资料进行对比分析,并与人工雨量筒观测作以比较。结果表明:Parsivel测值是可信的,在累积降水量观测上,与雨量计具有很好的相关性,但测值始终偏高,该现象主要是粒子相互遮挡造成的。雨量计的反应时间,明显滞后于Parsivel。雨量计测值接近人工测值;而Parsivel与人工测值的偏差明显大于雨量计。结合实验分析与业务应用,提出3点使用建议:(1)仪器应架设在无遮蔽物的开阔地带。(2)采样周期应随着降水强度(地理位置)的不同而改变。(3)对降水微物理参量特征以及粒子谱分析时,可剔除直径过大、速度很低的粒子。

Feasibility analyses and recommendations of Parsivel optical distrometer in measurements of strong precipitation

In order to study the performance of the optical disdrometer Parsivel in strong precipitation, this article compares three kinds of rain equipment including Parsivel, SL3-1 tipping bucket rain gauge and traditional rain gauge based on 4 typical rain events during June and July 2012 in Nanjing. The result shows: The value measured by Parsivel is credible, a good linear correlation and consistency exit between Parsivel and tipping bucket rain gauge in terms of accumulated precipitation, Parsivel gives higher accumulated data systematically than the latter. We suggest that the reason is the mutual occlusions of small particles; the precipitation starting time measured by rain gauge lags behind that by PARSIVEL; the rain gauge is very close to the measured value of the artificial observations, thus the instrumental deviation from Parsivel is significantly greater than the rain gauge. In addition, we propose the following three points during using Parsivel: (1) Parsivel should be set up in the open area without shelter in order to avoid particle deformation. (2)Parsivel's sampling period should be changed with the different precipitation intensity. (3) It is necessary to neglect those particles which are too large and too slow to analyse precipitation microphysical parameters' characteristics and the particle spectrum correctly.