祁连山TRwS204与中国标准雨量筒降水观测对比研究

Intercomparison Study on Precipitation Observations of TRwS204 and Chinese Standard Precipitation Gauge in the Qilian Mountains

山区降水类型、过程和气候条件复杂多变,不同雨量筒观测结果均存在一定的误差,亟需了解常用人工和自记雨量筒之间及其与实际降水量之间的差异。针对中国标准雨量筒[无防风措施(CSPG_(UN))和配备单层Alter防风圈(CSPG_(SA))]和在祁连山常用的TRwS204称重式雨雪量计[配备单层Alter防风圈(TRwS_(SA))],于2014年9月至2017年8月在祁连山黑河上游葫芦沟小流域开展了同步降水观测对比试验,以按照世界气象组织推荐的固态降水测量标准安装的中国标准雨量筒的修正值作为标准降水量。结果表明:(1)CSPG_(UN)、CSPG_(SA)和TRwS_(SA)降雨观测的平均动力损失(平均动力损失与平均标准降雨量的百分比)分别为0.21 mm(3.4%)、0.12 mm(1.9%)和0.61 mm(9.8%),雨夹雪分别为0.37 mm(7.6%)、0.16 mm(3.3%)和0.51 mm(10.5%),降雪分别为0.27 mm(10.2%)、0.09 mm(3.4%)和0.57mm(21.4%)。(2)CSPGUN和CSPG_(SA)动力损失的差异主要与防风圈的使用有关,而CSPG_(SA)和TRwS_(SA)动力损失的差异主要与雨量筒形状不同有关,同时本研究结果还可能受到TRwS204特定误差的影响。(3)当风速高于2.0 m·s^(-1)时,各雨量筒降雨捕捉率出现明显的降低。因雨夹雪和降雪期间的平均风速较低,只有CSPGUN降雪捕捉率随风速的增加出现一定的降低。

The type and process of precipitation, and the climate condition are complex in mountainous area, and biases exist in the observations of various precipitation gauges. It is urgent to understand the difference between measurements from manual and automatic gauges, and the difference between the gauge measurements and the real precipitation. Comparison of precipitation measurements was carried out in the Hulu watershed of Heihe river upstream in the Qilian Mountains from September 2014 to August 2017. The Chinese standard precipitation gauge [ no wind shield （CSPGuN） and equipped with single Alter wind shield （CSPGsA） ] and the TRwS204 weighing precipitation gauge [ equipped with single Alter wind shield （ TRWSsA ） ]which was commonly used in the Qilian Mountains were used. Choosing the adjustments of the measurements from the Chinese standard precipitation gauge installed in accordance with the Double Fence Intercomparison Reference recommended by the World Me- teorological Organization as standard precipitation. The results show that： （i） The average dynamic losses （the percentage of the average dynamic losses relative to the average standard precipitation） of CSPGuN, CSPGsA and TRWSsA were 0. 21 mm （3. 4%）, 0. 12 mm （1. 9%） and 0. 61 mm （9. 8%） for rain, and 0. 37 mm （7. 6% ）, 0. 16 mm （3.3%） and 0.51 mm （ 10.5% ）for sleet, and 0.27 mm（ 10.2% ）, 0.09 mm （3.4%） and 0. 57 mm （21. 4% ） for snow, respectively. （2） The difference between dynamic losses of CSPGuN and CSPGsA was mainly related to the effect of the wind shield. The difference between dynamic losses of CSPGsA and TRwSsA was mainly related to the different gauge shape, and it could also be affected by the specific errors of TRwS204. （3） For rain, gauge catch ratio decreased a lot when mean wind speed was higher than 2. 0 m · s-1. Because the mean wind speed was relatively low for sleet and snow, only the catch ratio of CSPGUN decreased with the increase of wind speed for snow.