CAJ | 학술논문

利用71个气象站1960~2009年共50年的冬季逐日降水、风速和天气现象资料,以及3个站降水对比观测试验数据,对东北地区降雪测量记录的风场变形误差进行了评价和订正,并在此基础上分析了风场变形误差对研究区降雪量变化趋势估算结果的影响.结果如下:1)东北地区冬季降雪量台站观测记录普遍被低估,全区观测的冬季平均降雪量为15.1 mm,而风场变形误差订正后冬季平均降雪量为22.5 mm.各站绝对误差介于1.1~19.4 mm,平均绝对误差为7.5 mm,各站相对误差介于11.8%~50.8%,平均相对误差为34.1%.2)主要由于受气象台站观测环境改变导致的风速减弱现象影响,东北地区大部分台站雨量计对降雪的捕获率有所增加,冬季降水观测中的风场变形误差减小,引起实测的降雪量变化趋势估算值被高估.风场变形误差订正前,东北地区近50年的冬季降雪量变化趋势为0.4 mm·(10 a)–1,而风场变形误差订正后,冬季降雪量变化趋势为0.1 mm·(10 a)–1.3)东北南部地区台站受风场变形误差影响尤其明显,冬季实测的降雪量变化趋势偏高更大,订正后和订正前趋势差值为-1 mm·(10 a)–1,即订正前冬季降雪量变化趋势被高估程度达到了64.3%.
이용71개기상참1960~2009년공50년적동계축일강수、풍속화천기현상자료,이급3개참강수대비관측시험수거,대동북지구강설측량기록적풍장변형오차진행료평개화정정,병재차기출상분석료풍장변형오차대연구구강설량변화추세고산결과적영향.결과여하:1)동북지구동계강설량태참관측기록보편피저고,전구관측적동계평균강설량위15.1 mm,이풍장변형오차정정후동계평균강설량위22.5 mm.각참절대오차개우1.1~19.4 mm,평균절대오차위7.5 mm,각참상대오차개우11.8%~50.8%,평균상대오차위34.1%.2)주요유우수기상태참관측배경개변도치적풍속감약현상영향,동북지구대부분태참우량계대강설적포획솔유소증가,동계강수관측중적풍장변형오차감소,인기실측적강설량변화추세고산치피고고.풍장변형오차정정전,동북지구근50년적동계강설량변화추세위0.4 mm·(10 a)–1,이풍장변형오차정정후,동계강설량변화추세위0.1 mm·(10 a)–1.3)동북남부지구태참수풍장변형오차영향우기명현,동계실측적강설량변화추세편고경대,정정후화정정전추세차치위-1 mm·(10 a)–1,즉정정전동계강설량변화추세피고고정도체도료64.3%.
@@@@Datasets of daily precipitation, wind speed, and weather phenomena of 71 stations during 1960–2009 and experimental observations of precipitation from three stations are used to estimate wind-induced errors in winter snowfall records over northeastern China, and to analyze the effects of wind-induced under-catch on long-term winter snowfall trends. The results show that winter snowfall is generally undervalued. Although the region’s average annual snowfall was measured at 15.1 mm, the corrected snowfall was 22.5 mm, which indicates an average error of 7.5 mm, or relative error of approximately 34.1%. In recent years, the gauge catch rate has increased due to the weakening of surface wind speed resulting from urbanization and micro-environmental change surrounding the stations, which have led to an overestimate of winter snowfall trends in the study region. This analysis shows a 50-year linear trend of winter snowfall of 0.4 mm/10 a when original precipitation data are included and a long-term trend of winter snowfall at 0.1 mm/10 a when adjusted data are used. The effect of wind-induced error on the estimates of winter snowfall trends is particularly significant in the southern part of the study region, with an overestimate for long-term trends reaching?1 mm/10 a, or approximately 64.3%in terms of relative bias.