2种仪器测量日照时数的对比分析

为了比较日照计与总辐射表在测量日照时数上存在的差异,通过对南宁国家基本气象站2008～2009年间暗筒式日照计与总辐射表进行测量所得的日照时数资料进行统计分析,结果发现2种仪器测量所得的日照时数差异明显,总辐射表测量的日照总时数明显多于暗筒式日照计所测的,且二者的差值有明显的年、月、时的变化规律;分析发现,引起差异的主要原因是总辐射表比暗筒式日照计有更高的灵敏度,相对暗筒式日照计而言,总辐射表测量的数据更客观,虽然测值有一定的差别,但两者有很好的相关性;分析还发现,不同的天气条件也是导致两者差异的原因,一般晴好天气差别较少,多云天气差值较大。

Comparative Analysis of Sunshine Duration Measured by Two Instruments

In order to compare the difference of sunshine duration measured by heliograph and pyranometer,the data of sunshine duration measured by heliograph and pyranometer in Nanning national basic weather station during year 2008-2009 was analyzed.The results showed that the difference of sunshine duration measured by heliograph and pyranometer was significant,sunshine duration measured by pyranometer was more significant than that measured by heliograph,and there were variation laws of year,month and hour in the difference of sunshine duration measured by the two instruments.Further analysis found that the main reasons caused the difference were that pyranometer was more sensitive than heliograph,and the data measured by pyranometer was more objective than that measured by heliograph.However,although there was a certain difference,the data measured by pyranometer was well related with that measured by heliograph.Analysis also found another reason caused the difference was that the weather conditions were different.Generally,the difference was small on the sunny day,while it was large on the cloudy day.