The effects of micro-environmental conditions on the observations of surface air temperature within a standard observational field are unclear.In this paper,the surface observation data of a parallel observational experiment at Mohe Station in 2010 are analyzed.The conclusions are as follows:(1) The annual mean temperature at Site A (close to a house) was lower than that of the standard observational field (Site B),but the monthly mean temperature in January and June at Site A was higher than that of Site B.(2) Between 06:00 and 17:00 (BJT),and at 21:00,lower temperature occurred at Site A;between 18:00 and 05:00 (except 21:00),however,mean temperature at Site A was higher.(3) Lower temperature was recorded at the near-obstacle site for all times in spring (March to May);summer (June to August) also saw the relatively lower temperature at Site A from 06:00 to 17:00;autumn (September to November) mean temperature at Site A was higher than that of the observational field only at 01:00,03:00,19:00,23:00,and it was lower for other times;winter (December to February) mean temperature at Site A was generally lower from 07:00 to 19:00,but higher from 20:00 to 06:00 at night.In cold season (October to March),the mean temperature at Site A was lower than that of the observation field in both daytime and nighttime;but in the warm season (April to September) mean temperature at Site A was lower only during daytime,and higher during nighttime.(4) Minimum and maximum temperatures were recorded at approximately the same time at points A and B,but the maximum temperature was lower,and the minimum temperature is higher at Site A.(5) In the fog weather condition,the temperature at Site A was mostly higher than that at Site B;snow and rain weathers were generally characterized by a lower temperature at Site A;sunny days were more likely to experience lower temperature at Site A;and fair nights were more likely to see a higher temperature at Site A;fair and calm weather conditions were more often accompanied by higher temperature at Site A relative to Site B.It is therefore obvious that the surface air temperature observations are very sensitive to the micro-environmental change at Mohe Station.%测站附近微环境条件对地面气温观测记录的影响目前还不清楚.本文对2010年漠河国家基准气候站地面观测对比试验数据进行了分析,得到如下结论:①年平均地面气温近障碍物点低于标准观测场内,但1、6月的月平均气温近障碍物点偏高;②06:00-17:00和21:00,近障碍物地点的气温偏低;18:00至次日05:00(除21:00),近障碍物点气温偏高;③春季各时次近障碍物点地面气温均偏低;夏季06:00-17:00近障碍物点气温偏低,18:00至次日05:00相反;秋季仅01:00、03:00、19:00、23:00近障碍物点气温偏高,其他时次相反;冬季07:00-19:00近障碍物点气温偏低,20:00至次日06:00相反.冷季近障碍物点气温偏低;暖季昼间近障碍物点气温偏低,夜间相反;④日最高、最低气温出现时间不同地点大体相同,最高气温近障碍物点偏低,最低气温近障碍物点偏高,但最高气温偏低绝对值大于最低气温偏高绝对值;⑤有雾情况下近障碍物地点的气温偏高几率大;雨雪多云天气近障碍物地点气温均偏低;晴朗的白天近障碍物地点的气温偏低,有风天气更明显;而晴朗的夜间近障碍物地点气温偏高,无风天气更明显;晴朗天气条件下,无风时近障碍物地点与观测场内气温差值大于有风时.结果表明,地面气温观测记录对台站观测场附近微环境改变十分敏感,微环境条件的变化将导致地面气温观测出现明显不连续性,对气候变化分析产生影响.
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