The variation of air temperature measurement errors using two different radiation shields （DTR502B Vaisala,Finland,and HYTFZ01,Huayun Tongda Satcom,China） was studied.Datasets were collected in the field at the Daxi...The variation of air temperature measurement errors using two different radiation shields （DTR502B Vaisala,Finland,and HYTFZ01,Huayun Tongda Satcom,China） was studied.Datasets were collected in the field at the Daxing weather station in Beijing from June 2011 to May 2012.Most air temperature values obtained with these two commonly used radiation shields were lower than the reference records obtained with the new Fiber Reinforced Polymers （FRP） Stevenson screen.In most cases,the air temperature errors when using the two devices were smaller on overcast and rainy days than on sunny days; and smaller when using the imported rather than the Chinese shield.The measured errors changed sharply at sunrise and sunset,and reached maxima at noon.Their diurnal variation characteristics were,naturally,related to changes in solar radiation.The relationships between the record errors,global radiation,and wind speed were nonlinear.An improved correction method was proposed based on the approach described by Nakamura and Mahrt （2005） （NM05）,in which the impact of the solar zenith angle （SZA） on the temperature error is considered and extreme errors due to changes in SZA can be corrected effectively.Measurement errors were reduced significantly after correction by either method for both shields.The error reduction rate using the improved correction method for the Chinese and imported shields were 3.3％ and 40.4％ higher than those using the NM05 method,respectively.展开更多
近几个月是自从19世纪后期以来，最热的几个月．2016年7月也不例外。美国国家海洋和大气管理局（英语：National Oceanic and Atmospheric Administration。缩写为NOAA）科学家表示，全世界气温不断升高使得2016年7月成为现代历史上地...近几个月是自从19世纪后期以来，最热的几个月．2016年7月也不例外。美国国家海洋和大气管理局（英语：National Oceanic and Atmospheric Administration。缩写为NOAA）科学家表示，全世界气温不断升高使得2016年7月成为现代历史上地球最热的月份。且创下有记录的137年以来全球气温的新高点。同时也是连续第15个月打破月均温纪录的月份，创有记录的137年以来打破月均温最长的时期。展开更多
基金financially supported by the Meteorological Key Technology Integration and Application Project funded by the China Meteorological Administration (Grant No.CAMGJ2012M01)the Special Fund of Beijing Meteorological Bureau (Grant No.2011BMBKYZX04)the Nation Natural Science Foundation of China (Grant No.41275114)
文摘The variation of air temperature measurement errors using two different radiation shields （DTR502B Vaisala,Finland,and HYTFZ01,Huayun Tongda Satcom,China） was studied.Datasets were collected in the field at the Daxing weather station in Beijing from June 2011 to May 2012.Most air temperature values obtained with these two commonly used radiation shields were lower than the reference records obtained with the new Fiber Reinforced Polymers （FRP） Stevenson screen.In most cases,the air temperature errors when using the two devices were smaller on overcast and rainy days than on sunny days; and smaller when using the imported rather than the Chinese shield.The measured errors changed sharply at sunrise and sunset,and reached maxima at noon.Their diurnal variation characteristics were,naturally,related to changes in solar radiation.The relationships between the record errors,global radiation,and wind speed were nonlinear.An improved correction method was proposed based on the approach described by Nakamura and Mahrt （2005） （NM05）,in which the impact of the solar zenith angle （SZA） on the temperature error is considered and extreme errors due to changes in SZA can be corrected effectively.Measurement errors were reduced significantly after correction by either method for both shields.The error reduction rate using the improved correction method for the Chinese and imported shields were 3.3％ and 40.4％ higher than those using the NM05 method,respectively.
文摘近几个月是自从19世纪后期以来，最热的几个月．2016年7月也不例外。美国国家海洋和大气管理局（英语：National Oceanic and Atmospheric Administration。缩写为NOAA）科学家表示，全世界气温不断升高使得2016年7月成为现代历史上地球最热的月份。且创下有记录的137年以来全球气温的新高点。同时也是连续第15个月打破月均温纪录的月份，创有记录的137年以来打破月均温最长的时期。
