摘要
Temperature and relative humidity profiles derived from two China-made global positioning system（GPS） radiosondes（GPS-TK and CF-06-A） during the east tropical Indian Ocean（ETIO） experiment were compared with Vaisala RS92-SGP to assess the performances of China-made radiosondes over the tropical ocean.The results show that there have relative large biases in temperature observations between the GPSTK and the RS92-SGP in the low troposphere,with a warm bias of greater than 2 K in the day and a cooling bias of 0.6 K at night.The temperature differences of the CF-06-A were small in the troposphere both in daytime and nighttime,and became large peak-to-peak fluctuations in the stratosphere.The intercomparison of the relative humidity showed that the CF-06-A had large random errors due to the limitation of sensors and the lack of correction scheme,and the GPS-TK had large systematic biases in the low troposphere which might be related to the temperature impact.GPS height measurements are clearly suitable for China-made radiosonde systems operation.At night,the CF-06-A and the GPS-TK could provide virtual potential temperature and atmospheric boundary layer height measurements of suitable quality for both weather and climate research.As a result of the intercomparison experiment,major errors in the Chinamade radiosonde systems were well indentified and subsequently rectified to ensure improving accuracy for historical and future radiosondes.
Temperature and relative humidity profiles derived from two China-made global positioning system（GPS） radiosondes（GPS-TK and CF-06-A） during the east tropical Indian Ocean（ETIO） experiment were compared with Vaisala RS92-SGP to assess the performances of China-made radiosondes over the tropical ocean.The results show that there have relative large biases in temperature observations between the GPSTK and the RS92-SGP in the low troposphere,with a warm bias of greater than 2 K in the day and a cooling bias of 0.6 K at night.The temperature differences of the CF-06-A were small in the troposphere both in daytime and nighttime,and became large peak-to-peak fluctuations in the stratosphere.The intercomparison of the relative humidity showed that the CF-06-A had large random errors due to the limitation of sensors and the lack of correction scheme,and the GPS-TK had large systematic biases in the low troposphere which might be related to the temperature impact.GPS height measurements are clearly suitable for China-made radiosonde systems operation.At night,the CF-06-A and the GPS-TK could provide virtual potential temperature and atmospheric boundary layer height measurements of suitable quality for both weather and climate research.As a result of the intercomparison experiment,major errors in the Chinamade radiosonde systems were well indentified and subsequently rectified to ensure improving accuracy for historical and future radiosondes.
基金
The National Basic Research Program(973 Program)of China under contract Nos 2011CB403503 and 2011CB403504
the National Natural Science Foundation of China under contract No.41276024
the Major Program of the National Natural Science Foundation of China under contract No.91228202
the National Foundation of the Indian Ocean Opening Voyage Project of China under contract Nos 41149903 and 41049908
