The Operational Complex Quality Control of Radiosonde Heights and Temperatures at the National Centers for Environmental Prediction. Part II: Examples of Error Diagnosis and Correction from Operational Use

The method of complex quality control of radiosonde heights and temperatures (CQCHT) has been under continuous development and improvement at the National Centers for Environmental Prediction since 1988. Part I of this paper gives the background for the method and details for the currently operational version of the code, which contains significant improvements over previous versions. Part II shows a number of interesting examples of operation of the algorithm and gives statistics on its performance during the first year of operation, September 1997 through August 1998. In a few examples, it is seen how even complicated errors may be corrected. The statistics show that of the 5700 hydrostatically detected errors each month, 77% were corrected. There is a great variation in the geographical distribution of errors, but it is found that a majority of all stations have at least one hydrostatically suspected error during a month’s time. In addition to hydrostatically detected errors, the CQCHT detects almost 16 000 so-called observation errors in height and temperature each month.