The Homogeneity Test And Adjustment To Chinese Radiosonde Data Of Temperature And Height For The Last 60 Years

Global warming is a hot topic worldwide. The fact of global warming attracts scientists to pay more attention to the homogeneity of meteorological data series recently. The reason for this is that the research of climate change is base on the climatic data series which reflect the truly climate change.As to the test of long-term climate change of China, there are a lot of questions about the homogeneity and reliability of the date. Acutally, the homogeneous time series are the series which only result from weather and climate change. But in the long process of climate change, factors such as station relocation, instrument changes, algorithm changes, and changes in observation time would lead the discontinuity problems in the climate data series.This paper is a part of job done by author in the 973 project of China Meteorological Administration. The title of the 973 project is the subject of the homogeneity test and adjustment to Chinese radiosonde data of temperature for the last 60 years. By the means of PMT and PMF, the rediosonde data of temperature and height of china is tested and adjusted for the late 60 years in this paper. The detail of research content is as follows:1. Throught the case analysis, the effect of test and adjustment is illustrated. The main reasons which lead to the inhomogeneity in radiosonde data of temperature and height in isobaric surface, numerical features of discontinuity point in regulation layers et.al are analyzed.2. The average revision amplitude of radioson data of temperature and height in different air pressure layers is calculated.3. The homogeneous time series of radiosonde data of temperature and height are constructed for the last 60 years, and trend of original temperate and height series are adjusted at the level of the botton of torosphate, middle and upper of torosphare, and the botton of stratosphare.The main conclusions could be summaried as follows:1. The main reasons lead to inhomegeneity of temperate series is instruments changes and radiation correction. The number of discontinuity number fluctuates at different pressure layer. With the height increase, the correction amplitude generally increases, the average temperature series drops 0.33℃at 00 time and the average temperature series drops 0.42℃at 12 time after adjusting.In addition, the temperature trend at the bottom of stratosphere increase 0.165℃/10a, the temperature trend of tropospere reduce 0.085℃/10a, and the middle and bottom layer of troposphere increase 0.0840℃/10a after adjusting.2. The main reasons which lead to inhomegeneity of height series is instruments changes and radiation correction. The impact of the change of observeation time is not obvious. With the height increase, the number of discontinuity and the correction amplitude generally increases. The average height series drops 11.35m at 00 time and the average height series drop15.20m at 12 time after adjusting.The height trends at the bottom of stratosphere increase 10.377m/10a, the temperature trends at the top of tropopause reduce 4.378m/10a, and the middle and bottom layer of troposphere increase 2.678m/10a after adjusting.