A new remote sensing method is described to determine the vertical distribution and total content of atmospheric ozone. The method combines surface infrared, satellite infrared and ultraviolet channels. The width of t...A new remote sensing method is described to determine the vertical distribution and total content of atmospheric ozone. The method combines surface infrared, satellite infrared and ultraviolet channels. The width of the infrared channels is 0.01 cm-1, less than Lorentz half-width at the earth's surface, rather than the present width, because these channels can obtain information about variations in the ozone profile below the profile main-peak. The numerical experiments show that the method has a satisfactory precision in determining total ozone content, just about I percent error, and vertical distribution from the earth to 65 km space. In addition, some semi-analysis functions lor calculating backscattered ultraviolet and a relaxation equation are described in this paper.展开更多
Results of the study of seasonal variation of total column content of aerosols in the 50—1100 m height region are presented,The columnar content of aerosols is computed by integrating the height profiles of nighttime...Results of the study of seasonal variation of total column content of aerosols in the 50—1100 m height region are presented,The columnar content of aerosols is computed by integrating the height profiles of nighttime aerosol number density estimated from the Argon ion lidar observations collected at the ⅡTM, Pune for the one year period from October 1986 to September 1987.The results of the study indicated that the aerosol content was higher during winter than during monsoon months by over 78% with an annual mean columnar aerosol content of 1.66×10~8 cm^(-2).The observed seasonal variaticn of aerosol content was found to be associated with that of surface wind,temperature,relative humidity(R.H.)and rainfall data recorded for the above one year period at the station.展开更多
Based on daily precipitation data, the spatial-temporal features of heavy rainfall events （HREs） during 1960-2009 are investigated. The results indicate that the HREs experienced strong decadal variability in the pa...Based on daily precipitation data, the spatial-temporal features of heavy rainfall events （HREs） during 1960-2009 are investigated. The results indicate that the HREs experienced strong decadal variability in the past 50 years, and the decadal features varied across regions. More HRE days are observed in the 1960s, 1980s, and 1999s over Northeast China （NEC）; in the 1960s, 1970s, and 1990s over North China （NC）; in the early 1960s, 1980s, and 2000s over the Huaihe River basin （HR）; in the 1970s 1990s over the mid-lower reaches of the Yangtze River valley （YR）; and in the 1970s and 1990s over South China （SC）. These decadal changes of HRE days in eastern China are closely associated with the decadal variations of water content and stratification stability of the local atmosphere. The intensity of HREs in each sub-region is also characterized by strong decadal variability. The HRE intensity and frequency co-vary on the long-term trend, and show consistent variability over NEC, NC, and YR, but inconsistent variability over SC and HR. Further analysis of the relationships between the annual rainfall and HRE frequency as well as intensity indicates that the HRE frequency is the major contributor to the total rainfall variability in eastern China, while the HRE intensity shows only relative weak contribution.展开更多
Daily precipitation data from 153 meteorological stations over Northwest China during summer from 1963 to 2012 were selected to analyze the spatiotemporal distribution of extreme summer precipitation frequency.The res...Daily precipitation data from 153 meteorological stations over Northwest China during summer from 1963 to 2012 were selected to analyze the spatiotemporal distribution of extreme summer precipitation frequency.The results show that the extreme precipitation frequency was regional dependent.Southern Gansu,northern Qinghai,and southern Shaanxi provinces exhibited a high extreme precipitation frequency and were prone to abrupt changes in the frequency.Northwest China was further divided into three sub-regions（northern,central,and southern） based on cluster analysis of the 50-yr extreme precipitation frequency series for each meteorological station.The extreme precipitation frequency changes were manifested in the northern region during the late 1970 s and in the central region from the end of the 1980 s to the 1990 s.The southern region fluctuated on a timescale of quasi-10 yr.This study also explored the mechanism of changes in extreme precipitation frequency.The results demonstrate that stratification stability,atmospheric water vapor content,and upward motion all affected the changes in extreme precipitation frequency.展开更多
文摘A new remote sensing method is described to determine the vertical distribution and total content of atmospheric ozone. The method combines surface infrared, satellite infrared and ultraviolet channels. The width of the infrared channels is 0.01 cm-1, less than Lorentz half-width at the earth's surface, rather than the present width, because these channels can obtain information about variations in the ozone profile below the profile main-peak. The numerical experiments show that the method has a satisfactory precision in determining total ozone content, just about I percent error, and vertical distribution from the earth to 65 km space. In addition, some semi-analysis functions lor calculating backscattered ultraviolet and a relaxation equation are described in this paper.
文摘Results of the study of seasonal variation of total column content of aerosols in the 50—1100 m height region are presented,The columnar content of aerosols is computed by integrating the height profiles of nighttime aerosol number density estimated from the Argon ion lidar observations collected at the ⅡTM, Pune for the one year period from October 1986 to September 1987.The results of the study indicated that the aerosol content was higher during winter than during monsoon months by over 78% with an annual mean columnar aerosol content of 1.66×10~8 cm^(-2).The observed seasonal variaticn of aerosol content was found to be associated with that of surface wind,temperature,relative humidity(R.H.)and rainfall data recorded for the above one year period at the station.
基金Supported by the National Science and Technology Support Program of China (2007BAC03A01)Strategic Priority Research Program on Climate Change of the Chinese Academy of Sciences (XDA05090306)+1 种基金National Basic Research and Development (973) Program of China (2012CB955401)National Natural Science Foundation of China (40905041)
文摘Based on daily precipitation data, the spatial-temporal features of heavy rainfall events （HREs） during 1960-2009 are investigated. The results indicate that the HREs experienced strong decadal variability in the past 50 years, and the decadal features varied across regions. More HRE days are observed in the 1960s, 1980s, and 1999s over Northeast China （NEC）; in the 1960s, 1970s, and 1990s over North China （NC）; in the early 1960s, 1980s, and 2000s over the Huaihe River basin （HR）; in the 1970s 1990s over the mid-lower reaches of the Yangtze River valley （YR）; and in the 1970s and 1990s over South China （SC）. These decadal changes of HRE days in eastern China are closely associated with the decadal variations of water content and stratification stability of the local atmosphere. The intensity of HREs in each sub-region is also characterized by strong decadal variability. The HRE intensity and frequency co-vary on the long-term trend, and show consistent variability over NEC, NC, and YR, but inconsistent variability over SC and HR. Further analysis of the relationships between the annual rainfall and HRE frequency as well as intensity indicates that the HRE frequency is the major contributor to the total rainfall variability in eastern China, while the HRE intensity shows only relative weak contribution.
基金Supported by the China Meteorological Administration Special Public Welfare Research Fund(GYHY201006017)National Natural Science Foundation of China(41375121 and 41305079)Scientific Research and Innovation Plan for College Graduates of Jiangsu Province of China(CXZZ13_0500 and CXZZ13_0521)
文摘Daily precipitation data from 153 meteorological stations over Northwest China during summer from 1963 to 2012 were selected to analyze the spatiotemporal distribution of extreme summer precipitation frequency.The results show that the extreme precipitation frequency was regional dependent.Southern Gansu,northern Qinghai,and southern Shaanxi provinces exhibited a high extreme precipitation frequency and were prone to abrupt changes in the frequency.Northwest China was further divided into three sub-regions（northern,central,and southern） based on cluster analysis of the 50-yr extreme precipitation frequency series for each meteorological station.The extreme precipitation frequency changes were manifested in the northern region during the late 1970 s and in the central region from the end of the 1980 s to the 1990 s.The southern region fluctuated on a timescale of quasi-10 yr.This study also explored the mechanism of changes in extreme precipitation frequency.The results demonstrate that stratification stability,atmospheric water vapor content,and upward motion all affected the changes in extreme precipitation frequency.
