In this study, the relationship between major meteorological factors and tobacco chemical components in different altitudes of Yongde County, Lincang Region of Yunnan Province was studied using correlation analysis an...In this study, the relationship between major meteorological factors and tobacco chemical components in different altitudes of Yongde County, Lincang Region of Yunnan Province was studied using correlation analysis and path analysis methods.The results showed that there was a difference on meteorological factors in different altitudes, causing different impacts on chemical components of flue-cured tobacco; contents of nicotine and total nitrogen decreased with the rising of altitude, conversely, total sugar and reducing sugar contents increased with the rising trend of altitude, and the differences on the contents of potassium （K） and chlorine（CI）, and the ratio of K to CI in different altitudes were not significant, at the altitude of 1 250-1 450 m, each chemical component indicator was better. The correlation between main meteorological factors and conventional chemical components of tobacco leaves was as follows： contents of reducing sugar and total sugar increased with the increase of rainfall and relative humidity, and decreased with the increase of sunshine duration; nicotine content increased with the increase of accumulated temperature and sunshine duration; total nitrogen （N） content increased with the increase of daily mean temperature and accumulated temperature; sugar-alkali ratio increased with the increase of rainfall. Path analysis showed that the direct effect of sunshine duration on reducing sugar and total sugar of tobacco leaves was faint, but the indirect effect was obvious; meanwhile, the direct and indirect effects of it on nicotine and total N were the greatest.展开更多
The work is a general survey using SSTA data of the Indian Ocean and of precipitation at 160Chinese weather stations over 1951～1997 (47 years). It reveals that the dipole oscillation of SST, especially the dipole ind...The work is a general survey using SSTA data of the Indian Ocean and of precipitation at 160Chinese weather stations over 1951～1997 (47 years). It reveals that the dipole oscillation of SST, especially the dipole index of March～May, in the eastern and western parts of the ocean correlates well with the precipitation during the June～August raining season in China. As shown in analysis of 500-hPa Northern Hemisphere geopotential height height by NCEP for 1958～1995, the Indian Ocean dipole index (IODI) is closely related with geopotential height anomalies in the middle- and higher- latitudes in the Eurasian region. As a negative phase year of IODI corresponds to significant Pacific-Japan (P J) wavetrain, it is highly likely that the SST for the dipole may affect the precipitation in China through the wavetrain. Additionally, correlation analysis of links between SST dipole index of the Indian Ocean region and air temperature in China also shows good correlation between the former and wintertime temperature in southern China.展开更多
The Huang-Huai-Hai Plain is one of the typical agri-ecosystems in China,which suffers from cold damage frequently resulting in substantial economic losses.In order to monitor the changes in the occurrence of cold dama...The Huang-Huai-Hai Plain is one of the typical agri-ecosystems in China,which suffers from cold damage frequently resulting in substantial economic losses.In order to monitor the changes in the occurrence of cold damage in an effective and large-scale manner,and to determine their meteorological causes,this paper collected low temperature data from the agricultural meteorological stations and remote sensing data of MODIS from 2005 to 2015,and constructed a monitoring model of cold damage to winter wheat in Huang-Huai-Hai Plain based on the Logistic regression model.This model was used to analyze the spatio-temporal changes of cold damage of winter wheat in Huang-Huai-Hai Plain from 2011 to 2020,and correlation analysis was performed with the spatio-temporal changes of meteorological factors to ascertain how they affect cold damage.The results show that the harm from cold damage in winter wheat has been gradually decreasing from 2011 to 2020,and the cold damage areas with high probability and high frequency are moving from north to south.The meteorological elements with the greatest impacts on the degree of cold damage from stronger to weaker are heat,precipitation and sunshine duration,whose influence has spatial variability.展开更多
文摘In this study, the relationship between major meteorological factors and tobacco chemical components in different altitudes of Yongde County, Lincang Region of Yunnan Province was studied using correlation analysis and path analysis methods.The results showed that there was a difference on meteorological factors in different altitudes, causing different impacts on chemical components of flue-cured tobacco; contents of nicotine and total nitrogen decreased with the rising of altitude, conversely, total sugar and reducing sugar contents increased with the rising trend of altitude, and the differences on the contents of potassium （K） and chlorine（CI）, and the ratio of K to CI in different altitudes were not significant, at the altitude of 1 250-1 450 m, each chemical component indicator was better. The correlation between main meteorological factors and conventional chemical components of tobacco leaves was as follows： contents of reducing sugar and total sugar increased with the increase of rainfall and relative humidity, and decreased with the increase of sunshine duration; nicotine content increased with the increase of accumulated temperature and sunshine duration; total nitrogen （N） content increased with the increase of daily mean temperature and accumulated temperature; sugar-alkali ratio increased with the increase of rainfall. Path analysis showed that the direct effect of sunshine duration on reducing sugar and total sugar of tobacco leaves was faint, but the indirect effect was obvious; meanwhile, the direct and indirect effects of it on nicotine and total N were the greatest.
基金Research on the Mechanism and Prediction of Major Climatic Calamities in China a national key program for developing basic science (G199804090303) Science Foundation of Yunnan (97D022G)
文摘The work is a general survey using SSTA data of the Indian Ocean and of precipitation at 160Chinese weather stations over 1951～1997 (47 years). It reveals that the dipole oscillation of SST, especially the dipole index of March～May, in the eastern and western parts of the ocean correlates well with the precipitation during the June～August raining season in China. As shown in analysis of 500-hPa Northern Hemisphere geopotential height height by NCEP for 1958～1995, the Indian Ocean dipole index (IODI) is closely related with geopotential height anomalies in the middle- and higher- latitudes in the Eurasian region. As a negative phase year of IODI corresponds to significant Pacific-Japan (P J) wavetrain, it is highly likely that the SST for the dipole may affect the precipitation in China through the wavetrain. Additionally, correlation analysis of links between SST dipole index of the Indian Ocean region and air temperature in China also shows good correlation between the former and wintertime temperature in southern China.
基金The National Key Research and Development Program of China(2017YD0300403)。
文摘The Huang-Huai-Hai Plain is one of the typical agri-ecosystems in China,which suffers from cold damage frequently resulting in substantial economic losses.In order to monitor the changes in the occurrence of cold damage in an effective and large-scale manner,and to determine their meteorological causes,this paper collected low temperature data from the agricultural meteorological stations and remote sensing data of MODIS from 2005 to 2015,and constructed a monitoring model of cold damage to winter wheat in Huang-Huai-Hai Plain based on the Logistic regression model.This model was used to analyze the spatio-temporal changes of cold damage of winter wheat in Huang-Huai-Hai Plain from 2011 to 2020,and correlation analysis was performed with the spatio-temporal changes of meteorological factors to ascertain how they affect cold damage.The results show that the harm from cold damage in winter wheat has been gradually decreasing from 2011 to 2020,and the cold damage areas with high probability and high frequency are moving from north to south.The meteorological elements with the greatest impacts on the degree of cold damage from stronger to weaker are heat,precipitation and sunshine duration,whose influence has spatial variability.
