The spatio-temporal variation of the tropopause height (TH) over the Indian region (5°N-35°N, 70°E-95°E) has been studied using monthly mean TH data, for 22-year period, 1965 to 1986. The study rev...The spatio-temporal variation of the tropopause height (TH) over the Indian region (5°N-35°N, 70°E-95°E) has been studied using monthly mean TH data, for 22-year period, 1965 to 1986. The study revealed that the stations south of 20° showed maximum TH in April / May and minimum in September. This variation in TH has been attributed to the corresponding variation of average sea surface temperature (SST) over ± 20° latitudinal belt over Indian Ocean, Arabian Sea and Bay of Bengal. Further the stations north of 20°N showed maximum in June and minimum in October/ November. This maximum in TH has primarily been attributed to the increased insolation and convection. Furthermore it is noticed that the anomaly of TH moved northwards during the period April to July.The interannual variability of the Indian Summer Monsoon Activity (ISMA) has been studied in relation to all India mean TH (at 12 GMT) for six months April through September. The composites of mean TH for good and bad monsoon years showed that all India mean TH is statistically higher in good monsoon years than in bad monsoon years. The relationship between ISMA and all India mean May TH has been studied using the contingency table. The study suggested that the forecast of ISMA could be prepared using mean May TH.展开更多
The atmospheric ozone in East Asia has been studied with satellite remote sensing. The relationship between atmospheric ozone and tropopause height is analyzed and its response to weather processes has been discussed....The atmospheric ozone in East Asia has been studied with satellite remote sensing. The relationship between atmospheric ozone and tropopause height is analyzed and its response to weather processes has been discussed. The mean deviation between the total atmospheric ozone content derived from TOVS data and that got from ground-based Dobson spectrophotometer observation is 3.67%. The total atmospheric ozone content increases with the latitude increasing in East Asia. The correlation coefficient between total ozone content and tropopause height is negative. The average is 74%. The total atmospheric ozone content is closely related to weather processes. Ozone content increases while arctic air mass invading and decreases while tropic air mass coming.展开更多
Trend uncertainty in the ozone valley over the Tibetan Plateau(OVTP)and the South Asian high(SAH)during1979–2009 in ERA-Interim(interim reanalysis data from the ECMWF),JRA-55(55-yr reanalysis data from the Jap...Trend uncertainty in the ozone valley over the Tibetan Plateau(OVTP)and the South Asian high(SAH)during1979–2009 in ERA-Interim(interim reanalysis data from the ECMWF),JRA-55(55-yr reanalysis data from the Japan Meteorological Agency),and NCEP-CFSR(Climate Forecast System Reanalysis)datasets was evaluated.The results showed that the NCEP-CFSR OVTP became strong in the summers of 1979–2009,whereas it became weak according to ERA-Interim and JRA-55.Satellite data merged with TOMS(Total Ozone Mapping Spectrometer)and OMI(Ozone Monitoring Instrument)agreed with the OVTP trend of NCEP-CFSR.The OVTP strengthening in NCEP-CFSR may have been caused by SAH intensification,a rising tropopause,and increasing ozone over non-TP(non-Tibetan Plateau)areas(27°–37°N,〈75°E and〉105°E).Analogously,the OVTP weakening in ERA-Interim and JRA-55 may have been affected by weakening SAH,descending tropopause,and decreasing non-TP ozone.展开更多
文摘The spatio-temporal variation of the tropopause height (TH) over the Indian region (5°N-35°N, 70°E-95°E) has been studied using monthly mean TH data, for 22-year period, 1965 to 1986. The study revealed that the stations south of 20° showed maximum TH in April / May and minimum in September. This variation in TH has been attributed to the corresponding variation of average sea surface temperature (SST) over ± 20° latitudinal belt over Indian Ocean, Arabian Sea and Bay of Bengal. Further the stations north of 20°N showed maximum in June and minimum in October/ November. This maximum in TH has primarily been attributed to the increased insolation and convection. Furthermore it is noticed that the anomaly of TH moved northwards during the period April to July.The interannual variability of the Indian Summer Monsoon Activity (ISMA) has been studied in relation to all India mean TH (at 12 GMT) for six months April through September. The composites of mean TH for good and bad monsoon years showed that all India mean TH is statistically higher in good monsoon years than in bad monsoon years. The relationship between ISMA and all India mean May TH has been studied using the contingency table. The study suggested that the forecast of ISMA could be prepared using mean May TH.
文摘The atmospheric ozone in East Asia has been studied with satellite remote sensing. The relationship between atmospheric ozone and tropopause height is analyzed and its response to weather processes has been discussed. The mean deviation between the total atmospheric ozone content derived from TOVS data and that got from ground-based Dobson spectrophotometer observation is 3.67%. The total atmospheric ozone content increases with the latitude increasing in East Asia. The correlation coefficient between total ozone content and tropopause height is negative. The average is 74%. The total atmospheric ozone content is closely related to weather processes. Ozone content increases while arctic air mass invading and decreases while tropic air mass coming.
基金Supported by the National Natural Science Foundation of China(41305039,41675039,91537213,41375047,41375092,41475140,41641042,and 41575057)Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)
文摘Trend uncertainty in the ozone valley over the Tibetan Plateau(OVTP)and the South Asian high(SAH)during1979–2009 in ERA-Interim(interim reanalysis data from the ECMWF),JRA-55(55-yr reanalysis data from the Japan Meteorological Agency),and NCEP-CFSR(Climate Forecast System Reanalysis)datasets was evaluated.The results showed that the NCEP-CFSR OVTP became strong in the summers of 1979–2009,whereas it became weak according to ERA-Interim and JRA-55.Satellite data merged with TOMS(Total Ozone Mapping Spectrometer)and OMI(Ozone Monitoring Instrument)agreed with the OVTP trend of NCEP-CFSR.The OVTP strengthening in NCEP-CFSR may have been caused by SAH intensification,a rising tropopause,and increasing ozone over non-TP(non-Tibetan Plateau)areas(27°–37°N,〈75°E and〉105°E).Analogously,the OVTP weakening in ERA-Interim and JRA-55 may have been affected by weakening SAH,descending tropopause,and decreasing non-TP ozone.