In this paper, solar active region (AR) 6891 is studied. The long term temporal (over a 8 day period) relationahip between vertical current evolution and flare are examined. We found that the day to day variation of t...In this paper, solar active region (AR) 6891 is studied. The long term temporal (over a 8 day period) relationahip between vertical current evolution and flare are examined. We found that the day to day variation of the flare number in the active region is more closly associated with the variation of net current intensity than that of total current intensity. The increase in negative current in the weak following polarity area is due to the reduction in negative current in the strong preceding area.展开更多
Visibility observed at different altitudes is favorable to understand the causes of air pol-lution.We conducted 4-years of observations of visibility at 2.8 and 60 m and particulate matter(PM)concentrations from 2015 ...Visibility observed at different altitudes is favorable to understand the causes of air pol-lution.We conducted 4-years of observations of visibility at 2.8 and 60 m and particulate matter(PM)concentrations from 2015 to 2018 in Shenyang,a provincial city in Northeast China.The results indicated that visibility increased with the increasing height in winter(especially at night),and decreased with height in summer(especially at the daytime).PM concentration exhibited opposite vertical variation to visibility,reflecting that visibility de-grades with the increase of aerosol concentration in the air.The radiosonde meteorological data showed that weak turbulence in the planetary boundary layer(PBL)in winter favored aerosols'accumulation near the surface.Whereas in summer,unstable atmospheric con-ditions,upper-level moister environment,and regional transport of air pollutants resulted in the deterioration of upper-level visibility.Inter-annual variation in the two-level visibility indicated that the upper-level visibility improved more significantly than low-level visibil-ity,much likely due to the reduction in emission of elevated point sources in Shenyang.Our study suggested that strengthening the control of surface non-point emissions is a promis-ing control strategy to improve Shenyang air quality.展开更多
文摘In this paper, solar active region (AR) 6891 is studied. The long term temporal (over a 8 day period) relationahip between vertical current evolution and flare are examined. We found that the day to day variation of the flare number in the active region is more closly associated with the variation of net current intensity than that of total current intensity. The increase in negative current in the weak following polarity area is due to the reduction in negative current in the strong preceding area.
基金This work was supported by the National Natural Science Foundation of China(No.41730647)the Natural Science Foundation of Liaoning Province(No.2020-MS-350)+3 种基金the Science&Technology Project of Liaoning Province(No.2019JH8/10300095)the Key Program of Science Foundation of Liaoning Meteorological Office(Nos.201904,D202101)the Basic Research Funds of Central Public Welfare Research Institutes(Nos.2018SYIAEZD4,2020SYIAEZD1)the Open Project of Shangdianzi National Atmosphere Background Station(No.SDZ2020620)
文摘Visibility observed at different altitudes is favorable to understand the causes of air pol-lution.We conducted 4-years of observations of visibility at 2.8 and 60 m and particulate matter(PM)concentrations from 2015 to 2018 in Shenyang,a provincial city in Northeast China.The results indicated that visibility increased with the increasing height in winter(especially at night),and decreased with height in summer(especially at the daytime).PM concentration exhibited opposite vertical variation to visibility,reflecting that visibility de-grades with the increase of aerosol concentration in the air.The radiosonde meteorological data showed that weak turbulence in the planetary boundary layer(PBL)in winter favored aerosols'accumulation near the surface.Whereas in summer,unstable atmospheric con-ditions,upper-level moister environment,and regional transport of air pollutants resulted in the deterioration of upper-level visibility.Inter-annual variation in the two-level visibility indicated that the upper-level visibility improved more significantly than low-level visibil-ity,much likely due to the reduction in emission of elevated point sources in Shenyang.Our study suggested that strengthening the control of surface non-point emissions is a promis-ing control strategy to improve Shenyang air quality.
