In this study, the relationship between the neutral components （N2 and 02） in the E-region of the ionosphere （at 110 km altitude） for the Singapore （01.23 N; 103.55 E） station in the equatorial region and the FI...In this study, the relationship between the neutral components （N2 and 02） in the E-region of the ionosphere （at 110 km altitude） for the Singapore （01.23 N; 103.55 E） station in the equatorial region and the FI0.7 solar flux and z-component of Interplanetary Magnetic Field （IMF-Bz） was investigated. This relationship was determined by means of statistical multiple regression model. As a result, it was observed that the changes in F10.7 solar flux and IMF-Bz were inversely proportional to the changes in N2 and 02. 92% and 83% of changes in N2 and O2 were found to be explained by F10.7 solar flux and IMF-Bz, respectively. When the F10.7 solar flux is changed by 1 s.f.u., it causes a decrease of 2.61×10TM m-3 in N2 and 2.96×1014 m-3 in O2. Change of I nT in IMF-Bz causes a decrease of 9.95× 1015 m-3 in N2 and 1.69× 1015 m-3 in O2.展开更多
A range of analysis approaches,namely continuous wavelet,cross wavelet,and wavelet coherence analyses,are employed to clarify the phase relationship between the smoothed monthly mean sunspot number and solar 10.7 cm f...A range of analysis approaches,namely continuous wavelet,cross wavelet,and wavelet coherence analyses,are employed to clarify the phase relationship between the smoothed monthly mean sunspot number and solar 10.7 cm flux(F10.7).Analysis shows that there is a region of high spectral power sitting across the Schwabe cycle belt,where the two time series are in phase.However,analysis of the cross-wavelet transform and wavelet coherence unveils asynchronous behavior featured with phase mixing in the high-frequency components of sunspot activity and solar F10.7,which may explain the different activity properties of the photosphere and corona on a short time scale.展开更多
In order to uncover a possible influence on the Earth's climate, we need a much longer time series, i.e., the total solar irradiance (TSI) which is also an interesting issue in its own right in solar physics. By c...In order to uncover a possible influence on the Earth's climate, we need a much longer time series, i.e., the total solar irradiance (TSI) which is also an interesting issue in its own right in solar physics. By comparing different solar indices associated with TSI during the period 1979 to 2009, several empirical models in the TSI are presented. We verify that the reconstruction model based on the three variables: sunspot number, sunspot area, and solar 10.7 cm radio flux, is the best one. As demonstrated by model calculations, the history of TSI was reconstructed back to 1947 based on 3-indices and to 1874 based on 2-indices, respectively. The reason that the reduced irradiance on the trough during 2006 to 2009 lasts long may be due to the about 85-year cycle of solar activity, which modulates the intensity of the 11-year cycle (Schwabe cycles), possesses a considerable potential to produce an effective reducing, and holds on a steadily lower level of irradiance.展开更多
文摘In this study, the relationship between the neutral components （N2 and 02） in the E-region of the ionosphere （at 110 km altitude） for the Singapore （01.23 N; 103.55 E） station in the equatorial region and the FI0.7 solar flux and z-component of Interplanetary Magnetic Field （IMF-Bz） was investigated. This relationship was determined by means of statistical multiple regression model. As a result, it was observed that the changes in F10.7 solar flux and IMF-Bz were inversely proportional to the changes in N2 and 02. 92% and 83% of changes in N2 and O2 were found to be explained by F10.7 solar flux and IMF-Bz, respectively. When the F10.7 solar flux is changed by 1 s.f.u., it causes a decrease of 2.61×10TM m-3 in N2 and 2.96×1014 m-3 in O2. Change of I nT in IMF-Bz causes a decrease of 9.95× 1015 m-3 in N2 and 1.69× 1015 m-3 in O2.
基金supported by the National Natural Science Foundation of China(41074132,40931056)the Foundation for Standout Youth of Anhui Province(2010SQRL039)
文摘A range of analysis approaches,namely continuous wavelet,cross wavelet,and wavelet coherence analyses,are employed to clarify the phase relationship between the smoothed monthly mean sunspot number and solar 10.7 cm flux(F10.7).Analysis shows that there is a region of high spectral power sitting across the Schwabe cycle belt,where the two time series are in phase.However,analysis of the cross-wavelet transform and wavelet coherence unveils asynchronous behavior featured with phase mixing in the high-frequency components of sunspot activity and solar F10.7,which may explain the different activity properties of the photosphere and corona on a short time scale.
基金supported by the National Natural Science Foundation of China (Grant No. 10978007)the Excellent Scientists Training Program of Beijing
文摘In order to uncover a possible influence on the Earth's climate, we need a much longer time series, i.e., the total solar irradiance (TSI) which is also an interesting issue in its own right in solar physics. By comparing different solar indices associated with TSI during the period 1979 to 2009, several empirical models in the TSI are presented. We verify that the reconstruction model based on the three variables: sunspot number, sunspot area, and solar 10.7 cm radio flux, is the best one. As demonstrated by model calculations, the history of TSI was reconstructed back to 1947 based on 3-indices and to 1874 based on 2-indices, respectively. The reason that the reduced irradiance on the trough during 2006 to 2009 lasts long may be due to the about 85-year cycle of solar activity, which modulates the intensity of the 11-year cycle (Schwabe cycles), possesses a considerable potential to produce an effective reducing, and holds on a steadily lower level of irradiance.
