Using the observational data of total solar irradiance(TSI)from 1976 to 2006,the evolution of total solar irradiance and the rela-tionship between TSI and sunspot number(SSN)have been analyzed with the wavelet technique.The results of the continuous wavelet transform(CWT)indicate that the TSI has multi-scale evolutionary characteristics.In the low frequency band,the TSI and SSN show similar variation with a significant and steady oscillation period from 8 to 11.4 a.While in the high frequency band,only around the maximum time of solar cycles,both the TSI and SSN present a significant intermittent oscillation period from 2 to 6 months.The results of the cross wavelet transform indicate that there is significant in-phase resonance oscillation between the TSI and SSN in 8-11.4 a band,where the variation of the SSN is 2 months ahead of that of TSI.Those results confirm the SSN as the primary cause for TSI's periodic variation in the time scale of 8-11.4 a.However for the 2-6 month band,significant resonance periodicity is observed only within the maximum time of solar cycle,but the phase relationship between the TSI and SSN is unsteady.Finally,a reliable TSI monthly series from 1878 to 1975 is reconstructed and tested.
Based on the atmospheric circulation data provided by ECMWF and the sea surface temperature data by NOAA, we studied the mechanism for the impact of sea surface temperature anomaly on the ridgeline surface of western Pacific using an improved high truncated spectral model. Our results show that the wave-wave interaction and the wave-mean flow interactions are weaker in the inner dynamic process of atmospheric circulation, when atmospheric circulation is forced by the sea surface temperature of El Ni-o pattern. With the external thermal forcing changed from winter to summer pattern, the range of ridgeline surface of western Pacific moving northward is smaller, which causes the ridgeline surface of western Pacific on south of normal. On the contrary, the wave-wave interaction and the wave-mean flow interaction are stronger, when atmospheric circulation is forced by the sea surface temperature of La Ni-a pattern. With the external thermal forcing turning from winter to summer pattern, the ridgeline surface of western Pacific shifts northward about 19 latitude degrees, which conduces the ridgeline surface of western Pacific on north of normal. After moving to certain latitude, the ridgeline surface of western Pacific oscillates with the most obvious 30-60 d period and the 4°-7° amplitude. It is one of the important reasons for the interannual variation of ridgeline surface of Western Pacific that the at- mospheric inner dynamical process forced out by different sea surface temperature anomaly pattern is different.
