Solar activity excites the 50-day oscillation of the Earth 
             rotation and atmospheric angular momentum

                      Li Zhian  Lin Qiao
         (Department of Astronomy, Beijing Normal University)

                             Abstract

The physical origin of the 50-day oscillation of the earth rotation 
and the atmospheric angular momentum  was detected by D.Djurovic 
and P.Paquet.  In this work, analysed 4 data series, that composed 
of the length of day (LOD), atmos "
pheric angular momentum (AAM), the 
daily solar flux of 2800MHz (SF) and relative sunspot numbers (SN)
(1980-1994). The results show that the variable curves of the 50-day 
oscillation are very similar and that the range of the variable periods 
is between 40d to 55d. It merits attention that the variations of 50-day  
fluctuation of the solar activity are before that of LOD and AAM, and 
that the El Nino events of the equatorial  eastern Pacific happened 
while the variant periods of the 50-day  of  "
solar activity were reached 
the minimum values in the periods 1982, 1987 and 1991. From the results, 
it follows that the solar activity is perhaps an excitation that leads 
to the 50-day fluctuation of LOD, AAM and El Nino event.