  From 1998 to 2003 the CCD Solar Astrolabe of the Observatorio Nacional in Rio
de Janeiro made more than 20000 observations of the Solar Semidiameter. In the
present work similar corrections for the observational results of 2002 and 2003
were determined. Initially, the values have been corrected in function of their
mean quadratic offset to the local trend averages, therefore without modifying
the measured variations. Finally, the values have been corrected for the bias,
using coefficients obtained from the correlation between some observational
parameters and the observational measures.
  Then the total series was compared with series of pointers of the solar
activity. The hypothesis of variation of the semidiameter tied to the solar
activity was examined through the correlations between the different pairs of
pointers. Strong correlations between some pairs were obtained. Next, the same
correlations were obtained now considering time delays of one series in
relation to the other. Several pairs have shown an increase on the correlation,
indicating the presence of a significant phase shift between them. For the pair
solar semidiameter and irradiance the mode of the phase for maximum correlation
was calculated for two distinct cases: either for the complete series of data,
or leaving off the data relative to the epochs of the two summits of the solar
activity cycle. The comparison shows that the solar semidiameter responds
closely to variations of irradiance in the conditions where the peaks of
activity are considered; inversely, it precedes the variations of irradiance,
by at least one hundred days, when the peak values are discarded, thus
indicating the existence of two distinct regimes.
  We also studied how the semidiameter of the Sun varies throughout its
latitudes. It was noted that each band of latitude has a different response,
even so there is a global variation in time.
