An update regarding Auroral Activity, Hemispheric Power 
Estimates,from NOAA-19 and NOAA-16

  Comparisons between hemispheric power estimates obtained from NOAA-15, NOAA-17, NOAA-18
and MetOp-02 instruments and the provisional estimates from the NOAA-19 instrument after
6 months operation indicate the provisional NOAA-19 inter-satellite normalization factor
that has been used should be increased by 30% to bring the NOAA-19 estimates into agreement
with those from the earlier satellites.  As of September 23, 2009 the NOAA-19 processing
has been updated with the new factor and all prior NOAA-19 hemispheric power estimates
beginning February 25, 2009 through the present date have been corrected and the updated
data placed in the power_2009.txt file on the ftp site.  Users may wish to update their
databases with the modified NOAA-19 hemispheric power estimates.

  Hemispheric power estimates from the NOAA-16 instrument should be treated with caution
because that instrument has lost significant sensitivity since 2006 and currently is
producing hemispheric power estimates that are typically only about 65% of those 
returned from instruments on the other satellites.