Lo que pasa es que al final pues ese mes entero sin manchas, con ultimo precedente en 1913, ya no es así.
Pero es curioso como mínimo, si miramos en el archivo del SIDC, el ISN para los días 21 y 22 de agosto es 0 en ambos casos, y en cambio a final de mes nos dan otra cosa.
Os copio lo que pone en el archivo para el 21 y 22:
:Issued: 2008 Aug 21 1224 UTC
:Product: documentation at
http://www.sidc.be/products/meu#--------------------------------------------------------------------#
# DAILY BULLETIN ON SOLAR AND GEOMAGNETIC ACTIVITY from the SIDC #
# (RWC Belgium) #
#--------------------------------------------------------------------#
SIDC URSIGRAM 80821
SIDC SOLAR BULLETIN 21 Aug 2008, 1218UT
SIDC FORECAST (valid from 1230UT, 21 Aug 2008 until 23 Aug 2008)
SOLAR FLARES : Quiet conditions (<50% probability of C-class flares)
GEOMAGNETISM : Quiet (A<20 and K<4)
SOLAR PROTONS : Quiet
PREDICTIONS FOR 21 Aug 2008 10CM FLUX: 066 / AP: 003
PREDICTIONS FOR 22 Aug 2008 10CM FLUX: 067 / AP: 002
PREDICTIONS FOR 23 Aug 2008 10CM FLUX: 066 / AP: 002
COMMENT: The only sunspot group on the solar disk (Catania number 84,
no NOAA number yet) is small and weak, so it is unlikely to produce a
C-flare. The Earth is currently inside the slow (around 400 km/s) solar
wind flow with average (around 4 nT) magnitude of the interplanetary
magnetic field. We expect quiet geomagnetic conditions.
TODAY'S ESTIMATED ISN : 000, BASED ON 10 STATIONS.
:Issued: 2008 Aug 22 1238 UTC
:Product: documentation at
http://www.sidc.be/products/meu#--------------------------------------------------------------------#
# DAILY BULLETIN ON SOLAR AND GEOMAGNETIC ACTIVITY from the SIDC #
# (RWC Belgium) #
#--------------------------------------------------------------------#
SIDC URSIGRAM 80822
SIDC SOLAR BULLETIN 22 Aug 2008, 1209UT
SIDC FORECAST (valid from 1230UT, 22 Aug 2008 until 24 Aug 2008)
SOLAR FLARES : Quiet conditions (<50% probability of C-class flares)
GEOMAGNETISM : Quiet (A<20 and K<4)
SOLAR PROTONS : Quiet
PREDICTIONS FOR 22 Aug 2008 10CM FLUX: 066 / AP: 004
PREDICTIONS FOR 23 Aug 2008 10CM FLUX: 067 / AP: 002
PREDICTIONS FOR 24 Aug 2008 10CM FLUX: 066 / AP: 003
COMMENT: The only sunspot group on the solar disc (Catania number 84,
no NOAA number) is too small to produce a C-flare. The Earth is inside
the slow (around 370 km/s) solar wind flow with average values of the
interplanetary magnetic field magnitude (4-5 nT). We expect quiet
geomagnetic conditions.
TODAY'S ESTIMATED ISN : 000, BASED ON 07 STATIONS.
Podeis verlo vosotros mismos aqui:
http://sidc.oma.be/html/SWAPP/dailyreport/dailyreport.html