SOHO/Solar Wind Anisotropies (SWAN) Data Archive

The SWAN (Solar Wind ANisotropies) instrument is one of twelve
instruments onboard SOHO (SOlar Heliospheric Observatory)
satellite. It is a collaboration between Finnish Meteorological
Institute and Service d'Aeronomie. Technical Research Centre of
Finland was responsible for the construction, mechanics, thermal
design, and central processor of the instrument itself.

A solar Lyman alpha radiation is scattered by hydrogen atoms, which
flow into the solar system. The scattered radiation is called
interplanetary Lyman alpha radiation. SWAN observes interplanetary
Lyman alpha radiation from all directions of the sky. Usually SWAN
observes three radiation maps of the whole sky per week. In each map
the radiation is strongest near the inflow direction of the
interstellar hydrogen gas. However, the overall picture of the sky has
changed considerably from the solar minimum 1996 to the solar
maximum. Theoretical results have shown that this kind of a change can
be caused by the solar wind proton flux which varies according to the
distance to the heliospheric current sheet.

All SOHO/CDS data are available from the public SOHO data archive:
http://sohowww.nascom.nasa.gov/data/archive.html

Mirror archives are available at:
SOHO Archive at Rutherford Appleton Laboratory, UK.:
http://trace.solararchive.rl.ac.uk/soho/

SOHO Archive at the Institut d'Astrophysique Spatiale, France:
http://idc-medoc.ias.u-psud.fr/

SOHO Archive at Osservatorio Astronomico di Torino, Torino, Italy:
http://solar.to.astro.it/