Modulation of galactic cosmic rays in the declining phase of solar cycles 22 and 23: COSPIN/KET observations

Details Modulation of galactic cosmic rays in the declining phase of solar cycles 22 and 23: COSPIN/KET observations Modulation of galactic cosmic rays in the declining phase of solar cycles 22 and 23: COSPIN/KET observations

Apr 2003

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2003eaeja.....9127h&link_type=abstract

EGS - AGU - EUG Joint Assembly, Abstracts from the meeting held in Nice, France, 6 - 11 April 2003, abstract #9127

Computer Science

Scientific paper

Ulysses was launched in October 1990 during the maximum/declining phase of solar cycle 22. Because of its unique trajectory (almost perpendicular to the ecliptic) and instrumentation, it provides crucial observations to understand the propagation of charged particles in the inner heliosphere. When comparing the spacecraft orbital period of 6.2 years with the 11 years of the solar sunspot cycle, it is evident, that the present heliospheric conditions are similar to those, when Ulysses began its first out-of-ecliptic orbit. The crucial difference is that the heliospheric magnetic field has reversed its polarity from an A>0 to an A<0 solar magnetic epoch. Galactic cosmic rays undergo drifts. These drift patterns depend also on the polarity of the heliospheric magnetic field, leading to positive and negative latitudinal gradients in an A>0 and A<0 solar magnetic epoch, respectively. The electron to proton ratio at solar maximum in 2000/2001 had practically the same value as in the previous solar maximum. With the reversal of the solar magnetic field and in the declining phase of the solar cycle this ratio should increase. This was, however, only observed from mid 2002 on, probably because the solar wind carrying the new reversed polarity first has to fill major parts of the heliosphere in order for us to see this effect.Results of a time-dependent modulation model will be shown and discussed in an accompanying paper. In contrast to high energy galactic cosmic rays, MeV electrons do not experience large drifts. Since Jupiter is a strong source of MeV electrons and with Ulysses, approaching Jupiter from northern polar latitudes, MeV electron measurements are a useful tool to understand particle diffusion. A comparison of in-ecliptic and out-of-ecliptic data will be performed.

Affiliated with

Also associated with

No associations

Rating

Modulation of galactic cosmic rays in the declining phase of solar cycles 22 and 23: COSPIN/KET observations does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Modulation of galactic cosmic rays in the declining phase of solar cycles 22 and 23: COSPIN/KET observations, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Modulation of galactic cosmic rays in the declining phase of solar cycles 22 and 23: COSPIN/KET observations will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-844710