MAGNETIC-FIELDS AND COSMIC-RAYS IN THE DISTANT HELIOSPHERE AT SOLAR MAXIMUM - VOYAGER-2 OBSERVATIONS NEAR 32-AU DURING 1990

The intensity of >70 MeV cosmic ray protons observed during solar cycl e 22 by Voyager 2 (V2) in the distant heliosphere reached a minimum in 1990, corresponding to the maximum of solar activity in mid-1989 (all owing for the propagation time of the solar wind from the sun to Voyag er 2 near 32 AU). A step decrease in the cosmic ray intensity observed within the first approximate to 125 days of 1990 was caused by a glob al merged interaction region (GMIR), consisting of a cluster of large- amplitude magnetic field strength fluctuations, in which the field was predominantly stronger than average. The step decrease consists of fo ur events in each of which the decrease in cosmic ray intensity is rel atively large, and the recovery is either brief or absent. The relatio n between the cosmic ray intensity and the magnetic field strength obs erved near 32 AU during this period at the maximum of solar activity i n 1989/1990 is similar to that which Voyager 2 observed near 11 AU in 1982/1983 following the maximum of solar activity in the previous sola r cycle in 1980. The local changes in the cosmic ray intensity profile are related to the magnetic field strength. Near solar maximum the em ission rate of ejecta, which contain magnetic fields that deviate sign ificantly from the spiral direction, is a maximum. Nevertheless, the d istribution of elevation angles of the magnetic field observed by Voya ger 2 during 1990 is essentially the same as that observed during earl ier parts of the solar cycle from 1986 through 1989, including solar m inimum in 1986 and 1987. During 1990, the width of the distribution of elevation angles at approximate to 32 AU was the same as that observe d at 1 AU. Sectors were observed, but no sector structure was present during 1990, just as in 1988, 1989, and 1991. The distribution of dail y averages of the magnetic field strength is lognormal for 0.05 nT < B < 0.25 nT. However there are more strong magnetic fields than the log normal distribution predicts for 0.25 nT < B < 0.4 nT, owing to the la rge MIRs. The large-scale fluctuations of the magnetic field strength have a multifractal structure in the low-frequency range from 2.7 days to at least 21.3 days that influences the cosmic ray intensity profil e.