Publication Date:
2019-06-28
Description:
Voyager 1 and 2 measurements of galactic cosmic ray proton gradients greater than 70 MeV over a period which coincides with the initial phase of cosmic ray recovery, following a minimum reached in late 1980-early 1981, are analyzed. The intensity difference between the two spacecraft, as they increase their heliolatitude separation from 3 to 16 deg, is consistent with either a positive radial gradient of about 2 percent/AU assuming zero heliolatitude gradient, or a small heliolatitude gradient of about 0.4 percent/degree, assuming zero helioradial gradient. If the radial gradient during the 1981-1982 recovery period remains at the 2-4 percent/AU level determined from multispacecraft measurements during the 1977-1980 decay period, then the heliolatitude gradient is negligible and may be accounted zero percent/deg over 16 deg heliolatitude separation in 8-13 AU.
Keywords:
SPACE RADIATION
Type:
Astrophysical Journal, Part 2 - Letters to the Editor (ISSN 0004-637X); 278; L119-L12
Format:
text
