Statistical analysis of the pitch angle distribution of magnetospheric Solar protons during geomagnetic activity

Main Article Content

M. Scholer
G. Morfill
D. Hovestadt


The pitch angle distributions of energetic Solar protons in the pseudo-trapping region were used in order to examine magnetospheric processes. Temporal and spatial variations of these processes should give insight into the magnetospheric dynamics. Data from two instruments (viewing angle perpendicular and 45° with respect to the local geomagnetic field) on board the low altitude polar orbiting satellite GRS/Azur give a rough measure of the pitch angle distribution of energetic Solar protons (1.5<E<2.7 MeV) over the polar cap. For several Solar particle events the ratios of the counting rates of the two instruments were ordered according to invariant latitude, magnetic local time and geomagnetic activity. The geomagnetic activity was expressed by the time phase relative to the expansion of isolated substorms and the H-component of the magnetic field at a near midnight auroral station. Thus the analysis shows substorm-related effects on energetic particles in the pseudo-trapping region.

Google Scholar      ARK:



Article Details

How to Cite
Scholer, M., Morfill, G., & Hovestadt, D. (1974). Statistical analysis of the pitch angle distribution of magnetospheric Solar protons during geomagnetic activity. Journal of Geophysics, 40(1), 37-56. Retrieved from
Bookmark and Share


Achtermann, E., Hausler, B., Hovestadt, D., Kiinneth, E., Laeverenz, P., Paschmann, G. (1970) Die Experimente EISS and EI93 zur Messung von energiereichen Elektronen, Protonen und Alphateilchen im Satelliten Azur. Rep. BMBWFBW 70-67

Aubry, M.P., Russell, C.T., Kivelson, M.G. (1970) On inward motion of the magnetopause before a substorm. J. Geophys. Res. 75, 7018-7031

Behannon, K.W. (1970) Geometry of the geomagnetic tail. J. Geophys. Res. 75, 743-753

Bewick, A., Haskell, G.P., Hynds, R.J., Morfill, G. (1973) Low energy solar protons in the pseudo-trapping region of the magnetosphere. J. Geophys. Res. 78, 597-606

Bewick, A., Haskell, G.P., Hynds, R.J. (1970) Penetration of low energy solar protons to low geomagnetic latitudes. J. Geophys. Res. 75, 4605-4612

Blake, J.B., Paulikas, G.A., Freden, S.C. (1968) Latitude intensity structure and pitch angle distributions of low energy solar cosmic rays at low altitude. J. Geophys. Res. 73, 4927-4934

Fairfield, D.H., Ness, N.F. (1970) Configuration of the geomagnetic tail during substorms. J. Geophys. Res. 75, 7032-7047

Flindt, H.R. (1970) Local time dependence of geomagnetic cut-offs for solar protons 0.52 =< Ep =< 4 MeV. J. Geophys. Res. 75, 39-49

Gendrin, R. (1968) Pitch angle diffusion of low energy protons due to gyroresonant interaction with hydromagnetic waves. J. Atmospheric. Terrest. Phys. 30, 1313-1330

Hausler, B., Scholer, M., Hovestadt, D. (197J) Variations of the trapped particle population and of cut-off and pitch angle distribution of simultaneously observed magnetospheric solar protons during substorm activity. Submitted to J. Geophys. Res.

Imhof, W.L., Reagan, J.B., Gaines, E.E. (1971) Solar particle cut-offs as observed at low altitudes. J. Geophys. Res. 76, 4276-4290

McPherron, R.L., Coleman, P.J. (1970) Magnetic fluctuations during magnetospheric substorms. 1. Expansion phase. J. Geophys. Res. 75, 3927-3931

Morfill, G. (1972) A coordinate system for use with high latitude energetic particle phenomena. J. Geophys. Res. 77, 4010--4020

Morfill, G. (1973a) Nonadiabatic particle motion in the magnetosphere. J. Geophys. Res. 78, 588-596

Morfill, G. (1973b) Solar particle access into the inner magnetosphere. Preprint, 7. ESLAB Symposium, Saulgau, Germany

Ness, N.F. (1966) Williams,D.J. Correlated magnetic tail and radiation belt observations. J. Geophys. Res. 71, 322-325

Paulikas, G.A., Blake, J.B., Freden, S.C. (1968) Low energy solar cosmic ray cutoffs: diurnal variations and pitch angle distributions. J. Geophys. Res. 73, 87-95

Paulikas, G.A., Blake, J.B., Vampola, A.L. (1970) Solar particle observations over the polar caps. In: lntercorrelated satellite observations related to solar events. (V. Manno and D. E. Page, eds) Dordrecht-Holland

Roberts, C.S. (1969) Pitch angle diffusion of electrons in the magnetosphere. Rev. Geophys. 7, 305-337

Schindler, K., Ness, N.F. (1972) Internal structure of the geomagnetic neutral sheet. J. Geophys. Res. 77, 91-100

Williams, D.J., Heuring, F.T. (1973) Strong pitch angle diffusion and magnetospheric solar protons. J. Geophys. Res. 78, 37-50

Williams, D.J., Ness, N.F. (1966) Simultaneous trapped electron and magnetic tail field observations. J. Geophys. Res. 71, 5117-5128