Three dimensional model of the interplanetary magnetic field and 27-day variation of the galactic cosmic ray intensity A. Wawrzynczak1, R. Modzelewska2, and M. V. Alania2,3 1Institute of Computer Science, University of Natural Science and Humanities in Siedlce, Poland 2Institute of Mathematics and Physics, University of Natural Science and Humanities in Siedlce, Poland 3Institute of Geophysics of Tbilisi State University, Tbilisi, Georgia
Received: 15 Nov 2010 – Revised: 03 May 2011 – Accepted: 09 May 2011 – Published: 02 Sep 2011
Abstract. We present a model of the 27-day variation of the galactic cosmic
ray (GCR) intensity for three dimensional (3-D) heliosphere with
the heliolongitudinal and heliolatitudinal dependent radial solar
wind speed for the period of 1995 – minimum epoch of solar
activity (A>0). In the present model we implement
heliolongitudinal asymmetry of solar wind velocity reproducing as
the sum of first and second harmonics depending on the
heliolatitudes and the regular part of the solar wind velocity
(V0) changing versus heliolatitudes in accord to in situ
measurements of the Ulysses spacecraft. We show that the range of
changes of the sum of the first and second harmonics of the
27-day variation of the GCR intensity for Kiel neutron monitor is
little less than expected from the modelling, however, they are
comparable.
Citation: Wawrzynczak, A., Modzelewska, R., and Alania, M. V.: Three dimensional model of the interplanetary magnetic field and 27-day variation of the galactic cosmic ray intensity, Astrophys. Space Sci. Trans., 7, 351-354, doi:10.5194/astra-7-351-2011, 2011.