ANGEO Annales Geophysicae ANGEO Ann. Geophys. 1432-0576 Copernicus Publications Göttingen, Germany 10.5194/angeo-21-1341-2003 On the heliolatitudinal variation of the galactic cosmic-ray intensity. Comparison with Ulysses measurements Exarhos G. 2 1 Moussas X. 1 Laboratory of Astrophysics, Department of Astrophysics, Astronomy and Mechanics, School of Science, Faculty of Physics, National and Kapodistrian University of Athens, Panepistimiopolis GR 15783, Zografos, Athens, Greece Siemens Hellas A.E., Promitheos 12, Nea Kifisia, Athens, Greece 30 06 2003 21 6 1341 1345 Copyright: © 2003 G. Exarhos 2003 This work is licensed under the Creative Commons Attribution 3.0 Unported License. To view a copy of this licence, visit https://creativecommons.org/licenses/by/3.0/ This article is available from https://angeo.copernicus.org/articles/21/1341/2003/angeo-21-1341-2003.html The full text article is available as a PDF file from https://angeo.copernicus.org/articles/21/1341/2003/angeo-21-1341-2003.pdf

We study the dependence of cosmic rays with heliolatitude using a simple method and compare the results with the actual data from Ulysses and IMP spacecraft. We reproduce the galactic cosmic-ray heliographic latitudinal intensity variations, applying a semi-empirical, 2-D diffusion-convection model for the cosmic-ray transport in the interplanetary space. This model is a modification of our previous 1-D model (Exarhos and Moussas, 2001) and includes not only the radial diffusion of the cosmic-ray particles but also the latitudinal diffusion. Dividing the interplanetary region into &quot;spherical magnetic sectors&quot; (a small heliolatitudinal extension of a spherical magnetized solar wind plasma shell) that travel into the interplanetary space at the solar wind velocity, we calculate the cosmic-ray intensity for different heliographic latitudes as a series of successive intensity drops that all these &quot;spherical magnetic sectors&quot; between the Sun and the heliospheric termination shock cause the unmodulated galactic cosmic-ray intensity. Our results are compared with the Ulysses cosmic-ray measurements obtained during the first pole-to-pole passage from mid-1994 to mid-1995.<br><br><b>Key words. </b>Interplanetary physics (cosmic rays; interplanetray magnetic fields; solar wind plasma)