Latitude Survey Of Cosmic Ray Nucleonic Component During 1996-1997 From Italy To Antartica

During the 1996-97 austral summer, we operated a neutron monitor on board the ship ''Italica'' of the Italian Antarctic Program to record cosmic ray neutron intensities in seas from Italy to Antarctica and back. The main purpose of the survey is to obtain a reliable latitude curve of cosmic ray nucleonic intensity to be utilized for studying cosmic ray spectral changes over different time scales, from day to day till the solar cycle time span. We show a preliminary latitude curve of cosmic ray nucleonic intensity. The data have been corrected for atmospheric pressure changes by using the well known dependence of pressure coefficients with cut-off rigidity. Cut-off rigidities of vertically incident cosmic ray particles have been calculated for every daily average geographic location of the ship. The total geomagnetic field, for the epoch 1996-97, is represented by a sofisticated model which takes into account internal sources, and their secular variations, together with magnetospheric sources (for quiet conditions Kp=0).