Anisotropy in the South Atlantic Anomaly

<p>The South Atlantic Anomaly (SAA) is an area of increased radiation that poses a danger to satellites and manned spacecraft. From June 2000 through July 2006 the TSX-5 satellite measured proton fluxes in the SAA using its CEASE instrument. A review of the satellite data by scientists at AFRL/VSBX revealed an unanticipated recurring bi-modal structure in histograms of the proton counts. This research identified the bi-modal behavior as anisotropic in nature and the result of two separate processes. At low altitudes the anisotropy was well described by the classic East-West Effect. Comparisons of the satellite data to simple analytical models are presented. At high altitudes the anisotropy was the result of the detector measuring protons at different pitch angles when looking east vs. west. The sampled pitch angles were also found to be function of location leading to a latitudinal variation to this anisotropy. Finally we also examined a series of unusually high readings that affected some of the statistics in this study. These anomalous counts were found to have a possible solar cycle dependence leading to questions about the suitability of the current time-independent scheme used to sort the satellite's data set. Other possible explanations for the anomalous counts are also presented.</p><p>This work has been selected by scholars as being culturally important and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact and remains as true to the original work as possible. Therefore you will see the original copyright references library stamps (as most of these works have been housed in our most important libraries around the world) and other notations in the work.</p><p>This work is in the public domain in the United States of America and possibly other nations. Within the United States you may freely copy and distribute this work as no entity (individual or corporate) has a copyright on the body of the work.</p><p>As a reproduction of a historical artifact this work may contain missing or blurred pages poor pictures errant marks etc. Scholars believe and we concur that this work is important enough to be preserved reproduced and made generally available to the public. We appreciate your support of the preservation process and thank you for being an important part of keeping this knowledge alive and relevant.</p>