Fuzzy clustering analysis to study geomagnetic coastal effects

• Published in: Annales geophysicae (1988) Vol. 23; no. 4; pp. 1157 - 1163
• Main Authors: Sridharan, M., Gururajan, N., Ramasamy, A. M. S.
• Format: Journal Article
• Language: English
• Published: Katlenburg-Lindau European Geophysical Society 01.01.2005; Copernicus GmbH; European Geosciences Union; Copernicus Publications
• Subjects: Earth Sciences; Earth, ocean, space; Exact sciences and technology; External geophysics; Marine; Ocean, Atmosphere; Physics of the high neutral atmosphere; Physics of the ionosphere; Physics of the magnetosphere; Sciences of the Universe; Asia; Pondicherry; India; India, Andhra Pradesh, Hyderabad; ISW, India, Pondicherry; Cluster analysis; coastal effects; time variations; sea-floor spreading; Geomagnetism and paleomagnetism (Spatial variations attributed to sea floor spreading; Time variations; spatial variations; classification; vertical component; Long term; secular and long term; General or miscellaneous; Equatorial electrojet; pattern recognition
• ISSN: 1432-0576; 0992-7689; 1432-0576
• DOI: 10.5194/angeo-23-1157-2005

The utility of fuzzy set theory in cluster analysis and pattern recognition has been evolving since the mid 1960s, in conjunction with the emergence and evolution of computer technology. The classification of objects into categories is the subject of cluster analysis. The aim of this paper is to employ Fuzzy-clustering technique to examine the interrelationship of geomagnetic coastal and other effects at Indian observatories. Data from the observatories used for the present studies are from Alibag on the West Coast, Visakhapatnam and Pondicherry on the East Coast, Hyderabad and Nagpur as central inland stations which are located far from either of the coasts; all the above stations are free from the influence of the daytime equatorial electrojet. It has been found that Alibag and Pondicherry Observatories form a separate cluster showing anomalous variations in the vertical (Z)-component. H- and D-components form different clusters. The results are compared with the graphical method. Analytical technique and the results of Fuzzy-clustering analysis are discussed here.