STUDIES ON THE OCCURRENCE OF DUCT AND SUPERREFRACTION OVER INDIAN REGION
Cosmic GPS data for the years 2007 and 2008 is taken to analyze the occurrence of ducts and super refraction over Indian region corresponding to latitudes -5 o to 40 o and longitudes from 60 o to 100 o up to a height of 5Km from sea level. Number of duct regions, high duct strength regions and superrefraction regions are counted over Arabian Sea, Bay of Bengal and land regions. Arabian sea region has more number of duct regions during postmonsoon (September, October, and November), premonsoon (March, April, May) and winter (December, January, February) seasons and less number during summer monsoon (June, July, August,) season. More number of duct regions observed over Bay of Bengal during winter than other seasons. Land region has more number of duct regions during post monsoon season. More number of superrefraction regions occurs over Arabian Sea in pre monsoon season; over Bay of Bengal during winter and Pre monsoon seasons and over land region during post monsoon season. Majority of duct regions are found to occur at heights less than 1.5 Km and majority