CaII Κ Imaging to Understand UV Irradiance Variability

Abstract

To identify and understand the underlying physical mechanisms of total solar and UV irradiance variability and to estimate the contribution of various hromospheric features to UV irradiance, detailed analysis of spatially resolved data is required. The various chromospheric features have been segregated and different parameters have been derived from CaII Κ Spectroheliograms of NSO/Sac Peak and Kodaikanal Observatory and compared with UV irradiance flux measured in MgII h and k lines by NOAA 9 satellite. The important results of this detailed analysis of CaII Κ Images of 1992 together with UV irradiance data will be discussed in this paper.contribution of various chromospheric features to UV irradiance, detailedanalysis of spatially resolved data is required. The various chromosphericfeatures have been segregated and different parameters have been derivedfrom CaII Κ Spectroheliograms of NSO/Sac Peak and Kodaikanal Observatory and compared with UV irradiance flux measured in MgII h and klines by NOAA 9 satellite. The important results of this detailed analysisof CaII Κ Images of 1992 togeth