Ca II K spectroheliograms for studies of long-term changes in solar irradiance

Abstract

We address the importance of historical full disc Ca II K spectroheliograms for solar activity and irradiance reconstruction studies. We review our work on processing such data to enable them to be used in irradiance reconstructions. We also present our preliminary estimates of the plage areas from five of the longest available historical Ca II K archives.

5 pages, 3 figures

References in corpus (1)

• Brightness of Solar Magnetic Elements as a Function of Magnetic Flux at High Spatial Resolution

Cited by in corpus (8)

• Analysis of full disc Ca II K spectroheliograms. II. Towards an accurate assessment of long-term variations in plage areas
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• Reconstructing solar irradiance from historical Ca II K observations. I. Method and its validation
• Modelling solar irradiance from ground-based photometric observations
• Delving into the Historical Ca II K Archive from the Kodaikanal Observatory: the Potential of the Most Recent Digitised Series
• Scrutinizing the relationship between plage areas and sunspot areas and numbers
• Analysis of full-disc H alpha observations: Carrington maps and filament properties in 1909-2022