Spatial and Temporal Distribution of Solar Green Line Corona for Solar Cycles 18-24

Abstract

Homogeneous coronal data set (HCDS) of the green corona (Fe XIV) and coronal index of the solar activity (CI) have been used to study time-latitudinal distribution in solar cycles 18-24 and compared with similar distribution of sunspots, the magnetic fields and the solar radio flux 10.7 cm. The most important results are: (a) distribution of coronal intensities related to the cycle maximum are different for individual cycles, (b) the poleward migration of the HCDS from mid latitudes in each cycle exists, even in extremely weak Cycle 24, and the same is valid for the equatorward migration (c) the overall values of HCDS are slightly stronger for the northern hemisphere than for the southern one, (d) distribution of the HDCS are in coincidence with strongest photospheric magnetic fields (B>50 Gauss) and histogram of the sunspot groups, (e) Gnevyshev gap was confirmed with at least 95% confidence in the CI, however, with different behavior for odd and even cycles. Principal component analysis (PCA) showed that the first and second component account for 87.7% and 7.3% of the total variation of the CI. Furthermore, the PC2 of the green corona was quite different for cycle 21, compared with other cycles.

21 pages, 14 figures, accepted to Solar Physics

References in corpus (5)

• A new method to estimate annual solar wind parameters and contributions of different solar wind structures to geomagnetic activity
• Comparison of geomagnetic indices during even and odd solar cycles SC17-SC24: Signatures of Gnevyshev gap in geomagnetic activity
• Comparison of the shape and temporal evolution of even and odd solar cycles
• Separating aa-index into Solar and Hale Cycle Related Components Using Principal Component Analysis
• Temporal Distribution of Solar Cycle 24 Sunspot Groups: Comparison to Cycles 12-23

Cited by in corpus (3)

• Investigating the Behavior and Spatiotemporal Variations of Green Line Emission in the Solar Corona
• Analysis of the Solar Flare Index for Solar Cycles 18-24: Extremely Deep Gnevyshev Gap in the Chromosphere
• Temporal and Latitudinal Variation in Penumbra-Umbra Ratios of the Sunspots: Analyses of RGO, Kodaikanal and Debrecen Databases