2012/11/04 by Leonid Didkovsky, L. V. Didkovsky, А. Г. Косовичев +6 · 6 citations
Physics and Astronomy · #Amplitude #Astronomy #Astrophysics #Atmospheric sciences #Corona (planetary geology) #Coronal hole #Coronal mass ejection #Extreme ultraviolet #Extreme ultraviolet lithography #Ionosphere and magnetosphere dynamics #Irradiance #Magnetic field #Observatory #Optics #Photosphere #Physics #Plasma #Solar and Space Plasma Dynamics #Solar cycle #Solar irradiance #Solar minimum #Solar wind #Spectral line #Stellar, planetary, and galactic studies #Sunspot #Ultraviolet #astro-ph.SR
paper · pdf · doi:10.1007/s11207-012-0186-3
published in Solar Physics 287(1-2), 171-184 (Springer Science+Business Media) · 17 pages, 7 figures
arxiv created 2012/11/04 · openalex publication_date 2012/11/22 · arxiv updated 2015/06/12 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Solar five-minute oscillations have been detected in the power spectra of two six-day time intervals from soft X-ray measurements of the Sun observed as a star using the Extreme Ultraviolet Spectrophotometer (ESP) onboard the Solar Dynamics Observatory (SDO)/Extreme Ultraviolet Variability Experiment (EVE). The frequencies of the largest amplitude peaks were found to match the known low-degree (ℓ=0 – 3) modes of global acoustic oscillations within 3.7 μHz and can be explained by a leakage of the global modes into the corona. Due to the strong variability of the solar atmosphere between the photosphere and the corona, the frequencies and amplitudes of the coronal oscillations are likely to vary with time. We investigated the variations in the power spectra for individual days and their association with changes of solar activity, e.g. with the mean level of the EUV irradiance, and its short-term variations caused by evolving active regions. Our analysis of samples of one-day oscillation power spectra for a 49-day period of low and intermediate solar activity showed little correlation with the mean EUV irradiance and the short-term variability of the irradiance. We suggest that some other changes in the solar atmosphere, e.g., magnetic fields and/or inter-network configuration may affect the mode leakage to the corona.