Photoelectric observations of chromospheric sunspot oscillations. III - Spatial distribution of power and frequency in umbrae

Abstract

view Abstract Citations (47) References (22) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Photoelectric Observations of Chromospheric Sunspot Oscillations. III. Spatial Distribution of Power and Frequency in Umbrae Lites, B. W. Abstract On the basis of analyses of the spatial distribution of oscillation power and frequency of data from Lites (1984), the multiple peaks frequently observed in average power spectra are noted to be due to the presence of cospatial modes with different frequencies. Changes in these modes' amplitudes and frequencies with time and place within an umbra appear to arise from an interference of modes in the driving force in the photosphere. High oscillatory power regions in the 3-min band are uncorrelated with high oscillatory power regions in the 5-min band within the umbrae, suggesting that the 5-min oscillations in the photosphere do not drive the 3-min chromospheric oscillations. These results are used to develop a consistent view of the umbral oscillation mechanism: attention is given to a photospheric resonator for fast magnetoatmospheric waves, driving the chromospheric resonator through nonlinear wave interaction. Publication: The Astrophysical Journal Pub Date: February 1986 DOI: 10.1086/163963 Bibcode: 1986ApJ...301..992L Keywords: Chromosphere; Electrophotometry; Resonant Frequencies; Solar Oscillations; Spatial Distribution; Sunspots; Power Spectra; Spectral Energy Distribution; Stellar Spectrophotometry; Umbras; Solar Physics; SUN: CHROMOSPHERE; SUN: OSCILLATIONS; SUN: SUNSPOTS full text sources ADS | Related Materials (4) Part 1: 1982ApJ...253..386L Part 2: 1984ApJ...277..874L Part 4: 1986ApJ...301.1005L Part 5: 1988ApJ...334.1054L