Long-period intensity oscillations of the quiet solar atmosphere from TRACE 1600 Å continuum observations

Abstract

We have analysed a 6-hour long time sequence of ultraviolet (uv) images obtained on May 24, 2003 in 1600 Å continuum under high spatial and temporal resolutions from the Transition Region and Coronal Explorer (TRACE). We have selected 15 isolated bright points, 15 network elements and 15 quiet background regions from these images for detailed analysis. We derived the cumulative intensity values and the light curves of these features for the total duration of observations, and performed also a power spectrum analysis using the complete time series data. We found that the uv bright points, the uv network and the uv background regions exhibit long-period intensity oscillations namely, 5.5 hours, 4.6 hours and 3.4 hours respectively, in addition to the more familiar small scale intensity fluctuations. We suggest that these longer periods of oscillation might be related to solar atmospheric g-modes.