2022/04/08 by K. M. Hiremath, Hiremath, K. M., Manjunath Hegde +3
Earth and Planetary Sciences · Physics and Astronomy · #FOS: Physical sciences #Geophysics and Gravity Measurements #Solar and Space Plasma Dynamics #Solar and Stellar Astrophysics (astro-ph.SR) #Stellar, planetary, and galactic studies #astro-ph.SR
paper · pdf · doi:10.48550/arxiv.2204.04193
openalex publication_date 2022/04/08 · arxiv created 2022/04/11 · arxiv updated 2022/04/12 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
For the period of 1997-2006, coronal holes detected in the SOHO/EIT 195 Å full disk calibrated images are used to compute the rotation rates of high latitude and near polar coronal holes and, their latitudinal variation is investigated. We find that, for different latitude zones between 80o north and 75o south, for all their area, the number of days observed on the solar disk, and their latitudes, coronal holes rotate rigidly. Estimated magnitudes of sidereal rotation rate of the coronal holes are: 13.051 ± 0.206 deg/day for the equator, 12.993 ± 0.064 deg/day in the region of higher latitudes and, 12.999 ± 0.329 deg/day near the polar regions. For all the latitudes and the area, we have also investigated the annual variation of rotation rates of these coronal holes. We find that, for all the years, coronal holes rotate rigidly and their magnitude of equatorial, high latitude and polar region rotation rates are independent of magnitude of solar activity.