INTENSITY AND DOPPLER OSCILLATIONS IN PORE ATMOSPHERE
Tuesday, 2 September 2014
Regency Ballroom (Hyatt Regency)
Kyung-Suk F Cho1,2, Su-Chan Bong1, Eun-kyung Lim3, Young-deuk Park1, Jongchul Chae4, Heesu Yang4, Hyungmin Park4, Valery M Nakariakov5 and Vasyl Yurchyshyn6, (1)Korea Astronomy and Space Science Institute, Daejeon, South Korea, (2)KASI, Daejeon, South Korea, (3)KASI Korea Astronomy and Space Science Institute, Daejeon, South Korea, (4)Seoul National University, Seoul, South Korea, (5)University of Warwick, Physics, Coventry, United Kingdom, (6)Big Bear Solar Observatory, Big Bear City, CA, United States
Abstract:
Due to the vertical structure of magnetic field, pores can be exploited to study the transport of mechanical energy by waves along the magnetic field to the chromosphere and corona. For a better understanding of physics of pores, we have investigated chromospheric traveling features (~ 55 km/s) running across two merged pores from their centers in an active region (AR 11828) that were observed on 2013 August 24 by using high time, spatial, and spectral resolution data from the Fast Imaging Solar Spectrograph (FISS) of the 1.6 meter New Solar Telescope (NST). We infer a LOS velocity by applying the bisector method to the CaII 8542Å band and HI band, and investigate intensity and LOS velocity changes at different wavelengths and different positions of the pores. We find that they have 3 minutes oscillations, and the intensity oscillation from line center is preceded by that from the core (-0.3 Å) of the bands. There is no phase difference between the intensity and the LOS velocity oscillations at a given wavelength, and the amplitude of LOS velocity near center is greater than that far from the center. These results support that the wave is a magnetoacoustic wave propagating along the magnetic fields of the pores. From FISS observation, we conclude that the fast traveling features may be an apparent motion of the magnetoacostic wave and a sudden decrease of their speeds beyond the pores can be explained by the inclination of magnetic field outside of the pores.
