Propagating waves in polar coronal holes as seen by SUMER and EIS
arXiv:0905.1013 · doi:10.1051/0004-6361/200912059
Abstract
To study the dynamics of coronal holes and the role of waves in the acceleration of the solar wind, spectral observations were performed over polar coronal hole regions with the SUMER spectrometer on SoHO and the EIS spectrometer on Hinode. Using these observations, we aim to detect the presence of propagating waves in the corona and to study their properties. The observations analysed here consist of SUMER spectra of the Ne VIII 770 A line (T = 0.6 MK) and EIS slot images in the Fe XII 195 A line (T = 1.3 MK). Using the wavelet technique, we study line radiance oscillations at different heights from the limb in the polar coronal hole regions. We detect the presence of long period oscillations with periods of 10 to 30 min in polar coronal holes. The oscillations have an amplitude of a few percent in radiance and are not detectable in line-of-sight velocity. From the time distance maps we find evidence for propagating velocities from 75 km/s (Ne VIII) to 125 km/s (Fe XII). These velocities are subsonic and roughly in the same ratio as the respective sound speeds. We interpret the observed propagating oscillations in terms of slow magneto-acoustic waves. These waves can be important for the acceleration of the fast solar wind.
5 pages, 7 figures Accepted as Astronomy and Astrophysics Letter
Cited by in corpus (38)
- MHD Waves and Coronal Seismology: an overview of recent results
- Persistent Doppler shift oscillations observed with HINODE/EIS in the solar corona: spectroscopic signatures of Alfvenic waves and recurring upflows
- Quasi-periodic Propagating Signals in the Solar Corona: The Signature of Magnetoacoustic Waves or High-Velocity Upflows?
- Hinode/EIS observations of propagating low-frequency slow magnetoacoustic waves in fan-like coronal loops
- The Spectroscopic Signature of Quasi-periodic Upflows in Active Region Timeseries
- Observation of High-speed Outflow on Plume-like Structures of the Quiet Sun and Coronal Holes with SDO/AIA
- A global view of velocity fluctuations in the corona below 1.3 with CoMP
- MHD Waves in open coronal structures
- Morphology, dynamics and plasma parameters of plumes and inter-plume regions in solar coronal holes
- Propagating MHD waves in coronal holes
- STEREO Observations of Quasi-Periodically Driven High Velocity Outflows in Polar Plumes
- Propagating intensity disturbances in polar corona as seen from AIA/SDO
- Propagating Disturbances in Coronal Loops: A Detailed Analysis of Propagation Speeds
- Accelerating waves in polar coronal holes as seen by EIS and SUMER
- Doppler Shift, Intensity, and Density Oscillations Observed with the EUV Imaging Spectrometer on Hinode
- Propagating Disturbances in The Solar Corona and Spicular Connection
- Observations of Dissipation of Slow Magneto-acoustic Waves in a Polar Coronal Hole
- Sources of quasi-periodic propagating disturbances above a solar polar coronal hole
- Spectroscopic Observations of Propagating Disturbances in a Polar Coronal Hole: Evidence of Slow Magneto-acoustic Waves
- Mode identification of MHD waves in an active region observed with Hinode/EIS
- Density Fluctuations in a Polar Coronal Hole
- How the area of solar coronal holes affects the properties of high-speed solar wind streams near Earth -- An analytical model
- Characteristics of polar coronal hole jets
- On the Parallel and Perpendicular Propagating Motions Visible in Polar Plumes: An Incubator For (Fast) Solar Wind Acceleration?
- Nature of Quiet Sun Oscillations Using Data from the Hinode, TRACE, and SOHO Spacecraft
- Self-consistent Simulations of Alfven Wave Driven Winds from the Sun and Stars
- MHD Waves in the coronal holes
- Wave amplitude modulation in fan loops as observed by AIA/SDO
- The fine-scale structure of polar coronal holes
- Damping and power spectra of quasi-periodic intensity disturbances above a solar polar coronal hole
- Modelling the connection between propagating disturbances and solar spicules
- On the Nature of Propagating Intensity Disturbances in Polar Plumes during the 2017 Total Solar Eclipse
- Reconnection generated plasma flows in the quasi-separatrix layer in localised solar corona
- Propagating Oscillations in the Lower Atmosphere under Coronal Holes
- A new model for heating of Solar North Polar Coronal Hole
- Ion-cyclotron waves in Solar Coronal Hole
- Properties of EUV Imaging Spectrometer (EIS) Slot Observations
- A multi-viewpoint comparison of the velocity field of coronal propagating disturbances