Physics
Scientific paper
Dec 2008
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2008agufmsh43a1639d&link_type=abstract
American Geophysical Union, Fall Meeting 2008, abstract #SH43A-1639
Physics
2159 Plasma Waves And Turbulence, 2164 Solar Wind Plasma, 7836 Mhd Waves And Instabilities (2149, 2752, 6050), 7844 Parametric Processes, 7868 Wave/Wave Interactions
Scientific paper
In this study, the role of a nearly-resonant three-wave parametric beating mechanism involving Alfvén and magnetoacoustic waves is examined in evolving turbulent spectra from the base of the solar corona to the outer heliophere. The mechanism is based upon a simple MHD treatment which yields a dissipation rate that is dependent only upon the wave frequency of the daughter wave, ωhjmn, the kinetic dissipation rate and a coupling efficiency, which in turn depends only upon the ratio of the fluctuating amplitude, uA, to the background Alfvén speed, vA , the plasma beta, β, and the angle of propagation of the daughter wave, θhjmn. It is shown that this mechanism may play an important role in shaping the energy spectrum via the production of fast magnetoacoustic daughter waves, particularly when β is of order unity. This is known to be the case in the sunspot region in the photosphere and lower chromosphere, in the plage region in the lower and middle corona (1.2 solar radii) and in significant portions of the upper corona and the slow solar wind. In these scenarios, this mechanism serves to heat plasma just enough to keep β above unity and drive down the damping rate. At peak efficiencies within the upper corona and near solar wind, the damping time of the driven waves is a few hours. This supports the observation that the total energy carried by Alfvén waves is observed to decrease as heliospheric distance increases, thereby diminishing the overall effectiveness of the mechanism. This feedback process may also control the temperature of plasmas that are attempting to cool by expansion or radiative processes.
Bekhor Steven H.
Dangoor O.
No associations
LandOfFree
Evolutive Studies of Heliospheric Turbulent Spectra via Parametric Beating does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Evolutive Studies of Heliospheric Turbulent Spectra via Parametric Beating, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Evolutive Studies of Heliospheric Turbulent Spectra via Parametric Beating will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1091615