Physics
Scientific paper
May 2008
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2008agusmsh34b..03c&link_type=abstract
American Geophysical Union, Spring Meeting 2008, abstract #SH34B-03
Physics
2149 Mhd Waves And Turbulence (2752, 6050, 7836), 2164 Solar Wind Plasma, 2169 Solar Wind Sources, 7509 Corona, 7863 Turbulence (4490)
Scientific paper
Gene Parker's insights from 50 years ago provided the key causal link between energy deposition in the solar corona and the acceleration of solar wind streams. However, the community is still far from agreement concerning the actual physical processes that give rise to this energy. It is still unknown whether the solar wind is fed by flux tubes that remain open (and are energized by footpoint-driven wavelike fluctuations) or if mass and energy is input more intermittently from closed loops into the open-field regions. No matter the relative importance of reconnections and loop-openings, though, we do know that waves and turbulent motions are present everywhere from the photosphere to the heliosphere, and it is important to determine how they affect the mean state of the plasma. In this presentation, I will give a summary of wave/turbulence models that seem to succeed in explaining the time-steady properties of the corona (and the fast and slow solar wind). The coronal heating and solar wind acceleration in these models comes from anisotropic turbulent cascade, which is driven by the partial reflection of low-frequency Alfven waves propagating along the open magnetic flux tubes. Specifically, a 2D model of coronal holes and streamers at solar minimum reproduces the latitudinal bifurcation of slow and fast streams seen by Ulysses. The radial gradient of the Alfven speed affects where the waves are reflected and damped, and thus whether energy is deposited below or above Parker's critical point. As predicted by earlier studies, a larger coronal expansion factor gives rise to a slower and denser wind, higher temperature at the coronal base, less intense Alfven waves at 1 AU, and correlative trends for commonly measured ratios of ion charge states and FIP-sensitive abundances that are in general agreement with observations. Finally, I will outline the types of future observations that would be most able to test and refine these ideas.
No associations
LandOfFree
Turbulence and Waves as Sources for the Solar Wind 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 Turbulence and Waves as Sources for the Solar Wind, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Turbulence and Waves as Sources for the Solar Wind will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1399591