Abstract
The low ionization state in parts of a sunspot may play an important
role in its evolution and dynamical state. The cool magnetic interior
region of the sunspot develops a substantial neutral atomic and
molecular hydrogen osmotic pressure which can drive a wind outward from
the umbra. Ambipolar diffusion against the magnetically pinned ionized
plasma component can also distort the umbral magnetic field into a
filamentary penumbral structure. This may be important for explaining
the development of the sunspot penumbra and the Evershed flow. This
fractionation process may also be important for the ``First Ionization
Potential'' (FIP) effect seen in the solar wind. In support of this
mechanism we find evidence for such ionization fractionization in UV
observations of molecular hydrogen in a sunspot umbra and penumbra.
Original language | English |
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Publisher | arXiv |
Number of pages | 4 |
Publication status | Published - 01 Sept 2005 |
Keywords
- sun
- magnetic fields
- sunspots
- solar wind