Study of the evolution of coronal holes based on ground and space observations

1Stepanian, NN, 1Malashchuk, VM
1Scientific-Research Institute “Crimean Astrophysical Observatory” of the Ministry for Education and Science of Ukraine, Nauchny, AR Crimea, Ukraine
Kosm. nauka tehnol. 2002, 8 ;(Supplement2):254-260
Publication Language: Russian
Abstract: 
According to observations of 104 coronal holes in lines He I 10830 Å, Fe IX, X 171 Å, Fe XII 195 Å and in the line Fe XV 284 Å, two groups of coronal holes are distinguished, differing in the nature of their area changes with height. The coronal holes of the first group are regions with an open magnetic configuration. For coronal holes of the second group, the magnetic structure at the coronal level cannot be considered completely open. For coronal holes of the first group, the change in area extends from below. In the second group, area changes at different levels are often not related to each other. The results obtained are important in developing methods for predicting solar wind characteristics. The use of observations of coronal holes only in the line He I 10830 Å for the forecast is not enough. It is necessary to attract data from the observation of the corona from space.
References: 
1. Kahler S. W., Davis J. M., and Harvey J. W. In: Sol. Phys., 87, 47-56 (1983).
2. Malanushenko E. V, Stepanian N. N. Comparison of Physical Conditions in Coronal Holes on Different Heights of Solar Atmosphere. In: Proc. Solar and Heliospheric plasma Physics, 13-18 May 1996. Thessaloniki, Greece, 38 (1997).
3. Stepanian N. N., Malanushenko E. V. Connection of coronal holes with surrounding magnetic fields. Izv. Krym. Astrofiz. Obs., 97, 69-75 (2001) [in Russian].
4. Stepanian N. N., Dolgopolova E. V., Elizarov A. I., et al. Solar universal spectrophotometer. Izv. Krym. Astrofiz. Obs., 96, 194-204 (2001) [in Russian].

5. Fleck D., Domingo V., Poland A. I. (Eds.) The SOHO Mission, 291– 312 (Kluwer Academic Publishers, 1995).