The Changing in the Vertical Boundaries of a Giant Coronal Hole

Abstract

We analyzed the vertical boundaries of a long-lived coronal hole and their variation in the solar atmosphere with time. The investigations are based on ground and space observations. Analyze of the boundaries of CH on the different heights showed next: the boundaries of the GCH, determined from the observations, are very close both in the E-W direction in the N-S direction. The boundaries of the GCH, determined from the magnetic field lines for the photosphere, are in good agreement at the moments of the beginning and end of the existence of the GCH with the observed boundaries, and differ in the maximum development of the GCH. The maximum expansion of the coronal hole is from the photosphere to the chromosphere. Approximately at height of 1.0045R ⊙ and beyond there is a radial expansion. The results obtained are important in the development of methods for predicting the solar wind.