منابع مشابه
The Magnetic Classification of Solar Active Regions
The purpose of this letter is to address a blind-spot in our knowledge of solar active region statistics. To the best of our knowledge there are no published results showing the variation of the Mount Wilson magnetic classifications as a function of solar cycle based on modern observations. We show statistics for all active regions reported in the daily Solar Region Summary from 1992 January 1 ...
متن کاملChirality of Intermediate Filaments and Magnetic Helicity of Active Regions
Filaments which form either between or around active regions (ARs) are called intermediate filaments. In spite of various theoretical studies, the origin of the chirality of filaments is still uncovered. We investigated how intermediate filaments are related to their associated ARs, especially from the point of view of magnetic helicity and the orientation of polarity inversion lines (PILs). Th...
متن کاملStatistical Properties of Magnetic Separators in Model Active Regions
Previous theoretical work suggests that magnetic reconnection in the solar corona should occur along particular topological boundaries in the coronal magnetic Ðeld known as separators. Thus, a ÐeldÏs topological structure predicts the locations of X-ray/EUV loops, assuming enhanced emission is related to reconnection. We use this topological model in a theoretical study of the statistical prope...
متن کاملHelical Magnetic Fields in Solar Active Regions: Theory vs. Observations
The mean value of the normalized current helicity αp = B · (∇×B)/B 2 in solar active regions is on the order of 10 m, negative in the northern hemisphere, positive in the southern hemisphere. Observations indicate that this helicity has a subsurface origin. Possible mechanisms leading to a twist of this amplitude in magnetic flux tubes include the solar dynamo, convective buffeting of rising fl...
متن کاملMagnetic field inclination and atmospheric oscillations above solar active regions
Recent observational evidence for magnetic field direction effects on helioseismic signals in sunspot penumbrae is suggestive of magnetohydrodynamic (MHD) mode conversion occurring at lower levels. This possibility is explored using wave mechanical and ray theory in a model of the Sun’s surface layers permeated by uniform inclined magnetic field. It is found that fastto-slow conversion near the...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Symposium - International Astronomical Union
سال: 1968
ISSN: 0074-1809
DOI: 10.1017/s0074180900021276