The Dependence of the Peak Velocity of High-Speed Solar Wind Streams as Measured in the Ecliptic by ACE and the STEREO satellites on the Area and Co-Latitude of their Solar Source Coronal Holes [PDF]
, 2018 We study the properties of 115 coronal holes in the time‐range from 2010/08 to 2017/03, the peak velocities of the corresponding high‐speed streams as measured in the ecliptic at 1AU, and the corresponding changes of the Kp index as marker of their geo ...
Heber, Bernd +5 more
core +2 more sources
Antarctic Record, 1980 This is an attempt to identify the causes of geomagnetic storms which occurred during a year and a half from January 1977 to June 1978. The assignment of geomagnetic storm causation to appropriate coronal holes or solar flares has been made by ...
Katsuhide MARUHASHI, Takahiroo ISHI
doaj +1 more source
Active Region Modulation of Coronal Hole Solar Wind [PDF]
The Astrophysical Journal, 2019 Abstract Active regions (ARs) are a candidate source of the slow solar wind (SW), the origins of which are a topic of ongoing research. We present a case study that examines the processes by which SW is modulated in the presence of an AR in the vicinity of the SW source.
Allan R. Macneil +6 more
openaire +3 more sources
SOLAR WIND AND CORONAL BRIGHT POINTS INSIDE CORONAL HOLES
The Astrophysical Journal, 2011 Observations of 108 coronal holes (CHs) from 1998-2008 were used to investigate the correlation between fast solar wind (SW) and several parameters of CHs. Our main goal was to establish the association between coronal bright points (CBPs; as sites of magnetic reconnection) and fast SW. Using in situ measurements of the SW, we have connected streams of
Nina V. Karachik, Alexei A. Pevtsov
openaire +1 more source
Empirical Forecast of Corotating Interacting Regions and Geomagnetic Storms Based on Coronal Hole Information [PDF]
Journal of Astronomy and Space Sciences, 2009 In this study, we suggest an empirical forecast of CIR (Corotating Interaction Regions) and geomagnetic storm based on the information of coronal holes (CH). For this we used CH data obtained from He I 10830 Å maps at National Solar Observatory-Kitt Peak
Ji-Hye Lee +3 more
doaj +1 more source
The solar and interplanetary causes of the recent minimum in geomagnetic activity (MGA23): a combination of midlatitude small coronal holes, low IMF BZ variances, low solar wind speeds and low solar magnetic fields [PDF]
Annales Geophysicae, 2011 Minima in geomagnetic activity (MGA) at Earth at the ends of SC23 and SC22 have been identified. The two MGAs (called MGA23 and MGA22, respectively) were present in 2009 and 1997, delayed from the sunspot number minima in 2008 and 1996 by ~1/2–1 years.
B. T. Tsurutani +3 more
doaj +1 more source
Automated identification of coronal holes from synoptic EUV maps [PDF]
, 2017 Coronal holes (CH) are regions of open magnetic field lines in the solar corona and the source of fast solar wind. Understanding the evolution of coronal holes is critical for solar magnetism as well as for accurate space weather forecasts. We study here
Asikainen, Timo +3 more
core +2 more sources
Can the Solar Wind be Driven by Magnetic Reconnection in the Sun's Magnetic Carpet? [PDF]
, 2010 The physical processes that heat the solar corona and accelerate the solar wind remain unknown after many years of study. Some have suggested that the wind is driven by waves and turbulence in open magnetic flux tubes, and others have suggested that ...
Adriaan A. van Ballegooijen +91 more
core +1 more source
The Nature of Solar Polar Rays [PDF]
, 2000 We use time series observations from the SOHO and Yohkoh spacecraft to study solar polar rays. Contrary to our expectations, we find that the rays are associated with active regions on the sun and are not features of the polar coronal holes.
Barry LaBonte +3 more
core +2 more sources
Automated Coronal Hole Detection using Local Intensity Thresholding Techniques
, 2009 We identify coronal holes using a histogram-based intensity thresholding technique and compare their properties to fast solar wind streams at three different points in the heliosphere.
A. Kavanagh +47 more
core +1 more source