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Related papers: Correlation of Coronal Hole Area Indices and Solar…

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Coronal holes (CHs) are regions of open magnetic flux which are the source of high speed solar wind (HSSW) streams. To date, it is not clear which aspects of CHs are of most influence on the properties of the solar wind as it expands…

Solar and Stellar Astrophysics · Physics 2018-12-12 Tadhg M. Garton , Sophie A. Murray , Peter T. Gallagher

It has long been known that the high-speed stream (HSS) peak velocity at Earth directly depends on the area of the coronal hole (CH) on the Sun. Different degrees of association between the two parameters have been shown by many authors. In…

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 1 AU, and the corresponding changes of the Kp index as marker…

Solar and Stellar Astrophysics · Physics 2018-04-27 Stefan J. Hofmeister , Astrid Veronig , Manuela Temmer , Susanne Vennerstrom , Bernd Heber , Bojan Vršnak

The study of the evolution of coronal holes (CHs) is especially important in the context of high-speed solar wind streams (HSS) emanating from them. Stream interaction regions may deliver large amount of energy into the Earths system, cause…

The present paper discusses results of a statistical study of the characteristics of coronal hole (CH) rotation in order to find connections to the internal rotation of the Sun. The goal is to measure CH rotation rates and study their…

Because of its distinctive compositional properties and variability, low-speed ($\lesssim 450$ km s$^{-1}$) solar wind is widely believed to originate from coronal streamers, unlike high-speed wind, which comes from coronal holes. An…

Solar and Stellar Astrophysics · Physics 2021-04-16 Y. -M. Wang , Y. -K. Ko

The relationship between the peak velocities of high-speed solar wind streams near Earth and the areas of their solar source regions, i.e., coronal holes, has been known since the 1970s, but it is still physically not well understood. We…

Solar and Stellar Astrophysics · Physics 2020-07-10 Stefan J. Hofmeister , Astrid M. Veronig , Stefaan Poedts , Evangelia Samara , Jasmina Magdalenic

An empirical model for forecasting solar wind speed related geomagnetic events is presented here. The model is based on the estimated location and size of solar coronal holes. This method differs from models that are based on photospheric…

Astrophysics · Physics 2008-11-26 S. Robbins , C. J. Henney , J. W. Harvey

Connecting in-situ measured solar-wind plasma properties with typical regions on the Sun can provide an effective constraint and test to various solar wind models. We examine the statistical characteristics of the solar wind with an origin…

Solar and Stellar Astrophysics · Physics 2017-02-22 Hui Fu , Maria S. Madjarska , Lidong Xia , Bo Li , Zhenghua Huang , Zhipeng Wangguan

We present a concept study of a solar wind forecasting method for Earth, based on persistence modeling from STEREO in-situ measurements combined with multi-viewpoint EUV observational data. By comparing the fractional areas of coronal holes…

Solar and Stellar Astrophysics · Physics 2018-02-01 M. Temmer , J. Hinterreiter , M. A. Reiss

Solar coronal holes are sources of high-speed solar wind streams, which cause persistent geomagnetic activity especially at high latitudes. Here we estimate seasonal solar wind speeds at 1 AU for the last 100 years using high-latitude…

Space Physics · Physics 2017-02-22 Kalevi Mursula , Lauri Holappa , Renata Lukianova

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.…

Space Physics · Physics 2018-05-02 Amr Hamada , Timo Asikainen , Ilpo Virtanen , Kalevi Mursula

Coronal holes are the coolest and darkest regions of the solar atmosphere, as observed both on the solar disk and above the solar limb. Coronal holes are associated with rapidly expanding open magnetic fields and the acceleration of the…

Solar and Stellar Astrophysics · Physics 2011-09-21 D. Banerjee , G. R. Gupta , L. Teriaca

High speed solar wind streams (HSSs) are very efficient drivers of geomagnetic activity at high latitudes. In this paper we use a recently developed $\Delta{H}$ parameter of geomagnetic activity, calculated from the night-side hourly…

Space Physics · Physics 2017-05-03 Renata Lukianova , Lauri Holappa , Kalevi Mursula

We present an empirical model based on the visible area covered by coronal holes close to the central meridian in order to predict the solar wind speed at 1 AU with a lead time up to four days in advance with a 1hr time resolution. Linear…

Solar and Stellar Astrophysics · Physics 2015-06-03 T. Rotter , A. M. Veronig , M. Temmer , B. Vrsnak

We study the properties and geoeffectiveness of solar wind high-speed streams (HSSs) emanating from coronal holes and associated with stream interaction regions (SIRs). This paper presents a statistical study of 588 SIR/HSS events with…

Space Physics · Physics 2020-06-12 Maxime Grandin , Anita T. Aikio , Alexander Kozlovsky

The solar wind, a stream of charged particles originating from the Sun and transcending interplanetary space, poses risks to technology and astronauts. In this work, we develop a prediction model to forecast the solar wind speed at the…

Solar and Stellar Astrophysics · Physics 2025-01-22 Daniel Collin , Yuri Shprits , Stefan J. Hofmeister , Stefano Bianco , Guillermo Gallego

We identify the coronal sources of the solar winds sampled by the ACE spacecraft during 1999-2008, and examine the in situ solar wind properties as a function of wind sources. The standard two-step mapping technique is adopted to establish…

Solar and Stellar Astrophysics · Physics 2015-05-05 Hui Fu , Bo Li , Xing Li , Zhenghua Huang , Chaozhou Mou , Fangran Jiao , Lidong Xia

We investigate the evolution of a well-observed, long-lived, low-latitude coronal hole (CH) over 10 solar rotations in the year 2012. By combining EUV imagery from STEREO-A/B and SDO we are able to track and study the entire evolution of…

Solar and Stellar Astrophysics · Physics 2018-08-01 S. G. Heinemann , M. Temmer , S. J. Hofmeister , A. M. Veronig , S. Vennerstroem

The acceleration of the young solar wind is studied using the first 17 encounters of Parker Solar Probe. We identify wind intervals from different source regions: coronal hole (CH) interiors, streamers, and low Mach number boundary layers…

Solar and Stellar Astrophysics · Physics 2024-10-23 Yiming Jiao , Ying D. Liu , Wenshuai Cheng , Hao Ran , Rui Wang
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