A Radio Study of the Evolution of Spatial Structure of an Active Region and Flare Productivity

2001 ◽  
Vol 133 (2) ◽  
pp. 467-482 ◽  
Author(s):  
M. R. Kundu ◽  
S. M. White ◽  
K. Shibasaki ◽  
J.‐P. Raulin
Keyword(s):  
Active Region ◽  
Spatial Structure ◽  
Flare Productivity

scholarly journals Solar active region emergence and flare productivity

2006 ◽  
Vol 2 (14) ◽  
pp. 614-614
Author(s):  
Silvia C. Dalla ◽  
Lyndsay Fletcher ◽  
Nicholas A. Walton
Keyword(s):  
Active Region ◽  
Solar Active Region ◽  
Virtual Observatory ◽  
The Sun ◽  
A Value ◽  
Significant Difference ◽  
Region Emergence ◽  
Two Populations ◽  
East West ◽  
Flare Productivity

AbstractWe use the workflow capabilities of the AstroGrid Virtual Observatory system (<http://www.astrogrid.org>) to analyse the relation between flare productivity and location of Active Region (AR) emergence on the Sun. Specifically, we investigate whether emergence of a new region near existing ones results in increased productivity of the new and/or pre-existing AR. To address this question, we build a series of workflows that perform queries to catalogues of regions and flares, and operations on the results of the queries. There is a strong East-West asymmetry in the location of emergence of new regions. We do not find a significant difference between the flaring rate of paired and isolated regions, when we choose a value of 12° as the cutoff between the two populations.

scholarly journals Characteristics of Flare-Productive Sunspot Groups

2002 ◽  
Vol 12 ◽  
pp. 395
Author(s):  
Takako T. Ishii ◽  
Hiroki Kurokawa ◽  
Tsutomu T. Takeuchi
Keyword(s):  
Active Region ◽  
Convection Zone ◽  
Active Regions ◽  
Flare Activity ◽  
Proper Motions ◽  
Flare Energy ◽  
Evolutionary Changes ◽  
Fine Structures ◽  
Flare Productivity ◽  
Sunspot Groups

AbstractThe mechanism of flare energy build-up is one of the most fundamental questions in the solar flare study, but is still to be solved. From the review of the previous studies, we notice that the formation process of the magnetic shear in an active region should be essential for the flare energy build-up mechanism. Based on this idea, we make detailed studies of the active region evolutions using high resolution Hα images obtained with the 60 cm Domeless Solar Telescope at Hida Observatory, Kyoto University.We study sunspot proper motions and evolutionary changes of Hα fine structures and magnetic fields in active regions NOAA 5395 (Ishii et al. 1998) and NOAA 4201 (Ishii et al. 2000). To explain the evolutionary characteristics found from the analysis of these two active regions, we propose schematic models of twisted flux bundles emerging from the convection zone. We also found that the occurrence of high flare activity in each active region was restricted to the rapidly emerging region of the twisted flux bundle. In conclusion, we suggest that the emergence of the twisted flux bundle should be the key to high flare-productivity of the sunspot group, or the flare energy build-up mechanism.

scholarly journals MAG4 versus alternative techniques for forecasting active region flare productivity

Space Weather ◽  
2014 ◽  
Vol 12 (5) ◽  
pp. 306-317 ◽  
Author(s):  
David A. Falconer ◽  
Ronald L. Moore ◽  
Abdulnasser F. Barghouty ◽  
Igor Khazanov
Keyword(s):  
Active Region ◽  
Alternative Techniques ◽  
Flare Productivity

Observations of the spatial structure of interstellar hydrogen

1967 ◽  
Vol 31 ◽  
pp. 45-46
Author(s):  
Carl Heiles
Keyword(s):  
High Resolution ◽  
Spatial Structure ◽  
Velocity Dispersion ◽  
Temperature Variations

High-resolution 21-cm line observations in a region aroundlII= 120°,b11= +15°, have revealed four types of structure in the interstellar hydrogen: a smooth background, large sheets of density 2 atoms cm-3, clouds occurring mostly in groups, and ‘Cloudlets’ of a few solar masses and a few parsecs in size; the velocity dispersion in the Cloudlets is only 1 km/sec. Strong temperature variations in the gas are in evidence.

Results of Spatial Structure of Atmosphere Radiation in a Spectral Range (1.5–2) µm Research

2018 ◽  
pp. 7-13
Author(s):  
Anton M. Mishchenko ◽  
Sergei S. Rachkovsky ◽  
Vladimir A. Smolin ◽  
Igor V . Yakimenko
Keyword(s):  
Spatial Structure ◽  
Unmanned Aerial Vehicle ◽  
Wavelength Range ◽  
Spectral Range ◽  
Near Ir ◽  
Optoelectronic Systems ◽  
Aerial Vehicle

Results of experimental studying radiation spatial structure of atmosphere background nonuniformities and of an unmanned aerial vehicle being the detection object are presented. The question on a possibility of its detection using optoelectronic systems against the background of a cloudy field in the near IR wavelength range is also considered.

Morphology of the flare-productive active region NOAA 9087

2020 ◽  
Vol 36 (3) ◽  
pp. 69-90
Author(s):  
S. N. Chornogor ◽  
◽  
N. N. Kondrashova ◽  
Keyword(s):  
Active Region ◽  
Active Region Noaa ◽  
Region Noaa
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