Active region upflows
نویسندگان
چکیده
منابع مشابه
Observations of nightside auroral plasma upflows in the F-region and topside ionosphere
Observations from the special UK EISCAT program UFIS are presented. UFIS is a joint UHF-VHF experiment, designed to make simultaneous measurements of enhanced vertical plasma flows in the F-region and topside ionospheres. Three distinct intervals of upward ion flow were observed. During the first event, upward ion fluxes in excess of 1013 m~2 s~1 were detected, with vertical ion velocities reac...
متن کاملProperties of Granules in Upflows and Downflows
Normal-mode observations of seven quiet regions, obtained by the Hinode spacecraft, are used to analyze the physical properties of granules with mean upward and downward Doppler velocity. We identify 75 146 granules from the observations with a granuledetection method. Then the granules are divided into two subsets: one with negative mean Doppler velocity (granule-upflows), and the other with p...
متن کاملActive Region Oscillations
We report here on an investigation of high frequency oscillations in active regions, carried out using high cadence observations of O V 629 Å, Mg IX 368 Å and Fe XVI 335 Å with the Coronal Diagnostic Spectrometer (CDS) on SOHO. Using the techniques of wavelet analysis on various temporal series datasets, we find that certain oscillation frequencies are favoured for each line. We find furthermor...
متن کاملStatistical Snakes: Active Region Models
This paper describes a new region-growing technique that uses a closed snake driven by a pressure force that is a function of the statistical characteristics of image data. This statistical snake expands until its elements encounter pixels that lie outside user-defined limits relative to a seed region; when these limits are violated the pressure force is reversed to make the model contract. Ten...
متن کاملUpflows in funnel-like legs of coronal magnetic loops
The prominent blue shifts of Ne viii associated with the junctions of the magnetic network in the quiet Sun are still not well understood. By comparing the coronal magnetic-field structures as obtained by a potential-field reconstruction with the conspicuous blue-shift patches on the dopplergram of Ne viii as observed in an equatorial quiet-Sun region, we find that most of the regions with sign...
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: Astronomy & Astrophysics
سال: 2015
ISSN: 0004-6361,1432-0746
DOI: 10.1051/0004-6361/201526339