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Paper: |
Ground-based Observations of the Solar Sources of Space Weather |
Volume: |
504, Coimbra Solar Physics Meeting: Ground-based Solar Observations in the Space Instrumentation Era |
Page: |
247 |
Authors: |
Veronig, A. M.; Pötzi, W. |
Abstract: |
Monitoring of the Sun and its activity is a task of growing importance in the
frame of space weather research and awareness. Major space weather disturbances
at Earth have their origin in energetic outbursts from the Sun: solar flares,
coronal mass ejections and associated solar energetic particles.
In this review we discuss the importance and complementarity of ground-based and
space-based observations for space weather studies. The main focus is drawn on
ground-based observations in the visible range of the spectrum, in particular
in the diagnostically manifold Hα spectral line, which enables
us to detect and study solar flares, filaments (prominences), filament
(prominence) eruptions, and Moreton waves. Existing Hα networks such as
the GONG and the Global High-Resolution Hα Network are discussed. As an
example of solar observations from space weather research to operations, we present
the system of real-time detection of Hα flares and filaments established
at Kanzelhöhe Observatory (KSO; Austria) in the frame of the space weather segment
of the ESA Space Situational Awareness programme (swe.ssa.esa.int).
An evaluation of the system, which is continuously running since July 2013 is
provided, covering an evaluation period of almost 2.5 years. During this period,
KSO provided 3020 hours of real-time Hα observations at the ESA SWE portal.
In total, 824 Hα flares were detected and classified by the real-time
detection system, including 174 events of Hα importance class 1 and larger.
For the total sample of events, 95 % of the automatically determined flare peak
times lie within ±5 min of the values given in the official optical flares
reports (by NOAA and KSO), and 76 % of the start times. The heliographic positions
determined are better than ±5°. The probability of detection of flares
of importance 1 or larger is 95 %, with a false alarm rate of 16 %. These
numbers confirm the high potential of automatic flare detection and alerting from
ground-based observatories. |
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