caa a22 4500 445346906 CHVBK 20180317142831.0 cr unu---uuuuu 170323e20111201xx s 000 0 eng 10.1007/s11207-011-9806-6 doi (NATIONALLICENCE)springer-10.1007/s11207-011-9806-6 Nitta N. ADBS, Lockheed Martin Solar and Astrophysics Laboratory, Bldg 252, 3251 Hanover Street, 94304, Palo Alto, CA, USA aut Observables Indicating Two Major Coronal Mass Ejections During the WHI [Elektronische Daten] [N. Nitta] Two of the five fast (v≳900km s−1) coronal mass ejections (CMEs) between January 2007 and December 2009 were observed during the Whole Heliosphere Interval (WHI: 20 March - 16 April 2008). The main purpose of this article is to discuss possible observational signatures that could have been used to predict these CMEs. During the WHI, there were three active regions aligned almost East-West in a longitudinal span of about 60°. They were NOAA active region (AR) 10987, 10988, and 10989. In terms of the sunspot area, AR10988 was the largest. However, the fast CMEs were launched from AR10989 on 25 March and from AR10987 on 5 April. One explanation for this may be that AR10988, unlike the other two regions, emerged underneath a predominantly closed magnetic-field environment, as shown by global magnetic-field extrapolations. Around the times of these CMEs, however, magnetic-field observations of the source regions were essentially missing, because they were close to, or behind, the limb as viewed from Earth. Therefore, we explore an extended view in longitude of the regions from the Solar Terrestrial Relations Observatory (STEREO). The two STEREO spacecraft were located ≈ 24° East and West of the Sun-Earth line during the period of interest. We study the frequency of microflares in the three regions and changes in large-scale structures including streamers, but the CMEs do not seem to be correlated with either of them. Instead, activation of filaments or prominences may directly signal subsequent eruptions. Springer Science+Business Media B.V., 2011 Coronal mass ejections, low coronal signatures nationallicence Active regions, structure nationallicence Solar Physics Springer Netherlands 274/1-2(2011-12-01), 219-232 0038-0938 274:1-2<219 2011 274 11207 https://doi.org/10.1007/s11207-011-9806-6 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11207-011-9806-6 text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Nitta N. ADBS, Lockheed Martin Solar and Astrophysics Laboratory, Bldg 252, 3251 Hanover Street, 94304, Palo Alto, CA, USA aut NATIONALLICENCE 773 0- Solar Physics Springer Netherlands 274/1-2(2011-12-01), 219-232 0038-0938 274:1-2<219 2011 274 11207 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer