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: http://star.arm.ac.uk/annrep/annrep2004/node47.html
Дата изменения: Tue Apr 19 13:35:58 2005 Дата индексирования: Tue Oct 2 04:48:35 2012 Кодировка: Поисковые слова: comet tail |
We present, for the first time, blinker phenomena associated with brightenings in pre-existing coronal loops registered by the EIT in FeXII 195Å. The brightenings occur during the emergence of new magnetic flux as registered by the Big Bear Solar Observatory (BBSO) magnetograph. The blinkers were identified using simultaneous observations obtained with CDS and SUMER spectrographs. In light of the new observational results, we present one possible theoretical interpretation of the blinker phenomenon. We suggest that the blinker activity we observe is triggered by interchange reconnection, serving to provide topological connectivity between newly emerging flux and pre-existing flux. The EIT images show the existence of loop structures prior to the onset of the blinker activity. Based on the available spatial resolution, the blinker occurs within or nearby an existing coronal loop. The temperature interfaces created in the reconnection process between the cool plasma of the newly emerging loop and the hot plasma of the existing loop are what we suggest to cause the observed activity seen in both the SUMER and CDS data. As the temperature interfaces propagate with the characteristic speed of a conduction front, they heat up the cool chromospheric plasma to coronal temperatures, an increasing volume of which brightens at transition region temperatures. We believe this new interpretation gives further qualitative understanding about the evolution of newly emerging flux on the Sun. This also provides new insight into the dynamic nature of the solar transition region (Doyle, Roussev & Madjarska 2004).