Observations of solar drift pair bursts at the decameter wavelengths
Abstract
New results of observations of solar decametric drift pair bursts (DP) are considered. These observations were carried out during joint C-4 campaign (June-August, 2002) with decameter radiotelescope UTR-2 (Ukraine), equipped with new back-end equipment. High frequency and time resolution of this equipment allowed on the one hand to confirm already known DP characteristics with higher accuracy and reliability and on the other hand to obtain new information about their structure peculiarities at the lowest frequencies for ground-based observations. During noise storms July13-30, 2002, more than 3000 DPs were observed and processed. In general all measured parameters are in good conformity with already known ones at meter wavelengths. So the frequency drift rate lies between 0.5 and 2 MHz/s, time separation is 1-3s and separate trace durations are about 1-2s. In a majority of cases weak and moderate bursts were registered with fluxes from 1 to 100 SFU. Nevertheless features, which have not been described yet, were found. So, the drift rates of the reverse DPs are in average 1.5 times higher than that of forward DPs while the standard deviation of the first is 3.5 times wider than that of the second. Some of the DP traces are not smooth and have fine structure. Also many DPs were observed at frequencies from 16 to 25MHz, what have not been reported yet. There were observational days with considerable prevalence of either forward or reverse DPs. Some possible mechanisms of the observed DP bursts emission in the solar corona are discussed.
- Publication:
-
EGU General Assembly Conference Abstracts
- Pub Date:
- June 2004
- Bibcode:
- 2004EGUGA...6.4291M