Coronal jets as a cause of microwave negative bursts

We have investigated the cause of three “isolated” negative radio bursts recorded one after another at several frequencies in the 1-17 GHz range at the Nobeyama Radio Observatory, Ussuriysk Astrophysical Observatory, and Learmonth Solar Observatory on April 10-11, 2014. The cause of the rarely observed “isolated” negative bursts is the absorption of radio emission from the quiet Sun’s regions or a radio source in the material of a large eruptive filament. Analysis of observations in different spectral ranges using images from the Nobeyama radioheliograph and the Solar Dynamics Observatory/Atmospheric Imaging Assembly has shown that the cause of all the three radio emission depressions was the screening of the limb radio source by the material of recurrent coronal jets. Parameters of the absorbing material were estimated using a previously developed model. These estimates confirmed the absorption of solar radio emission in cold material with a temperature of ~104 K at the bottom of the jets.