The Microwave Ultra-Fast Absorption Phenomenon

In this paper, a microwaveult ra-fast abso rption phenomenon observed with high time resolution on June 29, 1988 is analyzed. This abso rption appeared at the atmospheric layer of 4.00 GHz above solar active region of NOAA/USAF 5060 from 07^h38^m50^s to 07^h38^m58^s UT. At atmospheric layers of 2.84 GHz and 1.42 GHz spike emissions appeared. AR5060 was of the configuration of bipolar magnetic field which had strong activity. Hαflares of 3B and 2B were generated from 07^h38^m to 08^h47^m UT. X-ray burst of M6.5 also occurred. Acco rding to the characteristics of harmonic abso rptio n peak of ECM, we have calculated the magnetic field of harmonic, S =2, 3, at three f requencies(4.00 GHz, 2.84 GHz and 1.42 GHz)and analysed the absorption by using the bipolar f ield model. It is possible that the third harmonic of ECM at frequency of 4.00 GHz, was absorbed when it passed the absorption region(Ψ_e =ω/3).