LF BAND TERRESTRIAL RADIO-BURSTS OBSERVED BY WIND WAVES/

We report on a constituent of Earth's radio spectrum that shows remark able similarities to Jovian ''type III'' or quasi-periodic bursts. The se terrestrial bursts lie in the radio LF band, down to the in situ pl asma frequency and are made of two spectral components. The lower freq uency component exhibits relatively rapid negative frequency drifts, s imilar to type III solar bursts but on a much shorter time scale. It a ppears to emanate from a large source region and its characteristics a re the same as those of isotropic terrestrial kilometric radiation des cribed by other authors. The higher frequency component does not drift much in frequency, only lasts about 1 to 5 minutes and sometimes exte nds up to 500 kHz. It appears to emanate from a discrete source. This high frequency component was never reported before because it is often hidden by AKR events. It might be produced by a mechanism which diffe rs from AKR. These LF bursts may belong to a more common class of radi o bursts representing a previously unappreciated segment of Earth's ra dio spectrum.