Ionogram scaling related to particle E event and its analysis

At the present time, the criterions and scaling method of particle E are inconsistent. A distinct particle E event occurred on 16 February 2012, observed by 14 ionosondes in China, with which the criterions were discussed and six criterions were developed with some references and experiences. Simultaneously, based on the several ionograms, the scaling method was presented. By using the ionograms registered by the 14 ionosondes, the particle E event was analyzed, and the results showed that the timedelay of low frequency of extraordinary wave was notable at higher latitude stations (such as Manzhouli, Urumqi, Beijing), particle E was discernable with long lifetime at middle latitude stations (such as Lanzhou, Chongqing, Lhasa, etc.), and was weaker with short lifetime at lower latitude stations (such as Haikou, Guangzhou). Furthermore, by analyzing geomagnetic indices and ionospheric critical frequency foF2, we found that the occurrence of this particle E event occurred in the main phase of the geomagnetic storm. Finally, the mechanism of particle E event was discussed.