Ionospheric E-F valley observed by a sounding rocket at the low latitude station Hainan and a model for its characteristics
Jiankui Shi1, Zheng Wang1, Klaus Torkar2, Martin Friedrich3
[1] State Key Laboratory of Space Weather / CSSAR, Chinese Academy of Sciences, Beijing
[2] Space Research Institute, Austrian Academy of Sciences, Graz, Austria
[3] Graz University of Technology, Graz, Austria
Correspondence to: JianKui Shi ()
Observation of the Ionospheric variation and disturbalence is very important for space weather studies. In this paper, basing on the sounding rocket experiment conducted at Hainan ionospheric observatory (19.5°N, 109.1°E), a observed ionosphric E-F valley is presented. The sounding rocket was launched in the morning (LT 06:15) on May 7, 2011 and the observed electron density profile out of the E-F valley agrees with the simultaneous observation by the DPS-4 digisonde at the same station. This is the first observation of the E-F valley in the low latitude region in the East Asian sector. The width of the observed valley was about 42 km, the depth was almost 50%, and the altitude of the electron density minimum was 123.5 km. The characteristics of the observed valley should be mainly related to the big solar zenith during the flight of the sounding rocket, and the low latitude and the sunrise should be also the reasons for the big width and depth of the observed valley. The IRI model could not describe the observed E-F valley. For this, according to the Chapman theory we choose the F- layer, E- layer and a sub E layer at the height of 90 km as Chapman layers to develop a new overlapping three-Chapman-layer model for the characteristics of the observed E-F valley. The model results are well consistent with the observation, which indicates that the photochemical process at the height of 90 km (the sub-E layer) has obvious effect on it.
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