Detailed Structure of Electron Temperature and Density inside the Sporadic E Layer

Unusual current-voltage characteristics were found by the Fast Langmuir Probe measurement inside sporadic E (Es) layer during S-520-29 sounding rocket flight. The characteristics are caused by a significant gradient of electron density inside the Es layer. We employ a new analysis method for accurate estimation of the electron temperature and density. It also allows us to obtain the temperature and density in a shorter time interval than the voltage sweep period. Our new observation and analysis method provide us with first detailed structure of electron density and temperature inside the Es layer with an unprecedented spatial resolution. The maximum electron density and the minimum electron temperature observed inside Es layer are estimated to be 9.7×10(exp 5) cm-3 and 550 K, respectively, at an altitude of 98 km. The total thickness of the layer is about 1 km. Furthermore, the detailed trend of the electron temperature from its boundary toward the center of Es layer was revealed so clearly owing to the new method. Electron temperature in the surrounding region of the Es layer is found to be quite high, suggesting significant heating at the altitude range. The observed reduction of electron temperature in the Es layer embedded in an elevated temperature region is interpreted in terms of dependence of heat sources and cooling processes on the thermal electron density.
形態: 図版あり
Physical characteristics: Original contains illustrations
資料番号: AA1830006000
レポート番号: JAXA-RR-18-002E