Academic Journal
Electric field measurements of DC and long wavelength structures associated with sporadic- E layers and QP radar echoes
| العنوان: | Electric field measurements of DC and long wavelength structures associated with sporadic- E layers and QP radar echoes |
|---|---|
| المؤلفون: | Pfaff, R., Freudenreich, H., Yokoyama, T., Yamamoto, M., Fukao, S., Mori, H., Ohtsuki, S., Iwagami, N. |
| المساهمون: | NASA Goddard Space Flight Center (GSFC), Research Institute for Sustainable Humanosphere (RISH), Kyoto University, National Institute of Information and Communications, Department of Earth and Planetary Science Tokyo, Graduate School of Science Tokyo, The University of Tokyo (UTokyo)-The University of Tokyo (UTokyo) |
| المصدر: | ISSN: 0992-7689. |
| بيانات النشر: | HAL CCSD European Geosciences Union |
| سنة النشر: | 2005 |
| المجموعة: | Institut national des sciences de l'Univers: HAL-INSU |
| مصطلحات موضوعية: | [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences |
| الوصف: | International audience ; Electric field and plasma density data gathered on a sounding rocket launched from Uchinoura Space Center, Japan, reveal a complex electrodynamics associated with sporadic- E layers and simultaneous observations of quasi-periodic radar echoes. The electrodynamics are characterized by spatial and temporal variations that differed considerably between the rocket's upleg and downleg traversals of the lower ionosphere. Within the main sporadic- E layer (95?110 km) on the upleg, the electric fields were variable, with amplitudes of 2?4 mV/m that changed considerably within altitude intervals of 1?3 km. The identification of polarization electric fields coinciding with plasma density enhancements and/or depletions is not readily apparent. Within this region on the downleg, however, the direction of the electric field revealed a marked change that coincided precisely with the peak of a single, narrow sporadic- E plasma density layer near 102.5 km. This shear was presumably associated with the neutral wind shear responsible for the layer formation. The electric field data above the sporadic- E layer on the upleg, from 110 km to the rocket apogee of 152 km, revealed a continuous train of distinct, large scale, quasi-periodic structures with wavelengths of 10?15 km and wavevectors oriented between the NE-SW quadrants. The electric field structures had typical amplitudes of 3?5 mV/m with one excursion to 9 mV/m, and in a very general sense, were associated with perturbations in the plasma density. The electric field waveforms showed evidence for steepening and/or convergence effects and presumably had mapped upwards along the magnetic field from the sporadic- E region below. Candidate mechanisms to explain the origin of these structures include the Kelvin-Helmholtz instability and the E s -layer instability. In both cases, the same shear that formed the sporadic- E layer would provide the energy to generate the km-scale structures. Other possibilities include gravity waves or a combination of these ... |
| نوع الوثيقة: | article in journal/newspaper |
| اللغة: | English |
| Relation: | hal-00317867; https://hal.science/hal-00317867; https://hal.science/hal-00317867/document; https://hal.science/hal-00317867/file/angeo-23-2319-2005.pdf |
| الاتاحة: | https://hal.science/hal-00317867 https://hal.science/hal-00317867/document https://hal.science/hal-00317867/file/angeo-23-2319-2005.pdf |
| Rights: | info:eu-repo/semantics/OpenAccess |
| رقم الانضمام: | edsbas.9B5C3824 |
| قاعدة البيانات: | BASE |
| الوصف غير متاح. |