Interpretation of equatorial electrojet irregularities observed with a broad beam HF zenithal radar
Interpretation of equatorial electrojet irregularities observed with a broad beam HF zenithal radar
复制标题
用宽波束高频天顶雷达观测到的赤道电喷射不规则现象的解释
DOI：
--
复制
发表时间：
1999
期刊：
影响因子：
--
通讯作者：
J. Villain
中科院分区：
文献类型：
--
作者：
T. Farges;E. Blanc;J. Villain
在国际赤道电射流年（1993-1994年）期间，在非洲利用磁赤道附近的探测和地球物理研究所的雷达对赤道电离层进行了观测。这种高分辨率天顶高频雷达使用宽波束天线，可以观察到复杂的回波结构。在100-500公里的雷达范围内出现了各种各样的不规则性，直到F区。在距离-时间-强度图中，一些不规则性出现在140至180公里之间的抛物线区域，中午最小。该区域仅在4和5 MHz之间的雷达频率下观察到。在这些频率下，100-140公里范围内垂直和倾斜方向产生的II型不规则性占主导地位，而I型不规则性很难清楚地识别。射线追踪和模拟表明，I型不规则性是一个可能的来源所观察到的抛物面区域。如Jicamarca雷达所观测到的，来自赤道“150公里区域”的辐射出现在略高的雷达范围内。
Observations of the equatorial ionosphere were performed in Africa with the radar of the Laboratoire de Détection et de Géophysique near the magnetic equator during the International Equatorial Electrojet Year (1993–1994). This high‐resolution zenithal HF radar uses a broad beam antenna, in which complex echo structures are observed. A diversity of irregularities appears in the 100–500 km radar range up to the F region. Some irregularities appear in range‐time‐intensity diagrams as a parabolic region between 140 and 180 km with a minimum at noon. This region is only observed for radar frequencies between 4 and 5 MHz. At these frequencies, type II irregularities arising from vertical and oblique directions in the 100–140 km range dominate the spectra, and type I irregularities are difficult to clearly identify. Ray tracing and simulations show that type I irregularities are a possible source of the observed parabolic region. Irregularities from the equatorial “150 km region” as observed with the Jicamarca radar appear at slightly higher radar ranges.