Characteristics of 150 km echoes linked with solar eclipse and their implications to the echoing phenomenon
Characteristics of 150 km echoes linked with solar eclipse and their implications to the echoing phenomenon
复制标题
与日食相关的150公里回波特征及其对回波现象的影响
DOI：
10.1029/2010ja016258
复制
发表时间：
2011
影响因子：
--
通讯作者：
D. Tiwari
中科院分区：
文献类型：
--
作者：
A. Patra;P. Chaitanya;D. Tiwari
本文介绍了一项基于Gadanki雷达对2010年1月15日日食期间发生在1122-1515 IST期间的150公里回波的研究。雷达回波仅在1150-1215 IST和1344-1356 IST分别与日食的进入和恢复阶段有关。最引人注目的观察结果是在这两个时间段内观察到的回声区域的不寻常的上升和下降特征。虽然这些回波发生在高于对照日的高度，但其信噪比和谱宽与对照日的低回波区相似。此外，多普勒速度表明存在与对照日不同的西向电场。同时进行的电离层观测显示F1层的上升和下降与在150公里回波中观测到的非常相似。这些观测和相关分析表明，观测到的回波是由电子密度梯度和与日食效应相关的复合率降低共同作用的结果。这些观测结果首次阐明了密度梯度和复合率在150 km回波过程中的作用。
[1] This paper presents a study based on Gadanki radar observations of 150 km echoes made during the solar eclipse of 15 January 2010 that occurred during 1122–1515 IST. Radar echoes were observed only during 1150–1215 IST and 1344–1356 IST linked with the entry and recovery phases of the eclipse, respectively. The most striking observation found is the unusual ascending and descending features of the echoing regions observed during these two time periods. Although these echoes occurred at higher altitudes than those of control days, SNR and spectral width of these echoes are similar to those of the lower echoing region observed on the control days. Further, Doppler velocities suggest the presence of westward electric field unlike those of the control days. Concurrent ionosonde observations showed ascent and descent of the F1 layer very similar to those observed in the 150 km echoes. These observations and related analysis suggest that the observed echoes were due to the combined action of the electron density gradients and the reduced recombination rate linked with the solar eclipse effect. These observations are first of its kind and elucidate the role of density gradient and recombination rate in the 150 km echoing process.