Imaging science at El Leoncito, Argentina
Imaging science at El Leoncito, Argentina
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阿根廷 El Leoncito 的成像科学
DOI：
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发表时间：
2006
期刊：
影响因子：
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通讯作者：
M. Mendillo
中科院分区：
文献类型：
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作者：
C. Martinis;J. Baumgardner;Steven M. Smith;M. Colerico;M. Mendillo
抽象。利用位于阿根廷El Leoncito（南纬31.8度，西经69.3度，北纬-18度）的全天成像仪对热层和中间层结构进行了研究。该站点在赤道电离异常（EIA）峰下的位置具有相对较高的地理纬度，因此观测可用于研究几个赤道过程侵入中纬度域。此外，它有一个共栖点接近我们的同伴成像仪在阿雷西博，PR的视野，允许研究半球间的影响。使用630.0 nm和777.4 nm观测研究了四种类型的现象：（1）与瑞利-泰勒不稳定性/赤道扩展F（RTI/ESF）过程有关的高度结构性气辉损耗，（2）与午夜温度最大值（MTM）有关的亮度波（BW），（3）与电离层风暴正相有关的强气辉增强，和（4）简单的（非结构性）气辉耗尽带，其特征与类帕金斯不稳定性相匹配。第五类研究利用557.7纳米的中间层观测，研究可能由低层大气扰动产生的重力波，以及与强垂直温度梯度有关的中间层孔。虽然ESF损耗和BW事件被相当频繁地检测到，但中纬度带却没有，因此它们在El Leoncito的成功成像提供了南美洲经度部分中纬度与低纬度耦合的第一个例子。本文介绍了这些功能的初步结果。两者合计，这五种类型的光学结构提供了机会，调查耦合，无论是在海拔和纬度，在低纬度的空气动力学过程在南半球的一个采样不足的经度部门。
Abstract. Thermospheric and mesospheric structures are studied using an all-sky imager located at El Leoncito, Argentina (31.8° S, 69.3° W, –18° mag lat). This site has relatively high geographic latitude for a location under the crest of the equatorial ionization anomaly (EIA), and thus observations can be used to study the intrusion of several equatorial processes into the midlatitude domain. In addition, it has a conjugate point close to the field of view of our companion imager at Arecibo, PR, allowing for the study of inter-hemispheric effects. Four types of phenomena were studied using 630.0 nm and 777.4 nm observations: (1) highly-structured airglow depletions associated with the Rayleigh-Taylor instability/equatorial spread-F (RTI/ESF) process, (2) brightness waves (BW) associated with the midnight temperature maximum (MTM), (3) strong airglow enhancements associated with the positive phase of ionospheric storms, and (4) simple (non-structured) bands of airglow depletions with characteristics matching a Perkins-like instability. Using 557.7 nm mesospheric observations, a fifth category of study deals with gravity waves probably generated by lower atmospheric disturbances, and mesospheric bores related to strong vertical temperature gradients. While ESF depletions and BW events are detected fairly frequently, the mid-latitude bands are not, and thus their successful imaging at El Leoncito offers the first example of the coupling from mid-latitudes to low-latitudes in the South American longitude sector. Preliminary results on these features are presented in this paper. Taken together, these five types of optical structures offer the opportunity to investigate coupling, both in altitude and latitude, of aeronomic processes at low latitudes in an under-sampled longitude sector in the Southern Hemisphere.