Collaborative Research: CEDAR: Searching for the Strongest Thermospheric Wind and Highest Temperature inside Strong Thermal Emission Velocity Enhancements

该奖项全部或部分由2021年美国救援计划法案（公法117-2）资助。极光是太阳高能粒子雨下并与地球高纬度大气层碰撞的壮观展示。 这些彩色显示器被广泛观察到具有几种典型的形状和颜色。 最近，在高纬度地区观察到了一种“新”类型的极光。 它通常由一个狭窄的紫色弧与狭窄的绿色“栅栏”的特点。 它独特的形状和颜色与典型的极光不同。 科学家将其命名为STEVE（Strong Thermal Emission Velocity Enhancement）。 由于STEVE发生在比典型极光低的纬度（称为亚极光区），它被认为与电离层中的带电粒子的强烈流动有关，电离层是我们大气层上方的一层，具有自由流动的离子和电子。 对STEVE的研究将有助于我们了解高纬和低纬电离层之间的相互作用，以及太阳能如何影响整个地球大气系统和空间天气。正如其名称所示，STEVE是由于在大离子漂移（~ 5000 m/s）下，强离子中性相互作用产生的热引起的发光反应。为了验证强离子-中性相互作用产生的热量导致STEVE的假设，离子漂移和热层风观测都是必要的。Swarm卫星在STEVE研究中提供了离子漂移数据，但缺少极光下区域热层风和温度观测数据。 为了获得热层温度和风的观测结果，以确定STEVE的发射机制，该项目将在阿萨巴斯卡大学（54.60 N，113.64 W，61 MLAT）部署一台法布里-珀罗干涉仪（FPI），该大学设有一个光学观测台，STEVE已被观测到。 此外，还将使用一台小型彩色CCD全天照相机监测STEVE和极光活动的发生，并将使用一台双波段全球定位系统接收机监测电离层总电子含量的变化。 该团队计划每年花费20个夜晚，以真实的时间拍摄所有天空相机图像，并在看到STEVE时将FPI天空扫描仪转向STEVE。计划在未来的太阳活动区事件之后对亚暴事件进行真实的实时监测，这将由美国国家海洋和大气管理局空间气象服务进行跟踪。极光图像和FPI数据将结合Swarm离子漂移数据进行研究，以实现对电离层和热层状况的相对完整的诊断。 该项目将涉及三个专题：1）与STEVE有关的热层条件及其对排放的影响; 2）SAPS对热层风的影响; 3）热层风对亚暴负相扩展的影响。考虑到与STEVE相关的极端电离层条件，可以观察到大的热层风速和高的中性温度，这可以改变我们对热层-电离层相互作用的看法。 拟议的阿萨巴斯卡FPI可以弥补Resolute和Boulder FPI之间的巨大空间差距，并允许跟踪高纬度到中纬度的亚暴效应。 由于阿萨巴斯卡位于亚暴负相影响强烈的纬度范围内，该项目的结果将直接解决空间天气预报的一个主要问题。由于公民科学家首次观察到STEVE，该项目将提高公众对高层大气物理学研究的认识，并将激励公众未来参与科学和技术。 该项目将促进多样化的合作，并建立NCAR和EPSCoR州的科学竞争机构之间的伙伴关系。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2).Auroras are a spectacular display of the effects of Sun's energetic particles raining down and colliding with Earth’s atmosphere at high latitudes. These colorful displays are widely observed to have several typical shapes and colors. Recently, a ‘new’ type of aurora-like light at high latitudes has been observed. It often consists of a narrow purple arc with narrow green ‘picket-fence’ features. Its distinct shapes and colors are different from typical auroras. Scientists named it as STEVE (Strong Thermal Emission Velocity Enhancement). Because STEVE occurs at lower latitudes than typical auroras (called sub-auroral region), it is believed to be associated with a strong flow of charged particles in the ionosphere, a layer above our atmosphere with free-flowing ions and electrons. Research on STEVE will help us understand the interactions between the high and low latitude ionosphere and how solar energy impacts the entire Earth’s atmosphere system and space weather.As its name suggested, STEVE is interpreted to be due to the chemiluminescent reactions induced by heat generated by strong ion neutral interaction at large ion drift (~ 5000 m/s). To test the hypothesis of heat from strong ion-neutral interaction causing STEVE, both ion drift and thermospheric wind observations are necessary. The Swarm satellites have provided ion drift data in STEVE studies, but observations are missing for the thermospheric wind and temperature observations in the sub-auroral region. To obtain thermospheric temperature and wind observations for ascertaining the STEVE emission mechanism, this project will deploy a Fabry Perot Interferometer (FPI) at Athabasca University (54.60N, 113.64W, 61 MLAT), where an optical observatory is located and STEVE had been observed. In addition, a small color CCD all sky camera will be used to monitor the occurrence of STEVE and auroral activities and a dual-band GPS receiver will be used to monitor ionospheric Total Electron Content variations. The team plans to spend 20 nights/year to take all sky camera images in real time and steer the FPI sky scanner toward the STEVE when it is sighted. The real time monitoring is planned for substorm events following future solar active region events, which will be tracked from NOAA space weather services. The auroral images and FPI data will be studied in combination with the Swarm ion drift data to achieve a comparatively complete diagnosis of the ionosphere and thermosphere conditions. The project will address three topics: 1) Thermospheric conditions associated with STEVE and their effect on its emission; 2) SAPS effects on thermospheric winds; 3) Thermospheric wind's effect on the expansion of the substorm negative phase. Given the extreme ionospheric condition associated with STEVE, large thermospheric wind speed and high neutral temperature could be observed, which can change our perception of thermosphere-ionosphere interactions. The proposed Athabasca FPI can bridge the large spatial gap between the Resolute and Boulder FPI and allow the substorm effect from high to mid latitudes to be tracked. Since Athabasca is located at a latitude range that is strongly affected by the substorm negative phase, the results of this project will directly address a major concern for space weather forecast.Since STEVE was first observed by citizen scientists, this project will generate a greater public awareness of the aeronomy research and will stimulate future public engagement with science and technology. The project will foster diverse collaborations and establish a partnership between NCAR and a scientifically competitive institution in an EPSCoR state. The proposing team would make this project an opportunity to promote STEM education, increase the participation of women and underrepresented minorities in STEM.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.