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在高纬度地区降落并与地球大气层相撞的壮观景象。这些彩色显示器被广泛观察到有几种典型的形状和颜色。最近，在高纬度地区观测到一种“新型”类似极光的光。它通常由狭窄的紫色弧线和狭窄的绿色“尖桩栅栏”特征组成。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（强热辐射速度增强）。由于STEVE发生在比典型极光更低的纬度（称为亚极光区），它被认为与电离层中带电粒子流的强烈流动有关，电离层是我们大气层之上的一层，有自由流动的离子和电子。对STEVE的研究将帮助我们了解高纬度和低纬度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。顾名思义，STEVE被解释为在大离子漂移（~ 5000 m/s）下，由强离子中性相互作用产生的热引起的化学发光反应。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，但是缺少对热层风和亚极光区域温度的观测。为了获得热层温度和风的观测数据，以确定STEVE的发射机制，该项目将在阿萨巴斯卡大学（54.60N, 113.64W, 61 MLAT）部署Fabry Perot干涉仪（FPI），该大学有一个光学天文台，已经观测到STEVE。此外，一个小型彩色CCD全天相机将用于监测STEVE和极光活动的发生，一个双频GPS接收器将用于监测电离层总电子含量的变化。该团队计划每年花20个晚上实时拍摄所有天空相机图像，并在看到史蒂夫时将FPI天空扫描仪转向史蒂夫。计划对未来太阳活动区事件之后的亚风暴事件进行实时监测，这将由NOAA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条件的比较完整的诊断。该项目将涉及三个主题：1)与STEVE相关的热层条件及其对其排放的影响；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，可以观测到大的热层风速和高的中性温度，这可能会改变我们对热层-电离层相互作用的看法。拟议的阿萨巴斯卡FPI可以弥合Resolute和Boulder FPI之间的巨大空间差距，并允许从高纬度到中纬度跟踪亚暴效应。由于阿萨巴斯卡所处的纬度范围受到亚风暴负相位的强烈影响，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STEVE最早是由公民科学家观察到的，这个项目将提高公众对航空研究的认识，并将激发公众对科学和技术的参与。该项目将促进多样化的合作，并在NCAR和EPSCoR州的一个具有科学竞争力的机构之间建立伙伴关系。提议小组将使这个项目成为促进STEM教育，增加妇女和代表性不足的少数民族参与STEM的机会。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识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.