Collaborative Research: CEDAR--Higher-Order Concentric Gravity Waves in the Northern Winter Thermosphere and Ionosphere

该奖项将确定山波的破碎如何影响地球表面上方约100-200英里的空间天气。山浪是由流过山脉的风形成的。当山浪到达足够高的山脉上方时，它们会破碎并翻转，类似于海浪在海滩上破碎。这个过程产生了湍流和大规模的波浪，这些波浪会传播到地球上方的更高高度。在地球表面100-200英里处，波中的中性分子与离子碰撞，在等离子体中产生称为电离层扰动（TID）的波。这些TID中的一些在GPS接收器的总电子含量的地图上看起来像圆环。TID会在太空天气中引起风暴，使其难以与绕地球轨道运行的卫星进行通信。 了解能量和动量是如何通过几个重力波产生和消散周期，包括第二和第三次重力波过程（多步垂直耦合过程），通过大气区域转移是重要的。 这个项目包括2名本科生在夏季为3年的时间，这一补助金。因此，这项研究将进一步发展和教育具有全球竞争力的STEM劳动力，并将促进科学的进步。 该团队将分享GPS/TEC信号处理例程，这将使社区受益。 本研究的主要目的是：1）通过详细的观测研究，确定冬季静时美国大陆（CONUS）和欧洲上空同心行进电离层扰动的重力波（GW）特征和来源，以及2）“多步垂直耦合”（MSVC）过程，其产生更高的-通过详细的模拟研究，从冬季美国大陆和欧洲的地形强迫中订购热层中的GWs。由于GPS/TEC观测在美国本土和欧洲密集，这些位置提供了研究这些同心TID的理想位置。该团队将识别和分析GPS/TEC在2012-2023年期间的5个冬季的安静时间12月至2月期间观测到的同心TID事件，并将使用GW分辨高海拔机械环流模型（HIAMCM）模拟和分析6-9个为期一周的山波（MW）事件。他们将解决SQ 1：在美国大陆和欧洲冬季GPS观测到的静时同心TID的GW特征、位置、发生率和来源是什么？SQ2：美国大陆和欧洲上空的地形强迫在热层中产生高阶同心GW的模拟耦合过程是什么？导致热层的大尺度变化是什么？该方法包括HIAMCM，一种射线跟踪模型（重力波源、射线追踪和重建模型（MESORAC）），以及公开可用的NRLMSISE-00和HWM-14模型，MERRA-2再分析数据，GOES和EUMETSAT卫星数据和全球定位系统/TEC数据。该奖项反映了NSF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进行评估，被认为值得支持的搜索.

This award will determine how the breaking of mountain waves affects space weather approximately 100-200 miles above the Earth’s surface. Mountain waves are created from the wind flowing over mountains. Mountain waves break and overturn when they get high enough above the mountains, similar to an ocean wave breaking on a beach. This process generates turbulence and large-scale waves which travel to higher heights above Earth. At 100-200 miles above the Earth’s surface, the neutral molecules in the waves collide with ions, which creates waves in the plasma called traveling ionospheric disturbances (TIDs). Some of these TIDs look like circular rings on maps of the total electron content from GPS receivers. TIDs can cause storms in the space weather that make it difficult to communicate with the satellites that orbit Earth. Understanding how energy and momentum are transferred through atmospheric regions via several gravity wave generation and dissipation cycles including secondary and tertiary gravity wave processes (multi-step vertical coupling processes) is important. This project includes 2 undergraduate students during the summertime for the 3-year duration of this grant. This research will therefore further the development and education of a globally competitive STEM workforce and will promote the progress of science. The team will share GPS/TEC signal processing routines which will benefit the community. The main objectives of this research are to determine 1) the gravity wave (GW) characteristics and sources of concentric traveling ionospheric disturbances over the quiettime winter continental United States (CONUS) and Europe through detailed observational studies, and 2) the “multi-step vertical coupling” (MSVC) processes which create higher-order GWs in the thermosphere from orographic forcing over the winter CONUS and Europe through detailed modeling studies. Because GPS/TEC observations are dense over the CONUS and Europe, these locations provide ideal locations to study these concentric TIDs. The team will identify and analyze concentric TID events observed by GPS/TEC during quiettime December-February for 5 winters during 2012-2023, and will simulate and analyze 6-9 one-week mountain wave (MW) events with the GW-resolving HIgh Altitude Mechanistic general Circulation Model (HIAMCM). They will address SQ1: What are the GW characteristics, locations, occurrence rates, and sources of the quiettime concentric TIDs observed by GPS over the winter CONUS and Europe? and SQ2: What are the simulated coupling processes by which orographic forcing over the CONUS and Europe creates higher-order concentric GWs in the thermosphere, and what are the large-scale changes that result in the thermosphere? The methodology includes HIAMCM, a ray trace model (the Model for gravity wavE SOurce, Ray trAcing and reConstruction (MESORAC)), and publicly-available NRLMSISE-00 and HWM14 models, MERRA-2 reanalysis data, GOES and EUMETSAT satellite data and GPS/TEC data.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.