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

合作研究：CEDAR——北方冬季热层和电离层的高阶同心重力波

• 批准号: 2329958
• 负责人: Sebastijan Mrak
• 金额: $ 18.88万
• 依托单位: University of Colorado at Boulder
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-11-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2329958&HistoricalAwards=false
• 关键词: Collaborative; Research; CEDAR; Higher; Order

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.

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。山波是由流过山脉的风产生的，当山波到达山脉上方足够高的高度时，山波会破碎并翻转。海浪冲击海滩时会产生湍流和大范围的波浪，这些波浪会传播到距地球表面 100-200 英里的更高高度，波浪中的中性分子与离子发生碰撞。它会在等离子体中产生称为行进电离层扰动 (TID) 的波，其中一些 TID 在 GPS 接收器的总电子含量地图上看起来像圆环，可能会在太空天气中引起风暴，从而导致与卫星的通信变得困难。了解能量和动量如何通过几个重力波产生和耗散循环（包括二次和三次重力波过程（多步垂直耦合过程））在大气区域中传递非常重要。因此，这项研究将在为期 3 年的夏季期间进一步培养和教育具有全球竞争力的 STEM 劳动力，并将促进科学进步，从而使社区受益。本研究的主要目标是通过详细的观测研究确定 1) 重力波 (GW) 特征以及美国冬季大陆 (CONUS) 和欧洲平静时期同心行进电离层扰动的来源，以及 2) “多步骤”垂直的“耦合”（MSVC）过程，通过详细的建模研究，通过冬季大陆和欧洲的地形强迫在热层中产生高阶重力波，因为 GPS/TEC 观测在大陆和欧洲上空密集，这些位置为研究这些提供了理想的地点。该团队将识别和分析 2012 年至 2023 年 5 个冬季 12 月至 2 月期间 GPS/TEC 观测到的同心 TID 事件，并模拟和分析 6-9 个同心 TID 事件。使用 GW 解析高空机械环流模型 (HIAMCM) 进行为期一周的山波 (MW) 事件 他们将解决 SQ1：GPS 观测到的安静时间同心 TID 的 GW 特征、位置、发生率和来源是什么。冬季美国大陆和欧洲？以及 SQ2：美国大陆和欧洲的地形强迫在热层中产生高阶同心引力波的模拟耦合过程是什么？该方法包括 HIAMCM、射线追踪模型（重力波源、射线追踪和重建模型 (MESORAC)）以及公开可用的 NRLMSISE-00 和 HWM14 模型、MERRA-2再分析数据、GOES 和 EUMETSAT 卫星数据以及 GPS/TEC 数据。该奖项反映了 NSF 的法定使命，并通过使用评估被认为值得支持基金会的智力价值和更广泛的影响审查标准。