The role of MLT dynamics at mid and high latitudes on the Ionosphere/Thermosphere weather II (DYNAMITE2)

电离层/热层系统由上方的太阳和磁层作用力以及下方较小但重要的低层大气作用力驱动。后者已经假设了很多年，但它的识别一直难以捉摸。这种强迫必须穿过中间层和低热层（MLT），在那里，广泛的波相互作用并耦合到I/T。这种耦合可以（a）直接通过波的传播发生，和/或（B）间接通过E区发电机发生。因此，MLT动力学通常很重要，但在中高纬度地区具有特殊的吸引力：（1）根据卫星观测，在这些纬度上观测到主要的重力波（GW）热点，以及（2）最近全球大气/电离层耦合模拟的研究表明，正是在这些纬度上，大气动力学，负责在低I/T纬度的大部分电动力学效应，在平流层突然变暖（SSW）事件期间被放大最多。作为我们第一阶段工作的一部分，到目前为止，已经在同行评审期刊上发表了9篇论文，其中一篇在EOS中突出显示。基于这些结果，我们提出了一些改变的方法和重点领域。 在第二阶段，我们建议继续在中高纬度地区使用独特的雷达和激光雷达能力来表征平流层和MLT波，平均流及其相互作用。我们将添加来自不同半球和半球的雷达数据，并将我们的激光雷达分析扩展到挪威北方的温度和风。这些研究将得到卫星和再分析数据的补充。将通过将MLT和平流层季节性和年度潮汐和重力波特征与Swarm和其他近极轨道卫星（如COSMIC）的I/T数据相关联来研究直接耦合，特别强调北方半球秋季过渡。不同的大气/电离层耦合模拟被用来补充这些研究。E区发电机效应的大气/电离层耦合模拟的帮助下，包括月球潮汐，在北方半球强极射流振荡（sPJOs）和非PJOs期间也进行了研究。我们的初步结果表明，不仅平流层，但也MLT动力学的影响后，许多周的发病PJO条件，这取决于PJO的类型。请注意，强PJO与主要SSW高度相关。我们通过地面和卫星电离层数据研究它们之间的联系及其对I/T系统的影响。在其他重要问题中，我们希望回答：（a）观察到的短期和季节性的影响，特别是在秋季过渡，MLT波和平均流的变化对I/T天气的影响是什么？(b)在PJO的不同行为及其相应的I/T效应期间，MLT平均流、潮汐和重力波的特征是什么？

The ionosphere/thermosphere (I/T) system is driven by solar and magnetospheric forcing from above and by smaller but important lower atmospheric forcing from below. The latter has been hypothesized for many years, but its identification has been elusive. This forcing has to pass through the mesosphere and lower thermosphere (MLT), where a wide spectrum of waves interacts and couples to the I/T. Such coupling can occur (a) directly via propagation of waves, and/or (b) indirectly via the E region dynamo. Therefore the MLT dynamics is in general important, but at mid and high latitudes have a special appeal: (1) over these latitudes are observed, according to satellite observations, the major gravity wave (GW) hot spots, and (2) recent studies from global atmospheric/ionospheric coupled simulations have shown that it is over these latitudes that the atmospheric dynamics, responsible for most of the electrodynamics effects at low I/T latitudes, is amplified the most during sudden stratospheric warming (SSW) events. As part of our first phase efforts, so far nine papers in peer-reviewed journals have resulted, including one highlighted in EOS. Based on these results, we propose some changes to the methodology and the focus areas. In this second phase, we propose to continue using unique radar and lidar capabilities at mid and high latitudes to characterize the stratosphere and MLT waves, mean flow, and their interactions. We will add radar data from different longitudes and hemispheres, as well as extend our lidar analysis to temperatures and winds over northern Norway. These studies will be complemented by satellite and reanalysis data. The direct coupling will be studied by correlating MLT and stratospheric seasonal and annual tidal and gravity wave signatures with I/T data from Swarm and other satellites with near-polar orbits (like COSMIC), with special emphasis in the northern hemisphere fall transition. Different atmospheric/ionospheric coupled simulations are used to complement these studies. The E region dynamo effects are also studied with the help of atmospheric/ionospheric coupled simulations with the inclusion of lunar tides, during northern hemispheric strong polar jet oscillations (sPJOs) and non-PJOs periods. Our preliminary results indicate that not only the stratospheric but also the MLT dynamics is affected many weeks after the onset PJO conditions, depending on the type of PJOs. Note that strong PJOs are highly correlated with major SSWs. We study their connection and their effects on the I/T system via ground-based and satellite ionospheric data. Among other important questions, we expect to answer: (a) what is the effect of the observed short-term and seasonal, particularly around the fall transition, variability of MLT waves and mean flows on the I/T weather? (b) what are the characteristics of MLT mean flow, tides and gravity waves during different behaviors of PJOs and their corresponding I/T effects?