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

中高纬度 MLT 动力学对电离层/热层天气 II (DYNAMITE2) 的作用

• 批准号: 273502374
• 负责人: Professor Dr. Jorge Chau, Ph.D.
• 金额: --
• 依托单位: Max-Planck-Institut für Meteorologie (MPI-M)
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2015
• 资助国家: 德国
• 起止时间: 2014-12-31 至 2021-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/273502374?language=en
• 关键词: role; MLT; dynamics; mid; latitudes

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?

电离层/热层（I/T）系统是由太阳能和磁层从上方和较小但重要的低大气强迫从下方驱动的。后者已经假设了多年，但其识别是难以捉摸的。这种强迫必须穿过中层和较低的热层（MLT），其中广泛的波浪与I/T相互作用。可以通过波的传播和/或通过E区域发电机间接地进行这种耦合（a）通过波的传播和/或（b）。因此，通常重要的是，MLT动力学至关重要，但是在中高纬度地区具有特殊的吸引力：（1）根据卫星观察结果，观察到这些纬度的主要重力波（GW）热点，以及（2）最新的研究，来自全球大气/电离层层层的模拟表明，它对这些含量的较低的效果是对大气的效果，最多的，大多数的动态效果，最多的动态范围，该效果是大多数的动态，这些效果是最多的动态。在突然的平流层变暖（SSW）事件中，纬度最大。作为我们第一阶段努力的一部分，到目前为止，已在同行评审期刊上进行了9篇论文，其中包括EOS中突出显示的一篇。基于这些结果，我们建议对方法和焦点领域进行一些更改。 在第二阶段，我们建议继续在中和高纬度上使用独特的雷达和激光雷达功能，以表征平流层和MLT波，平均流量及其相互作用。我们将添加来自不同纵向和半球的雷达数据，并将激光雷达分析扩展到挪威北部的温度和风。这些研究将由卫星和重新分析数据补充。直接耦合将通过将MLT和平流层季节性以及年度潮汐和重力波特征与来自群和其他卫星的I/T数据相关联，并具有近极轨道（例如宇宙），并特别强调了北半球的跌倒过渡。不同的大气/电离层耦合模拟用于补充这些研究。还可以在北半球强极极性喷射振荡（SPJOS）和非PJOS时期的情况下，借助大气/电离层耦合的模拟来研究E区域发电机效应。我们的初步结果表明，不仅平流层，而且MLT动力学在发作PJO条件后数周都受到影响，具体取决于PJOS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了它们的联系及其对I/T系统的影响。除其他重要问题外，我们希望回答：（a）观察到的短期和季节性的影响，尤其是在秋季过渡时期，MLT波的变异性以及对I/T天气的平均流量的影响？ （b）MLT平均流动，潮汐和重力波的特征是什么？