Lower-Thermospheric Winds and Temperatures at High Latitudes

大气中被称为低热层的区域（海拔80至130公里）比卫星可到达的高海拔区域和气球和飞机可到达的低海拔区域更难研究。高海拔的太阳风和太阳紫外线能量输入向下传播，低海拔的潮汐和重力波能量输入向上传播，两者都在途中储存了一些能量。要了解高层和低层大气之间的耦合，我们必须了解低层热层的结构和动力学，以及它如何影响通过低层热层传播的能量。鉴于极光能量的来源，高纬度地区的研究尤其重要。阿拉斯加州和瑞典的两个非相干散射雷达对上一个太阳周期进行了广泛的测量，可以分析得出温度和风及其随季节、磁活动和太阳周期的变化。

The region of the atmosphere known as the lower thermosphere (80 to 130 km in altitude) is more difficult to study than the regions at higher altitudes accessible to satellites and regions at lower altitudes accessible to balloons and aircraft. The high altitude energy inputs of the solar wind and solar ultraviolet propagate downward through it, and the lower altitude tidal and gravity wave energy inputs propagate upward through it, both depositing some of their energy on the way. To understand the coupling between the upper and lower atmosphere we must understand the structure and dynamics of the lower thermosphere and how it affects the energy propagating through it. High latitude studies are especially important in view of auroral energy sources. Two incoherent scatter radars in Alaska and Sweden have made extensive measurements over the last solar cycle that can be analyzed to yield the temperatures and winds and their variation with season, magnetic activity and solar cycle.