CEDAR Postdoc: The Effect of Atmospheric Tides on the Equatorial and Near-Polar Ionosphere

该项目研究赤道和近极地纬度中性低层大气与电离层之间的潮汐耦合。 最近发现，对流层潮汐在向上延伸到F区的高度上对赤道电离层结构有很大影响，这一发现推动了这项工作，也是将要采取的解决潮汐耦合对电离层影响的有针对性办法的基础。 对热层、电离层、中间层、能量学和动力学卫星和磁层-极光全球探测成像仪卫星最近进行的紫外线夜光观测的分析表明，夜间电离层中看到的带状结构与大气潮汐之间存在相关性。 耦合机制是中性大气中的潮汐与E区发电机的相互作用，通过F区高度的等离子体抬升耦合纬向结构。 该项目将利用实验数据和模拟相结合的方法，从电离层的明显起源到热层，研究潮汐对电离层的影响的全球性质。 气象、电离层及气候观测系统与台湾福尔摩沙卫星使命#3（COSMIC/FORMOSAT-3）使命提供1500多个全球定位系统（全球定位系统）每天从100至450公里高度的电子密度无线电掩星剖面，以及温度、压力、以及从近地表到60公里高度的太阳活动，具有相当高的地理和时间分辨率。 这些剖面具有严格的精确度，因此影响电离层的潮汐结构在电离层高度上应该是明显的;此外，在平流层和对流层中也可以探测到与对流层强迫相一致的潮汐特征。 GPS无线电掩星剖面的电子密度，温度，压力，和电离层活动，是一个很好的资源，比较电离层和潮汐研究使用非相干散射雷达（ISR）测量的电子密度，离子漂移速度和温度，并得出中性风。 从扑克坪、米尔斯通山和希卡马卡进行的ISR测量将用于检查在赤道、中纬度和北方高纬度地区的潮汐效应，并具有较高的时间和局部空间覆盖范围。 潮汐结构与海拔高度，纬度和季节的观测将与模拟从时间GCM/GSWM（热层电离层中间层电动力学环流模式/全球尺度波模式）进行比较。

This project investigates tidal coupling between the neutral lower atmosphere and the ionosphere at equatorial and near-polar latitudes. The recent discovery that tropospheric tides have a strong effect on the structure of the equatorial ionosphere at altitudes extending up through the F-region motivates this work, and was the basis for the targeted approach to addressing the effects of tidal coupling on the ionosphere that will be undertaken. Analysis of recent ultraviolet (UV) nightglow observations from the TIMED (Thermosphere Ionosphere Mesosphere Energetics and Dynamics) and IMAGE (Imager for Magnetosphere-to-Aurora Global Exploration) satellites demonstrated that there is a correlation between zonal structures seen in the nighttime ionosphere with the atmospheric tides. The coupling mechanism was interaction of tides in the neutral atmosphere with the E-region dynamo, which couples the zonal structure via plasma uplift through F-region altitudes. This project will use a combination of experimental data and simulations to investigate the global nature of tidal effects on the ionosphere, from their apparent origins through the thermosphere. The Constellation Observing System for Meteorology, Ionosphere and Climate and Taiwan's Formosa Satellite Mission #3 (COSMIC/FORMOSAT-3) mission provides over 1500 GPS (Global Positioning System's) radio occultation profiles of electron density from 100 to 450 km altitude every day, as well as profiles of temperature, pressure, and refractivity from near the surface to 60 km altitude with substantial geographic and temporal resolution. The profiles have tight accuracies such that the tidal structures that affect the ionosphere should be clearly evident at ionospheric altitudes; in addition, tidal features consistent with tropospheric forcing may also be detectable in the stratosphere and troposphere. The GPS radio occultation profiles, of electron density, temperature, pressure, and refractivity, are a good resource for comparison with ionospheric and tidal studies using incoherent scatter radar (ISR) measurements of electron density, ion drift velocities and temperatures, and derived neutral winds. ISR measurements from Poker Flat, Millstone Hill, and Jicamarca will be used to allow examination of tidal effects at equatorial, mid, and high northern latitudes with high temporal and local spatial coverage. The observations of tidal structure with altitude, latitude, and season will be compared with simulations from the TIME-GCM/GSWM (Thermosphere Ionosphere Mesosphere Electrodynamics General Circulation Model/Global Scale Wave Model).