CEDAR: Analysis of Planetary Waves and Atmospheric Tides Using Super Dual Auroral Radar Network (SuperDARN) and Thermosphere Ionosphere Mesosphere Energetics and Dynamics (TIMED)

研究人员将研究大气中的波浪如何在大距离和大气层之间传输能量和动量。在中间层和低热层(MLT)区域，最强烈的运动是由周期为一天或几天的太阳潮汐和周期超过一天的行星波引起的。迫切需要了解潮汐和行星波活动的性质、其能量的来源和汇，以及它们对大气的影响。此外，低层大气中的大扰动，如平流层突然警告(SSW)、准两年振荡(QBO)和厄尔尼诺和南方涛动(ENSO)，及其对天气和气候的已知和潜在影响，越来越多地被认为影响潮汐和行星波。为了研究大气中波动活动的许多方面，呼吁使用具有足够空间复盖率和时间分辨率的长期数据集来解析波动模式是有利的。超级双极光雷达网(SuperDARN)的高频(HF)雷达利用流星散射对中层风进行常规测量。在北半球，雷达沿着经度接近180度的弧线分布，有助于更全面地描述潮汐和波浪特征。多雷达测量可以追溯到1993年。这颗定时卫星包括使用宽带发射辐射测量仪对大气进行探测，该仪器自2002年以来提供了对大气性质的现场测量，可从中推断波的活动。测量结果的比较证实了不同技术中波动活动的一致性，并导致了对波动模式的扩展分析。这项研究将结合SuperDARN、TIMED/SABER和高纬度迈克尔逊羟基(OH)旋转温度的数据集，以确定MLT地区行星波和潮汐模式的长期气候学。具体地说，这项研究将确定：1)中高纬度行星波以及迁移和非迁移潮汐的可变性，以及2)长期活动与低层大气驱动因素的关系，如SSW、QBO和ENSO。QBO、SSW和ENSO所代表的扰动对天气和气候有影响，对中间层似乎有影响，可以通过对潮汐和行星波的观测来监测。有了这项研究可用的扩展数据流，调查人员将能够描述各种影响的特征，并深入了解大气扰动的来源。该项目将有助于建立这一能力的陆基雷达技术，即作为对大气扰动的“始终在线”监测。这项研究涉及两名大学生，他们从事与该产品相关的研究，目的是满足他们的论文要求，并将他们培训为卫星和雷达数据使用方面的专家。

The investigators will study how waves in the atmosphere transport energy and momentum across large distances and between atmospheric layers. In the mesosphere and lower thermosphere (MLT) region the strongest motions are due to solar tides with periods of a day or fractions thereof and planetary waves with periods that exceed a day. There is a critical need to understand the properties of the tidal and planetary wave activity, the sources and sinks of their energy, and their effects on the atmosphere. Moreover, large perturbations in the lower atmosphere, such as Sudden Stratospheric Warmings (SSWs), the Quasi-Biennial Oscillation (QBO), and the El Nino and Southern Oscillation (ENSO), with their known and potential impacts on weather and climate, are increasingly thought to affect tides and planetary waves. To study the many aspects of wave activity in the atmosphere it is advantageous to appeal to long-term data sets that have sufficient spatial coverage and temporal resolution to resolve the wave modes. The high frequency (HF) radars of the Super Dual Auroral Radar Network (SuperDARN) make routine measurements of mesospheric winds using meteor scatter. In the northern hemisphere the distribution of radars along an arc that measures nearly 180 degrees in longitude facilitates a larger characterization of tide and wave characteristics. The multi-radar measurements extend back to 1993. The TIMED satellite includes the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument which has since 2002 provided in situ measurements of atmospheric properties from which wave activity can be inferred. Comparison of the measurements confirms the coherence of wave activity across the different techniques and leads to an expanded analysis of the wave modes. The research will combine the data sets of SuperDARN and TIMED/SABER and high-latitude Michelson hydroxyl (OH) rotational temperatures to determine a long-term climatology of planetary waves and tidal modes in the MLT region. Specifically the study will determine: 1) the variability of planetary waves and of migrating and non-migrating tides in the middle and high latitudes, and 2) the relationship between long-term activity and drivers in the lower atmosphere such as SSWs, QBO, and ENSO. The perturbations represented by QBO, SSWs, and ENSO have impacts on weather and climate and appear to have consequences for the mesosphere that can be monitored by observations of tides and planetary waves. With the extended data streams that are available for this study, the investigators will be able to characterize the various effects and gain insight into the sources of atmospheric disturbance. This project will help establish the ground-based radar technique in this capacity, i.e., as an 'always-on' monitor of disturbance in the atmosphere. The study involves two university students in research related to this product with the aims of fulfilling their thesis requirements and training them to be experts in the use of satellite and radar data.