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

CEDAR：使用超级双极光雷达网络 (SuperDARN) 和热层电离层中间层能量学和动力学 (TIMED) 分析行星波和大气潮汐

• 批准号: 0640864
• 负责人: Elsayed Talaat
• 金额: $ 47.11万
• 依托单位: Johns Hopkins University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-06-01 至 2012-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0640864&HistoricalAwards=false
• 关键词: CEDAR; Analysis; Planetary; Waves; Atmospheric

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.

研究人员将研究大气中的波如何在大距离和大气层之间传输能量和动量。 在中层和低热层（MLT）区域，最强的运动是由于周期为一天或一天的几分之一的太阳潮汐和周期超过一天的行星波。 迫切需要了解潮汐和行星波活动的性质、其能量的来源和汇及其对大气的影响。 此外，低层大气中的大扰动，例如平流层突然变暖（SSW）、准两年期涛动（QBO）以及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，越来越多的人认为会影响潮汐和行星波。 为了研究大气中波动活动的许多方面，最好是利用具有足够空间覆盖范围和时间分辨率的长期数据集来分辨波动模式。 超级双极光雷达网（SuperDARN）的高频（HF）雷达利用流星散射对中间层风进行常规测量。 在北方，雷达沿着一个经向接近180度的弧线分布，便于对潮汐和波浪特性进行更大的表征。 多雷达测量可追溯到1993年。 TIMED卫星包括使用宽带发射辐射测量仪探测大气层的仪器，该仪器自2002年以来提供了大气层特性的现场测量结果，从中可以推断出波的活动。 测量结果的比较证实了不同技术的波活动的一致性，并导致波模式的扩展分析。 该研究将联合收割机的SuperDARN和TIMED/SABER和高纬度迈克尔逊羟基（OH）旋转温度的数据集，以确定在MLT地区的行星波和潮汐模式的长期气候。 具体而言，该研究将确定：1）中高纬度行星波和迁移和非迁移潮汐的变化，以及2）低层大气中长期活动与驱动因素（如SSW，QBO和ENSO）之间的关系。 由QBO，SSW和ENSO代表的扰动对天气和气候有影响，似乎对中间层有影响，可以通过潮汐和行星波的观测来监测。 有了这项研究的扩展数据流，研究人员将能够描述各种影响，并深入了解大气扰动的来源。 该项目将有助于建立这方面的地面雷达技术，即，作为一个“永远在线”的大气扰动监测器。 这项研究涉及两名大学生，他们从事与这一产品有关的研究，目的是完成论文要求，并将他们培训成为使用卫星和雷达数据的专家。