Advancing knowledge of Earth's thermosphere dynamics with new analyses of the existing and extended WINDII dataset

通过对现有和扩展 WINDII 数据集的新分析，增进对地球热层动力学的了解

• 批准号: 5959-2013
• 负责人: Shepherd, Gordon
• 金额: $ 2.4万
• 依托单位: York University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2013
• 资助国家: 加拿大
• 起止时间: 2013-01-01 至 2014-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=520857
• 关键词: Advancing; knowledge; Earth; thermosphere; dynamics

The Earth's atmosphere is divided into regions; troposphere, stratosphere, mesosphere, thermosphere. The troposphere is the region where weather occurs while the thermosphere extends upward from 100 km. These regions may be characterized by their population of species, e.g. ozone in the stratosphere and atomic oxygen in the thermosphere, by their temperature and by their winds. Measuring the winds is the most challenging, and the first major initiative was with WINDII, a Wind Imaging Interferometer developed and built in Canada and flown on NASA's Upper Atmosphere Research Satellite, launched in 1991. WINDII was a new and innovative adaptation of the Michelson interferometer using a CCD detector that imaged the airglow occurring in the mesosphere and thermosphere, a photochemical sub-visual glow in the high atmosphere produced by the action of sunlight in the daytime, but persisting at night. The airglow occurs in sharp spectral lines, so tiny shifts in wavelength arising from Doppler effect caused by the wind are measured with the interferometer. WINDII discovered the presence of a huge atmospheric 24 hr tide (250 km/hr) near the equator at 100 km altitude, caused not by the moon's gravitation, but by solar heating; called a "migrating" tide because it moves with the sun. Strong dynamical motions from other waves were found over the entire globe, moving constituents, such as atomic oxygen, from place to place. WINDII celebrated its 20th anniversary last year, and then, with UARS, plunged into the Pacific Ocean. Just recently it has been discovered that there are also "non-migrating" tides, that do not move with the sun, but are driven by strong thunderstorm convection in the troposphere, propagating up to 250 km in the thermosphere. These are seen with WINDII as four wind waves around the Earth, three coming from the three continents and one from tidal propagation as seen from the satellite. The details of the character of these waves and the study of tropospheric effects reaching the thermosphere are the subject of this proposal. Knowledge of this transport of energy from the lower to the upper atmosphere will provide better atmospheric models in the future, for climate and weather prediction.

地球的大气层分为对流层、平流层、中间层和热层。对流层是天气发生的区域，而热层从100公里向上延伸。这些区域的特征可能在于其物种数量，例如平流层中的臭氧和热大气层中的原子氧，以及它们的温度和风。测量风是最具挑战性的，第一个重大举措是WINDII，这是一个在加拿大开发和建造的风成像干涉仪，搭载在1991年发射的美国宇航局高层大气研究卫星上。WINDII是对迈克尔逊干涉仪的一种新的创新性改造，使用了一个CCD探测器，对中层和热层中出现的气辉进行成像，这是白天阳光作用在高层大气中产生的一种光化学亚视觉辉光，但在夜间持续存在。气辉出现在尖锐的光谱线中，因此由风引起的多普勒效应引起的波长的微小变化可以用干涉仪测量。 WINDII发现在赤道附近100公里的高度存在一个巨大的大气24小时潮汐（250公里/小时），不是由月球的引力引起的，而是由太阳加热引起的;称为“迁移”潮汐，因为它与太阳一起移动。在整个地球仪上发现了来自其他波的强烈动力学运动，将原子氧等成分从一个地方移动到另一个地方。去年，WINDII庆祝了它的20周年纪念日，然后，与UARS一起坠入太平洋。就在最近，人们发现还有“非迁移”潮汐，它们不随太阳移动，而是由对流层中的强雷暴对流驱动，在热层中传播到250公里。这些被WINDII看作是围绕地球的四个风浪，三个来自三个大陆，一个来自卫星上看到的潮汐传播。这些波的特征的细节以及对流层对热层的影响的研究是这项建议的主题。了解这种从低层大气到高层大气的能量传输将在未来为气候和天气预测提供更好的大气模型。