CEDAR: Quantifying Mesospheric Gravity Waves and Associated Temperature Variability Over the Andes

CEDAR：量化安第斯山脉的中层重力波和相关温度变化

• 批准号: 0737698
• 负责人: Michael Taylor
• 金额: $ 25.81万
• 依托单位: Utah State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-01-01 至 2011-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0737698&HistoricalAwards=false
• 关键词: CEDAR; Quantifying; Mesospheric; Gravity; Waves

This project is a novel experimental investigation to quantify the role of gravity waves on the dynamics, momentum transport, deposition and subsequent forcing of the Mesosphere and Lower Thermosphere (MLT) region (~80-100 km) over South America, and specifically near the Andes Mountains. The Andes region is an excellent natural laboratory for investigating gravity wave influences on the MLT dynamics. During the summer months the dominant gravity wave forcing results from deep convection arising from severe thunderstorms over the continent to the east. During the winter, strong orographic forcing dominates, due to intense prevailing zonal winds blowing eastward from the Pacific Ocean which suddenly encounter the towering Andes mountain range. This creates large amplitude waves that have been measured well into the stratosphere but have yet to be unambiguously measured at MLT heights. There are strong theoretical reasons to expect them to penetrate well into the mesosphere, especially during the winter months. Building on extensive experience gained as part of the highly successful Maui-MALT program (2002-2006), this project will deploy and remotely operate the Utah State University CEDAR Mesospheric Temperature Mapper (MTM) at Cerro Tololo, Chile (30.1 S, 70.8 W). The MTM is a robust, high-performance CCD imaging system designed to provide key temperature and intensity measurements on gravity waves using precise observations of two prominent airglow emissions, the NIR OH(6,2) centered near 87 km, and the O2(0,1)Atmospheric band, near 94 km. These data afford a unique capability to quantify wave propagation, growth, and dissipation at MLT heights. It is planned to perform these new measurements in coordination with Na wind-temperature lidar, meteor radar, all-sky imager and other optical instruments as part of a well proven instrument cluster, as employed successfully during the Maui-MALT program. The primary goals are: 1) To quantify the impact and seasonal variability of a broad spectrum of waves (including gravity waves, tides and planetary waves) over the Andes using coordinated wave, wind, and temperature measurements; 2) To perform a unique investigation of mountain waves present at MLT heights during winter months, quantifying their characteristics and associated momentum fluxes, and comparing with similar measurements during the summertime due to convective forcing. The broader impact of the project includes strong student involvement, which will contribute to training the next generation of researchers in novel optical measurements and image processing techniques. In addition, the recognized role of gravity waves in driving the mean and variable structure of the MLT makes an understanding of their various contributions a high priority for the aeronomy community. In particular, the need to be able to accurately describe these effects in state-of-the-art models has broad implications for predicting their regional, seasonal and global influences under variable solar forcing and climate change conditions.

该项目是一项新的实验研究，旨在量化重力波对南美洲上空，特别是安第斯山脉附近的中间层和低热层区域（~80-100公里）的动力学、动量输送、沉积和随后的强迫的作用。 安第斯山脉地区是研究重力波对MLT动力学影响的极好的天然实验室。 在夏季的几个月里，主要的重力波强迫是由大陆东部的强雷暴引起的深对流造成的。 在冬季，强烈的地形强迫占主导地位，由于强烈的盛行纬向风吹向东从太平洋突然遇到高耸的安第斯山脉。 这就产生了大振幅的波，这些波在平流层中已经被很好地测量到，但在MLT高度还没有被明确地测量到。 理论上有充分的理由认为它们会很好地渗透到中间层，特别是在冬季。 在作为非常成功的毛伊岛-MALT计划（2002-2006年）的一部分而获得的广泛经验的基础上，该项目将在智利托洛洛山（30.1 S，70.8 W）部署和远程操作犹他州州立大学CEDAR中间层温度成像仪（MTM）。 MTM是一个强大的，高性能的CCD成像系统，旨在提供关键的温度和强度测量重力波使用两个突出的气辉发射，近红外OH（6，2）中心附近87公里，和O2（0，1）大气带，近94公里的精确观测。 这些数据提供了一个独特的能力，以量化波的传播，增长，并在MLT高度耗散。 计划与Na风温激光雷达、流星雷达、全天空成像仪和其他光学仪器协调进行这些新的测量，作为Maui-MALT计划期间成功使用的经过验证的仪器组的一部分。 主要目标是：1）量化各种波浪的影响和季节变化（包括重力波、潮汐和行星波）在安第斯山脉上使用协调的波、风和温度测量; 2）对冬季MLT高度出现的山波进行独特的调查，量化其特征和相关的动量通量，并与夏季对流强迫下的类似观测结果进行了比较。 该项目更广泛的影响包括学生的强烈参与，这将有助于培养新一代光学测量和图像处理技术的研究人员。 此外，重力波在驱动MLT的平均和可变结构方面的公认作用使得对它们的各种贡献的理解成为高层大气科学界的高度优先事项。 特别是，需要能够准确地描述这些影响的国家的最先进的模型有广泛的影响，预测其区域，季节和全球的影响，在可变的太阳强迫和气候变化条件。