CEDAR Postdoc: Seasonal Variations in Mesopause Region Temperatures, Zonal and Meridional Winds: Climatology and Variability of Mean-State, Diurnal and Semidiurnal Tides

CEDAR 博士后：中层顶地区温度、纬向和经向风的季节变化：平均状态、日潮和半日潮汐的气候学和变化

• 批准号: 0335127
• 负责人: Chiao-Yao She
• 金额: $ 16万
• 依托单位: Colorado State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-01-01 至 2006-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0335127&HistoricalAwards=false
• 关键词: CEDAR; Postdoc; Seasonal; Variations; Mesopause

This is a study of seasonal variations of temperatures and meridional winds in the mesopause region. The Colorado State sodium lidar has been upgraded to a two-beam system capable of simultaneous measurements of mesopause region temperature and winds, over full diurnal cycles, weather permitting. Regular observations in this mode of operation began in May 2002, and by the end of April 2003, one full year of data acquisition was completed giving a total of 1,388 hours of observation with 634 hours under sunlit conditions. The salient feature of a dataset with full-diurnal-cycle coverage lies in its ability to decompose the vertical profiles of dynamical fields (temperature, zonal and meridional winds) into a unique linear superposition of diurnal-mean and oscillations with different tidal periods, plus a residual. In this manner, the diurnal-mean and the amplitude and phase of tidal period oscillations can be determined solely from experimental data. The coherence of tidal excitation and of mean solar forcing prevails over the variability, leading to the convergence of the climatological mean in a multi-day observation. The 6-day composite yields means and diurnal tides that resemble model predictions very well. Preliminary analyses on data acquired in other months have generally shown similar variability and coherent convergence to climatological means, though the behavior in each month depends on the availability of full-diurnal-cycle data and the occurrence frequency of atypical profiles. Though the results of the first year of observation have exceeded expectations, at the present rate, it would require three years of data acquisition to produce a reliable study of climatology and variability. This study will continue the observations and associated science study as a post-doctoral program.

这是对中层顶区温度和经向风的季节变化的研究。科罗拉多州立大学的钠激光雷达已经升级为双波束系统，能够在天气允许的情况下，在整个全天周期内同时测量中层顶区的温度和风。这种工作模式的定期观测从2002年5月开始，到2003年4月底，完成了整整一年的数据采集，总共进行了1,388小时的观测，其中634小时是在阳光充足的条件下进行的。具有全日周期覆盖的数据集的显著特征在于它能够将动态场(温度、纬向风和经向风)的垂直剖面分解为不同潮汐周期的日平均和振荡的唯一线性叠加加上残差。通过这种方法，潮汐周期振荡的日平均、幅度和相位可以仅由实验数据确定。潮汐激发和平均太阳强迫的一致性压倒了变率，导致了气候平均值在多天观测中的收敛。6天的综合结果产生的平均潮汐和日潮与模型预测非常相似。对其他月份获得的数据进行的初步分析通常显示出与气候学手段类似的变异性和连贯的趋同，尽管每个月的行为取决于是否有全日循环数据和非典型轮廓的出现频率。尽管第一年的观测结果超出了预期，但按照目前的速度，需要三年的数据采集才能产生可靠的气候学和变异性研究。这项研究将作为博士后计划继续进行观察和相关的科学研究。