CEDAR: Solar Cyclic and Climatic Influences on Upper Atmospheric Hydrogen Distributions

该项目从观测和模拟两个角度探讨太阳可变性和温室气体增加对高层大气氢分布的影响。法布里-珀罗对中纬度北部地区在三个太阳极小期期间的高层大气氢巴尔默-阿尔法排放的观测建立了一个参考数据集，可用于与未来的观测和大气模型进行比较。这一数据集显示，由于温室气体的增加，氢的丰度增加，氢光学排放量明显上升，其幅度大于单独预测的幅度。为了确保这不是校准伪影的结果，将通过使用关于背景银河发射强度的最新知识、当前的分析工具和最新的对流层散射校正代码来提高北半球长期巴尔默-阿尔法数据集的准确性。此外，还将比较来自北半球和南半球的观测结果。该项目要解决的主要科学问题如下：太阳周期和气候对控制含氢物种从低层大气到高层大气耦合的机制有什么影响？地冠氢是地球含氢物种分布的上界，在观测到的地冠氢的排放方面，太阳周期以及可能更长期的趋势是什么？预测的含氢物种的变化幅度是多少？为了解决这一问题，将使用全大气社区气候模式(WACCM)来开展太阳循环和气候对中上层大气氢物种分布的影响的敏感性研究。NCAR全球平均模式将被用来研究这些强迫如何通过热层传播。威斯康星州一所两年制大学的教职员工和本科生将参与这项工作。将开展公众宣传活动，旨在提高公众对气候变化科学的认识，并促进青年接触和参与科学的机会。

This project addresses the influence of solar variability and greenhouse gas increases on upper atmospheric hydrogen distributions from both an observational and modeling perspective. Fabry-Perot observations of upper atmospheric hydrogen Balmer-alpha emissions from Northern mid-latitudes over the time period spanning three solar minima establish a reference data set that can be used to compare with future observations and with atmospheric models. This data set shows an apparent upward trend in hydrogen optical emissions of greater magnitude than predicted alone from increases in hydrogen abundance due to the rise in greenhouse gases. In order to ensure that this is not a result of a calibration artifact, the accuracy of the Northern hemisphere long-term Balmer-alpha data set will be improved through use of updated knowledge of the background Galactic emission intensity, current analysis tools, and an updated tropospheric scattering correction code. In addition, observations from the Northern and Southern Hemisphere will be compared. The major science questions to be addressed by this project are as follows: What are the solar cyclic and climatic influences on mechanisms governing lower to upper atmospheric coupling of hydrogenous species? What are the solar cyclic and possibly longer-term trends in emission observations from geocoronal hydrogen, the upper boundary of the Earth's hydrogenous species distribution? What are the predicted magnitudes for changes in hydrogen-containing species? To address this, the Whole Atmosphere Community Climate Model (WACCM) will be used to carry out sensitivity studies of solar cyclic and climatic influences on middle and upper atmospheric hydrogeneous species distributions. The NCAR Global Mean Model will be used to study how these forcings propagate through the thermosphere.A faculty member at a two-year UW college campus and undergraduate students will be involved in this work. Public outreach activities will be carried out aimed at increasing public literacy about the science of climate change, and facilitating opportunities for youth exposure and involvement in the sciences.