Collaborative Research: Spatio-Temporal (4D) Atmospheric Environments of Jet Contrail Outbreaks for Potential Mitigation of their Climatic Impacts

在那些商业航班频繁的地区，飞机产生的尾迹和由此产生的卷云可能会加剧气候变暖。对于美国来说，大多数持续的尾迹以群集或“爆发”的形式出现，它们可以在相对较大的地区（即美国中西部）持续数小时。特别是，在原本基本晴朗的天空中出现的尾迹爆发，大大改变了辐射和能量收支，并有助于缩小低层大气白天和黑夜之间的温度范围。他们的研究将允许评估人类对气候因素的影响。最近，一些航空公司和外国政府表示希望减少航空对环境和气候的影响，包括与飞机尾迹有关的影响。要实现这一目标，就需要更充分地了解疾病爆发的空间和时间特征，并有能力及时预测它们的发生，从而可能允许在这些地区周围的高空飞行进行水平或垂直改道。这项研究将通过分析高分辨率卫星图像，以及飞机巡航高度附近按季节分层和按美国次区域分层的关键气象变量的合成数据，确定晴空轨迹爆发的地理和气象空间和时间尺度。这些分析将构成疫情预测（统计）模型的基础，以期最终用于业务预测。地理信息系统将用于统计模型的开发————利用传统气象数据、卫星云和湿度检索以及航空数据————以及对根据独立数据和时间段进行的疫情事件进行验证。先进的地质统计技术将应用于包含爆发的图像，以模拟它们的清除，并估计对辐射和能量预算以及地表温度造成的影响。这项研究还将进一步阐明飞机尾迹对地球表面温度的影响，并将通过侧重于个案研究调查中爆发的最佳子集来证明实施这些模型的潜在价值。

Aircraft-generated contrails and their resulting cirrus clouds may exacerbate climate warming in those areas characterized by frequent commercial flights. For the United States, the majority of persisting contrails occur as clusters, or "outbreaks", which can persist over relatively large regions (i.e. U.S. Midwest) for many hours. In particular, contrail outbreaks occurring in otherwise mostly clear skies significantly modify radiation and energy budgets, and help reduce the range of temperature in the lower atmosphere between day and night. Their study would allow for evaluating human influences on climatic factors. Recently, some airline companies and foreign governments have expressed a desire to reduce aviation impacts on the environment and climate, including those related to contrails. Realization of this goal requires both a fuller understanding of the space and time-scale characteristics of outbreaks, and an ability to forecast their occurrence in a timely manner, thus potentially permitting horizontal or vertical diversion of high-altitude flights around such areas. This research will determine the geographical and meteorological space and time scales of clear-sky contrail outbreaks through analysis of high resolution satellite imagery with data from composites of key meteorological variables near aircraft cruising altitudes stratified by season and by U.S. sub-regions. These analyses will form the basis for predictive (statistical) models of outbreaks with an eye towards their eventual use in operational forecasting. Geographic Information Systems will be used for both statistical model development---using conventional meteorological data, satellite cloud and moisture retrievals, and aviation data---and for validation of outbreak events conducted on independent data and time periods. Advanced geostatistical techniques will be applied to the imagery containing the outbreaks to simulate their removal and estimate resulting impacts on the radiation and energy budgets and surface temperature. The research also will further clarify the impacts of contrails on Earth surface temperatures and will demonstrate the potential value of implementing the models by focusing on an optimal subset of outbreaks for case study investigation.