Collaborative Research: A Satellite-Based Climatology of Jet Aircraft Contrails for the Contemporary Period (1995-2000)

人类活动对当代和未来气候变化的一个潜在贡献者是喷气式飞机的排放。 站的气候数据，密集的现场实验，和数值模拟揭示了喷射凝结尾迹（轨迹）卷云的影响，地面和大气辐射和能量收支。 一些科学家认为，在某些地区（例如，欧洲中西部）的凝结尾迹对气候的影响可能已经与目前人为的CO2强迫一样重要。 然而，在尝试评估凝灰云的气候影响之前，并为了推断预测的21世纪空中交通持续增加的影响，需要对当代（1995-2000年）凝灰云发生的全面空间气候学进行研究。 卫星高分辨率图像是一个接近理想的数据库，用于发展的气候学的凝结尾迹。 发展当代轨迹气候学是主要的研究目标，将利用美国国家海洋和大气管理局极地轨道飞行器的存档热红外图像在线提供。 1995-2000年期间美国上空凝结尾迹的空间和时间变化将使用手动技术在季中月份确定。 这一气候学将包括由日、月和年时间段合成的轨迹发生的标准化地图;不同时期的纬向频率图;以及利用地理信息系统方法按区域绘制的时间变化图。 对于大约7个轨迹“爆发”时期，包括地理位置、季中月份和天气气象条件的范围，将使用GOES图像跟踪轨迹扩散形成卷层云的发生率。 在这些情况下，卫星轨迹信息也将与飞机水平温度和风观测相结合，以帮助揭示与持续的轨迹相关的重要物理过程。为美国开发的当代轨迹气候学将有助于为评估轨迹的气候影响提供适当的边界条件，模拟轨迹在未来气候中的可能作用，并最终指导政策制定者。 更具体地说，分析将允许澄清天气气象条件和凝结尾迹之间的关联，并帮助提供有用的规则，用于实时预测的凝结尾迹。 研究的最终产品将是统计模型，这些模型量化了轨迹数据与喷气式飞机活动的其他代理指标（例如，喷气燃料使用）。 这些将允许外推到世纪上半叶的卷云可能增加的幅度和首选位置，这些卷云是由持续的凝结尾迹造成的，对气候很重要。

A potential contributor to contemporary and future climate changes from human activities is that due to jet aircraft emissions. Station climate data, intensive field experiments, and numerical modeling reveal the impacts of jet condensation trail (contrail) cirrus clouds on the surface and atmospheric radiation and energy budgets. Some scientists suggest that in certain regions (e.g., central Western Europe) contrails already may be as significant for climate as the present anthropogenic CO2 forcing. However, before attempting to evaluate the climatic impacts of contrails, and in order to extrapolate the effects of the predicted continued increase in air traffic into the 21st century, a comprehensive spatial climatology of contrail occurrences for the contemporary period (1995-2000) is required. Satellite high-resolution imagery are a close-to-ideal database for developing a climatology of contrails. The development of a contemporary contrail climatology is the primary research objective, and will be achieved using the archived thermal infrared imagery from the NOAA polar orbiters, available on-line. The spatial and temporal variations of contrails over the U.S. in the period 1995-2000 will be determined for mid-season months using a manual technique. This climatology will comprise normalized maps of contrail occurrences composited by diurnal, monthly, and annual time periods; graphed zonal frequencies for different periods; and temporal variations plotted by region, facilitated using geographic information system (GIS) methodology. For about 7 contrail "outbreak" periods comprising the range of geographical locations, mid-season months, and synoptic meteorological conditions, the incidence of contrail spreading to form cirrostratus clouds will be tracked using GOES imagery. For these cases also, the satellite contrail information will be allied with aircraft-level temperature and wind observations to help disclose the important physical processes associated with persisting contrails.The contemporary contrail climatology developed for the U.S. will help provide appropriate boundary conditions for assessing the climatic impacts of contrails, for modeling the possible role of contrails in future climate, and for ultimately guiding policymakers. More specifically, the analysis will permit clarification of the associations between synoptic meteorological conditions and contrails, and help provide rules useful for the real-time prediction of contrails. The ultimate products of the research will be statistical models that quantify the relationship between the contrail data and other proxy measures of jet aircraft activity (e.g., jet fuel usage). These will permit an extrapolation into the first half of the 21st century of the magnitude and preferred locations of likely increases in the cirrus clouds that result from persisting contrails, and which are important for climate.