Examination of the Mathematical Models Used in Atmospheric Source Apportionment Studies

在过去的二十年里，越来越多地使用多元素分析方法来表征空气中的颗粒物和收集的降水。随着这些大型多变量数据集的出现和计算机规模和速度的不断提高而变得实用的新的多变量统计方法，有了更多的机会从收集的颗粒或降水的特征数据中提取有关大气过程的信息。这一正在进行的研究方案的最初目标是继续审查与城市气溶胶来源识别和大规模分配有关的统计问题。在目前的赠款期间，该方案已将重点转向更大规模的现象以及开发和测试统计方法，以便从更大的空间和时间尺度上获得的分析样本中提取信息。具体地说，PI建议验证潜在源贡献函数(PSCF)分析和总潜在源贡献函数(TPSCF)分析技术，方法是将潜在源贡献函数应用于小规模数据集，并将潜在源贡献函数应用于北美示踪器实验(ANATEX)数据，其中源排放的位置和数量是已知的。通过将现有方法应用于更多的数据集，调查这些方法在有约束的情况下可能需要进行的更改，以及进一步研究经验正交函数及其在研究臭氧传输中的使用，来研究和进一步发展三元模型。

During the past 2 decades, there has been increasing use of multielemental analytical methods to characterize airborne particulate matter and collected precipitation. With the availability of these large multivariate data sets and new multivariate statistical methods that have been made practical by the continuing increases in computer size and speed, there is an enhanced opportunity to extract information about atmospheric processes from data characterizing collected particles or precipitation. The original objective of this on-going research program was to continue the examination of the statistical problems associated with the source identification and mass apportionment of urban aerosols. During the current grant period, the program has changed its emphasis toward larger scale phenomena and the development and testing of statistical methods to extract information from analyzed samples obtained on a larger spatial and temporal scale. Specifically, the PI proposes to validate the Potential Source Contribution Function (PSCF) analysis and Total Potential Source Contribution Function (TPSCF) analysis Techniques both by applying PSCF to small-scale data sets and applying PSCF to the Across North America Tracer Experiment (ANATEX) data where the location and quantities of source emissions are known, to study and further develop three- way modeling via the application of existing methods to additional data sets and an investigation into alterations that may be necessary to these methods in the presence of constraints, and the further study of empirical orthogonal functions and their use in studying ozone transport.