We introduce the Aurora software, which performs continuous time random walk (CTRW) particle tracking (PT) of dissolved contaminants on macroscopic groundwater flow fields computed using MODFLOW. This is a natural and practical approach to modeling transport at field scale: deterministic, explicitly resolved flow information is used directly while unresolved small-scale physical and chemical heterogeneity that may cause non-Fickian transport is captured by the CTRW. Existing particle trackers are limited to streamline tracing or to homogeneous velocity fields, and no existing software handles subsurface non-Fickian transport, so this represents a substantial technical advance. Fickian transport simulation can also benefit from Aurora's PT approach, which lacks numerical dispersion and other artifacts. We outline the equations Aurora implements and explain the technical and practical details of MODFLOW interoperation. Two demonstrations are presented of PT simulations using Aurora to model physics that would otherwise be difficult to treat analytically or numerically.

我们介绍了Aurora软件，该软件在使用MODFLOW计算的宏观地下水流场上对溶解的污染物执行连续时间随机游走（CTRW）粒子跟踪（PT）。这是在田间规模上模拟输运的一种自然而实用的方法：确定性的，明确解决的流量信息直接使用，而CTRW捕获了可能导致非菲尼克斯输运的未解决的小规模物理和化学异质性。现有的粒子跟踪器仅限于流线跟踪或均匀速度场，并且没有现有的软件可以处理地下非菲克式运输，因此这代表了一项重大的技术进步。Fickian传输模拟也可以从Aurora的PT方法中受益，该方法缺少数值离散和其他伪像。我们概述了Aurora实现的方程式，并解释了MODFLOW互操作的技术和实践细节。演示了使用Aurora对物理进行建模的PT模拟的两个演示，否则将很难进行解析或数值处理。