Open‐Source Code for Radium‐Derived Ocean‐Groundwater Modeling: Project Open RaDOM

Abstract

Radium has been commonly used as a tracer of submarine groundwater discharge to the ocean and embankments, as radium activities are commonly input into box models to calculate a groundwater flux. Similarly, isotopes of radium (Ra224, Ra223, Ra226, Ra228) have been used to calculate water mass ages, which have been used as a proxy for residence times. Less commonly, radium and other tracers have been utilized in mixing models to determine the relative contribution of ground-water to a marine system. In the literature, all of these methods have almost exclusively been solved using analytical methods prone to large errors and other issues. Project Open RaDOM, introduced here, is a collection of open‐source R scripts that numerically solve for groundwater flux, residence time, and relative contribution of groundwater to coastal systems. Solving these models numerically allows for over‐constrained systems to increase their accuracy and force real solutions. The scripts are written in a way to make them user‐friendly, even to scientists unfamiliar with R. This communication includes a description of the scripts in Project Open RaDOM, a discussion of examples in the literature, and case studies of the scripts using previously published data.