Reddy: An open-source toolbox for analyzing eddy-covariance measurements in heterogeneous environments

Land-atmosphere exchange is mediated by turbulent fluxes that can be quantified using eddy-covariance (EC) measurements.

EC has been widely used to measure ecosystem-scale vertical exchange between atmosphere and vegetation, and to test and refine atmospheric turbulence theories with the aim to improve the representation of turbulent fluxes in numerical models.

Traditionally, research has focused on idealized, homogeneous and flat surfaces, but recent work increasingly targets turbulent exchange in complex, heterogeneous environments under non-ideal conditions, where challenges include advective fluxes, mesoscale circulations between contrasting surface types, and non-stationary nighttime turbulence.

Here, we introduce the open-source R package Reddy, which combines multiple EC analysis methods into a single modular tool.

Reddy enables users to tailor post-processing choices to site-specific conditions, supports station management and facilitates detailed scientific analyses.

The package is accompanied by extensive documentation and a suite of Jupyter notebooks that provide hands-on introductions to EC data processing.

We demonstrate Reddy using measurements from three Norwegian sites: (1) a morning transition following a strongly stably stratified night at an alpine tundra valley, (2) spectral and ogive analysis before and after an ice-cover transition at a boreal lake, and (3) fitting flux-variance relations at a permafrost-affected palsa peatland.

Reddy extends existing EC software and helps moving towards a more holistic turbulence data analysis framework for heterogeneous, real-world environments.