A parallel, adaptive library for logically Cartesian, mapped, multiblock domains

What is ForestClaw?

ForestClaw is a parallel, multi-block adaptive finite volume library for solving PDEs on mapped, logically Cartesian meshes. For solving hyperbolic problems using explicit, single step algorithms, ForestClaw's block-structured adaptive algorithm, including multi-rate time stepping uses the Berger, Oliger and Colella AMR algorithms (JCP, 1984, 1989). The hyperbolic solvers are currently based on ClawPack (R. J. LeVeque). Future plans include support for general method-of-lines solvers in a multi-rate setting.

Where ForestClaw departs from the standard Berger-Oliger-Colella block-structured approach is that the multi-resolution grid hierarchy is not stored as overlapping, nested grids but rather as a composite structure of non-overlapping fixed sized grids, each of which is stored as a leaf in a forest of quad- or octrees. The particular code base we use for managing the tree is p4est (, (Carsten Burstedde, Univ. of Bonn).

Why develop another AMR code?

Currently, there are several AMR codes for doing block-structured AMR. What are the advantages of the ForestClaw approach?

Progress on the ForestClaw project

Publications and Presentations

Recent talks and posters


ForestClaw News

Working on the ForestClaw project

There are funding opportunities for students interested in working on developing numerical solvers and applications using ForestClaw. If you are a student interested in being involved the ForestClaw project, please email Donna Calhoun at

Talin Mirzakhanian (BS, California State Polytechnic University) graduates with thesis "Multi-rate Runge-Kutta-Chebyshev Time Stepping for Parabolic Equations on adaptively refined meshes" (May, 2017)

Melody Shih (Master's student, Columbia Univ.) is working with D. Calhoun and Kyle Mandli (Columbia Univ.) to port GeoClaw, a widely used application for modeling tsunamis, storm surges and debris flows, to ForestClaw. Check back for progress!

Where can I get ForestClaw?

(August, 2017) Forest Claw can be cloned/downloaded from GitHub, at ForestClaw. Please send us any feedback!


Lead Developers



Donna Calhoun would like to acknowledge the support of the Isaac Newton Institute and the program Adaptive Multiscale Numerics for the Ocean and Atmosphere, where much of the initial work in developing ForestClaw was done, and the National Science Foundation (NSF).


Tracer transport*
* more to come, including gas dynamics, acoustics and shallow water wave equations

Last modified: Thu Mar 16 06:55:34 MDT 2017