Monte Carlo Atmospheric Radiative Transfer Simulator (MCARaTS)

This is the MCARaTS (Monte Carlo Atmospheric Radiative Transfer Simulator) website. The MCARaTS is an open-source scientific software to simulate the three-dimensional (3-D) radiative transfer (RT) in the earth's atmosphere (atmospheric media with underlying surface). The MCARaTS is a free software distributed under GNU GPL. User's guides and announcements are available for the public. The radiative transfer code uses the forward-propagating Monte Carlo photon-transport algorithm. The code can be optionally parallelized to run efficiently on parallel computers. To quickly know applications of the software, have a look at a computer-generated art on the right. The codes can be applied to quantitative simulations of solar and/or infrared energy budget on the earth and quasi-observation of cloudy atmosphere with optical instruments.

Characteristics of the software are highlighted in highlight page and presented in showcase page with more details. One can learn how the softwares work from several sample cases, for which input and output data are included in the package. See also online manuals for details.

• What's good: Easy to use, fast, and parallelized.

• Basic algorithm: Forward-propagating Monte Carlo photon-transport algorithm.

• RT solvers: Fully-3-D RT, partially-3-D RT, independent column approximation, and so on

• Radiation sources: Solar source from top and/or thermal emission from the atmosphere and surface, or localized source (e.g. laser beam, isotropically emitting lamp, star in space, etc).

• Input: Three-dimensionally inhomogeneous media (gases, aerosols, hydrometeors etc), underlying inhomogeneous surface.

• Output: Radiative fluxes; heating rates; radiances and air mass factors; computer graphics; pathlength statistics

• Coding language: Fortran 90/95

• Requirements: A UNIX/Linux-like operating system and a Fortran 90/95 compiler. MPI (Message Passing Interface) is optionally needed for parallelization.

References

• Iwabuchi, H.: Efficient Monte Carlo methods for radiative transfer modeling. J. Atmos. Sci., 63, 2324-2339, 2006.

• Iwabuchi, H., and R. Okamura: Multispectral Monte Carlo radiative transfer simulation by using the maximum cross-section method. Journal of Quantitative Spectroscopy and Radiative Transfer, 193, 40–46, March 10, 2017. doi: 10.1016/j.jqsrt.2017.01.025

Codes and manuals

The software packages are available on the download page. Online manuals are available in HTML and PDF formats. HTML versions are always up-to-date because they are frequently edited on the Wiki site.

MCARaTS user's guide

• v0.10

• v0.9.5