The Mars Regional Atmospheric Modeling System (MRAMS) is a computer program that simulates the circulations of the Martian atmosphere at regional and local scales. MRAMS, developed by Scot Rafkin and Timothy Michaels, is derived from the Regional Atmospheric Modeling System (RAMS) developed by William R. Cotton and Roger A. Pielke to study atmospheric circulations on the Earth. Key features of MRAMS include a non-hydrostatic, fully compressible dynamics, explicit bin dust, water, and carbon dioxide ice atmospheric physics model, and a fully prognostic regolith model that includes carbon dioxide deposition and sublimation. Several Mars exploration projects, including the Mars Exploration Rovers, the Phoenix Scout Mission, and the Mars Science Laboratory have used MRAMS to study a variety of atmospheric circulations. The MRAMS operates at the mesoscale and microscale, modeling and simulating the Martian atmosphere. The smaller scale modeling of the MRAMS gives it higher resolution data points and models over complex terrain and topography. It is able to identify topography driven flows like katabatic and anabatic winds through valleys and mountains that produce changes in atmospheric circulation. (en)