Mars is a dusty planet dominated by vast, dry deserts, with no easily accessible sources of liquid water. Much like on Earth, dust is lifted from Mars' surface by wind and rotating air columns, transported through the atmosphere, and deposited back onto the planet's surface via sedimentation. The Martian dust cycle is governed by multiple factors, including interactions between the planetary surface and atmosphere, seasonal variations, and the formation of massive dust storms that can span the globe.

For humans to successfully visit or eventually inhabit Mars, accurate prediction of the Martian dust cycle and large-scale dust storms is critical—it will enable engineers to schedule critical mission launch windows during optimal conditions.

To address this issue, a team of scientists from the Institute of Atmospheric Physics (IAP) of the Chinese Academy of Sciencesrecently conducted a 50-year simulation of the Martian dust cycle using the Global Open Planetary Atmospheric Model for Mars (GoMars). This new modelcanpredict key characteristics of the Martian dust cycle and global-scale dust storms.

The team's findings were published on December 13 in the journal Advances in Atmospheric Sciences.

"The Martian dust cycle is a complex system with significant diurnal, seasonal, and interannual variability. Accurately simulating this cycle remains a core goal—and a major challenge—in the development and refinement of Mars General Circulation Models (MGCMs), which will support China's future Mars exploration missions," said LIU Shuai, a PhD candidate at IAP and first author of the study.

To validate their dust cycle simulation, the researchers compared the model's atmospheric predictions with data from the Mars Climate Database (MCD) and observations from the Mars Climate Sounder (MCS). For time periods where atmospheric data was unavailable for comparison, GoMars' predictions were compared to other available MGCMs (e.g., MarsWRF). The results showed that GoMars consistently replicated seasonal and spatial patterns of the dust cycle.

Notably, the 50-year simulation successfully captured the multi-timescale variability of the Martian dust cycle. It also demonstrated the model's ability to consistently and realistically reproduce the irregular occurrence of global dust storms (as observed) and the evolutionary processes of specific types of global dust storms—two long-standing challenges and key priorities in international Martian atmospheric modeling.

For instance, the simulation predicted that peak dust devil lifting (DDL)—the maximum amount of dust that heated, swirling air columns can lift from Mars' surface into the atmosphere—occurs between 12:00 and 13:00 local time, which matches measurements from the Mars Pathfinder mission. GoMars also accurately identified the location of intense dust devil activity in Amazonis, a region known as a major dust devil hotspot on Mars.

However, the current version of the GoMars MGCM is not yet perfect, and the team has identified areas to improve its dust cycle simulations.

"Our next step will focus on enhancing the model's resolution while continuously optimizing its dynamical core and physical parameterizations," said Prof. DONG Li, a co-author of the study. "Key improvements will include integrating more realistic data on surface dust and sand sources, refining the representation of dust-related physical processes, and expanding the model to simulate the Martian water cycle."