Liquid water availability is an important aspect of Mars habitability studies; however, current conditions allow only transient, localized liquid formation. Perchlorate salts have been identified across Martian latitudes and might deliquesce under ideal conditions. Deliquescence occurs when temperature and relative humidity exceed salt-specific thresholds. Atmospheric dust shapes near-surface microclimates where brine formation is possible and understanding how dust conditions influence deliquescence is essential for identifying when and where brines may form on Mars.

I used the Mars Climate Database v6.1 to model near-surface conditions in three climate scenarios. “Climatology” scenario represents a standard Martian year; “Warm” scenario sets dust opacity to the observed maximum (excluding global dust storms); “Cold” scenario corresponds to a clear atmosphere with dust opacity set to the minimum observed over Mars years 24-35. The model ran on a 3.75° x 5.625° latitude-longitude grid for one year. I selected the region where the overall deliquescence chance was the highest, between 73.125° W - 5.625° W and 33.75° N – 71.25° N. To compare the possibility of deliquescence between scenarios, I calculated the percentage of ideal days per year.

In the climatology scenario, deliquescence probability was the highest at 10 PM =–12 AM, with lower chances at 2 AM and 6 AM, and a secondary peak at 4 AM. In the warm scenario, the maximum probability occurred at 2 AM–4 AM, followed by a sharp decline. Between 6 PM–12 AM, the probability increased gradually. In the cold scenario, the probability increased after 8 PM, peaking at 12 AM, with lower values at 2 AM and 6 AM, and a small peak at 4 AM. Overall, the warm scenario shifted the peak to later in the night. Cold and climatology scenarios behaved similarly, with climatology yielding more ideal days except for 12 AM.