Road builder's skiers and climbers are always challenged by mountains now the clouds started assisting mountains. Scholars from several laboratories and universities found that mountainous, water-ice clouds have the multi-response when some tiny pollution particles are injected.

According to Phys.Org, the team found that high concentrations of pollution particles lead to many more shallow clouds in the California Central Valley and foothills, changing local circulation. The transport of moisture to the windward slope is strengthened when the Latent heat is given off. PNNL lead author Dr. Jiwen Fan said: "When the pollution particles fill the mountain-side mixed-phase clouds it dramatically increases snow precipitation, and this finding is different from previous modeling studies". 

A new mechanism for how pollution-caused particles can prompt these clouds was found by the authors. This mechanism suggests important visions for highly polluted mountainous regions in China and India, exclusively for water cycle and precipitation extremes. Researchers used the Weather Research and Forecasting regional model and coupled it with detailed cloud microphysics calculations.

The comparison of these very high-resolution model simulations with field measurements from two cloud cases that had winds and moisture conditions was made. The study on sensitivity simulations with the concentrations of cloud condensation nuclei and ice nuclei changed over a wide range from extremely low to extremely high concentrations in reaching findings. The study portrayed that pollution particles near the Sierra Nevada Mountains in the western U.S.A. mellow environment for forming droplets and ice particles. Snowfall increases when the particles range a certain quantity, over the mountain. 

Finding when and how much snow and rain will fall helps from weather forecasters to skiers, to farmers and water managers. This research makes a better knowledge of the processes that influence mixed-phase clouds and precipitation near mountains. The examination of new observation data obtained from the ACAPEX/CalWater2 campaign and conduct model simulations to further understand cloud will be studied by the team. The Team also studies and precipitation behaviors over the Western United States.