Researchers from Japan’s National Institute of Polar Research have identified marine bacteria as a factor in the formation of ice clouds in the planet’s polar regions. The findings appear in the science journal Geophysical Research Letters.
Understanding how clouds build over the poles is essential for protecting ice sheets from climate shifts and solar radiation. Scientists note that ice clouds over the Southern Ocean surrounding Antarctica form in the middle troposphere at temperatures around minus 10 degrees Celsius, a departure from the typical formation at much lower temperatures and higher altitudes.
To uncover the cause, the team traced warm, moist air flowing from Southern Africa toward Antarctica. They observed that African wind corridors encounter zones rich in chlorophyll a, the pigment associated with phytoplankton, and that the air also carries elevated levels of dimethyl sulfide, an organic sulfur compound released by these microorganisms.
The study concludes that marine bacteria can enter the atmosphere via sea spray and be transported thousands of kilometers to the South Pole. Once aloft, these microbes serve as nuclei for ice formation, enabling cloud development at relatively higher temperatures.
Experts say this insight improves climate predictions for polar regions that are highly responsive to global warming. Such refined forecasts help communities and policymakers in North America and Canada plan for evolving weather and ice conditions.
Earlier observations noted rapid melting of large Antarctic glaciers, underscoring the urgency of understanding Antarctic cloud and ice dynamics and their influence on regional climate patterns.