As autumn gives way to winter across the Arctic, the ground doesn’t immediately freeze solid. Instead, soils often linger near the freezing point for days or even weeks in a phase called the zero curtain. In a new NASAled study, researchers produced high-resolution maps of the Arctic zero curtain.
dioxide and methane into the atmosphere. Arctic permafrost stores an estimated 1.9 trillion tons (1.7 trillion metric tons) of organic carbon, which is nearly twice the amount currently in Earth’s atmosphere. As frozen ground thaws, more of that carbon could be released as microbes take advantage of the expanding zero curtain’s moist conditions. Mapping a longer thaw window In Scientific Reports researchers describe an artificial intelligence framework called GeoCryoAI that combines satellite observations and model outputs with field measurements dating back to 1891 to create the first detailed maps of zerocurtain conditions across the Arctic region.
The maps show that spring thaw generally produces much longer zero-curtain periods than autumn freeze-up and that regions with higher moisture levels experience longer zero-curtain periods.
The team designed GeoCryoAI to work with data from the US–India NISAR (NASA-ISRO Synthetic Aperture Radar) mission, which could help scientists observe how frozen landscapes respond to a changing climate and improve forecasts of future greenhouse gas emissions.
