At the top of the world, once permanently frozen soil holds vast pools of carbon. Microbes could free that carbon under the right conditions. To predict how the Arctic will respond to seasonal freeze-thaw-growing conditions, scientists need data. They built a system that gathers detailed data. It obtained data for a year, took measurements deep underground, and monitored a wide area on the surface. The data revealed insights about tundra system behavior that might help accelerate long-term thaws resulting in carbon releases in coastal permafrost regions.