Ice cave climate data and frost imagery at Sunset Crater, AZ: 02 March 2021 to 13 December 2022

The purpose of the data collection was to monitor the microclimate in the “Bonito Flow” Ice Cave located in Sunset Crater National Monument. This cave is considered a sacred spot for some southwestern tribes as it was a historical source for ice. The main purpose of the climate monitoring was to determine if the cave is still an active ice cave, i.e., a cave that contains perennial ice. The data acquired consists of temperatures, humidity, and pressures throughout the cave structure and also includes temperatures and humidity measured outside of the cave, near the entrance. Sensors were distributed throughout the cave but focus on a large ice puddle that forms on the cave floor during the winter months. Cave floors often show decreases in air temperatures that correspond to times when the outside air temperature is below that cave air temperature, suggesting that colder air flows into the cave at these times. Relative humidity measurements show the air in this cave is saturated most of the year. The driest periods, i.e., times of lowest relative humidity, occur during the winter. An air temperature gradient usually exists between the cave floor and ceiling; this is greatest during the summer. We acknowledge and appreciate the Hopi Tribe, Zuni Tribe, and Flagstaff Area National Monuments for approving this research.