Assessing the Impacts of Rapid Climate Change on Arctic Soil Conditions by Combining Satellite and In Situ Measurements

The Arctic region is undergoing accelerated climate change compared to the rest of the globe: in recent decades, it has had record amounts of shrinking sea ice, glaciers, and snow cover, as well as unprecedented rates of thawing permafrost. This study investigates the consequences of rapidly changing climate on soil conditions around the 1002 area of the Arctic National Wildlife Refuge (ANWR). Trends and patterns of soil moisture, soil temperature, and land surface temperature are explored using NASA satellite measurements and nearby in situ observations from the USDA National Water and Climate Center. In situ soil moisture data over the past decade in Prudhoe Bay (closest data site to 1002 area) illustrates a decreasing trend of -1.003 cm3/cm3/decade at two-inch sensor depth and -2.096 cm3/cm3/decade at eight-inch sensor depth. In situ soil temperature analysis over the past decade in Prudhoe Bay shows an increasing trend of 0.240 K/Decade at two-inch sensor depth. Statistical analysis of land surface temperature data during the past two decades from Moderate Resolution Imaging Spectroradiometer (MODIS) onboard the NASA Terra Satellite reveals a striking warming trend of 1.206 K/Decade at daytime and 1.269 K/Decade at nighttime over the 1002 area. Soil moisture data from Advanced Microwave Scanning Radiometer 2 (AMSR2), Soil Moisture and Ocean Salinity (SMOS), and Soil Moisture Active Passive (SMAP) satellites all show a similar seasonal pattern and trend over the 1002 area. However, these three soil moisture data products have significant biases, calibration and validation with in situ observations are required to get reliable soil moisture data from satellite measurements for the Arctic region. USGS just installed new soil sensors in the 1002 area, which will be invaluable for more accurate monitoring of the Arctic region.