Response of soil seasonal freeze to climate change from 1950 to 2010 across China

Abstract:

Abstract: Response of soil seasonal freeze depth to climate change may result in changes in surface energy and water balance, ecosystem, carbon cycle, and soil nutrient changes. In this study, we used data from about 800 meteorological stations to investigate the response of soil freeze depth to climate change across China. Data used for this study include daily air temperature, daily soil temperatures at various depths, mean monthly gridded air temperature, daily snow depth, and Normalized Differential Vegetation Index (NDVI). The primary results show that soil freeze depth decreased with a rate of about -1.75cm/decade and a net change of 8.05 cm over the period from 1967 to 2012 across China. In region-scale, decreasing rate of soil freeze depth varied between 0.0 and -0.4 cm/year in most parts of China from 1950 to 2009. Combined the climate and non-climate factors with soil freeze depth, we conclude that warming climate is responsible for decrease in soil seasonal freeze depth during this period across China. Changes in vegetation condition were negatively correlated with soil freeze depth. These results are important to understand the soil freeze/thaw dynamics and impacts of soil freeze depth to ecosystem and hydrological process.

Key words: freeze depth; climate change; climate factor; non-climate factor