Journal of Geophysical Research: Atmospheres
© American Geophysical Union
Impact Factor: 3.318
ISI Journal Citation Reports © Ranking: 2015: 27/184 (Geosciences Multidisciplinary)
Online ISSN: 2169-8996
Associated Title(s): Journal of Geophysical Research
Soil temperature trends in Canada
Global warming is increasingly becoming a concern for society. Most reported warming trends are based on measured increases in air temperatures. However, trends in soil temperatures, also an important indicator of climate change, are less often reported. Qian et al. (2011) analyzed soil temperature data from 30 climate stations across Canada covering the period from 1958 to 2008; the data cover soil temperatures at several depths up to 150 cm. They also analyzed air temperature, precipitation, and snow cover depth at the same locations. During that time period, rising soil temperatures were generally associated with rising air temperatures, and snow cover depth generally decreased, although there were variations between the sites. The researchers found that at about two thirds of the stations, soil temperatures at depths below 5 cm showed a warming trend over the 50-year record. Many sites showed a significant positive trend in average spring and summer soil temperatures but not in winter soil temperatures. Because snow insulates the ground, keeping soil warm, the trend of declining snow depth explains why winter soil temperatures did not show a warming trend. The median warming rate in spring for soil at all depths was about 0.3oC per decade.