Large regional variability of recent climatic change driven sub-surface temperature changes as derived from temperature logs-central Canada example

The analysis of the warming/cooling patterns from inversion of 94 well temperature logs for the study area of Central Canada shows very high variability (−1 to 3 °C). Analysis of the warming/cooling patterns in last 2–3 centuries indicates that warming has not affected the whole study area and some surface areas have significantly cooled. Regions of large cooling as well as regions of large warming are apparent. Largest cooling is observed in the NE part of the study area while large warming is observed in the area south–east of it in a ridge running NW–SE slightly north of Great Lakes. These patterns go against patterns of land development which is an unlikely factor forcing these regional scale changes derived mainly from the well sites chosen to be in remote and forested areas.