Intensified fragmentation and shrinkage of the polar climate zone in the Arctic.

Using both observation and CMIP5 simulation data, this study investigates the shifts of climate zones from a landscape perspective on the Arctic for the period 1940–2013. The results reveal that the reduction in area is often accompanied by the fragmentation of the spatial structure. In terms of percentage of landscape, the coverage of polar climate zone had undergone a rapid decrease from 1940 to 2013. Moreover, the polar climate has been facing an intensified fragmentation over the time 1940–2013. Further analysis shows that this fragmentation phenomenon can be attributed more to anthropogenic than natural forcing from 1940 to 2003, even though the change in patch density is not steady, by comparison of observations and simulation results. In addition, the fragmentation in the Arctic climate zone depends on the horizontal resolution of data. Although the fragmentation trends of observations at three spatial resolutions of 2°–0.5° are consistent, the magnitude of trends weakens as the spatial resolution decreases. [ABSTRACT FROM AUTHOR]