Think of Siberia and images of a cold, bleak, icy, snow-swept landscape come to mind. The reality is that this remote northern region of Russia is experiencing unseasonably warm weather that is changing the very nature of the landscape.
In some areas ice and snow are being replaced by heavy rain and green grass. Many lakes and rivers, which would normally be ice-bound at this time of year, are flowing freely.
During December the region would normally expect to be in the grips of winter. Although it remains cold here with the threat of snow, conditions are nowhere near as extreme as would normally occur.
In the northern city of Verkhoyansk average maximum temperatures are around minus 47C. Currently, they are some 14C warmer at minus 32C.
The southern city of Irkutsk is experiencing temperatures of minus 6C, ten degrees above average and this pattern is being repeated across much of the region.
What makes this change particularly interesting is that it seems to be part of a longer-term trend.
The warmer weather has been in evidence for several months. Back in July, Norilsk, the most northerly city in the world, recorded temperatures above 28C for eight consecutive days. Maximum temperatures here usually reach no higher than 16C. Such temperature anomalies were widespread across Siberia during the month.
Although temperatures have been increasing globally, since the mid-1970s temperatures here have risen by 0.34C per decade faster than the global average of 0.17C.
The trend towards warmer weather has been repeated elsewhere within the Arctic Circle and both Siberia and the US state of Alaska have experienced record wildfire seasons in the last few years.
Wildfires are thought to be contributing to the warming process, as soot on glaciers and ice sheets prevents the reflection of incoming solar radiation back out into space.
NASA researchers warn that the warming trend across Northern Russia is likely to cause the number of wildfires to double by the end of the century.