Long Term Arctic Temperature Trends
By Paul Homewood
As I pointed out in my post, Arctic Sea Ice Update, the other day, we currently have low sea ice extent and unusually high temperature anomalies in the Arctic.
Although much of this is just weather, there is an underlying pattern of warming related to pulses of unusually warm water, which have been entering the Arctic Ocean from the Atlantic for the last decade or more.
But just how unusual are conditions there? Are they as unprecedented as Neven suggested in the comments?
The area we are talking about spans from East Greenland across to Siberia. The CLIMAS project analysed a lot of data in 2000, and provided the above map of sites which they used, which all had good quality, long term data.
So what do the temperature trends tell us about the climate in that part of the world.
Akureyri in Iceland is regarded as being the Icelandic site most representative of climate in the Greenland Sea, as it is on the north coast.
I prepared this graph of annual mean temperatures a few months ago. It is based on temperature data provided by the Iceland Met Office, which has been carefully homogenised by Trausti Jonsson to take account of station moves, equipment changes, etc.
The warmest year recently was 2014, with a mean of 5.3C. But this was not as warm as 1933, which reached 5.6C.
Let’s look at some of the other sites around the Arctic, using GISS unadjusted data.
There is clearly very little “unprecedented” about any of this. Jan Mayen had the warmest year on record in 2014, and a couple of the Russian stations had warm years in 2012.
But overall temperatures in the last decade or two have been within the bounds of those set during the 1920s to 40s.
We also need to recognise that temperatures at Russian stations were almost certainly understated during the Soviet era.
It is fair to say that the current warm period has been more sustained, in comparison with the earlier one which also had several much colder years. But is this simply a case of weather?
What is clear though is that temperatures have plateaued, and there is no evidence that they will trend higher. Indeed, history suggests that the next move will be downwards.
As for the longer perspective, we only have to look at Greenland ice core data to see that there is nothing unprecedented about today’s climate there.