In April I visited the Torneträsk region for eight days, with a brief visit to Kiruna before and after. My visit prompted some thoughts regarding:
Briffa, K.R., Jones, P.D., Bartholin, T.S., Eckstein, D., Schweingruber, F.H, Karlen, W., Zetterberg, P. and Eronen, M., 1992
“Fennoscandian summers from A.D.500: temperature changes on short and long timescales.”
Climate Dynamics 7, 111-119 (R)
The post which follows is incomplete. I’m publishing it now in its incomplete form to preserve blog continuity, as this is the post I mentioned in my last post, but I want to finish it after I complete another post requesting some input on GHCN metadata.
Update (October 29th 2012): I never did get around to completing this post. As you may have suspected, I felt the suggestion of some unknown anthropogenic influence as explanation for the observed decline in tree ring response pretty weak, particularly after visiting the area. So I am now pleased to see:
Thomas M Melvin, Håkan Grudd, and Keith R Briffa, The Holocene 0959683612460791, first published on October 26, 2012 doi:10.1177/0959683612460791
Update (July 12th 2014): Inspiration has struck! Could that unknown anthropogenic influence used as explanation for the observed decline have been the change in Sweden from driving on the left to driving on the right? That would have been around the right time, so that must be it! 😀
What is the local view on the past? Two or three degrees warmer than today when people first settled. The guide published by Länsstyrelsen i Norrbotten län (County Administrative Board of Norrbotten) says:
People arrived here soon after the last ice age, about nine thousand years ago. They survived by hunting small game, moose and wild reindeer, and by fishing and collecting berries. At first, the climate was about two to three degrees warmer than it is today, and the summers were dry … Changes in climate affect people’s chances of survival and can lead to changes in behaviour. Approx 5000-4000 years ago there was a major change in the climate, which became colder and more humid. Hunting for wild reindeer increased, and domestic reindeer began to be used as lures and as pack animals … In the 12th century A.D. there was yet another climatic change for the worse, which may have forced people to make more intensive use of nature. Gradually they began to follow the reindeer on its migrations between different grazing areas. Settlements changed and spread out along the stretches used by the reindeer during the year.
Abisko – Tour Tips ISSN 0283-9636
I will return later to expand those thoughts on the Briffa et al. paper. For now I will just mention the choice of referenced material. I see references on “The role of climate on present and past vitality of silver fir forests in the Vosges mountains of northeastern France” and “An investigation of certain aspects of tree growth rates in relation to climate in the central Canadian boreal forests”, but I was surprised by the absence of any reference to more local studies among the list of twenty five references for the paper, other than specifically dendrochronological or dendroclimatological studies. In particular I was surprised by the omission of one obvious candidate:
“Human Influence on Vegetation in the Torneträsk Area during the Last Three Centuries”
Ecological Bulletins, No. 38, Copenhagen 1987.
Research in Arctic Life and Earth Sciences: Present Knowledge and Future Perspectives. Proceedings of a Symposium Held 4-6 September, 1985, at Abisko, Sweden (1987), pp. 95-111
Published by: Oikos Editorial Office
Stable URL: http://www.jstor.org/stable/20112975
Abisko, location of a long established research station, with particular emphasis on meteorology and plant ecology, and a long term rural temperature record, is of course on the south shore of Lake Torneträsk itself. (Torneträsk alone is sufficient locally – träsk means lake in Lapland, although not in the rest of Sweden, where it would mean fen or marsh).
I intend to add some extracts from this paper, but for now I will finish with some holiday photos and a little “tourist advice”.
Immediately on leaving arrivals at Kiruna airport (a two-hour two-leg flight north from Stockholm via Luleå) I spotted a sign not which I’ve not seen before at other airports:
And the tourist advice: check the opening hours of the airport on return. As a “well trained” passenger, with previous experience of long check-in times with manual check-in with skis, seeing a last check-in time of 05:20 for my flight back to Stockholm via Luleå, I thought it prudent to arrive at the airport at 04:30. But this was not an airport where such prudent behaviour was rewarded – the airport did not open until 05:00, leaving a half hour wait outside in sub-zero temperatures with added wind chill. Once the airport opened check-in for the small number of passengers on the first leg of the flight proceeded rapidly.
What about the environment around Abisko? Abisko is on the E10 highway from Kiruna to Narvik, opened in 1984, and has two railway stations, one serving the Tourist Station, below, and the other, and bigger station, Abisko East, serving the main year-round community, population 158 at the end of 2010. Other villages in the Torneträsk area are Torneträsk, population 12, Stenbacken, population 6, and the ski resort, Björkliden, population 28, all situated on the E10 highway and nearly parallel railway, electrified to the Norwegian border since 1915. The tourist populations of Abisko and Björkliden increase these figures in season, but still leave the Torneträsk area with a low population density.
Skiing south from Abisko, expect to encounter “heavy traffic”
The iron ore mine at Kiruna is 60 km or more distant from the tree ring sampling areas around Torneträsk, and is regarded as the largest and most modern underground iron ore mine in the world. Because of mining related subsidence, the town of Kiruna is to be moved eastwards to a new location over the next decade.