Recent warming of Arctic Water (AW)

Just a short post about a short article from Science which was published in January. Spielhagen et al (2011) counted assemblages of planktonic foraminifera from a 14C dated core taken from the West Coast of Svalbard, with a resolution of around 18 years, higher than previous works. In total the core was found to cover c.2000 years. Planktic foraminifers typically grow between 50-150m ocean depth and the 'bloom peak' is around August meaning these records are of summer ocean temperature. Estimates of temperature were calculated by a statistical comparison of assemblages found in the core to a modern dataset of foraminifera assemblages from areas with different environmental conditions. It's hoped that by using this Modern Analogue Technique (MAT), it's possible to match up two similar assemblages, and it's assumed that conditions which determine the two aren't going to be that much different. Clearly, the assumptions, and therefore possibility for error are pretty big, so results have to be pretty significant to be meaningful.

The results showed a large increase in temperature in the past c.150 years, which was unusual when compared to the past 2000 years, found to be similar to the observational records of the Arctic Atlantic Warm Layer (AAWL). This strongly suggests that Arctic Water (AW) inflow from the Atlantic is warming, which has the potential to significantly speed up sea ice melt.

Of course, this is based on only one core, so this article is more of a call for more research rather than necessarily conclusive findings. It will be interesting to see if the significance of these AW changes can be de-tangled from all the other influences of Arctic sea-ice levels.

SCPs in the Arctic (Arctic Pollution Part II)

Continuing from the last post on Arctic pollution, this post will look at the pollution record from Svalbard, a remote island off the coast of Norway high into the Arctic circle.

Due to it's remoteness, it's a great place to look for traces of long-range pollution transported from industry and agriculture in the Northern Hemisphere, especially from Russia. Many studies have found evidence of such long range contamination which gets to the Arctic via the atmosphere, rivers and oceans.

A more systematic study was carried out by a number of academics in the 1990s using lake sediments which, as we've learned, give a record of pollution far longer than atmospheric measurements can. For example, it's possible to estimate pre-industrial levels of pollution using this method. One paper from this study by Rose et al. (2004) was especially interesting and showed significant local sources of pollution, something I found surprising for such a

POPsicles in the Arctic? (Arctic Pollution Part I)

We've already considered one thing (other than climate change) which has the potential to affect the Arctic environment, increasing UV from an 'ozone hole'. Another one of these potential 'things' is pollution, or more scientifically, chemicals and compounds where they're not supposed to be naturally. One things humans have always done is burn things, and the record of these activities is clear in the palaeo-archives, from the prehistoric burning of small wood fires, through large scale burning for clearing right to the modern widescale burning of almost anything and everything seen since the industrial revolution. What is more recent though is the widespread use of pesticides and the growth of heavy industry. We tend to see the Arctic regions as a wilderness, wild and untouched. However, many types of pollutants have been found across the Arctic circle.

In this and the next post, I won't attempt to try and fully describe the extent of Arctic pollution. There are just too many pollutants and studies to do that! Rather, I'm going to focus on a couple of papers which have some interesting findings relating to POPs and SCPs (I did warn you about the acronyms).

States signed up to the Stockholm Convention on Persistent Organic Pollutants (green)
Source: http://toxipedia.org/display/toxipedia/Stockholm+Convention   

The Arctic Monitoring and Assessment Programme (AMAP) was set up in 1991 as part of the inter-governmental 'Arctic Council'. It's website it full of reports, both scientific and for the press which are freely available and are

An Arctic Ozone 'Hole' - a new threat?

I was looking at the news today and came across a very short article from the Independent, which, despite it's size, had been the sixth 'most-read' Environmental article in the Independent during 2011. I'm not sure whether it's the topic that drew the most readers, or the title: 'GIANT ozone HOLE found above Arctic' (own capitalisation!). Due to this likely exaggeration and the fact that I hadn't heard this apparently popular news story, I decided to have a look at the original paper the article was based on. The paper was published in Nature as is titled 'Unprecidented Arctic Ozone Loss in 2011' by Manney et al 2011.* They reported a record low ozone level of 220-230 Dobson Units (DU) recorded in March 2011, but could you day this was a 'huge hole'? Also, was this anything to do with climate change or this just a random and freak occurrence?

Polar Stratospheric Clouds (PSCs) photographed in Sweden
http://earthobservatory.nasa.gov/IOTD/view.php?id=622

According to the authors, the possibility of significant ozone 'holes' in the Arctic has been debated for decades, with some arguing that higher temperatures in the Arctic than the Antarctic prevented such formations. The basic

A short introduction to Arctic pollution...

One of the questions set out at the start of the blog was:

Is anything else apart from rising temperatures causing change?

In the next post I'm going to have a look at one other human impact on the arctic; pollution. The subject is filled with Three Letter Acronyms (TLAs...) so I'll generalise where possible. Here's a really short video which explains how the pollution gets there. Stay tuned for a discussion...

This video and others are freely available from the Arctic Monitoring and Assessment Programme website: http://www.amap.no/

Melting Permafrost - should I be worried?

Just before getting started, I found the video I really wanted to share with you guys before, but ended up using a replacement. It's from the fantastic series 'Earth: The Power of the Planet', presented by the brilliant Prof Iain Stewart, a Geologist at the University of Plymouth. He's like Geology's answer to Brian Cox! If you missed the series, I'd encourage you to have a catch-up. Interestingly, this video also features the same Dr Walter as the previous video..

Although it's the easiest and most spectacular way of showing the processes which are happening, it's not the lakes that are causing the most concern. Phrases like 'ticking time bomb' and 'unstoppable warming' are used

Treeline in the Arctic

As promised, I'm going to consider the Arctic Treeline for this next post. Just as a warning, one of the papers I use in this post includes some sites from below the 66 degrees latitude level, so I hope you'll forgive the slight digression from our brief.

An alpine treeline in the background. Although not an Arctic treeline,
the clear change illustrates the concept well.

Firstly, what is the Arctic treeline? As an intuitive general definition, a treeline separates regions where tree-growth is sustainable, and areas where climatic factors such as low temperatures prohibit the establishment

Exploding Ice

So far we've mostly looked at shifts in diatom and chironomid assemblages in the Arctic. Although interesting (I hope), it all might be a bit abstract and... small. So the next few posts are going to focus on changes in the arctic that are slightly more tangible. Firstly I'm going to discuss the treeline; what it is, how it has changed in the past and how it's been changing recently. Then, in the next post, I'll look at a change that is causing concern; the tundra shifting from being a sink of GHGs to a source through the melting of permafrost.

Before that though, here's a great video from the University of Alaska showing the build up of methane in frozen lakes during the winter, with some explosive results!

On thin ice? (another 'light' post)

I've just finished watching the final part of BBC's 'Frozen Planet' series called 'On Thin Ice', which was written and presented by David Attenborough. It's noteworthy for a few reasons. Firstly, the Discovery Channel in the USA only just decided to show this final episode, previously declining to show it to the American audience, likely fearing a backlash from Climate Change Skeptics. Reasons for the initial rejection are unclear, ranging from the patronising but innocent ie. "Who's David Attenborough?" (the series is being narrated by Alec Baldwin on Discovery) to the concerning; it's impact on the upcoming US elections. Of course, climate change campaigners had reacted to the announcement with anger.

This is a QR Code. Scan it with your smartphone to follow the link 

A more interesting response to it, in my view, and the one which has caused the bigger reaction from the makers of the program and the academics involved is..

Shrubland expansion - photographic evidence

To start off the posts on terrestrial ecosystem change, I'd like to share a short (one page!) correspondance article from Nature by Sturm et al (2001). It's pretty simple and is completely qualitative based on only two 'observations', but it's interesting nonetheless. The authors found high quality photographs, taken during oil reserves exploration in 1949 at around 68° latitude in the Alaskan Arctic. By taking 66 modern photographs at some of the same locations, they could compare the vegetation cover at the same sites over the 50 year period. Here's one of the comparisons:


A hillside in the Alaskan Arctic in 1949 and 2000. A and B show identical locations.

Although a crude assessment, it is clear that there is a difference between the two photographs. Abundance