GDGT distributions on the East Siberian Arctic Shelf

Our paper, “GDGT distributions on the East Siberian Arctic Shelf: implications for organic carbon export, burial and degradation” has now been published. You can download the paper, and the underlying data, from the Biogeosciences website here.

As I mentioned before, this paper has been submitted, reviewed and published completely open-access. This means that the original paper, the reviews and our response are all archived online forever. All of this is available freely to anyone, without the need to pay for access. You are free to copy, distribute and make use of the data and graphs as long as the original paper is cited (also known as a CC-BY copyright license)

Boxplots showing how GDGT biomarkers vary offshore
Boxplots showing how GDGT biomarkers vary offshore

In the paper we show the first map of GDGT biomarkers from the East Siberian Arctic Shelf. This region is extremely remote yet very important within the global carbon cycle. Our work shows that this is an area of complex interaction between rivers, coastal erosion and open ocean productivity. The GDGT biomarkers are very useful here as a tracer of carbon being washed away by the rivers and being produced in the oceans, and this allowed me to make a model of the Arctic Ocean in this region to better understand how all of the different processes interact.

Our model of biomarker export across the Arctic Shelf
Our model of biomarker export across the Arctic Shelf

As an author, the publishing process for Biogeosciences was interestingly different. There was a reasonable amount of time between submitting the paper and final publication, but that was mostly due to the interactive public discussion stage which most journals do not have. During this time the paper was available and citable, which means that although it was relatively slow progress towards final publication the story was out there very quickly. I’m keen to go for this style of publishing again in the future.

Redistribution of multi-phase particulate organic carbon in a marine shelf and canyon system during an exceptional river flood

I have recently had a paper accepted in the journal “Marine Geology“, which looks the transport of organic carbon during a major typhoon in Taiwan: “Redistribution of multi-phase particulate organic carbon in a marine shelf and canyon system during an exceptional river flood: Effects of Typhoon Morakot on the Gaoping River–Canyon system”.

Typhoon Morakot was a particularly severe tropical cyclone that hit the island in 2009, causing flooding, mudslides and hundreds of deaths. From an organic geochemistry perspective, it also transported sediment and organic carbon from the hillsides and floodplains out to the South China Sea. Some of this carbon was “fresh” material, coming from trees, grass, shrubs and soil. Other parts of the carbon was “fossil” carbon, sourced from the mountains running down the centre of the island, or from sedimentary rocks in the foothills and floodplains. It is important for the global carbon cycle to understand how much of the land-sourced (terrestrial) carbon makes it to the ocean floor, because this process can lead to carbon being stored in the sediments for millions of years.

Out at sea, all of this organic carbon and sediment was mixed together with material produced in the water column, by algae and plankton. Mixing three carbon sources together makes it very difficult to work out how much of each one is present in a sample, which is where my work comes in. By combining measurements of the nitrogen to carbon ratio with the carbon-13 to carbon-12 isotope ratio, these three inputs can be identified. I did this for samples collected in the Gaoping Canyon, a deep submarine channel running from the island out to the deep sea. I found that terrestrial organic carbon was the dominant form of carbon present in the canyon and that therefore millions of tonnes of carbon were transported to and buried in the ocean by the typhoon.

Figure from the paper
Unmixing plant matter, bedrock OC and marine carbon

 

This carbon will most likely be locked away in these sediments for thousands or millions of years, while on the island more trees will grow to replace the ones washed away in the storm. In the process, carbon dioxide will be taken out of the atmosphere, so the storm-flood-burial cycle should go some way towards slowing the rate of climate change.

If you would like to download the paper, it is available freely via open access or as a PDF.

GDGT distributions on the East Siberian Arctic Shelf: Discussion paper

My last post talked about Open Access publishing, and the various philosophies for spreading (and/or making money from) academic knowledge. Now there is a chance to play an active part in the publishing process. My latest paper has been submitted to a journal called “Biogeosciences” which is administered by the European Geosciences Union (EGU). Their journals are published using a super open process, where more than just the final paper is released free-of-charge to the world. Whereas in regular Open Access publishing anyone is free to read the final reviewed work, in EGU journals the initial version is also made available. Two reviewers are selected from the community, and their reviews are shown on the website as well. Everyone else is free to read and comment on the paper, raising questions that the authors have to respond to. It is hoped that this system is a) transparent b) open to more (constructive) criticism than the standard two-review system and c) faster, since the paper is available for people to read at an earlier stage of the process.

A figure from the paper showing land-sourced GDGT molecules
A figure from the paper showing land-sourced GDGT molecules

Our paper discusses the distribution of GDGT biomarkers on the East Siberian Arctic Shelf. We measured these biomarkers to determine whether the organic matter deposited on the shelf came from land or ocean sources. When we had made these measurements, a model was created to try and explain the observations and work out the budget for carbon being delivered to the shelf from large Arctic rivers.

If you want to read and comment on the paper it is available on the Biogeosciences website

What is: Open Access publishing?

Peer review is generally accepted to be the least-worst way to generate trust in the scientific publishing process. By allowing experts in the field to read, critique, confirm, challenge and improve your work before it enters the mainstream body of science, poor quality or erroneous work should be filtered out before it gets the chance to distort public perception and policy. However, it’s not without its critics. Anonymous reviews allow reviewers to partake in spiteful and/or personal attacks which do nothing to improve the science behind the work, and can delay or even prevent publication of perfectly acceptable work. Also, the system is based on a financial system that only seems to benefit the publishing companies. In traditional journals, scientists relinquish their copyright to a company that then charges them and their colleagues to read the work, restricting access to those in universities or with big budgets (individual papers can cost $30 or more, subscriptions run to the thousands). Journal reviewers and editors work for free, considering the process as part of their community obligation despite the for-profit journal getting the real benefits.

Recently, open-access publishing has started to change the way that ordinary people can read the research that they, through their taxes and charity donations, have paid for, but the business model for the publishers is generally similar. In a typical open access publishing workflow, the researchers submitting the paper pay an “article processing charge” (APC) once the work has been accepted. Paying this charge, which is often £1000 or more, allows them to retain the copyright, and lets anyone, anywhere in the world, read the paper for free. It shifts the costs for access from the distributed consumers, who would often lack the resources to pay for the research, to the universities producing the work in the first place. Most research grant bodies now request open access publishing, and have provided some funds to cover the APCs, for now at least. Reviewers and editors are still unpaid, and publishers still make a profit, in fact since many articles are not open access then universities (i.e. taxpayers) are on the hook for both the journal subscriptions and the APCs.

So why are researchers still paying these companies such large amounts of money (profit margins are amongst the best of any industry)? Well, academic promotion is mostly decided by your publication history; the easiest way to judge a publication history is to look at the journals that a researcher publishes in, rather than reading the papers themselves. Therefore the pressure is on, especially for young researchers, to publish in the most prestigious journals, and they tend to be the most expensive ones, where articles are either restricted access or have high APCs.

Recently, there has been a shift towards more open and accountable publishing systems, with journals allowing researchers to publish either draft versions or even the finished paper on their website without violating copyright. Many universities have created online repositories to let researchers store and share their work (mine is available through my Manchester profile page), which are imperfect, since it’s often hard to find the papers, but better than nothing.

Even within my short career, the way that people publish and access science has changed; open publishing is still in development and it’s likely that further innovation in the next 5-10 years will change the landscape even further.

Canadian permafrost as a source of easily-degraded organic carbon

The February issue of “Organic Geochemistry” will include a paper by David Grewer and colleagues from the University of Toronto and Queen’s University, Canada which investigates what happens to organic carbon in the Canadian High Arctic when the surface permafrost layer slips and erodes. This is a paper that I was involved in, not as a researcher but as a reviewer, helping to make sure that published scientific research is novel, clear and correct.

Map of Cape Bounty in the Canadian High Arctic
Map of Cape Bounty in the Canadian High Arctic

The researchers visited a study site in Cape Bounty, Nunavut, to study a process known as Permafrost Active Layer Detachments (ALDs). The permafrost active layer is the top part of the soil, the metre or so that thaws and re-freezes each year. ALDs are erosion events where the thawed top layer is transported down the hillslope and towards the river. Rivers can then erode and transport the activated material downstream towards the sea.

The team used organic geochemistry and nuclear magnetic resonance spectroscopy to find out which chemicals were present in the river above and below the ALDs. The found that the sediment eroded from the ALDs contains carbon that is easily degraded and can break down in the river, releasing CO2 to the atmosphere and providing food for bacteria and other micro-organisms in the water.

Arctic sea ice over one year

As 2014 draws to a close, what were the key features of the Arctic climate this year? Today let’s look at the sea ice coverage. The US National Snow and Ice Data Centre has a monthly running commentary on ice cover on their website, and in general 2014 has been “extremely ordinary”, by which they mean that sea ice grew and shrank at roughly the rates of the last few years. Ice cover was not as low as 2012, the record-breaking year for sea ice retreat, instead it was pretty average for recent times. Remember that this is still way down on the long-term average.

Monthly Arctic sea ice cover for the last few years (NSIDC)
Monthly Arctic sea ice cover for the last few years (NSIDC)

Using their monthly data, here is an animation of the sea ice changes over the last 12 months. It’s a reminder of just how dynamic the Arctic is. Sea ice cover is important for a number of reasons. First of all, the white colour reflects sunlight that shines onto the ice surface during the summer. Reflecting sunlight back into space means that it does not stay around to warm our planet, so having a decent covering of ice helps to regulate temperatures. As the summer sea ice cover has decreased in recent years, the amount of sunlight reflected back into space has decreased, meaning that there is a positive temperature feedback at work here.

animsm
Arctic sea ice cover over the last year

Sea ice cover is also important for the Arctic Ocean’s biological cycle. Many plankton require sunlight for photosynthesis, so the retreat of sea ice during the spring and summer causes a bloom in biological productivity in the surface ocean which feeds down the food chain, supporting large numbers of fish and whales. As organic geochemists, we can see this plankton bloom by looking in the ocean sediments biomarkers. There are specific chemicals that are produced by marine organisms that can be used to track the productivity, and it seems that there is a direct link between the ice-free areas and the highest amount of biological activity.

Manchester Museum – Siberia Exhibition

Starting this Saturday 4th October, and lasting until 1st March, the Manchester Museum will be holding a special exhibition on Siberia. This will contain a collection of special items from British and Russian museums, including a mummified baby mammoth and a brown bear, along with displays on the culture and natural history of the region, taking visitors beyond the stereotypical view of Siberia as an icy wasteland. Along with colleagues in Manchester, Newcastle and London, I have made a display board and video about Siberian climate change, which will be showing throughout the exhibition. More to follow once the exhibition opens…

Official Museum Poster

US Government review of climate change

This week the US government released their own review of the climate, including the current state of play and predictions for the future. They conclude that climate change is happening now, affecting lives today, and not just something to worry about 20+ years in the future.

 

Modelled temperatures with and without human CO2 emissions
Modelled temperatures with and without human CO2 emissions

The report website is very comprehensive and well-written, and I’m not going to reproduce it here. The section on Alaska, complete with interactive photos and charts, is relevant to permafrost research across the whole northern hemisphere.

 

What Is: GRAR?

Russia is big, really big, and to go with that, it has some very big rivers. The majority of the Russian river outflow is into the Arctic Ocean, especially in the central and eastern parts of the country, and this is generally concentrated into a series of very large rivers. The largest of these are known as the Great Russian Arctic Rivers (GRARs). From west to east, these are the Ob, Yenisety, Lena, Indigirka and Kolyma, of which the Ob and Lena are largest, and Indigirka the smallest (small enough to not count in some people’s list of GRARs).

Catchment areas of the Great Russian Arctic Rivers
Catchment areas of the Great Russian Arctic Rivers

The Ob river is the world’s fifth-longest and has the sixth-largest drainage basin, yet has only the 19th highest annual discharge, being overtaken by the smaller Yenisey and Lena rivers to the east of it. All of these river basins contain some permafrosted land, which can reduce discharge during the winter months and have a very large flood-period in late spring / early summer when the meltwater arrives (the “freshet”).

Permafrost within catchments of the GRARs
Permafrost within catchments of the GRARs

As the amount and continuity of permafrost increases from west to east, so the proportion of each permafrost type increases within the river basin. The Ob and Yenisey are largely free of continuous permafrost, allowing water to flow through the ground to the bedrock and into the river, whilst the Indigirka and Kolyma are practically 100% continuous permafrost, and thus any water discharging will have run along the top of the ground before entering the river itself. This can have consequences for the type of material, especially carbon, carried by the rivers.

Proportion of each type of permafrost within river basins
Proportion of each type of permafrost within river basins

This east-west contrast is worth exploring in more detail in a later post, since it shows how Siberia may behave very differently if the permafrost were to thaw. As a final reminder of just how large the rivers are, even the smallest, Indigirka, manages to cover more area than the British Isles! As usual the full-resolution PDFs of the figures from this article can be downloaded here: River catchments no permafrost, Catchments and permafrost, Permafrost chart, Catchments and UK.

Comparing the catchment areas to the British Isles
Comparing the catchment areas to the British Isles

 

Infographic

I am in the process of designing an infographic-style poster to explain our work in the Arctic in a few simple charts. Here are some early drafts of introductory slides.

Northern Hemisphere permafrost is only 16% of the global soil area
Northern Hemisphere permafrost is only 16% of the global soil area
Yet it represents over half of the global soil organic carbon poo;
Yet it represents over half of the global soil organic carbon pool
Global soils contain more organic carbon than fossil fuels or the atmosphere
Global soils contain more organic carbon than fossil fuels or the atmosphere