Important new publication

We publish most of our research results in scientific journals that are reviewed by other researchers (or peer-reviewed).  It is an important part of sharing the knowledge that we gain from research with others, much in the same way we try to share with this blog and our Facebook page.

This week an important new paper was published in Nature Scientific Reports by the CBAWO group.  You can download a copy for free at Nature Scientific Reports.  In this, we show how recent permafrost change at Cape Bounty has made a significant impact on the lakes, changing the chemical composition of some elements by up to 500% in a few years.  This is an incredible rate of change, and this work documents how quickly this can happen and that it occurred in both lakes at the same time.  We also used the otoliths (ear bones) from Arctic char in the lakes to determine if this chemical change had influenced the fish.  We found that many elements changed abruptly in the fish otoliths at the time of the rapid changes in the lakes, signalling that the fish are responding to this environmental change.  By using a fish condition measure (by looking at length and weight of each fish), we show that the condition of the fish in the East Lake is improving, so it would seem that the permafrost change we have observed in recent years is contributing to enhanced living conditions for the fish.

Ice-push ridges on the shore of West Lake, August 2017.  Notice the cloudy water that has been that way since the winter of 2011-12.  

There is likely much more to the story, as the lake ice cover has become less persistent and water temperatures have increased as well.  The West Lake also tells an interesting story with the opposite effect:  underwater landslides (or slumps) that have made the lake continuously muddy have resulted in a continuous deterioration of the condition of Arctic char. 

So it would seem that the two lakes are going in different directions, but both are showing strong impacts from recent environmental change.

Part of the reason this paper is so important is that it summarizes work that has been carried out since 2004 at Cape Bounty, when the first lake water samples were taken and the ecosystem sampled.  We have continued this work and expanded it by working with collaborators at Environment and Climate Change Canada who are experts in contaminants in northern ecosystems, and residents of Resolute that have important knowledge about the fish and lake ecosystems.  This collaborative effort is reflected in the range of authors of this paper- each person contributed important parts of the overall story. 

Like most research, these results generate many new questions but we are working hard to pursue these.  We hope to be able to share them with you in the months and years to come!

West Lake at Cape Bounty, August 2009.

2016 Reseach season: snow, soil and ice

This blog has been quiet for two years- hard to believe how fast the time went by.   We'll try to post more frequently, especially now that the field season is underway.

We opened the camp on May 18 and found the tents and equipment in generally good shape.   Conditions were already looking unusually warm based on weather from other stations in the area, and a pilot mentioned that he saw little snow on Melville Island while flying over in March.  

When we arrived, there seemed to be a lot of snow, especially around camp where we had to dig it out.  However, when we did our snow survey, we found it was quite the opposite.  Snow is a funny thing, you just can't measure it in one spot.  It blows around all winter and the depth tends to be quite different from place to place.  Each year we carry out a snow survey that involves 28 locations in the river basins and at each location, we measure depth in ten spots along a line.  We also collect snow samples with a metal tube and weigh the snow to determine how much water there actually is in the snow.  This gives us a way to calculate what hydrologists call the "snow water equivalence", or SWE (s-whee).  One way to think of SWE is how much water would be left on the land if you melted all of the snow.  It is measured as a depth, so you can think of the depth of water for a given SWE.  

The snow at CBAWO this year was very limited, the least we have measured since 2005.  It was 49 mm, about 60% of a typical year.  In many places, the snow was just a thin covering over the soil.  That indicates that there is very little water on the land for runoff this spring, something that is very important for many of the systems we monitor.

One of the things that we were interested in sampling this year was the frozen soil to see how much water was in it and how ice was formed the previous winter.  This affects how the soil thaws and how the water will flow in the soil.  Many researchers recover samples of the deeper permafrost, but this soil is not really permafrost, as it almost always thaws.  We refer to this as the "active layer", or the part of the soil that thaws during the summer.  As the name implies, this is the part of the soil where a lot of important things happen:  plants root, water moves and changes properties, and an important ecosystem of microbial life recycles dead plant matter and supports vegetation growth.  

To sample the frozen soil, we use a power auger and a hollow bit that cuts down and brings up frozen soil material.  The auger is big, powerful, and has a mind of it's own:  when it hits a rock, it can stop dead and throw the people operating it.  We give it a lot a respect and have affectionately named it 'Taz', after the Tasmanian Devil in the cartoons!

The frozen soil is pretty neat to look at.  This photo shows a section from 60-75 cm depth, and you can see some clear ice lenses and structure starting to appear.   Ice formed in these lenses late in the autumn and will only thaw late this coming summer.  When it does, the water released will be able to drain out, but we find the quality of this water is very different from snow runoff.  As you go deeper, there is even more ice, sometimes just ice for intervals of 10 cm or more.  

These samples will be analysed for their water content and we plan to get images of the ice structure while they are frozen using a special scanner like the ones they use in hospitals to image bones.  We hope by understanding how water is stored and moves through the soil at different times of year, we can better predict how climate changes will affect water in the High Arctic, and how this will contribute to the stability of the landscape and ecosystem.

And now to tease with an image that looks like something out of a movie.  No, it is not some futuristic weapon.  We actually put that underwater in the lakes to learn more about what is going on at the bottom.  That is a story for another time.  Thanks for following.

Ice caps melting

A short post to highlight news that has emerged, indicating that the ice caps in the Canadian Arctic are melting at an accelerated rate since 2005 (see article in Vancouver Sun).  This information is something that has been well understood in the research community for years, but it is striking that the increased loss of ice from these ice caps, including the Melville Ice Cap (about 150 km west of Cape Bounty) coincides with a period of remarkable warming at Cape Bounty.  The warmest July at Cape Bounty was in 2007, followed closely by 2011 and 2012.  Interestingly, July 2013 was cooler at Cape Bounty and reflects a cooling also noted in the article and on the ice caps.

These ice caps vary in size and sensitivity to change, and there are researchers working to understand these changes, but the same recent climate has had an important impact on our research at Cape Bounty.  In particular, and the widespread permafrost disturbance that we observed occurred in late July 2007 and occurred at a time when temperatures were greater than 20degC on some days.

One of the most visible forms of permafrost disturbance at Cape Bounty are slope failures called active layer detachments, or ALD for short.  These slides can be very large, up to 600 m long and 200 m wide, and move down slope long distances.  They move like a carpet slowly sliding down a slope, a thin layer that keeps moving until some obstruction slows it down.  As it loses momentum, the moving soil piles up in folds and comes to rest.

ALD are a potential risk to roads and other infrastructure that might be built in this region, and they impact water quality by increasing sediment erosion and causing additional salts to be released.  Other impacts likely occur, particularly by the release of soil organic matter that was buried for thousands of years, and allowing soil and water microorganisms to consume this different material.  How this affects the soil and water ecosystem remains poorly understood and is one of the topics we are studying at Cape Bounty.

While it is difficult to determine trends, especially with so much year to year variation in weather, both the ice caps and permafrost are responding to recent warming in the Canadian Arctic.  From the perspective of Cape Bounty, even if this trend reverses itself, the impact will remain on the land and affect the water for many years to come.