Today I sampled water and gases in lakes and ponds, helping the team figure out the fate of carbon from the melting tundra. As I’ve mentioned over and over in earlier blogs, this is important to know because there’s twice as much carbon frozen in the tundra as in all of the earth’s atmosphere. If this carbon is converted to CO2 and methane when permafrost melts, it could have a major effect on climate change.
But what exactly happens to carbon when permafrost melts? It’s a complicated question but I’m starting to understand how the team is trying to find answers. One way to understand the flow of carbon is to follow it from the land to the water and the air. This is what I’ve been doing so far.
The first step is to follow meltwater and runoff as it flows downhill. This is what we did on Wednesday when we sampled water from water tracks, where water flows downslope just under the surface of the tundra. Here’s a picture of a water track from the valley of Imnavait Creek, near Toolik. You can see the darker green color of the wet ground of the water track.
Water track at Imnavait.
We stuck soil needles in the ground and sucked water out with syringes, like Katie is doing in this picture.
We took samples from the water track back to the lab to find out what type of carbon compounds are present and at what concentration.
At the bottom of the slope, the water tracks flow into small “beaded streams” -- little ponds linked by flowing water. Today Ben and I sampled gases from the surface of the ponds; they’ll be analyzed for CO2 and methane.
Sampling gases from the water surface.
In addition to knowing the type of carbon compound present and its concentration, it’s also critical to know the volume of water flowing off of the tundra. This picture shows a flume for accurately measuring water flow.
Flume on Imnavait Creek.
As little tundra streams like this flow across the North Slope to the Arctic Ocean, they run into larger lakes and coalesce into rivers, and we sample them, too. On Wednesday we sampled the Sagavanirktok River for gases and water samples.
Sampling the Sagavanirktok River with Susanna
Today we went out on Toolik Lake and collected samples of lake water and dissolved gases to analyze for carbon.
Heading out on Toolik Lake with Colleen and Sara.
Sara extracting gases from a water sample on Toolik Lake
We also measure light intensity to understand how light might be affecting carbon compounds, especially as light can break them down and make them more easily converted into CO2 and methane.
Measuring light intensity on Toolik Lake.
So, in just three days I’ve been out with the team to collect and analyze samples from soil, streams, ponds, lakes and rivers to piece together the puzzle of how carbon moves from land to the water and the air. I'll be going to more sample locations across the North Slope and learning more about the flow of carbon in the coming weeks, and posting more pictures and videos.
Another critical question in understanding the movement of carbon from the melting tundra is the role of microbes. How do they affect the cycle and what’s their role in making CO2 and methane? I’ll talk about that in a future blog, also.
Rainbow on the Tundra 6-27-13