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Author Topic: Arctic Methane Release  (Read 354790 times)

Alumril

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Re: Arctic Methane Release
« Reply #1200 on: December 02, 2020, 03:52:35 AM »
Kassy, so I had a think about this, and tried to come up with sites that are more likely to have increased in methane faster than the global average.
I tried Niwot Ridge, Colorado, United States (NWR) due to the local fracking activity and Mt. Waliguan, Peoples Republic of China (WLG) due to increased rice production and increased industrial activity. I don't have any local knowledge of these places, so it was a bit of a guess.

There is a slight increased trend on both sites vs south pole data. While the trend for Barrow  (BRW) is flat.

Now I did deliberately pick these sites because I thought would have the largest increase in emissions. But then I originally expected to see the same trend in Barrow and Tiksi and didn't find it.

I'm no expert on this, so I'm happy for any challenge of these methods.

morganism

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ArgonneForest

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Re: Arctic Methane Release
« Reply #1202 on: December 02, 2020, 06:51:20 AM »
Kassy, so I had a think about this, and tried to come up with sites that are more likely to have increased in methane faster than the global average.
I tried Niwot Ridge, Colorado, United States (NWR) due to the local fracking activity and Mt. Waliguan, Peoples Republic of China (WLG) due to increased rice production and increased industrial activity. I don't have any local knowledge of these places, so it was a bit of a guess.

There is a slight increased trend on both sites vs south pole data. While the trend for Barrow  (BRW) is flat.

Now I did deliberately pick these sites because I thought would have the largest increase in emissions. But then I originally expected to see the same trend in Barrow and Tiksi and didn't find it.

I'm no expert on this, so I'm happy for any challenge of these methods.
Great data! I've asked around on Twitter for a couple of scientists about what happened to the Tiksi station. I'll let you guys know if they get back to me

kassy

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Re: Arctic Methane Release
« Reply #1203 on: December 02, 2020, 11:00:52 AM »
Finding out more about Tiksi would be great.

Sentinel-5 might help but it will be a couple of years before it launches.

When i looked at the arctic stations the big problem is that there are so little stations.
If there were a lot more stations then you could look at other details. IIRC there was a specific error code for measures removed because of some local source made the readings too high.

If there had been more stations with a good spatial distribution it would be interesting to see if  dates with those codes relate to local sea ice break up for example but with the amount of stations we have now that does not work. 
Þetta minnismerki er til vitnis um að við vitum hvað er að gerast og hvað þarf að gera. Aðeins þú veist hvort við gerðum eitthvað.

vox_mundi

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Re: Arctic Methane Release
« Reply #1204 on: December 14, 2020, 08:05:35 PM »
The Moon Controls the Release of Methane in Arctic Ocean
https://phys.org/news/2020-12-moon-methane-arctic-ocean.html

Small pressure changes affect methane release. A recent paper in Nature Communications even implies that the moon has a role to play.

The moon controls one of the most formidable forces in nature—the tides that shape our coastlines. Tides, in turn, significantly affect the intensity of methane emissions from the Arctic Ocean seafloor.

"We noticed that gas accumulations, which are in the sediments within a meter from the seafloor, are vulnerable to even slight pressure changes in the water column. Low tide means less of such hydrostatic pressure and higher intensity of methane release. High tide equals high pressure and lower intensity of the release," says co-author of the paper Andreia Plaza Faverola.

"It is the first time that this observation has been made in the Arctic Ocean. It means that slight pressure changes can release significant amounts of methane.

Plaza Faverola points out that the observations were made by placing a tool called a piezometer in the sediments and leaving it there for four days.

It measured the pressure and temperature of the water inside the pores of the sediment. Hourly changes in the measured pressure and temperature revealed the presence of gas close to the seafloor that ascends and descends as the tides change. The measurements were made in an area of the Arctic Ocean where no methane release has previously been observed but where massive gas hydrate concentrations have been sampled.

"This tells us that gas release from the seafloor is more widespread than we can see using traditional sonar surveys. We saw no bubbles or columns of gas in the water. Gas burps that have a periodicity of several hours won't be identified unless there is a permanent monitoring tool in place, such as the piezometer," says Plaza Faverola

These observations imply that the quantification of present-day gas emissions in the Arctic may be underestimated. High tides, however, seem to influence gas emissions by reducing their height and volume.

"What we found was unexpected and the implications are big. This is a deep-water site. Small changes in pressure can increase the gas emissions but the methane will still stay in the ocean due to the water depth. But what happens in shallower sites? This approach needs to be done in shallow Arctic waters as well, over a longer period. In shallow water, the possibility that methane will reach the atmosphere is greater," says Knies

... The question remains whether sea-level rise due to global warming might partially counterbalance the effect of temperature on submarine methane emissions.



Nabil Sultan et al, Impact of tides and sea-level on deep-sea Arctic methane emissions, Nature Communications (2020).
https://www.nature.com/articles/s41467-020-18899-3
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