Thread by @DrTELS

#ArcticFires have been burning for 6+ weeks, starting earlier than usual & releasing more CO2 in June/July than any year in the 17-yr record.

A crucial question is whether these fires have ignited peat soils. This THREAD takes a closer look.

https://twitter.com/m_parrington/status/1154055716551962625

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Peat fires are important because they burn carbon that was sequestered over 1000s of years. Unlike a grass/forest fire, emissions cannot be treated as carbon neutral. Once ignited, peat burns for a long time and is difficult to extinguish.
SOURCE: publish.csiro.au/wf/pdf/WF17084

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Thanks to raw fire data from @m_parrington (red dots = Jun/Jul 2019 fires) and PEATMAP (green shaded areas) (sciencedirect.com/science/articl…), we can establish that this year's fires are definitely burning on known peatlands.

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The question is whether the fires exist only on the surface, or have ignited peat soils. These peatland fires in Eastern Siberia and NE Alaska have been burning for a number of weeks on the same land, spreading slowly - this suggests a deep-seated smouldering peat fire.

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This animation shows a fire in NE Alaska, near Chalkyitsik. The animation spans 4 weeks, from end of June through to 24 July (image is ~250 km wide). The fire spreads slowly and some hotspots have been persistent for the whole period of the fire, suggesting a peat fire.

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You should notice a brown/yellow tinge to the smoke. This is also indicative of a peat fire [see Tweet 2/7]

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Peat fires are part of a climate system positive feedback loop. Higher Arctic temperatures increase the likelihood of peat ignitions during a fire, as the extra heat dries the (normally moist) peat out. Resultant greenhouse gas emissions will only lead to more heating
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This is a follow-up to an earlier thread:

https://twitter.com/DrTELS/status/1151868725336952832