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Anna Virkkala

@annvirkk.bsky.social
181 followers 94 following 9 posts

Research scientist @Woodwell Climate Research Center and @University of Helsinki. Arctic, carbon, climate change.

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Anna Virkkala @annvirkk.bsky.social · 26/02/2026
Looking for a post doc position? One more week left to apply for this 3-yr post doc position with me on Arctic shrubification and C balance, based in Helsinki: valtiolle.fi/en/jobs/post...
valtiolle.fi
Postdoctoral researcher (atmosphere-ecosystem interactions) - The Finnish Meteorological Institute
Open job: Postdoctoral researcher (atmosphere-ecosystem interactions), The Finnish Meteorological Institute - Find all jobs in Valtiolle.fi
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Anna Virkkala @annvirkk.bsky.social · 21/10/2025
It has taken more than two years (plus all the years data contributors have spent on their data collection), but finally our data descriptor manuscript preprint on Arctic-boreal carbon fluxes across terrestrial and freshwater ecosystems is out: essd.copernicus.org/preprints/es... Go have a look!
essd.copernicus.org
ABCFlux v2: Arctic–boreal CO2 and CH4 monthly flux observations and ancillary information across terrestrial and freshwater ecosystems
Abstract. Measurements of surface-atmosphere carbon dioxide (CO2) and methane (CH4) fluxes have been relatively sparse across the Arctic tundra and boreal biomes, causing significant uncertainties in ...
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Dr. Merritt Rae Turetsky @queenofpeat.bsky.social · 24/07/2025
Hot off the presses! Abrupt permafrost thaw is a critical climate feedback but is poorly defined & understood. In an awesome collaboration between my team & the Permafrost Carbon Network, PhD student Hailey Webb provides a formal definition to guide future studies. link.springer.com/article/10.1...
link.springer.com
A Review of Abrupt Permafrost Thaw: Definitions, Usage, and a Proposed Conceptual Framework - Current Climate Change Reports
Purpose of Review We review how ‘abrupt thaw’ has been used in published studies, compare these definitions to abrupt processes in other Earth science disciplines, and provide a definitive framework f...
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Permafrost Pathways @permafrostpathways.bsky.social · 17/06/2025
Congratulations to Dr. Ying and all co-authors, including @benpoulter.bsky.social @profdesai.bsky.social and @woodwellclimate.bsky.social @permafrostpathways.bsky.social's Jennifer Watts, Kyle Arndt, @annvirkk.bsky.social, Brendan Rogers, and Sue Natali. essd.copernicus.org/articles/17/...
essd.copernicus.org
WetCH4: a machine-learning-based upscaling of methane fluxes of northern wetlands during 2016–2022
Abstract. Wetlands are the largest natural source of methane (CH4) emissions globally. Northern wetlands (>45° N), accounting for 42 % of global wetland area, are increasingly vulnerable to carbon los...
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Anna Virkkala @annvirkk.bsky.social · 15/05/2025
If you need land cover datasets for the Arctic-boreal region, here is one great option for you at 1-km resolution: essd.copernicus.org/preprints/es.... It merges several regional products and separates dozens of key land cover types (e.g. bogs, fens, pine forest, spruce forest). 🌎🏞🏔
essd.copernicus.org
Fusing Regional and Global Datasets to Develop a Composite Land Cover Product Across High Latitudes
Abstract. Rapid warming across the Arctic is the primary driver of widespread permafrost thaw, with far-reaching consequences for local ecosystem resilience, the regional carbon budget, and the global...
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Greg Fiske @gfiske.bsky.social · 25/03/2025
Make a difference this summer -- Join @cmshintani.bsky.social and me for an internship at @woodwellclimate.bsky.social and contribute to critical research on climate change. Apply now: bit.ly/4l5D93W
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Anna Virkkala @annvirkk.bsky.social · 01/04/2025
First circumpolar maps of aboveground tundra biomass at 30 m resolution 💪 www.sciencedirect.com/science/arti... These new estimates show that in total tundra plants (above-and belowground) store around 8 Pg C while the upper 30 cm soils store ca 53 Pg C.
sciencedirect.com
Next generation Arctic vegetation maps: Aboveground plant biomass and woody dominance mapped at 30 m resolution across the tundra biome
The Arctic is warming faster than anywhere else on Earth, placing tundra ecosystems at the forefront of global climate change. Plant biomass is a fund…
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Permafrost Pathways @permafrostpathways.bsky.social · 30/01/2025
" The sooner we reduce global greenhouse gas emissions, the sooner we can get the permafrost to refreeze," said Sue Natali. Thanks @vivianla.bsky.social for covering this study!
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Mika Rantanen @mikarantane.bsky.social · 30/01/2025
Vuoden 2024 ilmastovuosikatsaus on julkaistu! www.ilmastokatsaus.fi/2025/01/30/i... Katsauksesta löydät muun muassa: - Säätapahtumat Suomessa ja maailmalla vuonna 2024 - Keskilämpötilan kehitys pitkällä aikavälillä Suomessa - Myrskypäivät Suomen merialueilla - Itämeren merilämpöaallot
Sinisellä pohjalla oleva Suomen maan äärirajat jonne on viivoilla lisätty tietoa eri säätapahtumista. Esim. vuoden alin lämpötila, vuoden suurin lumensyvyys ja vuoden kovin tuulennopeus. Pylväsdiagrammi Suomen keskilämpötilasta. Keskimääräistä kylmemmät vuodet ovat sinisellä ja lämpimämmät punaisella. Musta viiva kuvaa liukuvaa 10 vuoden keskiarvoa.
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Permafrost Pathways @permafrostpathways.bsky.social · 29/01/2025
We are so grateful for everyone's engagement and great questions on this study! We want to address a few of the main ones that have appeared 🧵
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Anna Virkkala @annvirkk.bsky.social · 28/01/2025
We are looking for a grant-funded doctoral resarcher on a project focusing on how tree and shrub expansion into the tundra impact biodiversity and carbon balance @Department of Geosciences and Geography @helsinkiuni.bsky.social! DM me if you are interested, and please share!
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Anna Virkkala @annvirkk.bsky.social · 28/01/2025
Last week's highlight was our study in @natclimchange.bsky.social showing over 30% of the Arctic-boreal region as a CO2 source: www.nature.com/articles/s41...
nature.com
Wildfires offset the increasing but spatially heterogeneous Arctic–boreal CO2 uptake - Nature Climate Change
How the carbon stocks of the Arctic–Boreal Zone change with warming is not well understood. Here the authors show that wildfires and large regional differences in net carbon fluxes offset the overall ...
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Anna Virkkala @annvirkk.bsky.social · 28/01/2025
First PhD paper (preprint) from a collaborator Nathalie Triches on some methodological tips related to Arctic N2O flux measurements: amt.copernicus.org/preprints/am... 🧐🏔🛢
amt.copernicus.org
Advancing N2O flux chamber measurement techniques in nutrient-poor ecosystems
Abstract. Nitrous oxide (N2O) is the third most important greenhouse gas, with its atmospheric concentration rising from 273 parts per billion (ppb) to 336 ppb since 1800, primarily due to agricultura...
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Robert G. Björk @robertgbjork.bsky.social · 27/01/2025
📢New paper🚨Excited to share our new review paper in @plosclimate.org on Browning events in Arctic ecosystems! 🌿❄️ A wonderful collaboration, brilliantly led by @garethphoenix.bsky.social. 🌿@naturvetenskap.bsky.social @vetenskapsradet.bsky.social
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Ben Bond-Lamberty @benbondlamberty.bsky.social · 24/01/2025
Filling the Gaps: Context and Design of Arctic Carbon Flux Measurement Networks eos.org/editor-highl... -- an Editor's Highlight in @jgrbiogeo.bsky.social
eos.org
Filling the Gaps: Context and Design of Arctic Carbon Flux Measurement Networks - Eos
Large scale observational networks are necessary for understanding the impact of a warming climate in the Arctic, but critical tools are crucial to how those networks are designed.
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Permafrost Pathways @permafrostpathways.bsky.social · 21/01/2025
🧊🔥 New paper @natclimchange.bsky.social: After millennia as a carbon deep-freezer for the planet, a third of the Arctic-boreal zone is now a CO2 source to the atmosphere. The int’l research team was led by @annvirkk.bsky.social ⬇️ Learn more: permafrost.woodwellclimate.org/after-millen...
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Permafrost Pathways @permafrostpathways.bsky.social · 16/01/2025
New paper in @agu.org Geophysical Research Letters: Detecting #Arctic hotspots using satellite and temp records shows extreme warming, drying and browning in Siberian forests and other areas of high ecosystem #climate stress in northern #Alaska & Northwest Territories of #Canada. #AGUPubs #GIS a 🧵:
Map of areas that experienced ecosystem climate stress in the Arctic-boreal region between 1997-2020 as detected by multiple variables including satellite data and long-term temperature records. Watts et al., 2025, Geophysical Research Letters
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Carolina Voigt @arctic-carolina.bsky.social · 28/11/2024
📣 Open PhD position in new #ERCStG project COLDSPOT. Are you interested in exploring processes regulating CH4 and N2O sinks in #permafrost soils? Excited to join Arctic field campaigns? Applying biogeochemical and microbial techniques? Come work with us! tinyurl.com/mu8fhscm @cenunihh.bsky.social
tinyurl.com
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