Swedish Polar Research Secretariat

Abstract. Carbon monoxide (CO) is an important trace gas in the atmosphere. However, its sinks and sources in terrestrial ecosystems remain poorly quantified. Understanding the terrestrial sink and source dynamics is crucial for better assessing the global CO budget. In this study, we investigated CO exchange in an Arctic peatland in northern Sweden to quantify the magnitude and key drivers of fluxes at the site. We measured CO fluxes using the eddy covariance method from August 2022 to September 2024. The study site was characterized by a heterogeneous surface structure with elevated dry palsas surrounded by wetter areas of bog. We found that the peatland was a net CO source during the measurement period, with fluxes ranging from –0.29 to 0.34 nmol m-2 s-1 (25th and 75th percentiles). The fluxes showed a systematic diurnal cycle, with daytime emission and nighttime uptake. Emissions were mainly driven by radiation, suggesting photo-driven production. Soil uptake was dependent on surface wetness, with higher consumption occurring in the dry parts of the peatland, suggesting that oxic conditions may favor CO uptake. The annual cumulative CO flux for the dry parts of the peatland was estimated to be -44 mg CO m-2 yr-1 in 2022–2023 and -52 mg CO m-2 yr-1 in 2023–2024, while the flux for the wet parts of the peatland was 93 mg CO m-2 yr-1 in 2022–2023 and 84 mg CO m-2 yr-1 in 2023–2024. Despite the relatively small amount of CO released from the peatland, our study suggests that current global models may underestimate the CO source from northern wetlands.

Knowledge and education are critical drivers of a nation's progress. Nepal, with its rich cultural and historical legacy, has seen significant developments in the field of education, research, and innovation. This paper explores the evolution of knowledge in Nepal, from traditional learning systems to modern education frameworks, research advancements, and the challenges faced in this domain. It also highlights the role of digital transformation and policy reforms in shaping the country's knowledge ecosystem. The study relies on various scholarly sources, government reports, and institutional research to provide a comprehensive view of Nepal’s educational landscape.

The database presents physical and chemical properties of soil, soil pore water and river in Abisko (Sweden), at Stordalen Mire on a natural gradient of permafrost degradation (palsa, intermediate, and degraded palsa sites) between September and November 2021. The air and soil temperatures, and the soil water content (SWC) were monitored continuously with a temporal resolution of 10 minutes. The soil redox potential was monitored every 30 minutes. Samples of soil pore water (n = 270) were collected at palsa, intermediate and degraded palsa sites at 10, 30, and 60 cm depth (except 45 cm depth for the palsa site because the permafrost table reaches 50 cm depth). Downstream river waters (n = 17) were collected every three days. On soil pore water, we measured pH, conductivity, DOC (dissolved organic carbon) concentrations, major cations (Fe, Ca, K, Mg, Mn, Na, P, S, Si) concentrations, silicon isotopic composition (δ30Si), percentage of colloidal Si and SUVA (Specific ultraviolet absorbance) index. On river waters, we measured pH, conductivity, DOC concentrations, major cations (Fe, Ca, K, Mg, Mn, Na, P, S, Si) concentrations, silicon isotopic composition (δ30Si), percentage of colloidal Fe and SUVA (Specific ultraviolet absorbance) index.

A land cover map of two arctic catchments near the Abisko Scientific Research Station was obtained based on a classification from a Sentinel-2 satellite image and a ground survey performed in July 2022. The two contiguous catchments, Miellajokka and Stordalen, are covered by various ecotypes, from boreal forest to alpine tundra and peatland. Two classification algorithms, support vector machine and random forest, were tested and gave very similar results. The percentage of correctly classified pixels was over 88% in both cases. The developed workflow relies solely on open-source software and acquired ground observations. Space organization was directed by the altitude as demonstrated by the intersection of the land cover with the topography. Comparison between this new land cover map and previous ones based on data acquired between 2008 and 2011 shows some trends in vegetation cover evolution in response to climate change in the considered area. This land cover map is key input data for permafrost modeling and, hence, for the quantification of climate change impacts in the studied area.

A land cover map of two arctic catchments, nearby the Abisko Scientific Research Station, was obtained from a classification of a Sentinel-2 satellite image and a ground survey performed in July 2022. The two contiguous catchments, Miellajokka and Stordalen, are covered by various ecotypes, from boreal forest to alpine tundra and peatland. The random forests algorithm correctly identified 88% of polygon pixels reserved for testing. The developed workflow relied solely on open source software and acquired ground observations. Space organization was directed by the altitude as demonstrated by the intersection of the land cover with the topography. Comparison between this new land cover map and previous ones based on data acquired between 2008 and 2011 shows some trends of vegetation cover evolution in response to climate change in the considered area.

Climate change induced alterations to winter conditions may affect decomposer organisms controlling the vast carbon stores in northern soils. Soil microarthropods are particularly abundant decomposers in Arctic ecosystems. We studied whether increased snow depth affected microarthropods, and if effects were consistent over two consecutive winters. We sampled Collembola and soil mites from a snow accumulation experiment at Svalbard in early summer and used soil microclimatic data to explore to which aspects of winter climate microarthropods are most sensitive. Community densities differed substantially between years and increased snow depth had inconsistent effects. Deeper snow hardly affected microarthropods in 2015, but decreased densities and altered relative abundances of microarthropods and Collembola species after a milder winter in 2016. Although increased snow depth increased soil temperatures by 3.2 °C throughout the snow cover periods, the best microclimatic predictors of microarthropod density changes were spring soil temperature and snowmelt day. Our study shows that extrapolation of observations of decomposer responses to altered winter climate conditions to future scenarios should be avoided when communities are only sampled on a single occasion, since effects of longer-term gradual changes in winter climate may be obscured by inter-annual weather variability and natural variability in population sizes.

<strong class="journal-contentHeaderColor">Abstract.</strong> The Arctic is exposed to even faster temperature changes than most other areas on Earth. Constantly increasing temperature will lead to thawing permafrost and changes in the methane (CH<span class="inline-formula">₄</span>) emissions from wetlands. One of the places exposed to those changes is the Abisko–Stordalen Mire in northern Sweden, where climate and vegetation studies have been conducted since the 1970s. In our study, we analyzed field-scale methane emissions measured by the eddy covariance method at Abisko–Stordalen Mire for 3 years (2014–2016). The site is a subarctic mire mosaic of palsas, thawing palsas, fully thawed fens, and open water bodies. A bimodal wind pattern prevalent at the site provides an ideal opportunity to measure mire patches with different permafrost status with one flux measurement system. The flux footprint for westerly winds was dominated by elevated palsa plateaus, while the footprint was almost equally distributed between palsas and thawing bog-like areas for easterly winds. As these patches are exposed to the same climatic and weather conditions, we analyzed the differences in the responses of their methane emission for environmental parameters. The methane fluxes followed a similar annual cycle over the 3 study years, with a gentle rise during spring and a decrease during autumn, without emission bursts at either end of the ice-free season. The peak emission during the ice-free season differed significantly for the two mire areas with different permafrost status: the palsa mire emitted 19 mg-C m<span class="inline-formula">^−2</span> d<span class="inline-formula">^−1</span> and the thawing wet sector 40 mg-C m<span class="inline-formula">^−2</span> d<span class="inline-formula">^−1</span>. Factors controlling the methane emission were analyzed using generalized linear models. The main driver for methane fluxes was peat temperature for both wind sectors. Soil water content above the water table emerged as an explanatory variable for the 3 years for western sectors and the year 2016 in the eastern sector. The water table level showed a significant correlation with methane emission for the year 2016 as well. Gross primary production, however, did not show a significant correlation with methane emissions. Annual methane emissions were estimated based on four different gap-filing methods. The different methods generally resulted in very similar annual emissions. The mean annual emission based on all models was 3.1 <span class="inline-formula">±</span> 0.3 g-C m<span class="inline-formula">^−2</span> a<span class="inline-formula">^−1</span> for the western sector and 5.5 <span class="inline-formula">±</span> 0.5 g-C m<span class="inline-formula">^−2</span> a<span class="inline-formula">^−1</span> for the eastern sector. The average annual emissions, derived from these data and a footprint climatology, were 2.7 <span class="inline-formula">±</span> 0.5 and 8.2 <span class="inline-formula">±</span> 1.5 g-C m<span class="inline-formula">^−2</span> a<span class="inline-formula">^−1</span> for the palsa and thawing surfaces, respectively. Winter fluxes were relatively high, contributing 27 %–45 % to the annual emissions.

<strong class="journal-contentHeaderColor">Abstract.</strong> The Arctic is exposed to even faster temperature changes than most other areas on Earth. Constantly increasing temperature will lead to thawing permafrost and changes in the methane (CH<span class="inline-formula">₄</span>) emissions from wetlands. One of the places exposed to those changes is the Abisko–Stordalen Mire in northern Sweden, where climate and vegetation studies have been conducted since the 1970s. In our study, we analyzed field-scale methane emissions measured by the eddy covariance method at Abisko–Stordalen Mire for 3 years (2014–2016). The site is a subarctic mire mosaic of palsas, thawing palsas, fully thawed fens, and open water bodies. A bimodal wind pattern prevalent at the site provides an ideal opportunity to measure mire patches with different permafrost status with one flux measurement system. The flux footprint for westerly winds was dominated by elevated palsa plateaus, while the footprint was almost equally distributed between palsas and thawing bog-like areas for easterly winds. As these patches are exposed to the same climatic and weather conditions, we analyzed the differences in the responses of their methane emission for environmental parameters. The methane fluxes followed a similar annual cycle over the 3 study years, with a gentle rise during spring and a decrease during autumn, without emission bursts at either end of the ice-free season. The peak emission during the ice-free season differed significantly for the two mire areas with different permafrost status: the palsa mire emitted 19 mg-C m<span class="inline-formula">^−2</span> d<span class="inline-formula">^−1</span> and the thawing wet sector 40 mg-C m<span class="inline-formula">^−2</span> d<span class="inline-formula">^−1</span>. Factors controlling the methane emission were analyzed using generalized linear models. The main driver for methane fluxes was peat temperature for both wind sectors. Soil water content above the water table emerged as an explanatory variable for the 3 years for western sectors and the year 2016 in the eastern sector. The water table level showed a significant correlation with methane emission for the year 2016 as well. Gross primary production, however, did not show a significant correlation with methane emissions. Annual methane emissions were estimated based on four different gap-filing methods. The different methods generally resulted in very similar annual emissions. The mean annual emission based on all models was 3.1 <span class="inline-formula">±</span> 0.3 g-C m<span class="inline-formula">^−2</span> a<span class="inline-formula">^−1</span> for the western sector and 5.5 <span class="inline-formula">±</span> 0.5 g-C m<span class="inline-formula">^−2</span> a<span class="inline-formula">^−1</span> for the eastern sector. The average annual emissions, derived from these data and a footprint climatology, were 2.7 <span class="inline-formula">±</span> 0.5 and 8.2 <span class="inline-formula">±</span> 1.5 g-C m<span class="inline-formula">^−2</span> a<span class="inline-formula">^−1</span> for the palsa and thawing surfaces, respectively. Winter fluxes were relatively high, contributing 27 %–45 % to the annual emissions.

Abstract. The Artic is exposed to faster temperature changes than most other areas on Earth. Constantly increasing temperature will lead to thawing permafrost and changes in the CH4 emissions from wetlands. One of the places exposed to those changes is the Abisko-Stordalen Mire in northern Sweden, where climate and vegetation studies have been conducted from the 1970s.In our study, we analyzed field-scale methane emissions measured by the eddy covariance method at Abisko-Stordalen Mire for three years (2014–2016). The site is a subarctic mire mosaic of palsas, thawing palsas, fully thawed fens, and open water bodies. A bimodal wind pattern prevalent at the site provides an ideal opportunity to measure mire patches with different permafrost statuses with one flux measurement system. The flux footprint for westerly winds is dominated by elevated palsa plateaus, while the footprint is almost equally distributed between palsas and thawing bog-like areas for easterly winds. As these patches are exposed to the same climatic conditions, we analyzed the differences in the responses of their methane emission for environmental parameters.The methane fluxes followed a similar annual cycle over the three study years, with a gentle rise during spring and a decrease during autumn and with no emission burst at either end of the ice-free season. The peak emission during the ice-free season differed significantly for the mire with two permafrost statuses: the palsa mire emitted 24 mg-CH4 m−2 d−1 and the thawing wet sector 56 mg-CH4 m−2 d−1. Factors controlling the methane emission were analyzed using generalized linear models. The main driver for methane fluxes was peat temperature for both wind sectors. Soil water content above the water table emerged as an explanatory variable for the three years for western sectors and the year 2016 in the eastern sector. Water table level showed a significant correlation with methane emission for the year 2016 as well. Gross primary production, however, did not show a significant correlation with methane emissions. Annual methane emissions were estimated based on four different gap-filing methods. The different methods generally resulted in very similar annual emissions. The mean annual emission based on all models was 4.2 ± 0.4 g-CH4 m−2 a−1 for western sector and 7.3 ± 0.7 g-CH4 m−2 a−1 for the eastern sector. The average annual emissions, derived from this data and a footprint climatology, were 3.6 ± 0.7 g-CH4 m−2 a−1 and 11 ± 2 g-CH4 m−2 a−1 for the palsa and thawing surfaces, respectively. Winter fluxes were relatively high, contributing 27–45 % to the annual emissions.

According to the International Maritime Organization (IMO), polar research vessels (PRVs) are vessels that are capable of carrying out marine research in polar waters. This is a very broad definition that encompasses a wide range of vessels from those capable of breaking sea ice to those that can work in open polar waters where the presence of ice is residual. Following from the breadth of the IMO definition, the European PRV fleet includes and wide array of vessels from research icebreakers to a large number of vessels capable of working only in ice-free waters. Recent IMO regulations on safety and technical requirements for ships working in polar waters might even expand the number of available European "polar" vessels, because with the appropriate modifications, many research vessels could have the capacity to become a Polar Class C vessel (ones that can work only in ice-free waters).