Arctic Climate Research Articles

Using a region-specific ice-nucleating particle parameterization improves the representation of Arctic clouds in a global climate model

Abstract. Projections of global climate change and Arctic amplification are sensitive to the representation of low-level cloud phase in climate models. Ice-nucleating particles (INPs) are necessary for primary cloud ice formation at temperatures above approximately −38 °C and thus significantly affect cloud phase and cloud radiative effect (CRE). Due to their complex and insufficiently understood variability, INPs constitute an important modelling challenge, especially in remote regions with few observations, such as the Arctic. In this study, INP observations were carried out at Andenes, Norway, in March 2021. These observations were used as a basis for an Arctic-specific and purely temperature-dependent INP parameterization, which was implemented into the Norwegian Earth System Model (NorESM). This implementation results in an annual average increase in cloud liquid water path (CLWP) of 70 % for the Arctic and improves the representation of cloud phase compared to satellite observations. The change in CLWP in boreal autumn and winter is found to likely be the dominant contributor to the annual average increase in net surface CRE of 2 W m−2. This large surface flux increase brings the simulation into better agreement with Arctic ground-based measurements. Despite the fact that the model cannot respond fully to the INP parameterization change due to fixed sea surface temperatures, Arctic surface air temperature increases by 0.7 °C in boreal autumn. These findings indicate that INPs could have a significant impact on Arctic climate and that a region-specific INP parameterization can be a useful tool to improve cloud representation in the Arctic region.

Detection of the Relationship Between the Inverse Variations of Sea Ice in the Okhotsk–Bering Sea During Spring and the 11‐Year Solar Cycle

ABSTRACTThe 11‐year solar cycle is a stable external forcing factor for the Earth system. However, its influence on decadal climate variability, including sea ice, remains uncertain. This study statistically analyses spring sea ice concentration (SIC) and annual sunspot numbers (SSNs) from 1960 to 2021, revealing a significant inverse correlation between the 11‐year solar activity cycle and spring sea ice variability in the Okhotsk Sea and Bering Sea. During solar maximum years, sea ice increases in the Okhotsk Sea while decreasing in the eastern Bering Sea. Further analysis shows that the spring sea ice concentration difference (SICD) index correlates closely with the preceding winter Pacific Meridional Mode (PMM) modulated by the 11‐year solar cycle. This suggests that solar activity may influence east–west sea ice variability in the North Pacific during spring through its impact on the winter PMM. Atmospheric circulation and numerical simulation results indicate that during high‐solar‐activity years in winter, changes in stratospheric ozone concentration lead to variations in stratospheric temperatures. This strengthens zonal westerlies in the subtropical stratosphere and troposphere. The propagation of planetary waves from the stratosphere to the mid‐ and high‐latitude troposphere converges over the Bering Sea, creating an easterly anomaly. This convergence stimulates a high pressure and a low pressure to its south, forming a pattern resembling the PMM in the North Pacific during winter. The sea surface temperature (SST) anomalies linked to the winter PMM persist into spring, influencing sea ice at high latitudes in the North Pacific and causing the observed inverse sea ice changes in the Okhotsk and Bering Seas. This study highlights the significant modulating effect of solar activity on sea ice variability, offering insights for understanding Arctic climate change and predicting sea ice changes.

Direct observation of Arctic Sea salt aerosol production from blowing snow and modeling over a changing sea ice environment

In the polar regions, there is significant model bias in the number concentrations and seasonality of sea salt aerosol (SSA) due to the lack of understanding of aerosol sources associated with sea ice, which is hampering accurate climate forecasts at high latitudes. Recently, SSA originating from the sublimation of blowing snow has been directly observed to be an important source of aerosol particles in the Antarctic during winter/spring, validating a mechanism proposed a decade ago. Here, we report in situ observations of coarse aerosol production (particle diameter 0.5–20.0 µm) dominated by sea salt from blowing snow above sea ice during winter/spring in the Central Arctic during the MOSAiC (Multidisciplinary drifting Observatory for the Study of Arctic Climate) expedition from October 2019 to September 2020. Blowing snow conditions occurred 20–40% of the time during each of the months from December 2019 to April 2020, with a total of 26 blowing snow events. During blowing snow periods, coarse aerosol number concentrations increased often by an order of magnitude compared to no-blowing snow periods. Mass fractions of sodium chloride in sub-micron aerosol (particle diameter 0.01–0.625 µm) available during December 2019 and 10 m wind speed showed a significant correlation (R = 0.61, P < 0.05), indicating that much of the aerosol observed during storms is sea salt released by sublimating blowing snow. We use these observations to refine the current model parameterization by considering the spatial and temporal variability of atmospheric and sea ice conditions. Snow particle size distributions and snow salinities are expressed as a function of wind speed and snowpack depth, respectively, which can be easily implemented into climate models. Validation of the snow particle size distribution parameterization with previous polar winter observations showed agreement in the Arctic (N-ICE2015 cruise, March 2015) above the threshold for drift and blowing snow, but a negative bias in the Antarctic (Weddell Sea, June to August 2013). Updating the blowing snow mechanism in the chemical transport model p-TOMCAT with wind-dependent snow particle size distributions results in 14% more SSA produced and a slightly better correlation with MOSAiC observations of coarse aerosol (R = 0.28). Significant increases in aerosol number concentration due to blowing snow sublimation are calculated by as much as 70 cm−3 during the Antarctic winter and 50 cm−3 during the Arctic winter compared to a baseline simulation with no blowing snow. Thus, taking into account SSA from blowing snow above sea ice will be important to improve model predictions of polar aerosol and climate.

Metagenome-assembled-genomes recovered from the Arctic drift expedition MOSAiC

The Multidisciplinary Observatory for Study of the Arctic Climate (MOSAiC) expedition consisted of a year-long drifting survey of the Central Arctic Ocean. The ecosystems component of MOSAiC included the sampling of molecular data, with metagenomes collected from a diverse range of environments. The generation of metagenome-assembled-genomes (MAGs) from metagenomes are a starting point for genome-resolved analyses. This dataset presents a catalogue of MAGs recovered from a set of 73 samples from MOSAiC, including 2407 prokaryotic and 56 eukaryotic MAGs, as well as annotations of a near complete eukaryotic MAG using the Joint Genome Institute (JGI) annotation pipeline. The metagenomic samples are from the surface ocean, chlorophyll maximum, mesopelagic and bathypelagic, within leads and under-ice ocean, as well as melt ponds, ice ridges, and first- and second-year sea ice. This set of MAGs can be used to benchmark microbial biodiversity in the Central Arctic Ocean, compare individual strains across space and time, and to study changes in Arctic microbial communities from the winter to summer, at a genomic level.

Precession modulates the poleward expansion of atmospheric circulation to the Arctic Ocean

Under sustained global warming, Arctic climate is projected to become more responsive to changes in North Pacific meridional heat transport as a result of teleconnections between low and high latitudes, but the underlying mechanisms remain poorly understood. Here, we reconstruct subarctic humidity changes over the past 400 kyr to investigate the role of low-to-high latitude interactions in regulating Arctic hydroclimate. Our reconstruction is based on precipitation-driven sediment input variations in the Subarctic North Pacific (SANP), which reveal a strong precessional cycle in subarctic humidity under the relatively low eccentricity variations that dominated the past four glacial-interglacial cycles. Combined with climate model simulations, we highlight that precession drives meridional shifts in the northern rim of the North Pacific Subtropical Gyre (NPSG) and modulates the efficiency of heat and water vapor transfer to the SANP and Arctic regions. Our findings suggest that projections of a northward shift of the NPSG in response to future global warming will lead to wetter conditions in the Arctic Ocean and enhanced sea-ice loss.

Long-term storage of seeds of plant genetic resources in permafrost conditions

Collections of plant genetic resources are the guarantor of the preservation of both natural biological diversity and breeding achievements. Basically, genetic collections consist of seeds and, proper storage in optimal conditions is a necessity (it frees them from frequent reproduction associated with material and labor costs). It is necessary to search for optimal natural conditions for long-term storage of seeds, because in case of emergency situations of a technogenic nature, they will be the most vulnerable. A long-term experiment of long-term storage of agricultural plant seeds in permafrost conditions is being carried out. The aim of research is to find optimal and safe conditions for long-term storage of seeds and grain for both sowing and food purposes, and to study the conditions of natural storage facilities for creation of strategic reserves of seeds and food. In 2010, consignments of seeds of the main grain crops were put into storage (spring wheat, spring barley, winter rye and oats); in 2016, a seed collection of 26 varieties of 8 types of vegetable crops was laid. Meteorological observations were carried out, thermographs and hygrographs were used in the storage. The first sample extraction took place after 6 years of storage. Laboratory analysis of seed quality was carried out using the following standard methods: GOST 12036-85; GOST 12038-84; GOST 12041-82; GOST 12042-80; and GOST R 52325-2005. The results showed high viability of seeds of grain and vegetable crops. Seeds of all samples of grain crops met the requirements for reproductive seeds (germination over 87 %) according to GOST R 52325-2005. Seeds of 17 samples of vegetable crops retained germination at the first-class level in accordance with the requirements of GOST 12038-84. Long-term meteorological observations show a gradual warming of the Arctic climate due to relatively high summer temperatures. In general, the continentality of the climate is growing. The experiment continues, most of the above seed batches remain in storage, further expeditions with the extraction of samples are planned for 2025, 2035 and 2050. The obtained weather data indicate an increase in the continentality of the Arctic climate and its general warming. The data obtained on the viability of cereal grains and vegetable seeds during long-term storage show the effectiveness of using permafrost conditions for this purpose.

The use of multiple evidence base methods to enrich climate change research and knowledge in the Arctic.

Indigenous and local knowledge (ILK) is increasingly used along with scientific knowledge (SK) to understand climate change. The multi evidence base (MEB) offers ways of combining knowledge systems together. Nonetheless, there is little guidance on how to use MEB approaches in research. Our aim is to systematically evaluate empirical cases using MEB approaches in Arctic climate change research; and explore ILK inclusion in research stages. The mapping followed the ROSES protocol, which provides a checklist of details to be included in the review. The literature search identified 1483 records referring to MEB approaches. We identified seven papers applying the cross-fertilization and nine applying the coproduction approach to combine ILK with SK. The theory of change framework was used to evaluate participation, revealing a distinct difference between the approaches in participant involvement in the research stages. Regardless of MEB approach, the output and outcome of the cases were less clear.

Melt pond CO2 dynamics and fluxes with the atmosphere in the central Arctic Ocean during the summer-to-autumn transition

Melt ponds are a common feature of the Arctic sea-ice environment during summer, and they play an important role in the exchange of heat and water vapor between the ocean and the atmosphere. We report the results of a time-series study of the CO2 dynamics within melt ponds (and nearby lead) and related fluxes with the atmosphere during the summer-to-autumn transition in the central Arctic Ocean during the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition. In late summer 2020, low-salinity meltwater was distributed throughout the melt ponds, and undersaturation of pCO2 in the meltwater drove a net influx of CO2 from the atmosphere. The meltwater layer subsequently thinned due to seawater influx, and a strong gradient in salinity and low-pCO2 water was observed at the interface between meltwater and seawater at the beginning of September. Mixing between meltwater and underlying seawater drives a significant drawdown of pCO2 as a result of the non-linearities in carbonate chemistry. By the middle of September, the strong stratification within the meltwater had dissipated. Subsequent freezing then began, and cooling and wind-induced drifting of ice floes caused mixing and an influx of seawater through the bottom of the melt pond. The pCO2 in the melt pond reached 300 µatm as a result of exchanging melt pond water with the underlying seawater. However, gas exchange was impeded by the formation of impermeable freshwater ice on the surface of the melt pond, and the net flux of CO2 was nearly zero into the pond, which was no longer a sink for atmospheric CO2. Overall, the melt ponds in this Arctic sea-ice area (both melt ponds and lead water) act as moderate sinks for atmospheric CO2.

Linking Radiative‐Advective Equilibrium Regime Transition to Arctic Amplification

AbstractEmission of anthropogenic greenhouse gases has resulted in greater Arctic warming compared to global warming, known as Arctic amplification (AA). From an energy‐balance perspective, the current Arctic climate is in radiative‐advective equilibrium (RAE) regime, in which radiative cooling is balanced by advective heat flux convergence. Exploiting a suite of climate model simulations with varying carbon dioxide () concentrations, we link the northern high‐latitude regime variation and transition to AA. The dominance of RAE regime in northern high‐latitudes under reduction relates to stronger AA, whereas the RAE regime transition to non‐RAE regime under increase corresponds to a weaker AA. Examinations on the spatial and seasonal structures reveal that lapse‐rate and sea‐ice processes are crucial mechanisms. Our findings suggest that if concentration continues to rise, the Arctic could transition into a non‐RAE regime accompanied with a weaker AA.

In What Ways Might Physical Tipping Points in the Climate System Pose Security Problems Now and in the Future?

This paper analyzes physical tipping points in the climate system and their implications for national security, food security and social stability. Physical tipping points are critical states in the climate system that, once passed, lead to irreversible, rapid, and self-accelerating changes. Major tipping points include melting glaciers and rising sea levels, the collapse of terrestrial ecosystems, and an increase in the frequency and intensity of climate extremes. The paper explores the far-reaching impact of these tipping points on security issues, proposes countermeasures and policy recommendations by analyzing the case of Arctic climate change on Russian security, and emphasizes the importance of interdisciplinary cooperation and policy responses to reduce the risks posed by climate change.

Arctic soil carbon insulation averts large spring cooling from surface–atmosphere feedbacks

The insulative properties of soil organic carbon (SOC) and surface organic layers (moss, lichens, litter) regulate surface-atmosphere energy exchanges in the Arctic through a coupling with soil temperatures. However, a physical description of this process is lacking in many climate models, potentially biasing their high-latitude climate predictions. Using a coupled surface-atmosphere model, we identified a strong feedback loop between soil insulation, surface air temperature, and snowfall. Without insulation, the latent heat needed for soil ice thawing leads to a late spring and summer cold bias in surface air temperature (above 2 °C) over Arctic regions. The integration of soil insulation eliminates this bias and significantly improves the simulation of permafrost dynamics. Our findings, including the potential consequences of large perturbations (e.g., fires), highlight the importance of combining soil water freezing with a physical representation of SOC and surface organic layer insulation in Earth system models, to improve Arctic climate predictions.

An estimate of the Arctic climate sensitivity based on the Arrhenius’s rule

Estimating the magnitude of the Arctic equilibrium climate sensitivity is key for understanding the climate dynamics of this polar region. Using a linear regression model, we find that the Arctic equilibrium climate sensitivity is 3.61°C. To the best of our knowledge, this is the first time that an estimate of the Arctic equilibrium climate sensitivity is provided. The obtained results confirm that this region is more sensitive to climate change than the rest of the world. The Arctic sensitivity is almost one and a half times that of the global sensitivity. In this paper, we have used the estimated Arctic equilibrium climate sensitivity to obtain projections of the Arctic temperature under different forcing scenarios.

Inter-comparisons of Arctic snow depth products

ABSTRACT Applying ICESat-2 and CryoSat-2 freeboards, the Arctic snow depth (ISCS) was obtained from October 2018 to April 2022. The results were assessed using Operation Ice Bridge (OIB) and Multidisciplinary Drifting Observatory for the Study of Arctic Climate (MOSAiC) in situ observations and compared with frequently used remote sensing (AMSR-E/AMSR2), climatology (modified W99 snow climatology data; MW99), and modelled (Pan-Arctic Ice Ocean Modelling and Assimilation Systems; PIOMAS) snow products. The ISCS snow depth exhibited high correlations (r = 0.67) and small mean bias (0.01 ± 0.06 m) against OIB results. We found good correlations (statistically significant) between MOSAiC and all snow depth products, except for MW99. Mean and absolute biases between ISCS and MOSAiC in situ observations were 0.01 ± 0.06 and 0.04 ± 0.04 m, respectively. The ISCS revealed clear spatial distribution from the Canadian Arctic Archipelago to open sea areas. In contrast, the PIOMAS snow depth revealed weak autumn variation, whereas the MW99 snow depth yielded distinct seasonal variability but a weak interannual change. Snow depth in October showed large differences among the various products, from which the AMSR topped the snow depth in the first-year ice region, while MW99 had the highest values for the multiyear ice zone.

Соотношение иммунокомпетентных клеток и индекса NLR у мужчин экстремальных профессий (гидрографов) в Арктическом регионе РФ

Rotational shift work in the Arctic region's northern seas has a substantial influence on the physiological condition of the human body and has a high risk of reducing reserve capacities, particularly the immune system. Assessing immune homeostasis by identifying immune balance, specifically the levels of expression of lymphoproliferation and lymphoapoptosis markers that determine the body's susceptibility to diseases, is important for maintaining public health in the Arctic region's extreme climatic and professional environments. The aim of this study is to assess the ratio of lymphocyte phenotypes CD10, CD71, CD95 and the NLR index in men working on rotating shifts in the Arctic. Materials and Methods. The study comprised 65 healthy adults aged 43,2±2,7 years: 45 males working rotating shifts of less than 3 months, 3 to 6 months, and more than 6 months, and 20 male residents (control). The neutrophil-to-lymphocyte ratio (NLR), lymphocytes with the CD10 marker to CD95, and lymphocytes with the CD71 marker to CD95 were estimated. Results. The median neutrophil to lymphocyte ratio (NLR) among rotating shift hydrographers is within the ideal normal range (1-2), regardless of shift duration, as in contrast to permanent residents, whose median NLR is stress-increased (2-3). In rotating shift workers, the CD10/CD95 ratio is balanced between 0.85 and 1.15, with evidence of a relative rise in CD10 expression levels with shift durations of more than 6 months. In 65% of Arctic inhabitants, CD10 expression levels are quite low. The CD71/CD95 ratio is balanced between 0.85 and 1.1, regardless of shift duration or permanent residence in the Arctic region. Conclusions. In the investigated hydrographers, fluctuations in the median NLR and the CD10/95 ratio are associated with the duration of the shift; the median CD71/95 ratio is least susceptible to fluctuations in both rotating shift workers and the control group; the CD71/95 ratio is stable, determines the immune balance of the surveyed, and can be used to assess the immune system's adaptability to Arctic conditions. Keywords: Arctic, Immune balance, Lymphoproliferation, Lymphopoptosis, Rotational shiftwork, Hydrographers

Inflammaging Markers in the Extremely Cold Climate: A Case Study of Yakutian Population.

Yakutia is one of the coldest permanently inhabited regions in the world, characterized by a subarctic climate with average January temperatures near -40 °C and the minimum below -60 °C. Recently, we demonstrated accelerated epigenetic aging of the Yakutian population in comparison to their Central Russian counterparts, residing in a considerably milder climate. In this paper, we analyzed these cohorts from the inflammaging perspective and addressed two hypotheses: a mismatch in the immunological profiles and accelerated inflammatory aging in Yakuts. We found that the levels of 17 cytokines displayed statistically significant differences in the mean values between the groups (with minimal p-value = 2.06 × 10-19), and 6 of them are among 10 SImAge markers. We demonstrated that five out of these six markers (PDGFB, CD40LG, VEGFA, PDGFA, and CXCL10) had higher mean levels in the Yakutian cohort, and therefore, due to their positive chronological age correlation, might indicate a trend toward accelerated inflammatory aging. At the same time, a statistically significant biological age acceleration difference between the two cohorts according to the inflammatory SImAge clock was not detected because they had similar levels of CXCL9, CCL22, and IL6, the top contributing biomarkers to SImAge. We introduced an explainable deep neural network to separate individual inflammatory profiles between the two groups, resulting in over 95% accuracy. The obtained results allow for hypothesizing the specificity of cytokine and chemokine profiles among people living in extremely cold climates, possibly reflecting the effects of long-term human (dis)adaptation to cold conditions related to inflammaging and the risk of developing a number of pathologies.

THEORY AND PRACTICE ORIGINAL ARTICLE COMPREHENSIVE ANALYSIS OF QUANTITATIVE VALUES OF METEOROLOGICAL FACTORS FOR TEMPERATE, SUBTROPICAL, EXTREMELY COLD AND ARCTIC CLIMATES

The article analyzes quantitative indicators of change in temperature and relative humidity of the ambient air of moderate, extremely cold, Arctic and subtropical climates recorded at weather stations in Saransk, Yakutsk, the village Tiksi and Gelendzhik between 2019 and 2023. The minimum, average, and maximum values, as well as temperature and relative humidity distribution curves, are analyzed depending on the month of 2022. The distribution of temperature and relative humidity of the air during the calendar year was revealed on heat maps, as well as on maps of the complex impact of these meteorological indicators for the four above-mentioned climatic zones in 2019-2023.

Impacts of Climate Change on Arctic Winter Cyclones

AbstractWe simulated Arctic climate using a high‐resolution implementation of WRF driven by HadGEM‐ES2 climate model outputs, following IPCC5 warming scenarios RCP 2.6, RCP 4.5 and RCP 8.5. The downscaled results indicate that, by the end‐of‐century, there are no significant changes in the average minimum central pressures or total number of winter Arctic cyclones. However, there are significant changes in the spatial patterns. For example, the frequency and vorticity of cyclones tend to increase over the western Arctic. Due to the poleward movement of the polar frontal zone and the increased low‐level tropospheric baroclinicity, more cyclones are expected to form within the Arctic Basin and migrate into the western‐central Arctic. We expect about 39% more cyclone tracks forming and dying in the Arctic Basin under RCP8.5, compared to present climate. On the other hand, with the reduced baroclinicity in the entire troposphere, there is a reduced genesis, frequency, and vorticity of cyclones over the Atlantic Arctic. Moreover, the depth of cyclones shows a robust decrease over the Arctic Basin, suggesting weakened eddy kinetic energy. With increasing greenhouse gases, the changes in cyclone vorticities and their depths tend to be stronger. In addition, the high resolution Polar WRF results demonstrate that changes in cyclone track density and intensities consistently become more pronounced with increasing radiative forcing.

Influence of metal structural heterogeneity in a sheet tube billet on forming mechanical properties and crack resistance of steel pipes for operation in the Arctic climate conditions

Influence of metal structural heterogeneity in a sheet tube billet on forming mechanical properties and crack resistance of steel pipes for operation in the Arctic climate conditions

Widespread Decline of the Warm Season Snow Depth Over Arctic Sea Ice Revealed by Satellite Passive Microwave Measurements

ABSTRACTSummer snow plays an essential role in Arctic hydrology and in maintaining mass and energy balance of sea ice. However, there are great challenges in retrieving long‐term summer snow depths over Arctic sea ice. Here, we proposed a combined novel five‐variable long short‐term memory (hereafter CN5VLSTM) model based on brightness temperature data to yield warm‐season snow depth estimates. Then, year‐round snow depth estimates were obtained for the first time. The CN5VLSTM model and five additional snow depth methods were assessed during the warm season based on the ice mass balance buoy (IMB), Alfred Wegener Institute (AWI) snow buoy (AWI‐SB) and Multidisciplinary Drifting Observatory for the Study of Arctic Climate (MOSAiC) snow buoy (MOSAiC‐SB). According to the three buoy products, the accuracy of the CN5VLSTM‐derived snow depth was highest among the five snow depth estimates with RMSEs of 10.2, 16.4, and 10.1 cm, respectively. Except for in May, the Arctic snow depth showed mainly a downward trend in warm months, and a significant downward trend was found in the Central Arctic. Excluding the Barents Sea, Kara Sea and Canadian Archipelago, the average year‐round snow depth decreased in the other subregions, and a significant negative trend was observed in the East Siberian and Chukchi Seas. Snowfall was an important factor that was related to the changes in snow depth in the East Siberian and Chukchi Seas. This study can provide new insights into the evolution characteristics of summer snow depth.

Another Hot Arctic Year Indicates a New Climate Regime

NOAA’s annual Arctic Report Card illustrates a warmer, wetter, and increasingly wonky Arctic climate.