polar environment
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2022 ◽  
Author(s):  
Dariusz Sebastian Ignatiuk ◽  
Małgorzata Błaszczyk ◽  
Tomasz Budzik ◽  
Mariusz Grabiec ◽  
Jacek Adam Jania ◽  
...  

Abstract. The warming of the Arctic climate is well documented, but the mechanisms of Arctic amplification are still not fully understood. Thus, monitoring of glaciological and meteorological variables and the environmental response to accelerated climate warming must be continued and developed in Svalbard. Long-term meteorological observations carried out in situ on glaciers in conjunction with glaciological monitoring are rare in the Arctic and significantly expand our knowledge about processes in the polar environment. This study presents the unique glaciological and meteorological data collected in 2009–2020 in southern Spitsbergen (Werenskioldbreen). The meteorological data are comprised of air temperature, relative humidity, wind speed and direction, shortwave and longwave upwelling and downwelling radiation on 10 minutes, hourly and daily timescale (2009–2020). The snow dataset includes 49 sampling points from 2009–2019 with the snow depth, snow bulk density and SWE data. The glaciological data consist of point and surface annual winter, summer and net balance for 2009–2020. The paper also includes modelling of the daily glacier surface ablation (2009–2020) based on the presented data. The high-quality and long-term datasets are expected to serve as accurate forcing data in hydrological and glaciological models and validation of remote sensing products. The datasets are available from the and Polish Polar Database (https://ppdb.us.edu.pl/) and Zenodo (https://doi.org/10.5281/zenodo.5791748, Ignatiuk, 2021a; https://doi.org/10.5281/zenodo.5792168, Ignatiuk, 2021b).


2021 ◽  
Vol 14 (11) ◽  
pp. 7123-7145
Author(s):  
Alexey B. Tikhomirov ◽  
Glen Lesins ◽  
James R. Drummond

Abstract. The absence of sunlight during the winter in the High Arctic results in a strong surface-based atmospheric temperature inversion, especially during clear skies and light surface wind conditions. The inversion suppresses turbulent heat transfer between the ground and the boundary layer. As a result, the difference between the surface air temperature, measured at a height of 2 m, and the ground skin temperature can exceed several degrees Celsius. Such inversions occur very frequently in polar regions, are of interest to understand the mechanisms responsible for surface–atmosphere heat, mass, and momentum exchanges, and are critical for satellite validation studies. In this paper we present the results of operations of two commercial remotely piloted aircraft systems, or drones, at the Polar Environment Atmospheric Research Laboratory, Eureka, Nunavut, Canada, at 80∘ N latitude. The drones are the Matrice 100 and Matrice 210 RTK quadcopters manufactured by DJI and were flown over Eureka during the February–March field campaigns in 2017 and 2020. They were equipped with a temperature measurement system built on a Raspberry Pi single-board computer, three platinum-wire temperature sensors, a Global Navigation Satellite System receiver, and a barometric altimeter. We demonstrate that the drones can be effectively used in the extremely challenging High Arctic conditions to measure vertical temperature profiles up to 75 m above the ground and sea ice surface at ambient temperatures down to −46 ∘C. Our results indicate that the inversion lapse rates within the 0–10 m altitude range above the ground can reach values of ∼ 10–30 ∘C(100m)-1 (∼ 100–300 ∘Ckm-1). The results are in good agreement with the coincident surface air temperatures measured at 2, 6, and 10 m levels at the National Oceanic and Atmospheric Administration flux tower at the Polar Environment Atmospheric Research Laboratory. Above 10 m more gradual inversion with order-of-magnitude smaller lapse rates is recorded by the drone. This inversion lapse rate agrees well with the results obtained from the radiosonde temperature measurements. Above the sea ice drone temperature profiles are found to have an isothermal layer above a surface-based layer of instability, which is attributed to the heat flux through the sea ice. With the drones we were able to evaluate the influence of local topography on the surface-based inversion structure above the ground and to measure extremely cold temperatures of air that can pool in topographic depressions. The unique technical challenges of conducting drone campaigns in the winter High Arctic are highlighted in the paper.


2021 ◽  
Author(s):  
Jiayi Wang ◽  
Haibin Li ◽  
Lihong Qu ◽  
Tao WANG ◽  
Di GAN ◽  
...  

Abstract Background: To investigate the relationship among individuals’ mood, sleep and personality traits in a long-term polar environment.Methods: A total of 85 Arctic expedition team members were recruited in this study. In addition to personality assessment, they also completed assessments of anxiety, depression, and sleep at baseline, the second and eighth week. The rank sum test was used to compare the differences between mood and sleep at different time periods, and the generalized linear mixed model was used to explore the relations between personality and mood, as well as sleep.Results: The PHQ-9 scores showed a statistically significant difference between baseline and week 8. The PSQI scores showed a significant difference between baseline and week 2. At the same time, there was a significant difference between those who are married and those being single. Single individuals scored significantly lower on GAD-7 than married ones. The relationship between personality traits and PHQ-9 scores was statistically significant and individuals’ coping styles have an impact on their subjective sleep quality, sleep disturbance and daytime dysfunction. Conclusion: In the polar environment, over time, people's mood and sleep will be affected, and that is related to individual characteristics, personality and coping styles.


2021 ◽  
Vol 22 (19) ◽  
pp. 10587
Author(s):  
Irena Roterman ◽  
Katarzyna Stapor ◽  
Piotr Fabian ◽  
Leszek Konieczny

The role of the environment in amyloid formation based on the fuzzy oil drop model (FOD) is discussed here. This model assumes that the hydrophobicity distribution within a globular protein is consistent with a 3D Gaussian (3DG) distribution. Such a distribution is interpreted as the idealized effect of the presence of a polar solvent—water. A chain with a sequence of amino acids (which are bipolar molecules) determined by evolution recreates a micelle-like structure with varying accuracy. The membrane, which is a specific environment with opposite characteristics to the polar aquatic environment, directs the hydrophobic residues towards the surface. The modification of the FOD model to the FOD-M form takes into account the specificity of the cell membrane. It consists in “inverting” the 3DG distribution (complementing the Gaussian distribution), which expresses the exposure of hydrophobic residues on the surface. It turns out that the influence of the environment for any protein (soluble or membrane-anchored) is the result of a consensus factor expressing the participation of the polar environment and the “inverted” environment. The ratio between the proportion of the aqueous and the “reversed” environment turns out to be a characteristic property of a given protein, including amyloid protein in particular. The structure of amyloid proteins has been characterized in the context of prion, intrinsically disordered, and other non-complexing proteins to cover a wider spectrum of molecules with the given characteristics based on the FOD-M model.


2021 ◽  
Vol 22 (9) ◽  
pp. 5002
Author(s):  
Magdalena Ptak-Kaczor ◽  
Mateusz Banach ◽  
Katarzyna Stapor ◽  
Piotr Fabian ◽  
Leszek Konieczny ◽  
...  

Protein solubility is based on the compatibility of the specific protein surface with the polar aquatic environment. The exposure of polar residues to the protein surface promotes the protein’s solubility in the polar environment. The aquatic environment also influences the folding process by favoring the centralization of hydrophobic residues with the simultaneous exposure to polar residues. The degree of compatibility of the residue distribution, with the model of the concentration of hydrophobic residues in the center of the molecule, with the simultaneous exposure of polar residues is determined by the sequence of amino acids in the chain. The fuzzy oil drop model enables the quantification of the degree of compatibility of the hydrophobicity distribution observed in the protein to a form fully consistent with the Gaussian 3D function, which expresses an idealized distribution that meets the preferences of the polar water environment. The varied degrees of compatibility of the distribution observed with the idealized one allow the prediction of preferences to interactions with molecules of different polarity, including water molecules in particular. This paper analyzes a set of proteins with different levels of hydrophobicity distribution in the context of the solubility of a given protein and the possibility of complex formation.


2021 ◽  
Vol 24 (1) ◽  
pp. 72-79
Author(s):  
Seung Gu Kang ◽  
Sang Hyup Lee ◽  
Eun Bi Lee ◽  
Kwang Bok Shin ◽  
Jae Hyun Park

2021 ◽  
Author(s):  
Svetlana R. Jeremić ◽  
Jelena R. Đorović Jovanović ◽  
Marijana S. Stanojević Pirković ◽  
Zoran S. Marković

The operative mechanism of the antioxidative action of 1,2,4-trihydroxythioxanthone (TX) is investigated in this contribution. Conclusions are made based on enthalpy values, as thermodynamical parameters. All calculations are done using the M06-2X/6-311++G(d,p) level of theory. To imitate polar and non-polar environments, calculations are done in water and benzene as the medium. It is found that, among three possible radicals that TX can generate, the most stable is the one obtained by homolytic cleavage of the O-H group in position 4. It was found that HAT (Hydrogen Atom Transfer) is the most plausible mechanism for that purpose in benzene. On the other hand, the most favorable mechanism in water is SPLET (Sequential Proton Loss Electron Transfer). Here is estimated the capacity of TX to deactivate hydroxyl (HO●), hydroperoxyl (HOO●) and methylperoxyl radical (CH3OO●). It is found that TX can deactivate all three free radicals following HAT and SPLET reaction mechanisms competitively, in the polar and non-polar environment. SET-PT (Single-Electron Transfer followed by Proton Transfer) is the inoperative mechanism for radicals scavenging, in the polar and non-polar environment.


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