Radiative closure and cloud effects on the radiation budget based on satellite and ship-borne observations during the Arctic summer research cruise PS106

For understanding Arctic climate change, it is critical to quantify and address uncertainties in climate data records on clouds and radiative fluxes derived from long-term passive satellite observations. A unique set of observations collected during the research vessel Polarstern PS106 expedition (28 May to 16 July 2017) by the OCEANET facility is exploited here for this purpose and compared with the CERES SYN1deg Ed. 4.1 satellite remote sensing products. Mean cloud fraction (CF) of 86.7 % for CERES and 76.1 % for OCEANET were found for the entire cruise. The difference of CF between both data sets is due to different spatial resolution and momentary data gaps due to technical limitations of the set of ship-borne instruments. A comparison of radiative fluxes during clear-sky conditions enables radiative closure for CERES products by means of independent radiative transfer simulations. Several challenges were encountered to accurately represent clouds in radiative transfer under cloudy conditions, especially for ice-containing clouds and low-level stratus (LLS) clouds. During LLS conditions, the OCEANET retrievals were in particular compromised by the altitude detection limit of 155 m of the cloud radar. Radiative fluxes from CERES show a good agreement with ship observations, having a bias (standard deviation) of −6.0 (14.6) W m−2 and 23.1 (59.3) W m−2 for the downward longwave (LW) and shortwave (SW) fluxes, respectively. Based on CERES products, mean values of the radiation budget and the cloud radiative effect (CRE) were determined for the PS106 cruise track and the central Arctic region (70°–90° N). For the period of study, the results indicate a strong influence of the SW flux in the radiation budget, which is reduced by clouds leading to a net surface CRE of −8.8 W m−2 and −9.3 W m−2 along the PS106 cruise and for the entire Arctic, respectively. The similarity of local and regional CRE supports that the PS106 cloud observations can be considered to be representative of Arctic cloudiness during early summer.

On the Radiative Impact of Biomass-Burning Aerosols in the Arctic: The August 2017 Case Study

Boreal fires have increased during the last years and are projected to become more intense and frequent as a consequence of climate change. Wildfires produce a wide range of effects on the Arctic climate and ecosystem, and understanding these effects is crucial for predicting the future evolution of the Arctic region. This study focuses on the impact of the long-range transport of biomass-burning aerosol into the atmosphere and the corresponding radiative perturbation in the shortwave frequency range. As a case study, we investigate an intense biomass-burning (BB) event which took place in summer 2017 in Canada and subsequent northeastward transport of gases and particles in the plume leading to exceptionally high values (0.86) of Aerosol Optical Depth (AOD) at 500 nm measured in northwestern Greenland on 21 August 2017. This work characterizes the BB plume measured at the Thule High Arctic Atmospheric Observatory (THAAO; 76.53∘N, 68.74∘W) in August 2017 by assessing the associated shortwave aerosol direct radiative impact over the THAAO and extending this evaluation over the broader region (60∘N–80∘N, 110∘W–0∘E). The radiative transfer simulations with MODTRAN6.0 estimated an aerosol heating rate of up to 0.5 K/day in the upper aerosol layer (8–12 km). The direct aerosol radiative effect (ARE) vertical profile shows a maximum negative value of −45.4 Wm−2 for a 78∘ solar zenith angle above THAAO at 3 km altitude. A cumulative surface ARE of −127.5 TW is estimated to have occurred on 21 August 2017 over a portion (∼3.1×106 km2) of the considered domain (60∘N–80∘N, 110∘W–0∘E). ARE regional mean daily values over the same portion of the domain vary between −65 and −25 Wm−2. Although this is a limited temporal event, this effect can have significant influence on the Arctic radiative budget, especially in the anticipated scenario of increasing wildfires.

Culturable Bacterial Isolates from Arctic Soil shows High Biotechnological Potential

Polar microbiology remains as the most fascinating area of research which mainly focuses on exploration of psychrophilic organisms for having their cold-active enzymes of biotechnological potential. In this study, we have explored a culturable bacterial community and isolated 27 bacterial isolates with a different morphology from an unexplored site of Arctic region, for the possibility of identifying various active biomolecules. Screening of various isolates in a culture dependent manner helped us to identify strains capable of producing extracellular enzymes. The optimal growth parameters of most of the isolates are ranges between 18-22°C temperature, 3-5 days of incubation, 6-9 pH, and 3-5% (w/v) NaCl in LB media. It has also been found that among these isolates, 63% are able to produce lipase, 17% amylase, 7% xylanase and 7% isolates have responded for phosphatase activity but there are no isolates found for gelatinase and cellulase production ability. In addition, few isolates can also produce secretory protease, urease, β-galactosidase, etc. 16SrRNA gene sequence-based phylogeny revealed that the isolates belong to the genera of Psychrobacter, Planococcus, Halomonas, Arthrobacter, Oceanisphaera, Marinbacter, Pseudomonas, Algoriphagus. Strikingly, none of the Arctic isolates showed resistance towards commonly used antibiotics which indicates that the unexplored habitat is devoid of antibiotic exposure and so does the rise of antimicrobial resistance. The structure-function relationship of the isolated bioactive compounds from these isolates are the major focus of future research.

Causes and Mechanisms of Global Warming/Climate Change

Comparison of the average mean surface air temperature around the world during 1951–1978 with that for 2010–2019 shows that the bulk of the warming is around the North Atlantic/Arctic region in contrast to the Antarctic ice sheet. Obviously, the temperature change is not global. Since there is a substantial difference between solar heat absorption between the equator and the poles, heat must be moving to the North Pole by surface ocean currents and tropical cyclones. The cold, dry Arctic air coming from Siberia picks up heat and moisture from the open oceans, making the sea water denser so that the warm water sinks slowly down to c. 2000 m. A deep-water thermohaline flow (THC) transports the excess hot (c. 18°C) water south to Antarctica. It is replaced by a cold (c. 2°C) surface water from that area. The latter quickly cool western Europe and Siberia, and glaciers start to advance in Greenland within about 10 years. The THC flow decreases in Interglacials, causing the increased build-up of heat in the Northern Hemisphere (c. 60% currently stored in the Atlantic Ocean), and the ice cover in the Arctic Ocean thaws. Several such cycles may take place during a single major cold event.

Summer stream habitat preferences of Nunavik anadromous Arctic char (Salvelinus alpinus) fry and parr

Arctic char is a fish species known to occupy diverse habitats within the Arctic region. However, summer habitat use during the juvenile stage of the anadromous form is largely unknown. The present study aims to characterize fry and parr summer habitat preferences. Surveys were conducted by electrofishing, associated with physical habitat characterization on several rivers of the Ungava Bay, Nunavik, Canada. At the microhabitat and station scales, fry showed significant habitat preferences for shallow water and slow velocity. At the mesohabitat scale, fry showed a significant habitat selectivity for riffles. This habitat selectivity implies that habitat models can be built to evaluate the potential of habitat suitability for Arctic char fry. However, no significant habitat selectivity was found for parr. Parr size was nonetheless positively correlated with velocity, which was found to be a limitative factor for juvenile habitat use. This first attempt at modeling juvenile anadromous Arctic char habitat in rivers emphasizes the importance of selecting an appropriate spatial scale and reiterates the fact that parr showed relatively high plasticity in stream habitat selection.

Epidemiological significance of microbiote monitoring of arctic settlements along the Northern Sea Route

Monitoring of polar ecosystems is one of the most important areas of research in the use of Arctic territories in economic activities. An important place in such work is occupied by biomedical research aimed at identifying the risks of the occurrence of foci of infectious diseases in the areas of polar settlements.The purpose: to develop an algorithm for microbiological monitoring in the Arctic region.Materials and methods: classical bacteriological, mycological research, molecular-genetic, MALDI-TOF mass spectrometric analysis, phenotypic methods for determining antibiotic resistance, methods of mathematical data processing.Results and their discussion. The paper considers the scientific and methodological principles and the main stages of microbiota monitoring in the areas of polar settlements. The results of the study of samples from several territories along the Northern Sea Route are presented. The main habitats where potentially dangerous microorganisms should be detected are indicated. The role of anthropogenic invasion in the formation of Arctic microbiocenoses is noted. The trends of increasing the number and diversity of pathogenic microorganisms, both in the natural biocenoses of the Arctic and in the areas of polar settlements, are discussed. The necessity of microbiological monitoring as an integral part of epidemiological monitoring in the areas of Arctic settlements along the Northern Sea Route is substantiated.

Assessment of the pathogenesis of visual impairment naval specialists of the arctic zone of the russian federation during the polar night

Introduction. The climatogeographic conditions of the Arctic Zone of the Russian Federation are determined by the proximity to the North Pole of the Earth and are characterized by a number of certain cyclical changes that do not take place in the middle latitudes — the polar day and the polar night. The high-latitude location determines the long period of the polar night, lasting from 98 to 133 days. Being the hallmark of the Arctic, the polar night is an integral part of service in the Arctic region, it has an impact on every geographically involved person, without exception.Purpose of work. To assess the mechanisms of the pathogenesis of visual impairment that develop during the polar night in naval specialists.Materials and research methods. The study involved 92 people. The surveyed contingent is male contract servicemen of the Navy, aged from 21 to 45 years. The analysis of the morbidity structure according to the ophthalmological profile was carried out during the polar night from November 20, 2020 to January 20, 2021 using an epidemiological method of a case-control study. The assessment of unfavorable climatic and geographical factors of the Arctic region during the polar night was carried out by the method of analytical observation and data recording from November 20, 2020 to January 20, 2021 using the example of the Novaya Zemlya archipelago, Belushya Guba village. On the basis of an integral analysis of epidemiological indicators, climatogeographic and clinical and morphological observations, a pathophysiological assessment of diseases of the organ of vision, developing during the polar night in naval specialists, was carried out.Research results show a high level of ophthalmological morbidity during the polar night among naval specialists serving on the Novaya Zemlya archipelago.Conclusions. Climatogeographic factors of the Arctic region have a polyetiological effect on the formation of mechanisms of pathogenesis of disorders of visual functions that develop in naval specialists during the polar night.

Uncovering Contributing Factors to Interruptions in the Power Grid: An Arctic Case

Electric failures are a problem for customers and grid operators. Identifying causes and localizing the source of failures in the grid is critical. Here, we focus on a specific power grid in the Arctic region of Northern Norway. First, we collected data pertaining to the grid topology, the topography of the area, the historical meteorological data, and the historical energy consumption/production data. Then, we exploited statistical and machine-learning techniques to predict the occurrence of failures. The classification models achieve good performance, meaning that there is a significant relationship between the collected variables and fault occurrence. Thus, we interpreted the variables that mostly explain the classification results to be the main driving factors of power interruption. Wind speed of gust and local industry activity are found to be the main controlling parameters in explaining the power failure occurrences. The result could provide important information to the distribution system operator for implementing strategies to prevent and mitigate incoming failures.

Financial Development and Sustainable Competitiveness in Arctic Region: A Dynamic Panel Data Analysis

The present study investigates the effect of financial development on sustainable competitiveness and its components (natural capital, resource intensity, and social cohesion) in the Arctic region. We employ bank-based, stock-market based, and composite index to measure financial development. To deal with endogeneity bias, system GMM is utilized. The results show a positive and significant effect of financial development on sustainable competitiveness. The estimates also assert that financial development encourages resource efficiency and social cohesion in the region. In contrast, we find the negative effect of financial development on natural capital. This suggests that overexploitation of natural resources may provide short-term benefits to the local and regional communities but it may threaten the long-term sustainability of the Arctic. Thus, the financial sector should be guided to support financing and investing activities in alternative eco-friendly technologies and ventures for reducing excessive natural resource utilization.