Highlights of Papers Published on Issue 34 (4) of Advances in Polar Science
The peer-reviewed journal Advances in Polar Science (APS) published Volume 34 Issue 4 in December 2023. This issue includes eight articles, and their titles and highlights are presented below respectively. All papers published on APS could be visited directly via DOI, and downloaded for free. Sharing and promoting the articles in APS is welcomed. See more details at APS homepage: https://aps.chinare.org.cn.
Cover of Issue 34(4)
Space weather has a remarkable effect on modern human activities, e.g., communication, navigation, space exploration etc. Space physics study from polar stations is as an important part of the entire solar-terrestrial space, and conducts quantitative research from the perspective of overall space plasma behavior. It has been almost 40 years since the first Chinese National Antarctic Research Expedition (CHINARE) took place in 1984. Space physics observation, survey and research conducted/merged during CHINARE program first began at Great Wall Station (GWS, 1985) and then at Zhongshan Station (ZHS, 1989) in Antarctica, and later in the Arctic at Yellow River Station (YRS, 2003), Kjell Henriksen Observatory (KHO, 2011) on Svalbard, and at the China-Iceland Joint Arctic Science Observatory (CIAO, 2018) in Iceland. The ZHS is located at a unique geographical site that is well suited to take measurements on the magnetospheric cusp where solar wind could entry directly into the Earth’s magnetosphere. Also, together with YRS, it provides excellent opportunity to perform conjugated space weather observations for both northern and southern hemispheres. In this review we summarized the space physics and astronomy research from Chinese polar stations, including the current and future directions.
Citation: Zong Q G, Hu Z J, Liu J J, et al. Space physics and astronomy research from Chinese polar stations: current and future directions. Adv Polar Sci, 2023, 34(4): 239-250, doi: 10.12429/j.advps.2023.0016
Even though the Arctic region is far from human activities, microplastics are still found in various environmental media such as seawater, snow, and sea ice. Microplastics tend to be distributed in a smaller size range, with fibers accounting for a larger proportion of the shape. Ocean currents and river transport are considered to be the main pathways for microplastics to reach the Arctic region, and a large number of microplastics are also frozen in sea ice. Atmospheric transport and deposition provide the possibility for the long-distance transport of microplastics, and the transport capacity may be related to the shape and size of microplastic fragments. Under global warming, microplastics will exacerbate glacier melting, sea surface temperature changes, and even affect the carbon cycle.
Citation: Gong T J, Xu G J, Chen L Q, et al. Current state of research on microplastics in the marine-atmosphere environment of the Arctic region. Adv Polar Sci, 2023, 34(4): 251-261, doi: 10.12429/j.advps.2023.0005
The West Antarctic Peninsula (WAP) region is characterized by complex topography and interconnected circulation patterns, which can strongly influence vertical stratification, nutrient availability and the distribution of marine organisms. By using 9-year hydrographic and ecological data of five transects collected in the WAP region, the spatial-temporal variations of phytoplankton biomass and the modulating physical-ecological processes were explored with a particular focus on chlorophyll (Chl) concentration. Regression analysis among area-averaged and single-station properties was also performed to reveal the relationship between the interannual variations of physical and ecological processes. The correlation results showed that the Chl concentration in this region exhibited a positive relationship with both the circumpolar deep water (CDW) intrusion and vertical stratification, and showed negative correlations with SAM at some specific stations. Certain driving factors or processes may play dominant roles for specific stations, not throughout the entire WAP region.
Citation: Wu S, Zhang Z R, Wang C N. Variations and relations between chlorophyll concentrations and physical-ecological processes near the West Antarctic Peninsula. Adv Polar Sci, 34(4): 262-271, doi: 10.12429/j.advps.2023.0010
Dissolved oxygen (DO) and apparent oxygen utilization (AOU) are crucial parameters for investigating marine ecosystem evolution and the marine environment. In this study, DO and AOU spatial distribution characteristics were explored in the Antarctic Cosmonaut Sea and Amundsen Sea in austral summer 2021. The standard deviation range of DO parallel samples was < 0.1–3.7 μmol·L–1, meeting the accuracy requirements of the survey method. The DO concentration decreased sharply with water depth in the photic zone and increased slowly to the bottom. AOU in the surface layer of the two seas was significantly negatively correlated with chlorophyll a (p < 0.01), and AOU was significantly lower in the south Cosmonaut Sea than in the north Cosmonaut Sea and Amundsen Sea (p < 0.01). In austral summer, AOU was as low as < 130 μmol·L–1 in the nearshore Cosmonaut Sea with thicker Antarctic Surface Water down to ca. 500 m. In early winter, AOU was lower than 50 μmol·L–1 in the north Amundsen Sea in subsurface water (75–150 m). The unmodified Circumpolar Deep Water with high AOU (> 160 μmol·L–1) could surge up to ca. 150–200 m in both seas, with stronger intrusion in the Amundsen Sea. The AOU in bottom water was significantly lower (p < 0.01) in the Cosmonaut Sea (118.9±11.8 μmol·L–1) than the Amundsen Sea (141.7±7.4 μmol·L–1), indicating the stable existence of fresh oxygen-rich Antarctic Bottom Water in the Cosmonaut Sea. Our study shows that AOU has the potential to be an indicator of the characteristics of water masses.
Citation: Guo J Y, Yang X F, Zhao J, et al. Distributions of dissolved oxygen and apparent oxygen utilization in the Cosmonaut Sea and Amundsen Sea in austral summer 2021. Adv Polar Sci, 2023, 34(4): 272-303, doi: 10.12429/j.advps.2023.0007
Primary productivity in the Antarctic aquatic environment with simple ecosystems is sensitive to climate and environmental fluctuations. We assessed the possibility of using the δ13C values of short-chain n-alkanoic acids in the lacustrine sediment profile to reconstruct historical changes in primary productivity, and found that the δ13C values of n-alkanoic acids produced by phototrophic organisms can be used as new proxies for the productivity of Antarctic lakes and ponds. The short-chain n-alkanoic acids in sediment had similar δ13C values to floating microbial mats, indicating that short-chain n-alkanoic acids in the sediment were primarily derived from phototrophic organisms. The carbon isotope compositions of short-chain n-alkanoic acids in the IIL3 sediment profile were mainly related to primary productivity in the studied pond. At a high photosynthesis efficiency, dissolved CO2 would have been rapidly consumed, resulting in CO2-diffusion-limited growth and more 13CO2 being assimilated into lipids in the aquatic microbial mats. The aquatic productivities predicted from the n-alkanoic acid δ13C values were compared with the aquatic productivities predicted using various proxies (sedimentary fluxes of n-alkanoic acids and sterols) in the same core. The C16 n-alkanoic acid δ13C values positively correlated with aquatic productivity, with 13C enrichment indicating higher productivity. The results indicated that the δ13C values of n-alkanoic acids derived from phototrophic organisms can be used as new reliable proxies for reconstructing historic changes in the primary productivity of lakes and ponds in Antarctica and then to indicate regional climate changes.
Citation: Chen X, Jin J, Nie Y G, et al. Carbon isotope ratios of n-alkanoic acids: new organic proxies for paleo-productivity in Antarctic ponds. Adv Polar Sci, 2023, 34(4): 304-317, doi: 10.12429/j.advps.2023.0004
The article contributes to the study of the content of major and trace elements in various types of natural waters of the Broknes Peninsula, Larsemann Hills, Antarctica collected in January–February 2014 and 2020 during the 7th and 12th Belarusian Antarctic Expeditions. Samples of old (13 samples) and newly fallen snow (5), lakes (23) and groundwater (8) were analyzed. The content of 25 major and trace elements was determined using ICP-MS method, main anions was determined by titrimetric and turbidimetric methods. Good similarity chemical composition of snow, groundwater and lake waters in spite of differences in the content of major ions and trace elements has been obtained. The influence of marine salts on natural waters are analyzed, and their accumulation in lake waters especially in the endorheic small and shallow lakes in spite of ultra-oligotrophic atmospheric precipitates are shown. The spatial heterogeneity of groundwater and temporal and spatial heterogeneity of lake waters have been demonstrated. The results are important for understanding the variabilities of major and trace elements content in snow, groundwater and lake waters, and their relationship, as well as for identifying trends in their change, taking into account anthropogenic loads in the region and climate change.
Citation: Kakareka S, Kukharchyk T, Giginyak Y, et al. Chemical composition of natural waters at Broknes Peninsula, Larsemann Hills, Antarctica. Adv Polar Sci, 2023, 34(4): 319-340, doi: 10.12429/j.advps.2023.0008
With the present day rise of interest in acquiring sustainability in the pharmaceutical industry, there has been an emphasis on finding natural resources to replace the use of synthetic compounds used in products. Microalgae have garnered significant attention owing to their natural and sustainable capability to produce a diverse array of bioactive compounds. Therefore, this study aims to evaluate the biochemical composition and antioxidant properties of Chlorella strains from a tropical region (Chlorella UMACC 051 and Chlorella UMACC 038) and a polar region (Chlorella UMACC 250 and Chlorella UMACC 234). The cultures were grown for 10 d. At the end of the experiment, the specific growth rate, chlorophyll-a content, carotenoid content, biomass, and biochemical composition such as carbohydrate, protein and lipid content were determined. In addition, the phytochemical properties were determined using a total phenolic assay while the antioxidant activities were determined using 2,2-diphenyl-1-picrylhydrazyl (DPPH). Of all Chlorella strains tested, the tropical Chlorella UMACC 051 showed the fastest growth rate and biomass while the polar Chlorella UMACC 234 contained the highest pigment content and tropical Chlorella UMACC 038 has the highest total phenolic content. The biochemical composition analysis showed all strains have a high lipid content ranging from 45.36% to 60.30% dry weight. All Chlorella strains exhibited a small amount of antioxidant activity (15.42% to 30.15%) and total phenolic content ranging from 1.91 ± 0.04 to 4.43 ± 0.10 mg GAE·g–1 dry weight. The results indicated that polar Chlorella UMACC 234 has the most potential in containing significant amounts of bioactive compounds.
Citation: Wong C Z-E, Teoh M-L, Chan S W, et al. Chlorella across latitudes: investigating biochemical composition and antioxidant activities for biotechnological applications. Adv Polar Sci, 2023, 34(4): 340-351, doi: 10.12429/j.advps.2023.0028
In this study, we used a high-resolution (3 km) WRF model to simulate the meteorology at two Arctic stations (i.e., Barrow and Summit) during April 2019. The simulation results were also thoroughly evaluated by using surface measurements, weather charts and statistical parameters. We found that the WRF model can accurately capture the changes in meteorological parameters and weather systems (i.e., cyclones and anticyclones) at these two Arctic stations. Besides, the Summit Station was found to possess superior predictions than the Barrow Station. Possible reasons for the deviations in meteorological predictions between these two stations were attributed to inaccurate representation of the sea ice and the inadequate parameterization of the cloud in the WRF model. In addition, the model was found to have the lowest accuracy in predicting the wind among all the meteorological parameters, which is possibly due to the overestimation of wind over the sea and at coastal stations. However, meteorological predictions in the Arctic by the WRF model were still found to be much better than those at mid-latitude stations, due to the differences in land features and anthropogenic heat sources between these regions.
Citation: Zhang T, Cao L, Li S M, et al. Evaluation of meteorological predictions by the WRF model at Barrow, Alaska and Summit, Greenland in the Arctic in April 2019. Adv Polar Sci, 34(4): 352-367, doi: 10.12429/j.advps.2023.0006
沪公网安备 31011502017260号