Metadata for a long-term climate series from the Russian meteorological station “Pyramiden” (1948-1957) at Svalbard ( Short Communication)

Soviet weather station "Pyramiden" was located in the same mining settlement on the northern shore of the Mimer bukta (Billefjorden, West Spitsbergen Island). Research station operated from 1948 to 1957, as a branch of Barentsburg research observatory (Grnfjorden, West Spitsbergen Island). It was the only station that held regular meteorological observations in the inland areas of the archipelago. Observational data (in the form of handwritten books and tables) are preserved in state fond of Arctic and Antarctic Research Institute (AARI, St. Petersburg, Russia). So far, these data have not been digitized and with their help not conducted any climate researches. Fruitful scientific collaboration between MET-Norway (Norwegian Meteorological Institute, Oslo) and AARI helped preserve these unique data to the polar scientific community. Now specialists-climatologists of both institutions complete joint climate researches that in the near future will be available to scientists, studying modern climate changes in the polar regions of the Earth

Warming of Atlantic Water in two west Spitsbergen fjords over the last century (1912-2009)

The recently observed warming of west Spitsbergen fjords has led to anomalous sea-ice conditions and has implications for the marine ecosystem. We investigated long-term trends of maximum temperature of Atlantic Water (AW) in two west Spitsbergen fjords. The data set is composed of more than 400 oceanographic stations for Isfjorden and Grønfjorden (78.1°N), spanning from 1876 to 2009. Trends throughout the last century (1912–2009) indicate an increase of 1.9°C and 2.1°C in the maximum temperature during autumn for Isfjorden and Grønfjorden, respectively. A recent warming event in the beginning of the 21st century is found to be more than 1°C higher than the second warmest period in the time series. Mean sea-level pressure (MSLP) data from ERA-40 and ERA-Interim data sets produced by the European Centre for Medium-Range Weather Forecasts and mean temperature in the core of the West Spitsbergen Current (WSC) at the Sørkapp Section along 76.3°N were used to explain the variability of the maximum temperature. A correlation analysis confirmed previous findings, showing that variability in the oceanography of the fjords can be explained mainly by two external factors: AW temperature variability in the WSC and regional patterns of the wind stress field. To take both processes into consideration, a multiple regression model accounting for temperature in the WSC core and MSLP over the area was developed. The predicted time series shows a reasonable agreement with observed maxima temperature in Isfjorden for the period 1977–2009 (N=24), with a statistically significant multiple correlation coefficient of 0.60 (R2=0.36) at P<0.05.publishedVersio

Sea ice metadata for Billefjorden and Grnfjorden, Svalbard

Description of sea ice conditions in the fjords of Svalbard is crucial for sea transport as well as studies of local climate and climate change. Old observations from the Russian Hydrometeorological stations in the mining settlements Barentsburg (Grnfjorden) and Pyramiden (Billefjorden) have now been digitized. These visual and instrumental observations are archived in the State Archive of Arctic and Antarctic Research Institute (AARI) and Murmansk Branch of the Russian Hydrometeorological Service. In this paper, we bring an overview of the sea ice metadata with few examples of yearly changes in sea ice extent

Contrasting optical properties of surface waters across the Fram Strait and its potential biological implications

AbstractUnderwater light regime is controlled by distribution and optical properties of colored dissolved organic matter (CDOM) and particulate matter. The Fram Strait is a region where two contrasting water masses are found. Polar water in the East Greenland Current (EGC) and Atlantic water in the West Spitsbergen Current (WSC) differ with regards to temperature, salinity and optical properties. We present data on absorption properties of CDOM and particles across the Fram Strait (along 79° N), comparing Polar and Atlantic surface waters in September 2009 and 2010. CDOM absorption of Polar water in the EGC was significantly higher (more than 3-fold) compared to Atlantic water in the WSC, with values of absorption coefficient, aCDOM(350), m−1 of 0.565±0.100 (in 2009) and 0.458±0.117 (in 2010), and 0.138±0.036 (in 2009) and 0.153±0.039 (in 2010), respectively. An opposite pattern was observed for particle absorption with higher absorption found in the eastern part of the Fram Strait. Average values of particle absorption (aP(440), m−1) were 0.016±0.013 (in 2009) and 0.014±0.011 (in 2010), and 0.047±0.012 (in 2009) and 0.016±0.014 (in 2010), respectively for Polar and Atlantic water. Thus absorption of light in eastern part of the Fram Strait is dominated by particles — predominantly phytoplankton, and the absorption of light in the western part of the strait is dominated by CDOM, with predominantly terrigenous origin. As a result the balance between the importance of CDOM and particulates to the total absorption budget in the upper 0–10m shifts across Fram Strait. Under water spectral irradiance profiles were generated using ECOLIGHT 5.4.1 and the results indicate that the shift in composition between dissolved and particulate material does not influence substantially the penetration of photosynthetic active radiation (PAR, 400–700nm), but does result in notable differences in ultraviolet (UV) light penetration, with higher attenuation in the EGC. Future changes in the Arctic Ocean system will likely affect EGC through diminishing sea-ice cover and potentially increasing CDOM export due to increase in river runoff into the Arctic Ocean. Role of attenuation of light by CDOM in determining underwater light regime will become more important, with a potential for future increase in marine productivity in the area of EGC due to elevated PAR and lowered UV light exposures

Linkages between the circulation and distribution of dissolved organic matter in the White Sea, Arctic Ocean

AbstractThe White Sea is a semi-enclosed Arctic marginal sea receiving a significant loading of freshwater (225–231km3yr−1 equaling an annual runoff yield of 2.5m) and dissolved organic matter (DOM) from river run-off. We report discharge weighed values of stable oxygen isotope ratios (δ18O) of −14.0‰ in Northern Dvina river for the period 10 May–12 October 2012. We found a significant linear relationship between salinity (S) and δ18O (δ18O=−17.66±0.58+0.52±0.02×S; R2=0.96, N=162), which indicates a dominant contribution of river water to the freshwater budget and little influence of sea ice formation or melt. No apparent brine additions from sea-ice formation is evident in the White Sea deep waters as seen from a joint analysis of temperature (T), S, δ18O and aCDOM(350) data, confirming previous suggestions about strong tidal induced vertical mixing in winter being the likely source of the deep waters. We investigated properties and distribution of colored dissolved organic matter (CDOM) and dissolved organic carbon (DOC) in the White Sea basin and coastal areas in summer. We found contrasting DOM properties in the inflowing Barents Sea waters and White Sea waters influenced by terrestrial runoff. Values of absorption by CDOM at 350nm (aCDOM(350)) and DOC (exceeding 10m−1 and 550µmoll−1, respectively) in surface waters of the White Sea basin are higher compared to other river-influenced coastal Arctic domains. Linear relationship between S and CDOM absorption, and S and DOC (DOC=959.21±52.99–25.80±1.79×S; R2=0.85; N=154) concentrations suggests conservative mixing of DOM in the White Sea. The strongest linear correlation between CDOM absorption and DOC was found in the ultraviolet (DOC=56.31±2.76+9.13±0.15×aCDOM(254); R2=0.99; N=155), which provides an easy and robust tool to trace DOC using CDOM absorption measurements as well as remote sensing algorithms. Deviations from this linear relationship in surface waters likely indicate contribution from different rivers along the coast of the White Sea. Characteristics of CDOM further indicate that there is limited removal or change in the DOM pool before it exits to the Barents Sea

Climate Change and the World’s “Sacred Sea”—Lake Baikal, Siberia

Lake Baikal—the world\u27s largest, oldest, and most biotically diverse lake—is responding strongly to climate change, according to recent analyses of water temperature and ice cover. By the end of this century, the climate of the Baikal region will be warmer and wetter, particularly in winter. As the climate changes, ice cover and transparency, water temperature, wind dynamics and mixing, and nutrient levels are the key abiotic variables that will shift, thus eliciting many biotic responses. Among the abiotic variables, changes in ice cover will quite likely alter food-web structure and function most because of the diverse ways in which ice affects the lake\u27s dominant primary producers (endemic diatoms), the top predator (the world\u27s only freshwater seal), and other abiotic variables. Melting permafrost will probably exacerbate the effects of additional anthropogenic stressors (industrial pollution and cultural eutrophication) and could greatly affect ecosystem functioning

Leads in Arctic pack ice enable early phytoplankton blooms below snow-covered sea ice

© The Author(s), 2017. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Scientific Reports 7 (2017): 40850, doi:10.1038/srep40850.The Arctic icescape is rapidly transforming from a thicker multiyear ice cover to a thinner and largely seasonal first-year ice cover with significant consequences for Arctic primary production. One critical challenge is to understand how productivity will change within the next decades. Recent studies have reported extensive phytoplankton blooms beneath ponded sea ice during summer, indicating that satellite-based Arctic annual primary production estimates may be significantly underestimated. Here we present a unique time-series of a phytoplankton spring bloom observed beneath snow-covered Arctic pack ice. The bloom, dominated by the haptophyte algae Phaeocystis pouchetii, caused near depletion of the surface nitrate inventory and a decline in dissolved inorganic carbon by 16 ± 6 g C m−2. Ocean circulation characteristics in the area indicated that the bloom developed in situ despite the snow-covered sea ice. Leads in the dynamic ice cover provided added sunlight necessary to initiate and sustain the bloom. Phytoplankton blooms beneath snow-covered ice might become more common and widespread in the future Arctic Ocean with frequent lead formation due to thinner and more dynamic sea ice despite projected increases in high-Arctic snowfall. This could alter productivity, marine food webs and carbon sequestration in the Arctic Ocean.This study was supported by the Centre for Ice, Climate and Ecosystems (ICE) at the Norwegian Polar Institute, the Ministry of Climate and Environment, Norway, the Research Council of Norway (projects Boom or Bust no. 244646, STASIS no. 221961, CORESAT no. 222681, CIRFA no. 237906 and AMOS CeO no. 223254), and the Ministry of Foreign Affairs, Norway (project ID Arctic), the ICE-ARC program of the European Union 7th Framework Program (grant number 603887), the Polish-Norwegian Research Program operated by the National Centre for Research and Development under the Norwegian Financial Mechanism 2009–2014 in the frame of Project Contract Pol-Nor/197511/40/2013, CDOM-HEAT, and the Ocean Acidification Flagship program within the FRAM- High North Research Centre for Climate and the Environment, Norway

Leads in Arctic pack ice enable early phytoplankton blooms below snow-covered sea ic

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Pivotal Role of Inosine Triphosphate Pyrophosphatase in Maintaining Genome Stability and the Prevention of Apoptosis in Human Cells

Pure nucleotide precursor pools are a prerequisite for high-fidelity DNA replication and the suppression of mutagenesis and carcinogenesis. ITPases are nucleoside triphosphate pyrophosphatases that clean the precursor pools of the non-canonical triphosphates of inosine and xanthine. The precise role of the human ITPase, encoded by the ITPA gene, is not clearly defined. ITPA is clinically important because a widespread polymorphism, 94C>A, leads to null ITPase activity in erythrocytes and is associated with an adverse reaction to thiopurine drugs. We studied the cellular function of ITPA in HeLa cells using the purine analog 6-N hydroxylaminopurine (HAP), whose triphosphate is also a substrate for ITPA. In this study, we demonstrate that ITPA knockdown sensitizes HeLa cells to HAP-induced DNA breaks and apoptosis. The HAP-induced DNA damage and cytotoxicity observed in ITPA knockdown cells are rescued by an overexpression of the yeast ITPase encoded by the HAM1 gene. We further show that ITPA knockdown results in elevated mutagenesis in response to HAP treatment. Our studies reveal the significance of ITPA in preventing base analog-induced apoptosis, DNA damage and mutagenesis in human cells. This implies that individuals with defective ITPase are predisposed to genome damage by impurities in nucleotide pools, which is drastically augmented by therapy with purine analogs. They are also at an elevated risk for degenerative diseases and cancer

Search for new particles in events with energetic jets and large missing transverse momentum in proton-proton collisions at root s=13 TeV

A search is presented for new particles produced at the LHC in proton-proton collisions at root s = 13 TeV, using events with energetic jets and large missing transverse momentum. The analysis is based on a data sample corresponding to an integrated luminosity of 101 fb(-1), collected in 2017-2018 with the CMS detector. Machine learning techniques are used to define separate categories for events with narrow jets from initial-state radiation and events with large-radius jets consistent with a hadronic decay of a W or Z boson. A statistical combination is made with an earlier search based on a data sample of 36 fb(-1), collected in 2016. No significant excess of events is observed with respect to the standard model background expectation determined from control samples in data. The results are interpreted in terms of limits on the branching fraction of an invisible decay of the Higgs boson, as well as constraints on simplified models of dark matter, on first-generation scalar leptoquarks decaying to quarks and neutrinos, and on models with large extra dimensions. Several of the new limits, specifically for spin-1 dark matter mediators, pseudoscalar mediators, colored mediators, and leptoquarks, are the most restrictive to date.Peer reviewe