Carbonate characteristics of the Gulf of Anadyr waters

The first field data describing the dynamics of the carbonate system, aragonite saturation state, and CO2 fluxes between the ocean and the atmosphere in the Gulf of Anadyr in the late autumn season are presented. It was established that during this period the gulf waters absorbed carbon dioxide from the atmosphere at a rate of -22,5 mmol m‑2 day‑1, which determined the “classical” mechanism of seawater acidification due to uptake of excess atmospheric CO2. In general, surface waters of the gulf were supersaturated with respect to aragonite. The exception was the highly dynamic region of Anadyr Strait, where the vertical distribution of the investigated parameters was homogeneous, the surface waters were close to equilibrium with respect to aragonite, and CO2 flux was directed to the atmosphere. Bottom waters of the gulf, in contrast, were characterized by significant seasonal corrosivity with respect to aragonite due primarily to remineralization of organic matter to CO2. It was shown that during the late fall relatively salty and acidic, quasi-equilibrium with respect to aragonite, and oxygen-depleted waters with high concentrations of nutrients and CO2 have been entered the Chirkov Basin and further the Arctic Ocean with the Navarin current.

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Impact of rapid sea-ice reduction in the Arctic Ocean on the rate of ocean acidification

Biogeosciences Discussions ◽

10.5194/bgd-8-10617-2011 ◽

2011 ◽

Vol 8 (5) ◽

pp. 10617-10644

Author(s):

A. Yamamoto ◽

M. Kawamiya ◽

A. Ishida ◽

Y. Yamanaka ◽

S. Watanabe

Keyword(s):

Sea Ice ◽

Arctic Ocean ◽

Surface Waters ◽

Co2 Concentration ◽

The Arctic ◽

Saturation State ◽

Aragonite Saturation ◽

The Arctic Ocean ◽

Arctic Surface ◽

Sea Ice Reduction

Abstract. The largest pH decline and widespread undersaturation with respect to aragonite in this century due to uptake of anthropogenic carbon dioxide in the Arctic Ocean have been projected. The reductions in pH and aragonite saturation state have been caused primarily by an increase in the concentration of atmospheric carbon dioxide. However, in a previous study, simulations with and without warming showed that these reductions in the Arctic Ocean also advances due to the melting of sea ice caused by global warming. Therefore, future projections of pH and aragonite saturation in the Arctic Ocean will be affected by how rapidly the reduction in sea ice occurs. In this study, the impact of sea-ice reduction rate on projected pH and aragonite saturation state in the Arctic surface waters was investigated. Reductions in pH and aragonite saturation were calculated from the outputs of two versions of an earth system model (ESM) with different sea-ice reduction rates under similar CO2 emission scenarios. The newer model version projects that Arctic summer ice-free condition will be achieved by the year 2040, and the older version predicts ice-free condition by 2090. The Arctic surface water was projected to be undersaturated with respect to aragonite in the annual mean when atmospheric CO2 concentration reached 480 (550) ppm in year 2040 (2048) in new (old) version. At an atmospheric CO2 concentration of 520 ppm, the maximum differences in pH and aragonite saturation state between the two versions were 0.08 and 0.15, respectively. The analysis showed that the decreases in pH and aragonite saturation state due to rapid sea-ice reduction were caused by increases in both CO2 uptake and freshwater input. Thus, the reductions in pH and aragonite saturation state in the Arctic surface waters are significantly affected by the difference in future projections for sea-ice reduction rate. The critical CO2 concentration, at which the Arctic surface waters become undersaturated with respect to aragonite on annual mean bias, would be lower by 70 ppm in the version with the rapid sea-ice reduction.

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Impact of the mining industry on surface waters in the Arctic zone of the Republic of Sakha (Yakutia)

IOP Conference Series Earth and Environmental Science ◽

10.1088/1755-1315/885/1/012048 ◽

2021 ◽

Vol 885 (1) ◽

pp. 012048

Author(s):

M I Ksenofontova

Keyword(s):

Surface Waters ◽

Mining Industry ◽

Specific Effect ◽

The Arctic ◽

Arctic Zone ◽

North West ◽

North East ◽

The North ◽

The Republic ◽

High Concentrations

Abstract The article presents the results of hydrochemical studies of northern rivers of the Arctic zone of the Republic of Sakha (Yakutia). It was revealed that the background hydrochemical composition of surface waters in the study area is diverse: from hydrocarbonate-sodium waters in the North-West and hydrocarbonate-sulphate waters in the North-East of Yakutia. During the study of the microelement composition of surface waters in the Arctic zone, high concentrations of total iron, manganese, and copper are found everywhere, indicating their natural origin. In places where groundwater influence is observed we found that the characteristic elements are lithium, strontium and barium. Analysing the research results, we can say that each mining enterprise has its own specific effect on surface waters, which makes its own adjustments to the chemical composition of surface waters.

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The vertical distribution of thin features over the Arctic analysed from CALIPSO observations. Part I: Optically thin clouds

Tellus B ◽

10.3402/tellusb.v63i1.16189 ◽

2011 ◽

Vol 63 (1) ◽

Author(s):

Abhay Devasthale ◽

Michael Tjernström ◽

Karl-Göran Karlsson ◽

Manu Anna Thomas ◽

Colin Jones ◽

...

Keyword(s):

Vertical Distribution ◽

The Arctic ◽

The Vertical Distribution

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Microplastics distribution in the Eurasian Arctic is affected by Atlantic waters and Siberian rivers

Communications Earth & Environment ◽

10.1038/s43247-021-00091-0 ◽

2021 ◽

Vol 2 (1) ◽

Cited By ~ 1

Author(s):

Evgeniy Yakushev ◽

Anna Gebruk ◽

Alexander Osadchiev ◽

Svetlana Pakhomova ◽

Amy Lusher ◽

...

Keyword(s):

Surface Water ◽

Surface Waters ◽

Water Masses ◽

The Arctic ◽

Plastic Pollution ◽

Siberian River ◽

Highest Weight ◽

Surface Samples ◽

Atlantic Origin ◽

Type Size

AbstractPlastic pollution is globally recognised as a threat to marine ecosystems, habitats, and wildlife, and it has now reached remote locations such as the Arctic Ocean. Nevertheless, the distribution of microplastics in the Eurasian Arctic is particularly underreported. Here we present analyses of 60 subsurface pump water samples and 48 surface neuston net samples from the Eurasian Arctic with the goal to quantify and classify microplastics in relation to oceanographic conditions. In our study area, we found on average 0.004 items of microplastics per m3 in the surface samples, and 0.8 items per m3 in the subsurface samples. Microplastic characteristics differ significantly between Atlantic surface water, Polar surface water and discharge plumes of the Great Siberian Rivers, allowing identification of two sources of microplastic pollution (p < 0.05 for surface area, morphology, and polymer types). The highest weight concentration of microplastics was observed within surface waters of Atlantic origin. Siberian river discharge was identified as the second largest source. We conclude that these water masses govern the distribution of microplastics in the Eurasian Arctic. The microplastics properties (i.e. abundance, polymer type, size, weight concentrations) can be used for identification of the water masses.

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Arctic Ocean stratification set by sea level and freshwater inputs since the last ice age

Nature Geoscience ◽

10.1038/s41561-021-00789-y ◽

2021 ◽

Author(s):

Jesse R. Farmer ◽

Daniel M. Sigman ◽

Julie Granger ◽

Ona M. Underwood ◽

François Fripiat ◽

...

Keyword(s):

Arctic Ocean ◽

Surface Waters ◽

Ice Age ◽

The Arctic ◽

Bering Strait ◽

Central Arctic Ocean ◽

Phytoplankton Productivity ◽

Nitrate Consumption ◽

Western Arctic ◽

Last Ice Age

AbstractSalinity-driven density stratification of the upper Arctic Ocean isolates sea-ice cover and cold, nutrient-poor surface waters from underlying warmer, nutrient-rich waters. Recently, stratification has strengthened in the western Arctic but has weakened in the eastern Arctic; it is unknown if these trends will continue. Here we present foraminifera-bound nitrogen isotopes from Arctic Ocean sediments since 35,000 years ago to reconstruct past changes in nutrient sources and the degree of nutrient consumption in surface waters, the latter reflecting stratification. During the last ice age and early deglaciation, the Arctic was dominated by Atlantic-sourced nitrate and incomplete nitrate consumption, indicating weaker stratification. Starting at 11,000 years ago in the western Arctic, there is a clear isotopic signal of Pacific-sourced nitrate and complete nitrate consumption associated with the flooding of the Bering Strait. These changes reveal that the strong stratification of the western Arctic relies on low-salinity inflow through the Bering Strait. In the central Arctic, nitrate consumption was complete during the early Holocene, then declined after 5,000 years ago as summer insolation decreased. This sequence suggests that precipitation and riverine freshwater fluxes control the stratification of the central Arctic Ocean. Based on these findings, ongoing warming will cause strong stratification to expand into the central Arctic, slowing the nutrient supply to surface waters and thus limiting future phytoplankton productivity.

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Bank filtration: a suitable process for the removal of iodinated X-ray contrast media?

Water Science & Technology ◽

10.2166/wst.2004.0336 ◽

2004 ◽

Vol 50 (5) ◽

pp. 261-268 ◽

Cited By ~ 33

Author(s):

S. Schittko ◽

A. Putschew ◽

M. Jekel

Keyword(s):

Drinking Water ◽

Contrast Media ◽

Surface Waters ◽

Sampling Period ◽

Transformation Products ◽

Bank Filtration ◽

Anoxic Conditions ◽

X Ray ◽

High Concentrations ◽

Media Concentration

After bank filtration, effluent influenced surface waters are often used as raw drinking water. It is known that high concentrations of iodinated X-ray contrast media are detectable in such surface waters and thus, more knowledge about the behaviour of the contrast media during bank filtration is necessary and the subject of investigations in this study. The adsorbable organic iodine (AOI), four widely used iodinated X-ray contrast media and four possible transformation products were quantified in an influenced lake, five groundwater wells and a drinking water well. Under anoxic conditions the AOI as well as the concentration of the contrast media are decreased by bank filtration, whereby the AOI is decreased by 64% and the contrast media concentration can be reduced up to 95%, depending on the compound. In the raw drinking water the following average concentrations were determined: Iopromid <20 ng/L, Diatrizote 166 ng/L, Iopamidol 166 ng/L and Iohexol 34 ng/L. Instationary conditions during the sampling period indicate that, at least under anoxic conditions, a large part of the contrast media and transformation products, which are still iodinated, may be associated to colloids and/or humic material.

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Processes determining the marine alkalinity and calcium carbonate saturation state distributions

Biogeosciences ◽

10.5194/bg-11-7349-2014 ◽

2014 ◽

Vol 11 (24) ◽

pp. 7349-7362 ◽

Cited By ~ 18

Author(s):

B. R. Carter ◽

J. R. Toggweiler ◽

R. M. Key ◽

J. L. Sarmiento

Keyword(s):

Calcium Carbonate ◽

The Arctic ◽

Effect Of Temperature ◽

Minor Role ◽

Co2 Solubility ◽

Saturation State ◽

Marine System ◽

Calcite Saturation ◽

River Mouths ◽

Arctic Surface

Abstract. We introduce a composite tracer for the marine system, Alk*, that has a global distribution primarily determined by CaCO3 precipitation and dissolution. Alk* is also affected by riverine alkalinity from dissolved terrestrial carbonate minerals. We estimate that the Arctic receives approximately twice the riverine alkalinity per unit area as the Atlantic, and 8 times that of the other oceans. Riverine inputs broadly elevate Alk* in the Arctic surface and particularly near river mouths. Strong net carbonate precipitation results in low Alk* in subtropical gyres, especially in the Indian and Atlantic oceans. Upwelling of dissolved CaCO3-rich deep water elevates North Pacific and Southern Ocean Alk*. We use the Alk* distribution to estimate the variability of the calcite saturation state resulting from CaCO3 cycling and other processes. We show that regional differences in surface calcite saturation state are due primarily to the effect of temperature differences on CO2 solubility and, to a lesser extent, differences in freshwater content and air–sea disequilibria. The variations in net calcium carbonate cycling revealed by Alk* play a comparatively minor role in determining the calcium carbonate saturation state.

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Mineral Phase-Element Associations Based on Sequential Leaching of Ferromanganese Crusts, Amerasia Basin Arctic Ocean

Minerals ◽

10.3390/min8100460 ◽

2018 ◽

Vol 8 (10) ◽

pp. 460 ◽

Cited By ~ 5

Author(s):

Natalia Konstantinova ◽

James Hein ◽

Amy Gartman ◽

Kira Mizell ◽

Pedro Barrulas ◽

...

Keyword(s):

Chemical Composition ◽

Arctic Ocean ◽

The Arctic ◽

Global Ocean ◽

Residual Fraction ◽

Ferromanganese Crusts ◽

Sequential Leaching ◽

Bottom Waters ◽

Complementary Techniques ◽

Chukchi Borderland

Ferromanganese (FeMn) crusts from Mendeleev Ridge, Chukchi Borderland, and Alpha Ridge, in the Amerasia Basin, Arctic Ocean, are similar based on morphology and chemical composition. The crusts are characterized by a two- to four-layered stratigraphy. The chemical composition of the Arctic crusts differs significantly from hydrogenetic crusts from elsewhere of global ocean by high mean Fe/Mn ratios, high As, Li, V, Sc, and Th concentrations, and high detrital contents. Here, we present element distributions through crust stratigraphic sections and element phase association using several complementary techniques such as SEM-EDS, LA-ICP-MS, and sequential leaching, a widely employed method of element phase association that dissolves mineral phases of different stability step-by-step: Exchangeable cations and Ca carbonates, Mn-oxides, Fe-hydroxides, and residual fraction. Sequential leaching shows that the Arctic crusts have higher contents of most elements characteristic of the aluminosilicate phase than do Pacific crusts. Elements have similar distributions between the hydrogenetic Mn and Fe phases in all the Arctic and Pacific crusts. The main host phases for the elements enriched in the Arctic crusts over Pacific crusts (Li, As, Th, and V) are the Mn-phase for Li and Fe-phase for As, Th, and V; those elements also have higher contents in the residual aluminosilicate phase. Thus, higher concentrations of Li, As, Th, and V likely occur in the dissolved and particulate phases in bottom waters where the Arctic crusts grow, which has been shown to be true for Sc, also highly enriched in the crusts. The phase distributions of elements within the crust layers is mostly consistent among the Arctic crusts, being somewhat different in element concentrations in the residual phase.

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Tropospheric BrO column densities in the Arctic derived from satellite: retrieval and comparison to ground-based measurements

Atmospheric Measurement Techniques ◽

10.5194/amt-5-2779-2012 ◽

2012 ◽

Vol 5 (11) ◽

pp. 2779-2807 ◽

Cited By ~ 31

Author(s):

H. Sihler ◽

U. Platt ◽

S. Beirle ◽

T. Marbach ◽

S. Kühl ◽

...

Keyword(s):

Boundary Layer ◽

The Arctic ◽

Trace Gas ◽

Natural Phenomenon ◽

Satellite Measurements ◽

Surface Layers ◽

Vertical Column ◽

Near Surface ◽

The Vertical Distribution ◽

Good Agreement

Abstract. During polar spring, halogen radicals like bromine monoxide (BrO) play an important role in the chemistry of tropospheric ozone destruction. Satellite measurements of the BrO distribution have become a particularly useful tool to investigate this probably natural phenomenon, but the separation of stratospheric and tropospheric partial columns of BrO is challenging. In this study, an algorithm was developed to retrieve tropospheric vertical column densities of BrO from data of high-resolution spectroscopic satellite instruments such as the second Global Ozone Monitoring Experiment (GOME-2). Unlike recently published approaches, the presented algorithm is capable of separating the fraction of BrO in the activated troposphere from the total BrO column solely based on remotely measured properties. The presented algorithm furthermore allows to estimate a realistic measurement error of the tropospheric BrO column. The sensitivity of each satellite pixel to BrO in the boundary layer is quantified using the measured UV radiance and the column density of the oxygen collision complex O4. A comparison of the sensitivities with CALIPSO LIDAR observations demonstrates that clouds shielding near-surface trace-gas columns can be reliably detected even over ice and snow. Retrieved tropospheric BrO columns are then compared to ground-based BrO measurements from two Arctic field campaigns in the Amundsen Gulf and at Barrow in 2008 and 2009, respectively. Our algorithm was found to be capable of retrieving enhanced near-surface BrO during both campaigns in good agreement with ground-based data. Some differences between ground-based and satellite measurements observed at Barrow can be explained by both elevated and shallow surface layers of BrO. The observations strongly suggest that surface release processes are the dominating source of BrO and that boundary layer meteorology influences the vertical distribution.

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Prominent bacterial heterotrophy and sources of <sup>13</sup>C-depleted fatty acids to the interior Canada Basin

Biogeosciences ◽

10.5194/bg-10-7065-2013 ◽

2013 ◽

Vol 10 (11) ◽

pp. 7065-7080 ◽

Cited By ~ 4

Author(s):

S. R. Shah ◽

D. R. Griffith ◽

V. Galy ◽

A. P. McNichol ◽

T. I. Eglinton

Keyword(s):

Fatty Acids ◽

Particulate Matter ◽

Organic Carbon ◽

Suspended Particulate Matter ◽

Surface Waters ◽

Canada Basin ◽

The Arctic ◽

Deep Basin ◽

Suspended Particulate ◽

Chemoautotrophic Bacteria

Abstract. In recent decades, the Canada Basin of the Arctic Ocean has experienced rapidly decreasing summer sea ice coverage and freshening of surface waters. It is unclear how these changes translate to deeper waters, particularly as our baseline understanding of organic carbon cycling in the deep basin is quite limited. In this study, we describe full-depth profiles of the abundance, distribution and carbon isotopic composition of fatty acids from suspended particulate matter at a seasonally ice-free station and a semi-permanently ice-covered station. Fatty acids, along with suspended particulate organic carbon (POC), are more concentrated and 13C-enriched under ice cover than in ice-free waters. But this influence, apparent at 50 m depth, does not propagate downward below 150 m depth, likely due to the weak biological pump in the central Canada Basin. Branched fatty acids have δ13C values that are similar to suspended POC at all depths and are more 13C-enriched than even-numbered saturated fatty acids at depths above 3000 m. These are likely to be produced in situ by heterotrophic bacteria incorporating organic carbon that is isotopically similar to total suspended POC. Below surface waters, there is also the suggestion of a source of saturated even-numbered fatty acids which could represent contributions from laterally advected organic carbon and/or from chemoautotrophic bacteria. At 3000 m depth and below, a greater relative abundance of long-chain (C20–24), branched and unsaturated fatty acids is consistent with a stronger influence of re-suspended sedimentary organic carbon. At these deep depths, two individual fatty acids (C12 and iso-C17) are significantly depleted in 13C, allowing for the possibility that methane oxidizing bacteria contribute fatty acids, either directly to suspended particulate matter or to shallow sediments that are subsequently mobilized and incorporated into suspended particulate matter within the deep basin.

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