Articles | Volume 13, issue 12
https://doi.org/10.5194/bg-13-3833-2016
© Author(s) 2016. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
https://doi.org/10.5194/bg-13-3833-2016
© Author(s) 2016. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
Research article
| 
01 Jul 2016
Research article |
| 01 Jul 2016
Identification and analysis of low-molecular-weight dissolved organic carbon in subglacial basal ice ecosystems by ion chromatography
Emily C. O'Donnell
CORRESPONDING AUTHOR
School of Geography, University of Nottingham, University Park,
Nottingham, NG7 2RD, UK
Bristol Glaciology Centre, School of Geographical Sciences, University
Road, Bristol, BS8 1SS, UK
Jemma L. Wadham
Bristol Glaciology Centre, School of Geographical Sciences, University
Road, Bristol, BS8 1SS, UK
Grzegorz P. Lis
Bristol Glaciology Centre, School of Geographical Sciences, University
Road, Bristol, BS8 1SS, UK
Martyn Tranter
Bristol Glaciology Centre, School of Geographical Sciences, University
Road, Bristol, BS8 1SS, UK
Amy E. Pickard
School of Geosciences, University of Edinburgh, Kings Buildings, West
Mains Rd, Edinburgh, EH9 3JN, UK
Marek Stibal
Department of Ecology, Charles University in Prague, Vinicna 7, 128 44
Prague 2, Czech Republic
Paul Dewsbury
Thermo Fisher Scientific, Stafford House, 1 Boundary Park, Hemel
Hempstead, Hertfordshire HP27 GE4, UK
Sean Fitzsimons
Department of Geography, University of Otago, P.O. Box 56, Dunedin, Otago
9056, New Zealand
Related authors
Jemma Louise Wadham, Jonathan Hawkings, Jon Telling, Dave Chandler, Jon Alcock, Emily O'Donnell, Preeti Kaur, Elizabeth Bagshaw, Martyn Tranter, Andre Tedstone, and Peter Nienow
Biogeosciences, 13, 6339–6352, https://doi.org/10.5194/bg-13-6339-2016, https://doi.org/10.5194/bg-13-6339-2016, 2016
Short summary
Short summary
Fjord and continental shelf environments in the polar regions are host to some of the planet's most productive ecosystems and support economically important fisheries. A key limiting nutrient for many of these marine phytoplankton is nitrogen. Here we evaluate the potential for a melting Greenland Ice Sheet to supply nitrogen to Arctic coastal ecosystems. We show nitrogen fluxes of a similar order of magnitude to one large Arctic river but yields that are double those typical of Arctic rivers.
E. C. Lawson, J. L. Wadham, M. Tranter, M. Stibal, G. P. Lis, C. E. H. Butler, J. Laybourn-Parry, P. Nienow, D. Chandler, and P. Dewsbury
Biogeosciences, 11, 4015–4028, https://doi.org/10.5194/bg-11-4015-2014, https://doi.org/10.5194/bg-11-4015-2014, 2014
Eva L. Doting, Ian T. Stevens, Anne M. Kellerman, Pamela E. Rossel, Runa Antony, Amy M. McKenna, Martyn Tranter, Liane G. Benning, Robert G. M. Spencer, Jon R. Hawkings, and Alexandre M. Anesio
EGUsphere, https://doi.org/10.5194/egusphere-2024-492, https://doi.org/10.5194/egusphere-2024-492, 2024
Short summary
Short summary
This study provides new insights into the transformation of dissolved organic matter (DOM) that takes place as meltwater flows through the porous crust of weathering ice that covers glacier ice surfaces during the melt season. Movement of water through the weathering crust is slow, allowing microorganisms and sunlight to alter the DOM in glacial meltwater. This is important as supraglacial meltwaters deliver DOM and nutrients to microorganisms living in downstream receiving aquatic environments.
Beatriz Gill-Olivas, Jon Telling, Mark Skidmore, and Martyn Tranter
Biogeosciences, 20, 929–943, https://doi.org/10.5194/bg-20-929-2023, https://doi.org/10.5194/bg-20-929-2023, 2023
Short summary
Short summary
Microbial ecosystems have been found in all subglacial environments sampled to date. Yet, little is known of the sources of energy and nutrients that sustain these microbial populations. This study shows that crushing of sedimentary rocks, which contain organic carbon, carbonate and sulfide minerals, along with previously weathered silicate minerals, produces a range of compounds and nutrients which can be utilised by the diverse suite of microbes that inhabit glacier beds.
Miranda J. Nicholes, Christopher Williamson, Martyn Tranter, Alexandra Holland, Marian Yallop, and Alexandre Anesio
Biogeosciences Discuss., https://doi.org/10.5194/bg-2020-227, https://doi.org/10.5194/bg-2020-227, 2020
Publication in BG not foreseen
Short summary
Short summary
This incubation experiment assessed the role of solar radiation and heterotrophic bacteria in the degradation of organic carbon in surface ice of the Greenland Ice Sheet. Although ultraviolet radiation was found to alter carbon composition, heterotrophic degradation caused the greatest changes to both carbon composition and quantity. Both processes are likely interlinked within the surface ice and are fundamental to controlling the composition of carbon exported to downstream environments.
Moya L. Macdonald, Jemma L. Wadham, Dickon Young, Chris R. Lunder, Ove Hermansen, Guillaume Lamarche-Gagnon, and Simon O'Doherty
Atmos. Chem. Phys., 20, 7243–7258, https://doi.org/10.5194/acp-20-7243-2020, https://doi.org/10.5194/acp-20-7243-2020, 2020
Short summary
Short summary
Climate change has caused glaciers in the Arctic to shrink, uncovering new soils. We used field measurements to study the exchange of a group of gases involved in ozone destruction, called halocarbons, between these new soils and the atmosphere. We found that mats of cyanobacteria, early colonisers of soils, are linked to a larger-than-expected exchange of halocarbons with the atmosphere. We also found that gases which are commonly thought to be marine in origin were released from these soils.
Andrew J. Tedstone, Joseph M. Cook, Christopher J. Williamson, Stefan Hofer, Jenine McCutcheon, Tristram Irvine-Fynn, Thomas Gribbin, and Martyn Tranter
The Cryosphere, 14, 521–538, https://doi.org/10.5194/tc-14-521-2020, https://doi.org/10.5194/tc-14-521-2020, 2020
Short summary
Short summary
Albedo describes how much light that hits a surface is reflected without being absorbed. Low-albedo ice surfaces melt more quickly. There are large differences in the albedo of bare-ice areas of the Greenland Ice Sheet. They are caused both by dark glacier algae and by the condition of the underlying ice. Changes occur over centimetres to metres, so satellites do not always detect real albedo changes. Estimates of melt made using satellite measurements therefore tend to be underestimates.
Joseph M. Cook, Andrew J. Tedstone, Christopher Williamson, Jenine McCutcheon, Andrew J. Hodson, Archana Dayal, McKenzie Skiles, Stefan Hofer, Robert Bryant, Owen McAree, Andrew McGonigle, Jonathan Ryan, Alexandre M. Anesio, Tristram D. L. Irvine-Fynn, Alun Hubbard, Edward Hanna, Mark Flanner, Sathish Mayanna, Liane G. Benning, Dirk van As, Marian Yallop, James B. McQuaid, Thomas Gribbin, and Martyn Tranter
The Cryosphere, 14, 309–330, https://doi.org/10.5194/tc-14-309-2020, https://doi.org/10.5194/tc-14-309-2020, 2020
Short summary
Short summary
Melting of the Greenland Ice Sheet (GrIS) is a major source of uncertainty for sea level rise projections. Ice-darkening due to the growth of algae has been recognized as a potential accelerator of melting. This paper measures and models the algae-driven ice melting and maps the algae over the ice sheet for the first time. We estimate that as much as 13 % total runoff from the south-western GrIS can be attributed to these algae, showing that they must be included in future mass balance models.
Alexandra T. Holland, Christopher J. Williamson, Fotis Sgouridis, Andrew J. Tedstone, Jenine McCutcheon, Joseph M. Cook, Ewa Poniecka, Marian L. Yallop, Martyn Tranter, Alexandre M. Anesio, and The Black & Bloom Group
Biogeosciences, 16, 3283–3296, https://doi.org/10.5194/bg-16-3283-2019, https://doi.org/10.5194/bg-16-3283-2019, 2019
Short summary
Short summary
This paper provides a preliminary data set for dissolved nutrient abundance in the Dark Zone of the Greenland Ice Sheet. This 15-year marked darkening has since been attributed to glacier algae blooms, yet has not been accounted for in current melt rate models. We conclude that the dissolved organic phase dominates surface ice environments and that factors other than macronutrient limitation control the extent and magnitude of the glacier algae blooms.
Joseph M. Cook, Andrew J. Hodson, Alex S. Gardner, Mark Flanner, Andrew J. Tedstone, Christopher Williamson, Tristram D. L. Irvine-Fynn, Johan Nilsson, Robert Bryant, and Martyn Tranter
The Cryosphere, 11, 2611–2632, https://doi.org/10.5194/tc-11-2611-2017, https://doi.org/10.5194/tc-11-2611-2017, 2017
Short summary
Short summary
Biological growth darkens snow and ice, causing it to melt faster. This is often referred to as
bioalbedo. Quantifying bioalbedo has not been achieved because of difficulties in isolating the biological contribution from the optical properties of ice and snow, and from inorganic impurities in field studies. In this paper, we provide a physical model that enables bioalbedo to be quantified from first principles and we use it to guide future field studies.
Andrew J. Tedstone, Jonathan L. Bamber, Joseph M. Cook, Christopher J. Williamson, Xavier Fettweis, Andrew J. Hodson, and Martyn Tranter
The Cryosphere, 11, 2491–2506, https://doi.org/10.5194/tc-11-2491-2017, https://doi.org/10.5194/tc-11-2491-2017, 2017
Short summary
Short summary
The bare ice albedo of the south-west Greenland ice sheet varies dramatically between years. The reasons are unclear but likely involve darkening by inorganic particulates, cryoconite and ice algae. We use satellite imagery to examine dark ice dynamics and climate model outputs to find likely climatological controls. Outcropping particulates can explain the spatial extent of dark ice, but the darkening itself is likely due to ice algae growth controlled by meltwater and light availability.
Amy E. Pickard, Kate V. Heal, Andrew R. McLeod, and Kerry J. Dinsmore
Biogeosciences, 14, 1793–1809, https://doi.org/10.5194/bg-14-1793-2017, https://doi.org/10.5194/bg-14-1793-2017, 2017
Short summary
Short summary
Peatland catchments export significant volumes of photoreactive carbon to aquatic systems, particularly headwater streams. Delivery of photoreactive material is subject to seasonal variation, and is also influenced by the timing and magnitude of rainfall events. We suggest that photoprocessing of peatland derived carbon may contribute to carbon dioxide emissions from aquatic systems, although considerable uncertainty remains as to how much material is processed
in situwithin these systems.
Sophie L. Nixon, Jon P. Telling, Jemma L. Wadham, and Charles S. Cockell
Biogeosciences, 14, 1445–1455, https://doi.org/10.5194/bg-14-1445-2017, https://doi.org/10.5194/bg-14-1445-2017, 2017
Short summary
Short summary
Despite their permanently cold and dark characteristics, subglacial environments (glacier ice–sediment interface) are known to harbour active microbial communities. However, the role of microbial iron cycling in these environments is poorly understood. Here we show that subglacial sediments harbour active iron-reducing microorganisms, and they appear to be cold-adapted. These results may have important implications for global biogeochemical iron cycling and export to marine ecosystems.
Jemma Louise Wadham, Jonathan Hawkings, Jon Telling, Dave Chandler, Jon Alcock, Emily O'Donnell, Preeti Kaur, Elizabeth Bagshaw, Martyn Tranter, Andre Tedstone, and Peter Nienow
Biogeosciences, 13, 6339–6352, https://doi.org/10.5194/bg-13-6339-2016, https://doi.org/10.5194/bg-13-6339-2016, 2016
Short summary
Short summary
Fjord and continental shelf environments in the polar regions are host to some of the planet's most productive ecosystems and support economically important fisheries. A key limiting nutrient for many of these marine phytoplankton is nitrogen. Here we evaluate the potential for a melting Greenland Ice Sheet to supply nitrogen to Arctic coastal ecosystems. We show nitrogen fluxes of a similar order of magnitude to one large Arctic river but yields that are double those typical of Arctic rivers.
James A. Bradley, Sandra Arndt, Marie Šabacká, Liane G. Benning, Gary L. Barker, Joshua J. Blacker, Marian L. Yallop, Katherine E. Wright, Christopher M. Bellas, Jonathan Telling, Martyn Tranter, and Alexandre M. Anesio
Biogeosciences, 13, 5677–5696, https://doi.org/10.5194/bg-13-5677-2016, https://doi.org/10.5194/bg-13-5677-2016, 2016
Short summary
Short summary
Soil development following glacier retreat was characterized using a novel integrated field, laboratory and modelling approach in Svalbard. We found community shifts in bacteria, which were responsible for driving cycles in carbon and nutrients. Allochthonous inputs were also important in sustaining bacterial production. This study shows how an integrated model–data approach can improve understanding and obtain a more holistic picture of soil development in an increasingly ice-free future world.
Robert Raiswell, Jon R. Hawkings, Liane G. Benning, Alex R. Baker, Ros Death, Samuel Albani, Natalie Mahowald, Michael D. Krom, Simon W. Poulton, Jemma Wadham, and Martyn Tranter
Biogeosciences, 13, 3887–3900, https://doi.org/10.5194/bg-13-3887-2016, https://doi.org/10.5194/bg-13-3887-2016, 2016
Short summary
Short summary
Iron is an essential nutrient for plankton growth. One important source of iron is wind-blown dust. The polar oceans are remote from dust sources but melting icebergs supply sediment that contains iron which is potentially available to plankton. We show that iceberg sediments contain more potentially bioavailable iron than wind-blown dust. Iceberg sources will become increasingly important with climate change and increased plankton growth can remove more carbon dioxide from the atmosphere.
D. M. Chandler, J. D. Alcock, J. L. Wadham, S. L. Mackie, and J. Telling
The Cryosphere, 9, 487–504, https://doi.org/10.5194/tc-9-487-2015, https://doi.org/10.5194/tc-9-487-2015, 2015
Short summary
Short summary
The Greenland Ice Sheet surface shows a diverse range of characteristics, and hosts active microbial communities in debris-rich ''cryoconite holes'' (CHs). Field and satellite data for a complete melt season revealed significant links between surface albedo, CH coverage and biological activity. This suggests satellites may be able to monitor CH biological processes. Nevertheless, caution is needed when extrapolating point measurements of biological processes to larger space and time scales.
E. C. Lawson, J. L. Wadham, M. Tranter, M. Stibal, G. P. Lis, C. E. H. Butler, J. Laybourn-Parry, P. Nienow, D. Chandler, and P. Dewsbury
Biogeosciences, 11, 4015–4028, https://doi.org/10.5194/bg-11-4015-2014, https://doi.org/10.5194/bg-11-4015-2014, 2014
R. Death, J. L. Wadham, F. Monteiro, A. M. Le Brocq, M. Tranter, A. Ridgwell, S. Dutkiewicz, and R. Raiswell
Biogeosciences, 11, 2635–2643, https://doi.org/10.5194/bg-11-2635-2014, https://doi.org/10.5194/bg-11-2635-2014, 2014
N. J. Cullen, P. Sirguey, T. Mölg, G. Kaser, M. Winkler, and S. J. Fitzsimons
The Cryosphere, 7, 419–431, https://doi.org/10.5194/tc-7-419-2013, https://doi.org/10.5194/tc-7-419-2013, 2013
Related subject area
Biogeochemistry: Organic Biogeochemistry
Latitudinal distribution of biomarkers across the western Arctic Ocean and the Bering Sea: an approach to assess sympagic and pelagic algal production
Sinking fate and carbon export of zooplankton fecal pellets: insights from time-series sediment trap observations in the northern South China Sea
Environmental controls on the brGDGT and brGMGT distributions across the Seine River basin (NW France): Implications for bacterial tetraethers as a proxy for riverine runoff
Low cobalt inventories in the Amundsen and Ross seas driven by high demand for labile cobalt uptake among native phytoplankton communities
Potential bioavailability of representative pyrogenic organic matter compounds in comparison to natural dissolved organic matter pools
Distributions of bacteriohopanepolyols in lakes and coastal lagoons of the Azores Archipelago
Recently fixed carbon fuels microbial activity several meters below the soil surface
Environmental and hydrologic controls on sediment and organic carbon export from a subalpine catchment: insights from a time series
Climate and geology overwrite land use effects on soil organic nitrogen cycling on a continental scale
Compositions of dissolved organic matter in the ice-covered waters above the Aurora hydrothermal vent system, Gakkel Ridge, Arctic Ocean
Organic matter characteristics of a rapidly eroding permafrost cliff in NE Siberia (Lena Delta, Laptev Sea region)
Microbial labilization and diversification of pyrogenic dissolved organic matter
Bacterial and eukaryotic intact polar lipids point to in situ production as a key source of labile organic matter in hadal surface sediment of the Atacama Trench
What can we learn from amino acids about oceanic organic matter cycling and degradation?
Bacteriohopanetetrol-x: constraining its application as a lipid biomarker for marine anammox using the water column oxygen gradient of the Benguela upwelling system
Active and passive fluxes of carbon, nitrogen, and phosphorus in the northern South China Sea
Cyanobacteria net community production in the Baltic Sea as inferred from profiling pCO2 measurements
Reviews and syntheses: Heterotrophic fixation of inorganic carbon – significant but invisible flux in environmental carbon cycling
Revised fractional abundances and warm-season temperatures substantially improve brGDGT calibrations in lake sediments
Archaeal intact polar lipids in polar waters: a comparison between the Amundsen and Scotia seas
Reproducible determination of dissolved organic matter photosensitivity
Technical note: Uncovering the influence of methodological variations on the extractability of iron-bound organic carbon
Anthropocene climate warming enhances autochthonous carbon cycling in an upland Arctic lake, Disko Island, West Greenland
Novel hydrocarbon-utilizing soil mycobacteria synthesize unique mycocerosic acids at a Sicilian everlasting fire
Alkenone isotopes show evidence of active carbon concentrating mechanisms in coccolithophores as aqueous carbon dioxide concentrations fall below 7 µmol L−1
Seasonal variability and sources of in situ brGDGT production in a permanently stratified African crater lake
Sediment release of dissolved organic matter to the oxygen minimum zone off Peru
Better molecular preservation of organic matter in an oxic than in a sulfidic depositional environment: evidence from Thalassiphora pelagica (Dinoflagellata, Eocene) cysts
Assessing branched tetraether lipids as tracers of soil organic carbon transport through the Carminowe Creek catchment (southwest England)
The nonconservative distribution pattern of organic matter in the Rajang, a tropical river with peatland in its estuary
Predominance of hexamethylated 6-methyl branched glycerol dialkyl glycerol tetraethers in the Mariana Trench: source and environmental implication
High-pH and anoxic conditions during soil organic matter extraction increases its electron-exchange capacity and ability to stimulate microbial Fe(III) reduction by electron shuttling
Sterol preservation in hypersaline microbial mats
Structural elucidation and environmental distributions of butanetriol and pentanetriol dialkyl glycerol tetraethers (BDGTs and PDGTs)
Distribution and degradation of terrestrial organic matter in the sediments of peat-draining rivers, Sarawak, Malaysian Borneo
Validation of carbon isotope fractionation in algal lipids as a pCO2 proxy using a natural CO2 seep (Shikine Island, Japan)
Composition and cycling of dissolved organic matter from tropical peatlands of coastal Sarawak, Borneo, revealed by fluorescence spectroscopy and parallel factor analysis
Latitudinal variations in δ30Si and δ15N signatures along the Peruvian shelf: quantifying the effects of nutrient utilization versus denitrification over the past 600 years
Diapycnal dissolved organic matter supply into the upper Peruvian oxycline
Composition and vertical flux of particulate organic matter to the oxygen minimum zone of the central Baltic Sea: impact of a sporadic North Sea inflow
Main drivers of transparent exopolymer particle distribution across the surface Atlantic Ocean
Biochemical and structural controls on the decomposition dynamics of boreal upland forest moss tissues
Spatiotemporal transformation of dissolved organic matter along an alpine stream flow path on the Qinghai–Tibet Plateau: importance of source and permafrost degradation
A quest for the biological sources of long chain alkyl diols in the western tropical North Atlantic Ocean
Long-chain diols in rivers: distribution and potential biological sources
Leaf wax n-alkanes in modern plants and topsoils from eastern Georgia (Caucasus) – implications for reconstructing regional paleovegetation
The role of diatom resting spores in pelagic–benthic coupling in the Southern Ocean
Calcium content and high calcium adaptation of plants in karst areas of southwestern Hunan, China
Substrate potential of last interglacial to Holocene permafrost organic matter for future microbial greenhouse gas production
Variation pattern of particulate organic carbon and nitrogen in oceans and inland waters
Youcheng Bai, Marie-Alexandrine Sicre, Jian Ren, Vincent Klein, Haiyan Jin, and Jianfang Chen
Biogeosciences, 21, 689–709, https://doi.org/10.5194/bg-21-689-2024, https://doi.org/10.5194/bg-21-689-2024, 2024
Short summary
Short summary
Algal biomarkers were used to assess sea ice and pelagic algal production across the western Arctic Ocean with changing sea-ice conditions. They show three distinct areas along with a marked latitudinal gradient of sea ice over pelagic algal production in surface sediments that are reflected by the H-Print index. Our data also show that efficient grazing consumption accounted for the dramatic decrease of diatom-derived biomarkers in sediments compared to that of particulate matter.
Hanxiao Wang, Zhifei Liu, Jiaying Li, Baozhi Lin, Yulong Zhao, Xiaodong Zhang, Junyuan Cao, Jingwen Zhang, Hongzhe Song, and Wenzhuo Wang
Biogeosciences, 20, 5109–5123, https://doi.org/10.5194/bg-20-5109-2023, https://doi.org/10.5194/bg-20-5109-2023, 2023
Short summary
Short summary
The sinking of zooplankton fecal pellets is a key process in the marine biological carbon pump. This study presents carbon export of four shapes of fecal pellets from two time-series sediment traps in the South China Sea. The results show that the sinking fate of fecal pellets is regulated by marine primary productivity, deep-dwelling zooplankton community, and deep-sea currents in the tropical marginal sea, thus providing a new perspective for exploring the carbon cycle in the world ocean.
Zhe-Xuan Zhang, Edith Parlanti, Christelle Anquetil, Jérôme Morelle, Anniet Laverman, Alexandre Thibault, Elisa Bou, and Arnaud Huguet
EGUsphere, https://doi.org/10.31223/X5PQ17, https://doi.org/10.31223/X5PQ17, 2023
Short summary
Short summary
Bacterial tetraethers have important implications for palaeoclimate reconstruction. However, fundamental understanding of how these lipids are transformed from land to sea and which environmental factors influence their distributions is lacking. Here, we investigate the sources of brGDGTs and brGMGTs and the factors controlling their distributions in a large dataset (n=237). We propose a novel proxy to trace riverine runoff, which is applicable in modern systems and in paleorecord.
Rebecca J. Chmiel, Riss M. Kell, Deepa Rao, Dawn M. Moran, Giacomo R. DiTullio, and Mak A. Saito
Biogeosciences, 20, 3997–4027, https://doi.org/10.5194/bg-20-3997-2023, https://doi.org/10.5194/bg-20-3997-2023, 2023
Short summary
Short summary
Cobalt is an important micronutrient for plankton, yet it is often scarce throughout the oceans. A 2017/2018 expedition to coastal Antarctica, including regions of the Amundsen Sea and the Ross Sea, discovered lower concentrations of cobalt compared to two past expeditions in 2005 and 2006, particularly for the type of cobalt preferred as a nutrient by phytoplankton. This loss may be due to changing inputs of other nutrients, causing higher uptake of cobalt by plankton over the last decade.
Emily B. Graham, Hyun-Seob Song, Samantha Grieger, Vanessa A. Garayburu-Caruso, James C. Stegen, Kevin D. Bladon, and Allison N. Myers-Pigg
Biogeosciences, 20, 3449–3457, https://doi.org/10.5194/bg-20-3449-2023, https://doi.org/10.5194/bg-20-3449-2023, 2023
Short summary
Short summary
Intensifying wildfires are increasing pyrogenic organic matter (PyOM) production and its impact on water quality. Recent work indicates that PyOM may have a greater impact on aquatic biogeochemistry than previously assumed, driven by higher bioavailability. We provide a full assessment of the potential bioavailability of PyOM across its chemical spectrum. We indicate that PyOM can be actively transformed within the river corridor and, therefore, may be a growing source of riverine C emissions.
Nora Richter, Ellen C. Hopmans, Danica Mitrović, Pedro M. Raposeiro, Vítor Gonçalves, Ana C. Costa, Linda A. Amaral-Zettler, Laura Villanueva, and Darci Rush
Biogeosciences, 20, 2065–2098, https://doi.org/10.5194/bg-20-2065-2023, https://doi.org/10.5194/bg-20-2065-2023, 2023
Short summary
Short summary
Bacteriohopanepolyols (BHPs) are a diverse class of lipids produced by bacteria across a wide range of environments. This study characterizes the diversity of BHPs in lakes and coastal lagoons in the Azores Archipelago, as well as a co-culture enriched for methanotrophs. We highlight the potential of BHPs as taxonomic markers for bacteria associated with certain ecological niches, which can be preserved in sedimentary records.
Andrea Scheibe, Carlos A. Sierra, and Marie Spohn
Biogeosciences, 20, 827–838, https://doi.org/10.5194/bg-20-827-2023, https://doi.org/10.5194/bg-20-827-2023, 2023
Short summary
Short summary
We explored carbon cycling in soils in three climate zones in Chile down to a depth of 6 m, using carbon isotopes. Our results show that microbial activity several meters below the soil surface is mostly fueled by recently fixed carbon and that strong decomposition of soil organic matter only occurs in the upper decimeters of the soils. The study shows that different layers of the critical zone are tightly connected and that processes in the deep soil depend on recently fixed carbon.
Melissa Sophia Schwab, Hannah Gies, Chantal Valérie Freymond, Maarten Lupker, Negar Haghipour, and Timothy Ian Eglinton
Biogeosciences, 19, 5591–5616, https://doi.org/10.5194/bg-19-5591-2022, https://doi.org/10.5194/bg-19-5591-2022, 2022
Short summary
Short summary
The majority of river studies focus on headwater or floodplain systems, while often neglecting intermediate river segments. Our study on the subalpine Sihl River bridges the gap between streams and lowlands and demonstrates that moderately steep river segments are areas of significant instream alterations, modulating the export of organic carbon over short distances.
Lisa Noll, Shasha Zhang, Qing Zheng, Yuntao Hu, Florian Hofhansl, and Wolfgang Wanek
Biogeosciences, 19, 5419–5433, https://doi.org/10.5194/bg-19-5419-2022, https://doi.org/10.5194/bg-19-5419-2022, 2022
Short summary
Short summary
Cleavage of proteins to smaller nitrogen compounds allows microorganisms and plants to exploit the largest nitrogen reservoir in soils and is considered the bottleneck in soil organic nitrogen cycling. Results from soils covering a European transect show that protein turnover is constrained by soil geochemistry, shifts in climate and associated alterations in soil weathering and should be considered as a driver of soil nitrogen availability with repercussions on carbon cycle processes.
Muhammed Fatih Sert, Helge Niemann, Eoghan P. Reeves, Mats A. Granskog, Kevin P. Hand, Timo Kekäläinen, Janne Jänis, Pamela E. Rossel, Bénédicte Ferré, Anna Silyakova, and Friederike Gründger
Biogeosciences, 19, 2101–2120, https://doi.org/10.5194/bg-19-2101-2022, https://doi.org/10.5194/bg-19-2101-2022, 2022
Short summary
Short summary
We investigate organic matter composition in the Arctic Ocean water column. We collected seawater samples from sea ice to deep waters at six vertical profiles near an active hydrothermal vent and its plume. In comparison to seawater, we found that the organic matter in waters directly affected by the hydrothermal plume had different chemical composition. We suggest that hydrothermal processes may influence the organic matter distribution in the deep ocean.
Charlotte Haugk, Loeka L. Jongejans, Kai Mangelsdorf, Matthias Fuchs, Olga Ogneva, Juri Palmtag, Gesine Mollenhauer, Paul J. Mann, P. Paul Overduin, Guido Grosse, Tina Sanders, Robyn E. Tuerena, Lutz Schirrmeister, Sebastian Wetterich, Alexander Kizyakov, Cornelia Karger, and Jens Strauss
Biogeosciences, 19, 2079–2094, https://doi.org/10.5194/bg-19-2079-2022, https://doi.org/10.5194/bg-19-2079-2022, 2022
Short summary
Short summary
Buried animal and plant remains (carbon) from the last ice age were freeze-locked in permafrost. At an extremely fast eroding permafrost cliff in the Lena Delta (Siberia), we found this formerly frozen carbon well preserved. Our results show that ongoing degradation releases substantial amounts of this carbon, making it available for future carbon emissions. This mobilisation at the studied cliff and also similarly eroding sites bear the potential to affect rivers and oceans negatively.
Aleksandar I. Goranov, Andrew S. Wozniak, Kyle W. Bostick, Andrew R. Zimmerman, Siddhartha Mitra, and Patrick G. Hatcher
Biogeosciences, 19, 1491–1514, https://doi.org/10.5194/bg-19-1491-2022, https://doi.org/10.5194/bg-19-1491-2022, 2022
Short summary
Short summary
Wildfire-derived molecules are ubiquitous in the aquatic environment, but their biological fate remains understudied. We have evaluated the compositional changes that occur to wildfire-derived molecules after incubation with soil microbes. We observe a significant degradation but also a production of numerous new labile molecules. Our results indicate that wildfire-derived molecules can be broken down and the carbon and nitrogen therein can be incorporated into microbial food webs.
Edgart Flores, Sebastian I. Cantarero, Paula Ruiz-Fernández, Nadia Dildar, Matthias Zabel, Osvaldo Ulloa, and Julio Sepúlveda
Biogeosciences, 19, 1395–1420, https://doi.org/10.5194/bg-19-1395-2022, https://doi.org/10.5194/bg-19-1395-2022, 2022
Short summary
Short summary
In this study, we investigate the chemical diversity and abundance of microbial lipids as markers of organic matter sources in the deepest points of the Atacama Trench sediments and compare them to similar lipid stocks in shallower surface sediments and in the overlying water column. We evaluate possible organic matter provenance and some potential chemical adaptations of the in situ microbial community to the extreme conditions of high hydrostatic pressure in hadal realm.
Birgit Gaye, Niko Lahajnar, Natalie Harms, Sophie Anna Luise Paul, Tim Rixen, and Kay-Christian Emeis
Biogeosciences, 19, 807–830, https://doi.org/10.5194/bg-19-807-2022, https://doi.org/10.5194/bg-19-807-2022, 2022
Short summary
Short summary
Amino acids were analyzed in a large number of samples of particulate and dissolved organic matter from coastal regions and the open ocean. A statistical analysis produced two new biogeochemical indicators. An indicator of sinking particle and sediment degradation (SDI) traces the degradation of organic matter from the surface waters into the sediments. A second indicator shows the residence time of suspended matter in the ocean (RTI).
Zoë R. van Kemenade, Laura Villanueva, Ellen C. Hopmans, Peter Kraal, Harry J. Witte, Jaap S. Sinninghe Damsté, and Darci Rush
Biogeosciences, 19, 201–221, https://doi.org/10.5194/bg-19-201-2022, https://doi.org/10.5194/bg-19-201-2022, 2022
Short summary
Short summary
Anaerobic ammonium oxidation (anammox) is an important nitrogen-removal process in the ocean. We assess the distribution of bacteriohopanetetrol-x (BHT-x), used to trace past anammox, along a redox gradient in the water column of the Benguela upwelling system. BHT-x / BHT ratios of >0.18 correspond to the presence of living anammox bacteria and oxygen levels <50 μmol L−1. This allows for a more robust application of BHT-x to trace past marine anammox and deoxygenation in dynamic marine systems.
Jia-Jang Hung, Ching-Han Tung, Zong-Ying Lin, Yuh-ling Lee Chen, Shao-Hung Peng, Yen-Huei Lin, and Li-Shan Tsai
Biogeosciences, 18, 5141–5162, https://doi.org/10.5194/bg-18-5141-2021, https://doi.org/10.5194/bg-18-5141-2021, 2021
Short summary
Short summary
We report measured active and passive fluxes and their controlling mechanisms in the northern South China Sea (NSCS). The total fluxes were higher than most reports in open oceans, indicating the significance of NSCS in atmospheric CO2 uptake and in storing that CO2 in the ocean’s interior. Winter cooling and extreme events enhanced nutrient availability and elevated fluxes. Global warming may have profound impacts on reducing ocean’s uptake and storage of CO2 in subtropical–tropical oceans.
Jens Daniel Müller, Bernd Schneider, Ulf Gräwe, Peer Fietzek, Marcus Bo Wallin, Anna Rutgersson, Norbert Wasmund, Siegfried Krüger, and Gregor Rehder
Biogeosciences, 18, 4889–4917, https://doi.org/10.5194/bg-18-4889-2021, https://doi.org/10.5194/bg-18-4889-2021, 2021
Short summary
Short summary
Based on profiling pCO2 measurements from a field campaign, we quantify the biomass production of a cyanobacteria bloom in the Baltic Sea, the export of which would foster deep water deoxygenation. We further demonstrate how this biomass production can be accurately reconstructed from long-term surface measurements made on cargo vessels in combination with modelled temperature profiles. This approach enables a better understanding of a severe concern for the Baltic’s good environmental status.
Alexander Braun, Marina Spona-Friedl, Maria Avramov, Martin Elsner, Federico Baltar, Thomas Reinthaler, Gerhard J. Herndl, and Christian Griebler
Biogeosciences, 18, 3689–3700, https://doi.org/10.5194/bg-18-3689-2021, https://doi.org/10.5194/bg-18-3689-2021, 2021
Short summary
Short summary
It is known that CO2 fixation by photoautotrophic organisms is the major sink from the atmosphere. While biologists are aware that CO2 fixation also occurs in heterotrophic organisms, this route of inorganic carbon, and its quantitative role, is hardly recognized in biogeochemistry. We demonstrate that a considerable amount of CO2 is fixed annually through anaplerotic reactions in heterotrophic organisms, and a significant quantity of inorganic carbon is temporally sequestered in biomass.
Jonathan H. Raberg, David J. Harning, Sarah E. Crump, Greg de Wet, Aria Blumm, Sebastian Kopf, Áslaug Geirsdóttir, Gifford H. Miller, and Julio Sepúlveda
Biogeosciences, 18, 3579–3603, https://doi.org/10.5194/bg-18-3579-2021, https://doi.org/10.5194/bg-18-3579-2021, 2021
Short summary
Short summary
BrGDGT lipids are a proxy for temperature in lake sediments, but other parameters like pH can influence them, and seasonality can affect the temperatures they record. We find a warm-season bias at 43 new high-latitude sites. We also present a new method that deconvolves the effects of temperature, pH, and conductivity and generate global calibrations for these variables. Our study provides new paleoclimate tools, insight into brGDGTs at the biochemical level, and a new method for future study.
Charlotte L. Spencer-Jones, Erin L. McClymont, Nicole J. Bale, Ellen C. Hopmans, Stefan Schouten, Juliane Müller, E. Povl Abrahamsen, Claire Allen, Torsten Bickert, Claus-Dieter Hillenbrand, Elaine Mawbey, Victoria Peck, Aleksandra Svalova, and James A. Smith
Biogeosciences, 18, 3485–3504, https://doi.org/10.5194/bg-18-3485-2021, https://doi.org/10.5194/bg-18-3485-2021, 2021
Short summary
Short summary
Long-term ocean temperature records are needed to fully understand the impact of West Antarctic Ice Sheet collapse. Glycerol dialkyl glycerol tetraethers (GDGTs) are powerful tools for reconstructing ocean temperature but can be difficult to apply to the Southern Ocean. Our results show active GDGT synthesis in relatively warm depths of the ocean. This research improves the application of GDGT palaeoceanographic proxies in the Southern Ocean.
Alec W. Armstrong, Leanne Powers, and Michael Gonsior
Biogeosciences, 18, 3367–3390, https://doi.org/10.5194/bg-18-3367-2021, https://doi.org/10.5194/bg-18-3367-2021, 2021
Short summary
Short summary
Living things decay into organic matter, which can dissolve into water (like tea brewing). Tea receives its color by absorbing light. Similarly, this material absorbs light, which can then cause chemical reactions that change it. By measuring changes in these optical properties, we found that materials from some places are more sensitive to light than others. Comparing sensitivity to light helps us understand where these materials come from and what happens as they move through water.
Ben J. Fisher, Johan C. Faust, Oliver W. Moore, Caroline L. Peacock, and Christian März
Biogeosciences, 18, 3409–3419, https://doi.org/10.5194/bg-18-3409-2021, https://doi.org/10.5194/bg-18-3409-2021, 2021
Short summary
Short summary
Organic carbon can be protected from microbial degradation in marine sediments through association with iron minerals on 1000-year timescales. Despite the importance of this carbon sink, our spatial and temporal understanding of iron-bound organic carbon interactions globally is poor. Here we show that caution must be applied when comparing quantification of iron-bound organic carbon extracted by different methods as the extraction strength and method specificity can be highly variable.
Mark A. Stevenson, Suzanne McGowan, Emma J. Pearson, George E. A. Swann, Melanie J. Leng, Vivienne J. Jones, Joseph J. Bailey, Xianyu Huang, and Erika Whiteford
Biogeosciences, 18, 2465–2485, https://doi.org/10.5194/bg-18-2465-2021, https://doi.org/10.5194/bg-18-2465-2021, 2021
Short summary
Short summary
We link detailed stable isotope and biomarker analyses from the catchments of three Arctic upland lakes on Disko Island (West Greenland) to a recent dated sediment core to understand how carbon cycling has changed over the past ~500 years. We find that the carbon deposited in sediments in these upland lakes is predominately sourced from in-lake production due to the catchment's limited terrestrial vegetation and elevation and that recent increases in algal production link with climate change.
Nadine T. Smit, Laura Villanueva, Darci Rush, Fausto Grassa, Caitlyn R. Witkowski, Mira Holzheimer, Adriaan J. Minnaard, Jaap S. Sinninghe Damsté, and Stefan Schouten
Biogeosciences, 18, 1463–1479, https://doi.org/10.5194/bg-18-1463-2021, https://doi.org/10.5194/bg-18-1463-2021, 2021
Short summary
Short summary
Soils from an everlasting fire (gas seep) in Sicily, Italy, reveal high relative abundances of novel uncultivated mycobacteria and unique 13C-depleted mycocerosic acids (multi-methyl branched fatty acids) close to the main gas seep. Our results imply that mycocerosic acids in combination with their depleted δ13C values offer a new biomarker tool to study the role of soil mycobacteria as hydrocarbon consumers in the modern and past global carbon cycle.
Marcus P. S. Badger
Biogeosciences, 18, 1149–1160, https://doi.org/10.5194/bg-18-1149-2021, https://doi.org/10.5194/bg-18-1149-2021, 2021
Short summary
Short summary
Reconstructing ancient atmospheric CO2 is an important aim of palaeoclimate science in order to understand the Earth's climate system. One method, the alkenone proxy based on molecular fossils of coccolithophores, has been recently shown to be ineffective at low-to-moderate CO2 levels. In this paper I show that this is likely due to changes in the biogeochemistry of the coccolithophores when there is low carbon availability, but for much of the Cenozoic the alkenone proxy should have utility.
Loes G. J. van Bree, Francien Peterse, Allix J. Baxter, Wannes De Crop, Sigrid van Grinsven, Laura Villanueva, Dirk Verschuren, and Jaap S. Sinninghe Damsté
Biogeosciences, 17, 5443–5463, https://doi.org/10.5194/bg-17-5443-2020, https://doi.org/10.5194/bg-17-5443-2020, 2020
Short summary
Short summary
Branched glycerol dialkyl glycerol tetraethers (brGDGTs) are used as a paleothermometer based on their temperature dependence in global soils, but aquatic production complicates their use in lakes. BrGDGTs in the water column of Lake Chala, East Africa, respond to oxygen conditions and mixing. Changes in their signal can be linked to bacterial community composition rather than membrane adaptation to changing conditions. Their integrated signal in the sediment reflects mean air temperature.
Alexandra N. Loginova, Andrew W. Dale, Frédéric A. C. Le Moigne, Sören Thomsen, Stefan Sommer, David Clemens, Klaus Wallmann, and Anja Engel
Biogeosciences, 17, 4663–4679, https://doi.org/10.5194/bg-17-4663-2020, https://doi.org/10.5194/bg-17-4663-2020, 2020
Short summary
Short summary
We measured dissolved organic carbon (DOC), nitrogen (DON) and matter (DOM) optical properties in pore waters and near-bottom waters of the eastern tropical South Pacific off Peru. The difference between diffusion-driven and net fluxes of DOC and DON and qualitative changes in DOM optical properties suggested active microbial utilisation of the released DOM at the sediment–water interface. Our results suggest that the sediment release of DOM contributes to microbial processes in the area.
Gerard J. M. Versteegh, Alexander J. P. Houben, and Karin A. F. Zonneveld
Biogeosciences, 17, 3545–3561, https://doi.org/10.5194/bg-17-3545-2020, https://doi.org/10.5194/bg-17-3545-2020, 2020
Short summary
Short summary
Anoxic sediments mostly contain much more organic matter than oxic ones, and therefore organic matter in anoxic settings is often considered to be preserved better than in oxic settings. However, through the analysis of the same fossil dinoflagellate cyst species from both oxic and anoxic settings, we show that at a molecular level the preservation in the oxic sediments may be better since in the anoxic setting the cyst macromolecule has been altered by postdepositional modification.
Jingjing Guo, Miriam Glendell, Jeroen Meersmans, Frédérique Kirkels, Jack J. Middelburg, and Francien Peterse
Biogeosciences, 17, 3183–3201, https://doi.org/10.5194/bg-17-3183-2020, https://doi.org/10.5194/bg-17-3183-2020, 2020
Short summary
Short summary
The fluxes of soil organic carbon (OC) transport from land to sea are poorly constrained, mostly due to the lack of a specific tracer for soil OC. Here we evaluate the use of specific molecules derived from soil bacteria as a tracer for soil OC in a small river catchment. We find that the initial soil signal is lost upon entering the aquatic environment. However, the local environmental history of the catchment is reflected by these molecules in the lake sediments that act as their sink.
Zhuo-Yi Zhu, Joanne Oakes, Bradley Eyre, Youyou Hao, Edwin Sien Aun Sia, Shan Jiang, Moritz Müller, and Jing Zhang
Biogeosciences, 17, 2473–2485, https://doi.org/10.5194/bg-17-2473-2020, https://doi.org/10.5194/bg-17-2473-2020, 2020
Short summary
Short summary
Samples were collected in August 2016 in the Rajang River and its estuary, with tropical forest in the river basin and peatland in the estuary. Organic matter composition was influenced by transportation in the river basin, whereas peatland added clear biodegraded parts to the fluvial organic matter, which implies modification of the initial lability and/or starting points in the subsequent degradation and alternation processes after the organic matter enters the sea.
Wenjie Xiao, Yasong Wang, Yongsheng Liu, Xi Zhang, Linlin Shi, and Yunping Xu
Biogeosciences, 17, 2135–2148, https://doi.org/10.5194/bg-17-2135-2020, https://doi.org/10.5194/bg-17-2135-2020, 2020
Short summary
Short summary
The hadal zone (6–11 km depth) is the least explored habitat on Earth. We studied microbial branched glycerol dialkyl glycerol tetraethers (brGDGTs) in the Challenger Deep, Mariana Trench. One unique feature is the strong predominance of 6-methyl brGDGT, which likely reflects an adaption of brGDGT-producing bacteria to alkaline seawater and low temperature. BrGDGTs, with elemental and isotopic data, suggest an autochthonous product for brGDGT. A new approach is proposed for brGDGT sourcing.
Yuge Bai, Edisson Subdiaga, Stefan B. Haderlein, Heike Knicker, and Andreas Kappler
Biogeosciences, 17, 683–698, https://doi.org/10.5194/bg-17-683-2020, https://doi.org/10.5194/bg-17-683-2020, 2020
Short summary
Short summary
Biogeochemical processes of SOM are key for greenhouse gas emission and water quality. We extracted SOM by water or by NaOH–HCl under oxic–anoxic conditions. Chemical and anoxic extractions lead to higher SOM electron exchange capacities, resulting in stimulation of microbial Fe(III) reduction. Therefore, aqueous pH-neutral SOM extracts should be used to reflect environmental SOM redox processes, and artifacts of chemical extractions need to be considered when evaluating SOM redox processes.
Yan Shen, Volker Thiel, Pablo Suarez-Gonzalez, Sebastiaan W. Rampen, and Joachim Reitner
Biogeosciences, 17, 649–666, https://doi.org/10.5194/bg-17-649-2020, https://doi.org/10.5194/bg-17-649-2020, 2020
Short summary
Short summary
Today, sterols are widespread in plants, animals, and fungi but are almost absent in the oldest rocks. Microbial mats, representing the earliest complex ecosystems on Earth, were omnipresent in Precambrian marine environments and may have degraded the sterols at that time. Here we analyze the distribution of sterols through a microbial mat. This provides insight into how variations in biological and nonbiological factors affect the preservation of sterols in modern and ancient microbial mats.
Sarah Coffinet, Travis B. Meador, Lukas Mühlena, Kevin W. Becker, Jan Schröder, Qing-Zeng Zhu, Julius S. Lipp, Verena B. Heuer, Matthew P. Crump, and Kai-Uwe Hinrichs
Biogeosciences, 17, 317–330, https://doi.org/10.5194/bg-17-317-2020, https://doi.org/10.5194/bg-17-317-2020, 2020
Short summary
Short summary
This study deals with two membrane lipids called BDGTs and PDGTs. Membrane lipids are molecules forming the cell envelope of all organisms. Different organisms produce different lipids thus they can be used to detect the presence of specific organisms in the environment. We analyzed the structure of these new lipids and looked for potential producers. We found that they are likely made by microbes emitting methane below the sediment surface and could be used to track these specific microbes.
Ying Wu, Kun Zhu, Jing Zhang, Moritz Müller, Shan Jiang, Aazani Mujahid, Mohd Fakharuddin Muhamad, and Edwin Sien Aun Sia
Biogeosciences, 16, 4517–4533, https://doi.org/10.5194/bg-16-4517-2019, https://doi.org/10.5194/bg-16-4517-2019, 2019
Short summary
Short summary
Our understanding of terrestrial organic matter (TOM) in tropical peat-draining rivers remains limited, especially in Southeast Asia. We explored the characteristics of TOM via bulk parameters and lignin phenols of sediment in Malaysia. This showed that the most important plant source of the organic matter in these rivers is woody angiosperm C3 plants with limited diagenetic alteration. This slower degradation of TOM may be a link to higher total nitrogen content, especially for the small river.
Caitlyn R. Witkowski, Sylvain Agostini, Ben P. Harvey, Marcel T. J. van der Meer, Jaap S. Sinninghe Damsté, and Stefan Schouten
Biogeosciences, 16, 4451–4461, https://doi.org/10.5194/bg-16-4451-2019, https://doi.org/10.5194/bg-16-4451-2019, 2019
Short summary
Short summary
Carbon dioxide concentrations (pCO2) in the atmosphere play an integral role in Earth system dynamics, especially climate. Past climates help us understand future ones, but reconstructing pCO2 over the geologic record remains a challenge. This research demonstrates new approaches for exploring past pCO2 via the carbon isotope fractionation in general algal lipids, which we test over a high CO2 gradient from a naturally occurring CO2 seep.
Yongli Zhou, Patrick Martin, and Moritz Müller
Biogeosciences, 16, 2733–2749, https://doi.org/10.5194/bg-16-2733-2019, https://doi.org/10.5194/bg-16-2733-2019, 2019
Short summary
Short summary
We found that peatlands in coastal Sarawak, Borneo, export extremely humified organic matter, which dominates the riverine organic matter pool and conservatively mixes with seawater, while the freshly produced fraction is low and stable in concentration at all salinities. We estimated that terrigenous fractions, which showed high photolability, still account for 20 % of the coastal dissolved organic carbon pool, implying the importance of peat-derived organic matter in the coastal carbon cycle.
Kristin Doering, Claudia Ehlert, Philippe Martinez, Martin Frank, and Ralph Schneider
Biogeosciences, 16, 2163–2180, https://doi.org/10.5194/bg-16-2163-2019, https://doi.org/10.5194/bg-16-2163-2019, 2019
Alexandra N. Loginova, Sören Thomsen, Marcus Dengler, Jan Lüdke, and Anja Engel
Biogeosciences, 16, 2033–2047, https://doi.org/10.5194/bg-16-2033-2019, https://doi.org/10.5194/bg-16-2033-2019, 2019
Short summary
Short summary
High primary production in the Peruvian upwelling system is followed by rapid heterotrophic utilization of organic matter and supports the formation of one of the most intense oxygen minimum zones (OMZs) in the world. Here, we estimated vertical fluxes of oxygen and dissolved organic matter (DOM) from the surface to the OMZ. Our results suggest that DOM remineralization substantially reduces oxygen concentration in the upper water column and controls the shape of the upper oxycline.
Carolina Cisternas-Novoa, Frédéric A. C. Le Moigne, and Anja Engel
Biogeosciences, 16, 927–947, https://doi.org/10.5194/bg-16-927-2019, https://doi.org/10.5194/bg-16-927-2019, 2019
Short summary
Short summary
We investigate the composition and vertical fluxes of POM in two deep basins of the Baltic Sea (GB: Gotland Basin and LD: Landsort Deep). The two basins showed different O2 regimes resulting from the intrusion of oxygen-rich water from the North Sea that ventilated the deep waters in GB, but not in LD.
In GB, O2 intrusions lead to a high abundance of manganese oxides that aggregate with POM, altering its composition and vertical flux and contributing to a higher POC transfer efficiency in GB.
Marina Zamanillo, Eva Ortega-Retuerta, Sdena Nunes, Pablo Rodríguez-Ros, Manuel Dall'Osto, Marta Estrada, Maria Montserrat Sala, and Rafel Simó
Biogeosciences, 16, 733–749, https://doi.org/10.5194/bg-16-733-2019, https://doi.org/10.5194/bg-16-733-2019, 2019
Short summary
Short summary
Many marine microorganisms produce polysaccharide-rich transparent exopolymer particles (TEPs) for rather unknown reasons but with important consequences for the ocean carbon cycle, sea–air gas exchange and formation of organic aerosols. Here we compare surface–ocean distributions of TEPs and physical, chemical and biological variables along a N–S transect in the Atlantic Ocean. Our data suggest that phytoplankton and not bacteria are the main TEP producers, and solar radiation acts as a sink.
Michael Philben, Sara Butler, Sharon A. Billings, Ronald Benner, Kate A. Edwards, and Susan E. Ziegler
Biogeosciences, 15, 6731–6746, https://doi.org/10.5194/bg-15-6731-2018, https://doi.org/10.5194/bg-15-6731-2018, 2018
Short summary
Short summary
We explored the relationship between chemical composition and the temperature sensitivity of moss decomposition using 959-day lab incubations. Mass loss was low despite the predominance of carbohydrates, indicating the persistence of labile C. Scanning electron microscopy revealed little change in the moss cell-wall structure. These results suggest that the moss cell-wall matrix protects labile C from decomposition, contributing to the globally important stocks of moss-derived C.
Yinghui Wang, Robert G. M. Spencer, David C. Podgorski, Anne M. Kellerman, Harunur Rashid, Phoebe Zito, Wenjie Xiao, Dandan Wei, Yuanhe Yang, and Yunping Xu
Biogeosciences, 15, 6637–6648, https://doi.org/10.5194/bg-15-6637-2018, https://doi.org/10.5194/bg-15-6637-2018, 2018
Short summary
Short summary
With global warming, thawing of permafrost releases dissolved organic matter (DOM) into streams. By analyzing DOM along an alpine stream on the Qinghai–Tibet Plateau, we found DOM was mainly from the active layer, but with deepening of the active layer, the contribution of the deep permafrost layer increased, causing a change in the chemical composition of DOM. From the head- to downstream, DOM is undergoing rapid degradation, but some components are persistent and can be transported downstream.
Sergio Balzano, Julie Lattaud, Laura Villanueva, Sebastiaan W. Rampen, Corina P. D. Brussaard, Judith van Bleijswijk, Nicole Bale, Jaap S. Sinninghe Damsté, and Stefan Schouten
Biogeosciences, 15, 5951–5968, https://doi.org/10.5194/bg-15-5951-2018, https://doi.org/10.5194/bg-15-5951-2018, 2018
Short summary
Short summary
We tried to identify the microbes which biosynthesize a class of lipids widespread in seawater, the long chain alkyl diols (LCDs). We could not find any microorganism likely involved in the production of LCDs. The amounts of LCDs found are too high to be produced by living organisms and are likely to be part of the refractory organic matter persisting for long periods in the water column.
Julie Lattaud, Frédérique Kirkels, Francien Peterse, Chantal V. Freymond, Timothy I. Eglinton, Jens Hefter, Gesine Mollenhauer, Sergio Balzano, Laura Villanueva, Marcel T. J. van der Meer, Ellen C. Hopmans, Jaap S. Sinninghe Damsté, and Stefan Schouten
Biogeosciences, 15, 4147–4161, https://doi.org/10.5194/bg-15-4147-2018, https://doi.org/10.5194/bg-15-4147-2018, 2018
Short summary
Short summary
Long-chain diols (LCDs) are biomarkers that occur widespread in marine environments and also in lakes and rivers. In this study, we looked at the distribution of LCDs in three river systems (Godavari, Danube, and Rhine) in relation to season, precipitation, and temperature. We found out that the LCDs are likely being produced in calm areas of the river systems and that marine LCDs have a different distribution than riverine LCDs.
Marcel Bliedtner, Imke K. Schäfer, Roland Zech, and Hans von Suchodoletz
Biogeosciences, 15, 3927–3936, https://doi.org/10.5194/bg-15-3927-2018, https://doi.org/10.5194/bg-15-3927-2018, 2018
Short summary
Short summary
In this study, we systematically analyze leaf wax derived n-alkane patterns in eastern Georgia to test their potential for paleoenvironmental reconstructions in the semi-humid to semi-arid central southern Caucasus region. We investigated the influence of vegetation types on the leaf wax signal in modern plants and topsoil material. Our results show distinct and systematic differences in the n-alkane patterns between vegetation types and prove their potential for vegetation reconstructions.
Mathieu Rembauville, Stéphane Blain, Clara Manno, Geraint Tarling, Anu Thompson, George Wolff, and Ian Salter
Biogeosciences, 15, 3071–3084, https://doi.org/10.5194/bg-15-3071-2018, https://doi.org/10.5194/bg-15-3071-2018, 2018
Short summary
Short summary
Sinking phytoplankton from the surface ocean provide the principal energy source to deep-ocean ecosystems. Our aim was to understand how different phytoplankton communities impact the chemical nature of this sinking material. We show certain types of phytoplankton can preferentially export energy-rich storage compounds to the seafloor. Any climate-driven effects on phytoplankton community structure could thus impact remote deep-ocean ecosystems thousands of kilometres beneath the surface.
Xiaocong Wei, Xiangwen Deng, Wenhua Xiang, Pifeng Lei, Shuai Ouyang, Hongfang Wen, and Liang Chen
Biogeosciences, 15, 2991–3002, https://doi.org/10.5194/bg-15-2991-2018, https://doi.org/10.5194/bg-15-2991-2018, 2018
Short summary
Short summary
Karst is a kind of typical calcium-rich environment, which is widely distributed. We measured the Ca2+ content of 41 plant species, as well as soil total Ca2+ and exchange Ca2+. We found out that different plants have different ways to high Ca2+ adaptation. According to the different high Ca2+ adaptation of the 17 dominant species, we divided them into 3 categories: Ca-indifferent plants, high-Ca plants and low-Ca plants. Our results can provide a theoretical basis for vegetation restoration.
Janina G. Stapel, Georg Schwamborn, Lutz Schirrmeister, Brian Horsfield, and Kai Mangelsdorf
Biogeosciences, 15, 1969–1985, https://doi.org/10.5194/bg-15-1969-2018, https://doi.org/10.5194/bg-15-1969-2018, 2018
Short summary
Short summary
Climate warming in the Arctic results in thawing of permafrost deposits. This promotes the accessibility of freeze-locked old organic matter (OM) accumulated during the past. Characterizing OM of different depositional ages, we were able to show that OM from last glacial Yedoma deposits possess the highest potential to provide organic substrates such as acetate for microbial greenhouse gas production and therefore to accelerate the carbon–climate feedback cycle during ongoing global warming.
Changchun Huang, Quanliang Jiang, Ling Yao, Hao Yang, Chen Lin, Tao Huang, A-Xing Zhu, and Yimin Zhang
Biogeosciences, 15, 1827–1841, https://doi.org/10.5194/bg-15-1827-2018, https://doi.org/10.5194/bg-15-1827-2018, 2018
Short summary
Short summary
The latitudinal dependency of POC / PON in ocean and inland water is significant, regulated by trophic state and climate, etc. factors. POC / PON significantly increased from coastal water (6.89 ± 2.38) to open ocean (7.59 ± 4.22) with the increasing rate of 0.0024 / km. The re-examination of the global relationship between, and variations in, POC and PON could be important for the global and regional coupling between the carbon and nitrogen cycles in the ocean and freshwater.
Cited articles
Anesio, A. M., Hodson, A. J., Fritz, A., Psenner, R., and Sattler, B.: High microbial activity on glaciers: importance to the global carbon cycle, Global Change Biol., 15, 955–960, https://doi.org/10.1111/j.1365-2486.2008.01758.x, 2009.
Barker, J. D., Sharp, M. J., Fitzsimons, S. J., and Turner, R. J.: Abundance and dynamics of dissolved organic carbon in glacier systems, Arct. Antarct. Alp. Res., 38, 163–172, https://doi.org/10.1657/1523-0430(2006)38[163:AADODO]2.0.CO;2, 2006.
Barker, J. D., Sharp, M. J., and Turner, R. J.: Using synchronous fluorescence spectroscopy and principal component analysis to monitor dissolved organic matter dynamics in a glacier system, Hydrol. Process., 23, 1487–1500, https://doi.org/10.1002/hyp.7274, 2009.
Barker, J. D., Klassen, J., Sharp, M. J., Fitzsimons, S. J., and Turner, R. J.: Detecting biogeochemical activity in basal ice using fluorescence spectroscopy, Ann. Glaciol., 51, 47–55, https://doi.org/10.3189/172756411795931967, 2010.
Bhatia, M., Sharp, M., and Foght, J.: Distinct bacterial communities exist beneath a high arctic polythermal glacier, Appl. Environ. Microbiol., 72, 5838–5845, https://doi.org/10.1128/AEM.00595-06, 2006.
Bhatia, M., Das, S., Longnecker, K., Charette, M., and Kujawinski, E.: Molecular characterization of dissolved organic matter associated with the Greenland ice sheet, Geochim. Cosmochim. Acta, 74, 3768–3784, https://doi.org/10.1016/j.gca.2010.03.035, 2010.
Bhatia, M. P., Das, S. B., Xu, L., Charette, M. A., Wadham, J. L., and Kujawinski, E. B.: Organic carbon export from the Greenland ice sheet, Geochim. Cosmochim. Acta, 109, 329–344, https://doi.org/10.1016/j.gca.2013.02.006, 2013.
Biersmith, A. and Benner, R.: Carbohydrates in phytoplankton and freshly produced dissolved organic matter, Mar. Chem., 63, 131–144, 1998.
Blombach, B., Schreiner, M. E., Holatko, J., Bartek, T., Oldiges, M., and Eikmanns, B. J.: L-Valine production with pyruvate dehydrogenase complex-deficient Corynebacterium glutamicum, Appl. Environ. Microbiol., 73, 2079–2084, https://doi.org/10.1128/AEM.02826-06, 2007.
Borch, N. H. and Kirchmann, D. L.: Concentration and composition of dissolved combined neutral sugars (polysaccharides) in seawater determined by HPLC-PAD, Mar. Chem., 57, 85–95, https://doi.org/10.1016/S0304-4203(97)00002-9, 1997.
Coble, P. G.: Characterization of marine and terrestrial DOM in seawater using excitation emission matrix spectroscopy, Mar. Chem., 51, 325–346, https://doi.org/10.1016/0304-4203(95)00062-3, 1996.
Cohen, D.: Rheology of ice at the bed of Engabreen, Norway, J. Glaciol., 46, 611–621, 2000.
Dallmann, W., Hjelle, A., Ohta, Y., Salvigsen, O., Bjørnerud, M., Hauser, E., Maher, H., and Craddock, C.: Geological Map Svalbard, 1: 100,000: B11G Van Keulenfjorden, Norsk Polarinstitutt, Temakart, 15, 1–58, 1990.
De Souza Sierra, M., Donard, O., Lamotte, M., Belin, C., and Ewald, M.: Fluorescence spectroscopy of coastal and marine waters, Mar. Chem., 47, 127–144, https://doi.org/10.1016/0304-4203(94)90104-X, 1994.
Escher, A. and Watt, W. S.: The geology of Greenland, Geological Survey of Greenland, Copenhagen, 1976.
Fellman, J., D'Amore, D., Hood, E., and Boone, R.: Fluorescence characteristics and biodegradability of dissolved organic matter in forest and wetland soils from coastal temperate watersheds in southeast Alaska, Biogeochem., 88, 169–184, https://doi.org/10.1007/s10533-008-9203-x, 2008.
Ferrari, G. M. and Mingazzini, M.: Synchronous Fluorescence-Spectra of Dissolved Organic-Matter (Dom) of Algal Origin in Marine Coastal Waters, Mar. Ecol. Prog. Ser., 125, 305–315, 1995.
Foght, J., Aislabie, J., Turner, S., Brown, C. E., Ryburn, J., Saul, D. J., and Lawson, W.: Culturable bacteria in subglacial sediments and ice from two Southern Hemisphere glaciers, Microb. Ecol., 47, 329–340, https://doi.org/10.1007/s00248-003-1036-5, 2004.
Grannas, A. M., Hockaday, W. C., Hatcher, P. G., Thompson, L. G., and Mosley-Thompson, E.: New revelations on the nature of organic matter in ice cores, J. Geophys. Res., 111, D04304, https://doi.org/10.1029/2005JD006251, 2006.
Hendy, C. H.: Late Quaternary lakes in the McMurdo Sound region of Antarctica, Geografiska Annaler: Series A, Physical Geography, 82, 411–432, https://doi.org/10.1111/j.0435-3676.2000.00131.x, 2000.
Hodson, A., Anesio, A. M., Tranter, M., Fountain, A., Osborn, M., Priscu, J., Laybourn-Parry, J., and Sattler, B.: Glacial ecosystems, Ecological Monographs, 78, 41–67, https://doi.org/10.1890/07-0187.1, 2008.
Horwath Burnham, J. and Sletter, R. S.: Spatial distribution of soil organic carbon in northwest Greenland and underestimates of high Arctic carbon stores, Global Biogeochem. Cy., 24, GB3012, https://doi.org/10.1029/2009gb003660, 2010.
Hood, E., Fellman, J., Spencer, R., Hernes, P., Edwards, R., D'Amore, D., and Scott, D.: Glaciers as a source of ancient and labile organic matter to the marine environment, Nature, 462, 1044–1047, https://doi.org/10.1038/nature08580, 2009.
Hubbard, B. and Sharp, M.: Basal ice formation and deformation: a review, Prog. Phys. Geogr., 13, 529–558, https://doi.org/10.1177/030913338901300403, 1989.
Hubbard, B., Cook, S., and Coulson, H.: Basal ice facies: a review and unifying approach, Quaternary Sci. Rev., 28, 1956–1969, https://doi.org/10.1016/j.quascirev.2009.03.005, 2009.
Iverson, N. R. and Semmens, D. J.: Intrusion of ice into porous media by regelation: A mechanism of sediment entrainment by glaciers, J. Geophys. Res.-Solid Earth, 100, 10219–10230, https://doi.org/10.1029/95JB00043, 1995.
Jansen, K., Stupperich, E., and Fuchs, G.: Carbohydrate synthesis from acetyl CoA in the autotroph Methanobacterium thermoautotrophicum, Archives Microbiol., 132, 355–364, https://doi.org/10.1007/BF00413389, 1982.
Kastovska, K., Stibal, M., Sabacka, M., Cerna, B., Santruckova, H., and Elster, J.: Microbial community structure and ecology of subglacial sediments in two polythermal Svalbard glaciers characterized by epifluorescence microscopy and PLFA, Polar Biol., 30, 277–287, https://doi.org/10.1007/s00300-006-0181-y, 2007.
Kirchman, D. L., Meon, B., Ducklow, H. W., Carlson, C. A., Hansell, D. A., and Steward, G. F.: Glucose fluxes and concentrations of dissolved combined neutral sugars (polysaccharides) in the Ross Sea and Polar Front Zone, Antarctica, Deep Sea Res. Pt. II, 48, 4179–4197, https://doi.org/10.1016/S0967-0645(01)00085-6, 2001.
Knight, P.: The basal ice layer of glaciers and ice sheets, Quaternary Sci. Rev., 16, 975–993, https://doi.org/10.1016/S0277-3791(97)00033-4, 1997.
Knight, P., Waller, R., Patterson, C., Jones, A., and Robinson, Z.: Discharge of debris from ice at the margin of the Greenland ice sheet, J. Glaciol., 48, 192–198, 2002.
Larsen, N. K., Kronborg, C., Yde, J. C., and Knudsen, N. T.: Debris entrainment by basal freeze-on and thrusting during the 1995–1998 surge of Kuannersuit Glacier on Disko Island, west Greenland, Earth Surf. Process. Landforms, 35, 561–574, https://doi.org/10.1002/esp.1945, 2010.
Lawson, D. E., Strasser, J. C., Evenson, E. B., Alley, R. B., and Larson, G. J., Arcone, S. A.: Glaciohydraulic supercooling: a freeze-on mechanism to create stratified, debris-rich basal ice: I. Field evidence, J. Glaciol., 44, 547–567, 1998.
Lawson, E. C., Bhatia, M. P., Wadham, J. L., and Kujawinski, E. B.: Continuous summer export of nitrogen-rich organic matter from the Greenland Ice Sheet inferred by ultrahigh resolution mass spectrometry, Environ. Sci. Technol., 48, 14248–14257, https://doi.org/10.1021/es501732h, 2014a.
Lawson, E. C., Wadham, J. L., Tranter, M., Stibal, M., Lis, G. P., Butler, C. E. H., Laybourn-Parry, J., Nienow, P., Chandler, D., and Dewsbury, P.: Greenland Ice Sheet exports labile organic carbon to the Arctic oceans, Biogeosciences, 11, 4015–4028, https://doi.org/10.5194/bg-11-4015-2014, 2014b.
Liestøl, O.: Glacier surges in west Spitsbergen, Can. J. Earth Sci., 6, 895–897, 1999.
Mader, H. M., Pettitt, M. E., Wadham, J. L. E., Wolff, E. W., and Parkes, R. J.: Subsurface ice as a microbial habitat, Geology, 34, 169–172, https://doi.org/10.1130/G22096.1, 2006.
Maupetit, F. O. and Delmas, R. J.: Carboxylic acids in high-elevation Alpine glacier snow, J. Geophys. Res., 99, 16491–16500, https://doi.org/10.1029/94JD03315, 1994.
McKnight, D. M., Boyer, E. W., Westerhoff, P. K., Doran, P. T., Kulbe, T., and Andersen, D. T.: Spectrofluorometric characterization of dissolved organic matter for indication of precursor organic material and aromaticity, Limnol. Oceanogr., 46, 38–48, https://doi.org/10.4319/lo.2001.46.1.0038, 2001.
Miano, T. M. and Senesi, N.: Synchronous Excitation Fluorescence Spectroscopy Applied to Soil Humic Substances Chemistry, Sci. Total Environ., 118, 41–51, https://doi.org/10.1016/0048-9697(92)90071-Y, 1992.
Montross, S. N., Skidmore, M., Tranter, M., Kivimäki, A. L., and Parkes, R. J.: A microbial driver of chemical weathering in glaciated systems, Geology, 41, 215–218, https://doi.org/10.1130/G33572.1, 2012.
Paterson, W.: The physics of glaciers, 3rd edition ed, Oxford, 1999.
Pautler, B. G., Simpson, A. J., Simpson, M. J., Tseng, L. H., Spraul, M., Dubnick, A., Sharp, M. J., and Fitzsimons, S. J.: Detection and Structural Identification of Dissolved Organic Matter in Antarctic Glacial Ice at Natural Abundance by SPR-W5-WATERGATE 1H NMR Spectroscopy, Environ. Sci. Technol., 45, 4710–4717, https://doi.org/10.1021/es200697c, 2011.
Pautler, B. G., Woods, G. C., Dubnick, A., Simpson, A. J., Sharp, M. J., Fitzsimons, S., and Simpson, M. J.: Molecular characterization of dissolved organic matter in glacial ice: Coupling natural abundance 1H NMR and fluorescence spectroscopy, Environ. Sci. Technol., 46, 3753–3761, https://doi.org/10.1021/es203942y, 2012.
Péwé, T. L.: Multiple glaciation in the McMurdo Sound region, Antarctica: A progress report, J. Geol., 68, 498–514, 1960.
Porter, K. G. and Feig, Y. S.: The use of DAPI for identifying and counting aquatic microflora, Limnol. Oceanogr., 25, 943–948, https://doi.org/10.4319/lo.1980.25.5.0943, 1980.
Pusceddu, A., Dell'Anno, A., Fabiano, M., and Danovaro, R.: Quantity and bioavailability of sediment organic matter as signatures of benthic trophic status, Mar. Ecol. Prog. Ser., 375, 41–52, https://doi.org/10.3354/meps07735, 2009.
Rich, J., Gosselin, M., Sherr, E., Sherr, B., and Kirchman, D. L.: High bacterial production, uptake and concentrations of dissolved organic matter in the Central Arctic Ocean, Deep Sea Res. Part II, 44, 1645–1663, https://doi.org/10.1016/S0967-0645(97)00058-1, 1997.
Saigne, C., Kirchner, S., and Legrand, M.: Ion-chromatographic measurements of ammonium, fluoride, acetate, formate and methanesulphonate ions at very low levels in antarctic ice, Anal. Chim. Acta, 203, 11–21, https://doi.org/10.1016/0003-2670(87)90003-1, 1987.
Schillawski, S. and Petsch, S.: Release of biodegradable dissolved organic matter from ancient sedimentary rocks, Global Biogeochem. Cy., 22, GB3002, https://doi.org/10.1029/2007GB002980, 2008.
Sharp, M. J., Jouzel, J., Hubbard, B., and Lawson, W.: The character, structure and origin of the basal ice layer of a surge-type glacier, J. Glaciol., 40, 327–340, 1994.
Sharp, M., Parkes, J., Cragg, B., Fairchild, I. J., Lamb, H., and Tranter, M.: Widespread bacterial populations at glacier beds and their relationship to rock weathering and carbon cycling, Geology, 27, 107–110, https://doi.org/10.1130/0091-7613(1999)027<0107:WBPAGB>2.3.CO;2, 1999.
Simpson, M. J. R., Milne, G. A., Huybrechts, P., and Long, A. J.: Calibrating a glaciological model of the Greenland ice sheet from the Last Glacial Maximum to present-day using field observations of relative sea level and ice extent, Quaternary Sci. Rev., 28, 1631–1657, https://doi.org/10.1016/j.quascirev.2009.03.004, 2009.
Singh, B. K.: Biosynthesis of valine, leucine, and isoleucine. Plant amino acids: biochemistry and biotechnology, New York, Marcel Dekker, 227–247, 1999.
Skidmore, M. L., Foght, J. M., and Sharp, M. J.: Microbial life beneath a high Arctic glacier, Appl. Environ. Microbiol., 66, 3214–3220, https://doi.org/10.1128/AEM.66.8.3214-3220.2000, 2000.
Skoog, A. and Benner, R. Aldoses in Various Size Fractions of Marine Organic Matter: Implications for Carbon Cycling, Limnol. Oceanogr., 42, 1803–1813, https://doi.org/10.4319/lo.1997.42.8.1803, 1997.
Squyres, S. W., Andersen, D. W., Nedell, S. S., and Wharton Jr., R. A.: Lake Hoare, Antarctica: sedimentation through a thick perennial ice cover, Sedimentology, 38, 363–379, https://doi.org/10.1111/j.1365-3091.1991.tb01265.x, 1991.
Stibal, M., Lawson, E., Lis, G., Mak, K., Wadham, J., and Anesio, A.: Organic matter content and quality in supraglacial debris across the ablation zone of the Greenland ice sheet, Ann. Glaciol., 51, 1–8, https://doi.org/10.3189/172756411795931958, 2010.
Stibal, M., Wadham, J. L., Lis, G. P., Telling, J., Pancost, R. D., Dubnick, A., Sharp, M. J., Lawson, E. C., Butler, C. E. H., and Hasan, F.: Methanogenic potential of Arctic and Antarctic subglacial environments with contrasting organic carbon sources, Glob. Change Biol., 18, 3332–3345, https://doi.org/10.1111/j.1365-2486.2012.02763.x, 2012.
Stubbins, A., Hood, E., Raymond, P. A., Aiken, G. R., Sleighter, R. L., Hernes, P. J., Butman, D., Hatcher, P. G., Striegl, R. G., and Schuster, P.: Anthropogenic aerosols as a source of ancient dissolved organic matter in glaciers, Nature Geosci., 5, 198–201, https://doi.org/10.1038/ngeo1403, 2012.
Stuiver, M., Denton, G. H., Hughes, T. J., and Fastook, J. L.: History of the marine ice sheet in West Antarctica during the last glaciation: a working hypothesis, in: The Last Great Ice Sheets, edited by: Denton, G. H. and Hughes, T. J., 319–436, John Wiley and Sons, New York, 1981.
Sugden, D., Knight, P., Livesey, N., Lorrain, R., Souchez, R., Tison, J.-L., and Jouzel, J.: Evidence for two zones of debris entrainment beneath the Greenland ice sheet, Nature, 328, 238–241, https://doi.org/10.1038/328238a0, 1987.
Tison, J. L., Souchez, R., Wolff, E. W., Moore, J. C., Legrand, M. R., and de Angelis, M.: Is a periglacial biota responsible for enhanced dielectric response in basal ice from the Greenland Ice Core Project ice core?, J. Geophys. Res., 103, 18885–18894, https://doi.org/10.1029/98JD01107, 1998.
Valle, J., Da Re, S., Schmid, S., Skurnik, D., D'Ari, R., and Ghigo, J. M.: The amino acid valine is secreted in continuous-flow bacterial biofilms, J. Bacteriol., 190, 264–274, https://doi.org/10.1128/JB.01405-07, 2008.
Wadham, J. L., Bottrell, S., Tranter, M., and Raiswell, R.: Stable isotope evidence for microbial sulphate reduction at the bed of a polythermal high Arctic glacier, Earth Planet. Sci. Lett., 219, 341–355, https://doi.org/10.1016/S0012-821X(03)00683-6, 2004.
Wadham, J. L., Cooper, R. J., Tranter, M., and Bottrell, S.: Evidence for widespread anoxia in the proglacial zone of an Arctic glacier, Chem. Geol., 243, 1–15, https://doi.org/10.1016/j.chemgeo.2007.04.010, 2007.
Wadham, J. L., Tranter, M., Tulaczyk, S., and Sharp, M.: Subglacial methanogenesis: A potential climatic amplifier?, Global Biogeochem., Cy., 22, GB2021, https://doi.org/10.1029/2007GB002951, 2008.
Waller, R., Hart, J., and Knight, P.: The influence of tectonic deformation on facies variability in stratified debris-rich basal ice, Quaternary Sci. Rev., 19, 775–786, 2000.
Yamashita, Y. and Tanoue, E.: Chemical characterization of protein-like fluorophores in DOM in relation to aromatic amino acids, Mar. Chem., 82, 255–271, https://doi.org/10.1016/S0304-4203(03)00073-2, 2003.
Yde, J., Riger-Kusk, M., Christiansen, H., Knudsen, N., and Humlum, O.: Hydrochemical characteristics of bulk meltwater from an entire ablation season, Longyearbreen, Svalbard, J. Glaciol., 54, 259–272, https://doi.org/10.3189/002214308784886234, 2008.
Yde, J. C., Finster, K. W., Raiswell, R., Steffensen, J. P., Heinemeier, J., Olsen, J., Gunnlaugsson, H. P., and Nielsen, O. B.: Basal ice microbiology at the margin of the Greenland ice sheet, Ann. Glaciol., 51, 71–79, 2010.
Short summary
We use a novel ion chromatographic analysis that provides the first identification and quantification of major low-molecular-weight dissolved organic carbon (LMW-DOC) compounds in basal ice. LMW-DOC concentrations were dependent on the bioavailability of the overridden organic carbon, which in turn was influenced by the type of overridden material. The overridden material may thus act as a direct (abiotic leaching) and indirect (microbial cycling) source of DOC to the subglacial environment.
We use a novel ion chromatographic analysis that provides the first identification and...
Altmetrics
Final-revised paper
Preprint