Articles | Volume 11, issue 14
https://doi.org/10.5194/bg-11-4015-2014
© Author(s) 2014. 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-11-4015-2014
© Author(s) 2014. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
Research article
| 
31 Jul 2014
Research article |
| 31 Jul 2014
Greenland Ice Sheet exports labile organic carbon to the Arctic oceans
E. C. Lawson
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
J. L. Wadham
Bristol Glaciology Centre, School of Geographical Sciences, University Road, Bristol, BS8 1SS, UK
M. Tranter
Bristol Glaciology Centre, School of Geographical Sciences, University Road, Bristol, BS8 1SS, UK
M. Stibal
Department of Geochemistry, Geological Survey of Denmark and Greenland, Øster Voldgade 10, 1350 Copenhagen K, Denmark
G. P. Lis
Bristol Glaciology Centre, School of Geographical Sciences, University Road, Bristol, BS8 1SS, UK
C. E. H. Butler
Bristol Glaciology Centre, School of Geographical Sciences, University Road, Bristol, BS8 1SS, UK
J. Laybourn-Parry
Bristol Glaciology Centre, School of Geographical Sciences, University Road, Bristol, BS8 1SS, UK
P. Nienow
School of Geosciences, University of Edinburgh, Geography Building, Drummond Street, Edinburgh, EH8 9XP, UK
D. Chandler
Bristol Glaciology Centre, School of Geographical Sciences, University Road, Bristol, BS8 1SS, UK
P. Dewsbury
Thermo Fisher Scientific, 4, Albany Court, Camberley, GU16 7QL, Surrey, UK
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.
Emily C. O'Donnell, Jemma L. Wadham, Grzegorz P. Lis, Martyn Tranter, Amy E. Pickard, Marek Stibal, Paul Dewsbury, and Sean Fitzsimons
Biogeosciences, 13, 3833–3846, https://doi.org/10.5194/bg-13-3833-2016, https://doi.org/10.5194/bg-13-3833-2016, 2016
Short summary
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.
Emily A. Hill, Benoît Urruty, Ronja Reese, Julius Garbe, Olivier Gagliardini, Gaël Durand, Fabien Gillet-Chaulet, G. Hilmar Gudmundsson, Ricarda Winkelmann, Mondher Chekki, David Chandler, and Petra M. Langebroek
The Cryosphere, 17, 3739–3759, https://doi.org/10.5194/tc-17-3739-2023, https://doi.org/10.5194/tc-17-3739-2023, 2023
Short summary
Short summary
The grounding lines of the Antarctic Ice Sheet could enter phases of irreversible retreat or advance. We use three ice sheet models to show that the present-day locations of Antarctic grounding lines are reversible with respect to a small perturbation away from their current position. This indicates that present-day retreat of the grounding lines is not yet irreversible or self-enhancing.
Ronja Reese, Julius Garbe, Emily A. Hill, Benoît Urruty, Kaitlin A. Naughten, Olivier Gagliardini, Gaël Durand, Fabien Gillet-Chaulet, G. Hilmar Gudmundsson, David Chandler, Petra M. Langebroek, and Ricarda Winkelmann
The Cryosphere, 17, 3761–3783, https://doi.org/10.5194/tc-17-3761-2023, https://doi.org/10.5194/tc-17-3761-2023, 2023
Short summary
Short summary
We use an ice sheet model to test where current climate conditions in Antarctica might lead. We find that present-day ocean and atmosphere conditions might commit an irreversible collapse of parts of West Antarctica which evolves over centuries to millennia. Importantly, this collapse is not irreversible yet.
David M. Chandler and Petra M. Langebroek
EGUsphere, https://doi.org/10.5194/egusphere-2023-850, https://doi.org/10.5194/egusphere-2023-850, 2023
Short summary
Short summary
Sea-level rise and global climate change caused by ice melt in Antarctica is a puzzle of feedbacks between the climate, ocean and ice sheets, over tens to thousands of years. Antarctic Ice Sheet melting is caused mainly by warm deep water from the Southern Ocean. Here, we analyse close relationships between deep water temperatures and global climate in the last 800,000 years. This knowledge can help us to better understanding how climate and sea-level are likely to change in the future.
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.
Benjamin Joseph Davison, Tom Cowton, Andrew Sole, Finlo Cottier, and Pete Nienow
The Cryosphere, 16, 1181–1196, https://doi.org/10.5194/tc-16-1181-2022, https://doi.org/10.5194/tc-16-1181-2022, 2022
Short summary
Short summary
The ocean is an important driver of Greenland glacier retreat. Icebergs influence ocean temperature in the vicinity of glaciers, which will affect glacier retreat rates, but the effect of icebergs on water temperature is poorly understood. In this study, we use a model to show that icebergs cause large changes to water properties next to Greenland's glaciers, which could influence ocean-driven glacier retreat around Greenland.
Thomas Slater, Isobel R. Lawrence, Inès N. Otosaka, Andrew Shepherd, Noel Gourmelen, Livia Jakob, Paul Tepes, Lin Gilbert, and Peter Nienow
The Cryosphere, 15, 233–246, https://doi.org/10.5194/tc-15-233-2021, https://doi.org/10.5194/tc-15-233-2021, 2021
Short summary
Short summary
Satellite observations are the best method for tracking ice loss, because the cryosphere is vast and remote. Using these, and some numerical models, we show that Earth has lost 28 trillion tonnes (Tt) of ice since 1994 from Arctic sea ice (7.6 Tt), ice shelves (6.5 Tt), mountain glaciers (6.1 Tt), the Greenland (3.8 Tt) and Antarctic ice sheets (2.5 Tt), and Antarctic sea ice (0.9 Tt). It has taken just 3.2 % of the excess energy Earth has absorbed due to climate warming to cause this ice loss.
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.
David Chandler and Shona Mackie
Earth Syst. Sci. Data, 12, 897–906, https://doi.org/10.5194/essd-12-897-2020, https://doi.org/10.5194/essd-12-897-2020, 2020
Short summary
Short summary
The activity of microorganisms at the bottom of the marine food chain has rarely been measured under sea ice in winter. We present the first observations of Arctic winter microbial activity under sea ice in a west Greenland fjord. By measuring changes in the oxygen concentration of seawater under the ice, we found low but significant levels of activity, suggesting these microbial communities may constitute an important part of the winter marine ecosystem.
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.
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.
Emily C. O'Donnell, Jemma L. Wadham, Grzegorz P. Lis, Martyn Tranter, Amy E. Pickard, Marek Stibal, Paul Dewsbury, and Sean Fitzsimons
Biogeosciences, 13, 3833–3846, https://doi.org/10.5194/bg-13-3833-2016, https://doi.org/10.5194/bg-13-3833-2016, 2016
Short summary
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.
S. de la Peña, I. M. Howat, P. W. Nienow, M. R. van den Broeke, E. Mosley-Thompson, S. F. Price, D. Mair, B. Noël, and A. J. Sole
The Cryosphere, 9, 1203–1211, https://doi.org/10.5194/tc-9-1203-2015, https://doi.org/10.5194/tc-9-1203-2015, 2015
Short summary
Short summary
This paper presents an assessment of changes in the near-surface structure of the accumulation zone of the Greenland Ice Sheet caused by an increase of melt at higher elevations in the last decade, especially during the unusually warm years of 2010 and 2012. The increase in melt and firn densification complicate the interpretation of changes in the ice volume, and the observed increase in firn ice content may reduce the important meltwater buffering capacity of the Greenland Ice Sheet.
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.
C. C. Clason, D. W. F. Mair, P. W. Nienow, I. D. Bartholomew, A. Sole, S. Palmer, and W. Schwanghart
The Cryosphere, 9, 123–138, https://doi.org/10.5194/tc-9-123-2015, https://doi.org/10.5194/tc-9-123-2015, 2015
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
Related subject area
Biogeochemistry: Rivers & Streams
Alkalinity generation from carbonate weathering in a silicate-dominated headwater catchment at Iskorasfjellet, northern Norway
Physical and stoichiometric controls on stream respiration in a headwater stream
Local processes with a global impact: unraveling the dynamics of gas evasion in a step-and-pool configuration
Complex dissolved organic matter (DOM) on the roof of the world – Tibetan DOM molecular characteristics indicate sources, land use effects, and processing along the fluvial–limnic continuum
Maximum respiration rates in hyporheic zone sediments are primarily constrained by organic carbon concentration and secondarily by organic matter chemistry
Glacier loss and vegetation expansion alter organic and inorganic carbon dynamics in high-mountain streams
Particulate organic matter in the Lena River and its delta: from the permafrost catchment to the Arctic Ocean
Stable isotopic evidence for the excess leaching of unprocessed atmospheric nitrate from forested catchments under high nitrogen saturation
Nitrogen isotopes reveal a particulate-matter-driven biogeochemical reactor in a temperate estuary
High-resolution vertical biogeochemical profiles in the hyporheic zone reveal insights into microbial methane cycling
Organic matter transformations are disconnected between surface water and the hyporheic zone
CO2 emissions from peat-draining rivers regulated by water pH
Effects of peatland management on aquatic carbon concentrations and fluxes
Resistance and resilience of stream metabolism to high flow disturbances
Enhanced bioavailability of dissolved organic matter (DOM) in human-disturbed streams in Alpine fluvial networks
Spatial and temporal variability of pCO2 and CO2 emissions from the Dong River in south China
Fluvial carbon dioxide emission from the Lena River basin during the spring flood
Diel patterns in stream nitrate concentration produced by in-stream processes
Complex interactions of in-stream dissolved organic matter and nutrient spiralling unravelled by Bayesian regression analysis
Spatial–temporal variations in riverine carbon strongly influenced by local hydrological events in an alpine catchment
Rapid soil organic carbon decomposition in river systems: effects of the aquatic microbial community and hydrodynamical disturbance
Increased carbon capture by a silicate-treated forested watershed affected by acid deposition
Thermokarst amplifies fluvial inorganic carbon cycling and export across watershed scales on the Peel Plateau, Canada
Temporary and net sinks of atmospheric CO2 due to chemical weathering in subtropical catchment with mixing carbonate and silicate lithology
From canals to the coast: dissolved organic matter and trace metal composition in rivers draining degraded tropical peatlands in Indonesia
Distribution and flux of dissolved iron in the peatland-draining rivers and estuaries of Sarawak, Malaysian Borneo
Comparisons of dissolved organic matter and its optical characteristics in small low and high Arctic catchments
High-frequency measurements explain quantity and quality of dissolved organic carbon mobilization in a headwater catchment
Dissolved inorganic nitrogen in a tropical estuary in Malaysia: transport and transformation
Behaviour of Dissolved Phosphorus with the associated nutrients in relation to phytoplankton biomass of the Rajang River-South China Sea continuum
Synchrony in catchment stream colour levels is driven by both local and regional climate
The post-monsoon carbon biogeochemistry of the Hooghly–Sundarbans estuarine system under different levels of anthropogenic impacts
Riverine particulate C and N generated at the permafrost thaw front: case study of western Siberian rivers across a 1700 km latitudinal transect
Geochemistry of the dissolved loads during high-flow season of rivers in the southeastern coastal region of China: anthropogenic impact on chemical weathering and carbon sequestration
CO2 partial pressure and CO2 emission along the lower Red River (Vietnam)
Stable isotopes of nitrate reveal different nitrogen processing mechanisms in streams across a land use gradient during wet and dry periods
Riverine carbon export in the arid to semiarid Wuding River catchment on the Chinese Loess Plateau
Use of argon to measure gas exchange in turbulent mountain streams
Reviews and syntheses: Anthropogenic perturbations to carbon fluxes in Asian river systems – concepts, emerging trends, and research challenges
Shifts in stream hydrochemistry in responses to typhoon and non-typhoon precipitation
QUAL-NET, a high temporal-resolution eutrophication model for large hydrographic networks
Diel fluctuations of viscosity-driven riparian inflow affect streamflow DOC concentration
A comprehensive biogeochemical record and annual flux estimates for the Sabaki River (Kenya)
Hydro-ecological controls on dissolved carbon dynamics in groundwater and export to streams in a temperate pine forest
Regional-scale lateral carbon transport and CO2 evasion in temperate stream catchments
Carbon and nutrient export regimes from headwater catchments to downstream reaches
Influence of infrastructure on water quality and greenhouse gas dynamics in urban streams
Hydromorphological restoration stimulates river ecosystem metabolism
Quantifying nutrient fluxes with a new hyporheic passive flux meter (HPFM)
Sources, cycling and export of nitrogen on the Greenland Ice Sheet
Nele Lehmann, Hugues Lantuit, Michael Ernst Böttcher, Jens Hartmann, Antje Eulenburg, and Helmuth Thomas
Biogeosciences, 20, 3459–3479, https://doi.org/10.5194/bg-20-3459-2023, https://doi.org/10.5194/bg-20-3459-2023, 2023
Short summary
Short summary
Riverine alkalinity in the silicate-dominated headwater catchment at subarctic Iskorasfjellet, northern Norway, was almost entirely derived from weathering of minor carbonate occurrences in the riparian zone. The uphill catchment appeared limited by insufficient contact time of weathering agents and weatherable material. Further, alkalinity increased with decreasing permafrost extent. Thus, with climate change, alkalinity generation is expected to increase in this permafrost-degrading landscape.
Jancoba Dorley, Joel Singley, Tim Covino, Kamini Singha, Michael Gooseff, David Van Horn, and Ricardo González-Pinzón
Biogeosciences, 20, 3353–3366, https://doi.org/10.5194/bg-20-3353-2023, https://doi.org/10.5194/bg-20-3353-2023, 2023
Short summary
Short summary
We quantified how microbial respiration is controlled by discharge and the supply of C, N, and P in a stream. We ran two rounds of experiments adding a conservative tracer, an indicator of aerobic respiration, and nutrient treatments: a) N, b) N+C, c) N+P, and d) C+N+P. Microbial respiration remained similar between rounds and across nutrient treatments. This suggests that complex interactions between hydrology, resource supply, and biological community drive in-stream respiration.
Paolo Peruzzo, Matteo Cappozzo, Nicola Durighetto, and Gianluca Botter
Biogeosciences, 20, 3261–3271, https://doi.org/10.5194/bg-20-3261-2023, https://doi.org/10.5194/bg-20-3261-2023, 2023
Short summary
Short summary
Small cascades greatly enhance mountain stream gas emissions through the turbulent energy dissipation rate and air bubbles entrained into the water. We numerically studied the local contribution of these mechanisms driving gas transfer velocity used to quantify the outgassing. The gas evasion is primarily due to bubbles concentrated in irregular spots of limited area. Consequently, the gas exchange velocity is scale-dependent and unpredictable, posing concerns about its use in similar scenarios.
Philipp Maurischat, Michael Seidel, Thorsten Dittmar, and Georg Guggenberger
Biogeosciences, 20, 3011–3026, https://doi.org/10.5194/bg-20-3011-2023, https://doi.org/10.5194/bg-20-3011-2023, 2023
Short summary
Short summary
Production and consumption of organic matter (OM) on the Tibetan Plateau are important for this sensitive ecosystem. We investigated the chemical composition of dissolved organic matter and the most mobile fraction of OM in glaciers, wetlands, and groundwater as well as in the rivers and a large terminal lake. Our data show that the sources differ in the molecular composition of OM, that the stream is influenced by agriculture, and that the lake strongly changes the inflowing organic matter.
James C. Stegen, Vanessa A. Garayburu-Caruso, Robert E. Danczak, Amy E. Goldman, Lupita Renteria, Joshua M. Torgeson, and Jacqueline Hager
Biogeosciences, 20, 2857–2867, https://doi.org/10.5194/bg-20-2857-2023, https://doi.org/10.5194/bg-20-2857-2023, 2023
Short summary
Short summary
Chemical reactions in river sediments influence how clean the water is and how much greenhouse gas comes out of a river. Our study investigates why some sediments have higher rates of chemical reactions than others. We find that to achieve high rates, sediments need to have two things: only a few different kinds of molecules, but a lot of them. This result spans about 80 rivers such that it could be a general rule, helpful for predicting the future of rivers and our planet.
Andrew L. Robison, Nicola Deluigi, Camille Rolland, Nicolas Manetti, and Tom Battin
Biogeosciences, 20, 2301–2316, https://doi.org/10.5194/bg-20-2301-2023, https://doi.org/10.5194/bg-20-2301-2023, 2023
Short summary
Short summary
Climate change is affecting mountain ecosystems intensely, including the loss of glaciers and the uphill migration of plants. How these changes will affect the streams draining these landscapes is unclear. We sampled streams across a gradient of glacier and vegetation cover in Switzerland and found glacier loss reduced the carbon dioxide sink from weathering, while vegetation cover increased dissolved organic carbon in the stream. These changes are important to consider for mountains globally.
Olga Ogneva, Gesine Mollenhauer, Bennet Juhls, Tina Sanders, Juri Palmtag, Matthias Fuchs, Hendrik Grotheer, Paul J. Mann, and Jens Strauss
Biogeosciences, 20, 1423–1441, https://doi.org/10.5194/bg-20-1423-2023, https://doi.org/10.5194/bg-20-1423-2023, 2023
Short summary
Short summary
Arctic warming accelerates permafrost thaw and release of terrestrial organic matter (OM) via rivers to the Arctic Ocean. We compared particulate organic carbon (POC), total suspended matter, and C isotopes (δ13C and Δ14C of POC) in the Lena delta and Lena River along a ~1600 km transect. We show that the Lena delta, as an interface between the Lena River and the Arctic Ocean, plays a crucial role in determining the qualitative and quantitative composition of OM discharged into the Arctic Ocean.
Weitian Ding, Urumu Tsunogai, Fumiko Nakagawa, Takashi Sambuichi, Masaaki Chiwa, Tamao Kasahara, and Ken'ichi Shinozuka
Biogeosciences, 20, 753–766, https://doi.org/10.5194/bg-20-753-2023, https://doi.org/10.5194/bg-20-753-2023, 2023
Short summary
Short summary
By monitoring the concentration and Δ17O of stream nitrate in three forested streams, the new nitrogen saturation index of forested catchments (Matm/Datm ratio) was estimated. We found that (1) the unprocessed atmospheric nitrate in our studied forested stream (FK1 catchment) was the highest ever reported in forested streams; (2) the Matm/Datm ratio can be used as a robust index for evaluating nitrogen saturation in forested catchments as the Matm/Datm ratio is independent of the precipitation.
Kirstin Dähnke, Tina Sanders, Yoana Voynova, and Scott D. Wankel
Biogeosciences, 19, 5879–5891, https://doi.org/10.5194/bg-19-5879-2022, https://doi.org/10.5194/bg-19-5879-2022, 2022
Short summary
Short summary
Nitrogen is an important macronutrient that fuels algal production in rivers and coastal regions. We investigated the production and removal of nitrogen-bearing compounds in the freshwater section of the tidal Elbe Estuary and found that particles in the water column are key for the production and removal of water column nitrate. Using a stable isotope approach, we pinpointed regions where additional removal of nitrate or input from sediments plays an important role in estuarine biogeochemistry.
Tamara Michaelis, Anja Wunderlich, Ömer K. Coskun, William Orsi, Thomas Baumann, and Florian Einsiedl
Biogeosciences, 19, 4551–4569, https://doi.org/10.5194/bg-19-4551-2022, https://doi.org/10.5194/bg-19-4551-2022, 2022
Short summary
Short summary
The greenhouse gas methane (CH4) drives climate change. Microorganisms in river sediments produce CH4 when degrading organic matter, but the contribution of rivers to atmospheric CH4 concentrations is uncertain. To better understand riverine CH4 cycling, we measured concentration profiles of CH4 and relevant reactants that might influence the CH4 cycle. We found substantial CH4 production, especially in fine, organic-rich sediments during summer and signs of microbial CH4 consumption.
James C. Stegen, Sarah J. Fansler, Malak M. Tfaily, Vanessa A. Garayburu-Caruso, Amy E. Goldman, Robert E. Danczak, Rosalie K. Chu, Lupita Renteria, Jerry Tagestad, and Jason Toyoda
Biogeosciences, 19, 3099–3110, https://doi.org/10.5194/bg-19-3099-2022, https://doi.org/10.5194/bg-19-3099-2022, 2022
Short summary
Short summary
Rivers are vital to Earth, and in rivers, organic matter (OM) is an energy source for microbes that make greenhouse gas and remove contaminants. Predicting Earth’s future requires understanding how and why river OM is transformed. Our results help meet this need. We found that the processes influencing OM transformations diverge between river water and riverbed sediments. This can be used to build new models for predicting the future of rivers and, in turn, the Earth system.
Alexandra Klemme, Tim Rixen, Denise Müller-Dum, Moritz Müller, Justus Notholt, and Thorsten Warneke
Biogeosciences, 19, 2855–2880, https://doi.org/10.5194/bg-19-2855-2022, https://doi.org/10.5194/bg-19-2855-2022, 2022
Short summary
Short summary
Tropical peat-draining rivers contain high amounts of carbon. Surprisingly, measured carbon dioxide (CO2) emissions from those rivers are comparatively moderate. We compiled data from 10 Southeast Asian rivers and found that CO2 production within these rivers is hampered by low water pH, providing a natural threshold for CO2 emissions. Furthermore, we find that enhanced carbonate input, e.g. caused by human activities, suspends this natural threshold and causes increased CO2 emissions.
Amy E. Pickard, Marcella Branagan, Mike F. Billett, Roxane Andersen, and Kerry J. Dinsmore
Biogeosciences, 19, 1321–1334, https://doi.org/10.5194/bg-19-1321-2022, https://doi.org/10.5194/bg-19-1321-2022, 2022
Short summary
Short summary
Peatlands have been subject to a range of land management regimes over the past century. This has affected the amount of carbon that drains into surrounding streams and rivers. In our study, we measured carbon concentrations in streams draining from drained, non-drained, and restored areas of the Flow Country blanket bog in N Scotland. We found that drained peatland had higher concentrations and fluxes of carbon relative to non-drained areas. Restored peatland areas were highly variable.
Brynn O'Donnell and Erin R. Hotchkiss
Biogeosciences, 19, 1111–1134, https://doi.org/10.5194/bg-19-1111-2022, https://doi.org/10.5194/bg-19-1111-2022, 2022
Short summary
Short summary
A stream is defined by flowing water, but higher flow from storms is also a frequent disturbance. This paper tests how higher flow changes stream metabolism (respiration and photosynthesis, R and P). P was less resistant to changes in flow compared to R, and P took longer to recover from storms than R (2.2 versus 0.6 d). Further work on metabolic responses to flow disturbance is critical given projected increases in storms and the influence of higher flows on ecosystem health and functioning.
Thibault Lambert, Pascal Perolo, Nicolas Escoffier, and Marie-Elodie Perga
Biogeosciences, 19, 187–200, https://doi.org/10.5194/bg-19-187-2022, https://doi.org/10.5194/bg-19-187-2022, 2022
Short summary
Short summary
The bacterial mineralization of dissolved organic matter (DOM) in inland waters contributes to CO2 emissions to the atmosphere. Human activities affect DOM sources. However, the implications on DOM mineralization are poorly known. Combining sampling and incubations, we showed that higher bacterial respiration in agro-urban streams related to a labile pool from aquatic origin. Therefore, human activities may have a limited impact on the net carbon exchanges between inland waters and atmosphere.
Boyi Liu, Mingyang Tian, Kaimin Shih, Chun Ngai Chan, Xiankun Yang, and Lishan Ran
Biogeosciences, 18, 5231–5245, https://doi.org/10.5194/bg-18-5231-2021, https://doi.org/10.5194/bg-18-5231-2021, 2021
Short summary
Short summary
Spatial and temporal patterns of pCO2 in the subtropical Dong River basin were mainly affected by C inputs and in-stream metabolism, both of which varied due to differential catchment settings, land cover, and hydrological conditions. CO2 fluxes in the wet season were 2-fold larger than in the dry season due to high pCO2 and turbulence caused by high flow velocity. The absence of high CO2 fluxes in small rivers could be associated with the depletion effect caused by abundant precipitation.
Sergey N. Vorobyev, Jan Karlsson, Yuri Y. Kolesnichenko, Mikhail A. Korets, and Oleg S. Pokrovsky
Biogeosciences, 18, 4919–4936, https://doi.org/10.5194/bg-18-4919-2021, https://doi.org/10.5194/bg-18-4919-2021, 2021
Short summary
Short summary
In order to quantify riverine carbon (C) exchange with the atmosphere in permafrost regions, we report a first assessment of CO2 and CH4 concentration and fluxes of the largest permafrost-affected river, the Lena River, during the peak of spring flow. The results allowed identification of environmental factors controlling GHG concentrations and emission in the Lena River watershed; this new knowledge can be used for foreseeing future changes in C balance in permafrost-affected Arctic rivers.
Jan Greiwe, Markus Weiler, and Jens Lange
Biogeosciences, 18, 4705–4715, https://doi.org/10.5194/bg-18-4705-2021, https://doi.org/10.5194/bg-18-4705-2021, 2021
Short summary
Short summary
We analyzed variability in diel nitrate patterns at three locations in a lowland stream. Comparison of time lags between monitoring sites with water travel time indicated that diel patterns were created by in-stream processes rather than transported downstream from an upstream point of origin. Most of the patterns (70 %) could be explained by assimilatory nitrate uptake. The remaining patterns suggest seasonally varying dominance and synchronicity of different biochemical processes.
Matthias Pucher, Peter Flödl, Daniel Graeber, Klaus Felsenstein, Thomas Hein, and Gabriele Weigelhofer
Biogeosciences, 18, 3103–3122, https://doi.org/10.5194/bg-18-3103-2021, https://doi.org/10.5194/bg-18-3103-2021, 2021
Short summary
Short summary
Dissolved organic matter is an important carbon source in aquatic ecosystems, yet the uptake processes are not totally understood. We found evidence for the release of degradation products, efficiency loss in the uptake with higher concentrations, stimulating effects, and quality-dependent influences from the benthic zone. To conduct this analysis, we included interactions in the equations of the nutrient spiralling concept and solve it with a Bayesian non-linear fitting algorithm.
Xin Wang, Ting Liu, Liang Wang, Zongguang Liu, Erxiong Zhu, Simin Wang, Yue Cai, Shanshan Zhu, and Xiaojuan Feng
Biogeosciences, 18, 3015–3028, https://doi.org/10.5194/bg-18-3015-2021, https://doi.org/10.5194/bg-18-3015-2021, 2021
Short summary
Short summary
We show a comprehensive monitoring dataset on the discharge and carbon transport in a small alpine river on the Qinghai–Tibetan Plateau, where riverine carbon increased downstream in the pre-monsoon season due to an increasing contribution of organic matter derived from seasonal permafrost thaw while it fluctuated in the monsoon season induced by sporadic precipitation. These results indicate a high sensitivity of riverine carbon in alpine headwater catchments to local hydrological events.
Man Zhao, Liesbet Jacobs, Steven Bouillon, and Gerard Govers
Biogeosciences, 18, 1511–1523, https://doi.org/10.5194/bg-18-1511-2021, https://doi.org/10.5194/bg-18-1511-2021, 2021
Short summary
Short summary
We investigate the relative importance of two individual factors (hydrodynamical disturbance and aquatic microbial community) that possibly control SOC decomposition rates in river systems. We found aquatic microbial organisms led to rapid SOC decomposition, while effect of mechanical disturbance is relative minor. We propose a simple conceptual model: hydrodynamic disturbance is only important when soil aggregates are strong enough to withstand the disruptive forces imposed by water immersions.
Lyla L. Taylor, Charles T. Driscoll, Peter M. Groffman, Greg H. Rau, Joel D. Blum, and David J. Beerling
Biogeosciences, 18, 169–188, https://doi.org/10.5194/bg-18-169-2021, https://doi.org/10.5194/bg-18-169-2021, 2021
Short summary
Short summary
Enhanced rock weathering (ERW) is a carbon dioxide removal (CDR) strategy involving soil amendments with silicate rock dust. Over 15 years, a small silicate application led to net CDR of 8.5–11.5 t CO2/ha in an acid-rain-impacted New Hampshire forest. We accounted for the total carbon cost of treatment and compared effects with an adjacent, untreated forest. Our results suggest ERW can improve the greenhouse gas balance of similar forests in addition to mitigating acid rain effects.
Scott Zolkos, Suzanne E. Tank, Robert G. Striegl, Steven V. Kokelj, Justin Kokoszka, Cristian Estop-Aragonés, and David Olefeldt
Biogeosciences, 17, 5163–5182, https://doi.org/10.5194/bg-17-5163-2020, https://doi.org/10.5194/bg-17-5163-2020, 2020
Short summary
Short summary
High-latitude warming thaws permafrost, exposing minerals to weathering and fluvial transport. We studied the effects of abrupt thaw and associated weathering on carbon cycling in western Canada. Permafrost collapse affected < 1 % of the landscape yet enabled carbonate weathering associated with CO2 degassing in headwaters and increased bicarbonate export across watershed scales. Weathering may become a driver of carbon cycling in ice- and mineral-rich permafrost terrain across the Arctic.
Yingjie Cao, Yingxue Xuan, Changyuan Tang, Shuai Guan, and Yisheng Peng
Biogeosciences, 17, 3875–3890, https://doi.org/10.5194/bg-17-3875-2020, https://doi.org/10.5194/bg-17-3875-2020, 2020
Short summary
Short summary
About half of the global CO2 sequestration due to chemical weathering occurs in warm and high-runoff regions. To evaluate the temporary and net sinks of atmospheric CO2 due to chemical weathering, we selected a typical subtropical catchment as our study area and did fieldwork to sample surface water along the main channel and major tributaries in 1 hydrological year. The result of mass balance calculation showed that human activities dramatically decreased the CO2 net sink.
Laure Gandois, Alison M. Hoyt, Stéphane Mounier, Gaël Le Roux, Charles F. Harvey, Adrien Claustres, Mohammed Nuriman, and Gusti Anshari
Biogeosciences, 17, 1897–1909, https://doi.org/10.5194/bg-17-1897-2020, https://doi.org/10.5194/bg-17-1897-2020, 2020
Short summary
Short summary
Worldwide, peatlands are important sources of dissolved organic matter (DOM) and trace metals (TMs) to surface waters, and these fluxes may increase with peatland degradation. In Southeast Asia, tropical peatlands are being rapidly deforested and drained. This work aims to address the fate of organic carbon and its role as a trace metal carrier in drained peatlands of Indonesia.
Xiaohui Zhang, Moritz Müller, Shan Jiang, Ying Wu, Xunchi Zhu, Aazani Mujahid, Zhuoyi Zhu, Mohd Fakharuddin Muhamad, Edwin Sien Aun Sia, Faddrine Holt Ajon Jang, and Jing Zhang
Biogeosciences, 17, 1805–1819, https://doi.org/10.5194/bg-17-1805-2020, https://doi.org/10.5194/bg-17-1805-2020, 2020
Short summary
Short summary
This study offered detailed information on dFe concentrations, distribution and the magnitude of yield in the Rajang River, the largest river in Malaysia. Three blackwater rivers, draining from peatlands, were also included in our study. Compared with the Rajang River, the dFe concentrations and yield from three blackwater rivers were much higher. The precipitation and agricultural activities, such as palm oil plantations, may markedly increase the concentration dFe in these tropical rivers.
Caroline Coch, Bennet Juhls, Scott F. Lamoureux, Melissa J. Lafrenière, Michael Fritz, Birgit Heim, and Hugues Lantuit
Biogeosciences, 16, 4535–4553, https://doi.org/10.5194/bg-16-4535-2019, https://doi.org/10.5194/bg-16-4535-2019, 2019
Short summary
Short summary
Climate change affects Arctic ecosystems. This includes thawing of permafrost (ground below 0 °C) and an increase in rainfall. Both have substantial impacts on the chemical composition of river water. We compared the composition of small rivers in the low and high Arctic with the large Arctic rivers. In comparison, dissolved organic matter in the small rivers is more susceptible to degradation; thus, it could potentially increase carbon dioxide emissions. Rainfall events have a similar effect.
Benedikt J. Werner, Andreas Musolff, Oliver J. Lechtenfeld, Gerrit H. de Rooij, Marieke R. Oosterwoud, and Jan H. Fleckenstein
Biogeosciences, 16, 4497–4516, https://doi.org/10.5194/bg-16-4497-2019, https://doi.org/10.5194/bg-16-4497-2019, 2019
Short summary
Short summary
Increased dissolved organic carbon (DOC) concentration in streams can pose a threat to downstream water resources. Analyzing data from an in-stream probe we found that hydroclimatic and hydrological drivers can describe up to 72 % of the observed DOC concentration and composition variability. Variability was found to be highest during discharge events with warm and dry preconditions. The findings suggest an impact of climate change on DOC exports and thus also on downstream water quality.
Shan Jiang, Moritz Müller, Jie Jin, Ying Wu, Kun Zhu, Guosen Zhang, Aazani Mujahid, Tim Rixen, Mohd Fakharuddin Muhamad, Edwin Sien Aun Sia, Faddrine Holt Ajon Jang, and Jing Zhang
Biogeosciences, 16, 2821–2836, https://doi.org/10.5194/bg-16-2821-2019, https://doi.org/10.5194/bg-16-2821-2019, 2019
Short summary
Short summary
Three cruises were conducted in the Rajang River estuary, Malaysia. The results revealed that the decomposition of terrestrial organic matter and the subsequent soil leaching were the main sources of dissolved inorganic nitrogen (DIN) in the fresh river water. Porewater exchange and ammonification enhanced DIN concentrations in the estuary water, while intensities of DIN addition varied between seasons. The riverine DIN flux could reach 101.5 ton(N) / d, supporting the coastal primary producers.
Edwin Sien Aun Sia, Jing Zhang, Shan Jiang, Zhuoyi Zhu, Gonzalo Carrasco, Faddrine Holt Jang, Aazani Mujahid, and Moritz Müller
Biogeosciences Discuss., https://doi.org/10.5194/bg-2019-219, https://doi.org/10.5194/bg-2019-219, 2019
Revised manuscript not accepted
Short summary
Short summary
Nutrient loads carried by large rivers and discharged into the continental shelf and coastal waters are vital to support primary production. Our knowledge of tropical river systems is fragmented with very few seasonal studies available for Southeast Asia (SEA). We present data from three sampling campaigns on the longest river in Malaysia, the Rajang river. Our results show the generalization of SEA as a nutrient hotspot might not hold true for all regions and requires further investigation.
Brian C. Doyle, Elvira de Eyto, Mary Dillane, Russell Poole, Valerie McCarthy, Elizabeth Ryder, and Eleanor Jennings
Biogeosciences, 16, 1053–1071, https://doi.org/10.5194/bg-16-1053-2019, https://doi.org/10.5194/bg-16-1053-2019, 2019
Short summary
Short summary
This study explores the drivers of variation in the water colour of rivers, and hence organic carbon export, in a blanket peatland catchment. We used 6 years of weekly river water colour data (2011 to 2016) from three proximate river sub-catchments in western Ireland. in tandem with a range of topographical, hydrological and climate data, to discover the principle environmental drivers controlling changes in colour concentration in the rivers.
Manab Kumar Dutta, Sanjeev Kumar, Rupa Mukherjee, Prasun Sanyal, and Sandip Kumar Mukhopadhyay
Biogeosciences, 16, 289–307, https://doi.org/10.5194/bg-16-289-2019, https://doi.org/10.5194/bg-16-289-2019, 2019
Short summary
Short summary
The study focused on understanding C biogeochemistry of two adjacently located estuaries undergoing different levels of anthropogenic stresses. Different parameters related to C cycling were measured in an anthropogenically influenced and a mangrove-dominated estuary. Although the entire estuarine system acted as a source of carbon dioxide to the regional atmosphere, emission approximately 17 times higher was noticed from the anthropogenically affected estuary compared to mangrove-dominated one.
Ivan V. Krickov, Artem G. Lim, Rinat M. Manasypov, Sergey V. Loiko, Liudmila S. Shirokova, Sergey N. Kirpotin, Jan Karlsson, and Oleg S. Pokrovsky
Biogeosciences, 15, 6867–6884, https://doi.org/10.5194/bg-15-6867-2018, https://doi.org/10.5194/bg-15-6867-2018, 2018
Short summary
Short summary
We tested the effect of climate, permafrost and physio-geographical landscape parameters on particulate C, N and P concentrations in small- and medium- sized rivers in the Western Siberian Lowland (WSL). We discovered a maximum of particulate C and N concentrations at the beginning of the permafrost appearance. A northward shift of permafrost boundaries may increase the particulate C and N export by WSL rivers to the Arctic Ocean by a factor of 2.
Wenjing Liu, Zhifang Xu, Huiguo Sun, Tong Zhao, Chao Shi, and Taoze Liu
Biogeosciences, 15, 4955–4971, https://doi.org/10.5194/bg-15-4955-2018, https://doi.org/10.5194/bg-15-4955-2018, 2018
Short summary
Short summary
The southeastern coastal region is the top acid-rain-impacted area in China. It is worth evaluating the acid deposition impacts on chemical weathering and CO2 consumption there. River water geochemistry evidenced an overestimation of CO2 sequestration if H2SO4/HNO3 involvement was ignored, which accounted for 33.6 % of the total flux by silicate weathering in this area. This study quantitatively highlights the anthropogenic acid effects on chemical weathering and associated CO2 consumption.
Thi Phuong Quynh Le, Cyril Marchand, Cuong Tu Ho, Nhu Da Le, Thi Thuy Duong, XiXi Lu, Phuong Kieu Doan, Trung Kien Nguyen, Thi Mai Huong Nguyen, and Duy An Vu
Biogeosciences, 15, 4799–4814, https://doi.org/10.5194/bg-15-4799-2018, https://doi.org/10.5194/bg-15-4799-2018, 2018
Short summary
Short summary
The Red River is a typical south-east Asian river, strongly affected by climate and human activity. This study showed the spatial and seasonal variability of CO2 emissions at the water–air interface of the lower part of this river due to natural conditions (meteo-hydrological-geomorphological characteristics) and human activities (dam impoundment, population, land use). The Red River water was supersaturated with CO2, providing a mean water–air CO2 flux of 530 ± 17 mmol m−2 d−1.
Wei Wen Wong, Jesse Pottage, Fiona Y. Warry, Paul Reich, Keryn L. Roberts, Michael R. Grace, and Perran L. M. Cook
Biogeosciences, 15, 3953–3965, https://doi.org/10.5194/bg-15-3953-2018, https://doi.org/10.5194/bg-15-3953-2018, 2018
Short summary
Short summary
Over-enrichment of nitrate can pose substantial risk to the quality of freshwater ecosystems. Hence, understanding the dynamics of nitrate is the key to better management of waterways. This study evaluates the relationship between the effects of land use and rainfall on the major sources and processing of nitrate within and between five streams in five catchments spanning an agricultural land use gradient. We found that rainfall exerted significant control over the fate of nitrate.
Lishan Ran, Mingyang Tian, Nufang Fang, Suiji Wang, Xixi Lu, Xiankun Yang, and Frankie Cho
Biogeosciences, 15, 3857–3871, https://doi.org/10.5194/bg-15-3857-2018, https://doi.org/10.5194/bg-15-3857-2018, 2018
Short summary
Short summary
We systematically assessed the transport and fate of riverine carbon in the moderate-sized Wuding catchment on the Chinese Loess Plateau by constructing a riverine carbon budget and further relating it to terrestrial ecosystem productivity. The riverine carbon export accounted for 16 % of the catchment's net ecosystem production (NEP). It seems that a significant fraction of terrestrial NEP in this catchment is laterally transported from the terrestrial biosphere to the drainage network.
Robert O. Hall Jr. and Hilary L. Madinger
Biogeosciences, 15, 3085–3092, https://doi.org/10.5194/bg-15-3085-2018, https://doi.org/10.5194/bg-15-3085-2018, 2018
Short summary
Short summary
Streams exchange oxygen with the atmosphere, but this rate is difficult to measure. We added argon to small mountain streams to estimate gas exchange. We compared these rates with sulfur hexafluoride, an intense greenhouse gas. Argon worked well to measure gas exchange, but had higher-than-predicted rates than sulfur hexafluoride. Argon exchange is more likely to represent that for oxygen because they share similar physical properties. We suggest argon to measure gas exchange in small streams.
Ji-Hyung Park, Omme K. Nayna, Most S. Begum, Eliyan Chea, Jens Hartmann, Richard G. Keil, Sanjeev Kumar, Xixi Lu, Lishan Ran, Jeffrey E. Richey, Vedula V. S. S. Sarma, Shafi M. Tareq, Do Thi Xuan, and Ruihong Yu
Biogeosciences, 15, 3049–3069, https://doi.org/10.5194/bg-15-3049-2018, https://doi.org/10.5194/bg-15-3049-2018, 2018
Short summary
Short summary
Human activities are drastically altering water and material flows in river systems across Asia. This review provides a conceptual framework for assessing the human impacts on Asian river C fluxes and an update on anthropogenic alterations of riverine C fluxes, focusing on the impacts of water pollution and river impoundments on CO2 outgassing from the rivers draining South, Southeast, and East Asian regions that account for the largest fraction of river discharge and C exports from Asia.
Chung-Te Chang, Jr-Chuan Huang, Lixin Wang, Yu-Ting Shih, and Teng-Chiu Lin
Biogeosciences, 15, 2379–2391, https://doi.org/10.5194/bg-15-2379-2018, https://doi.org/10.5194/bg-15-2379-2018, 2018
Short summary
Short summary
Our analysis of ion input–output budget illustrates that hydrochemical responses to typhoon storms are distinctly different from those of regular storms. In addition, even mild land use change may have large impacts on nutrient exports/losses. We propose that hydrological models should separate hydrochemical processes into regular and extreme conditions to better capture the whole spectrum of hydrochemical responses to a variety of climate conditions.
Camille Minaudo, Florence Curie, Yann Jullian, Nathalie Gassama, and Florentina Moatar
Biogeosciences, 15, 2251–2269, https://doi.org/10.5194/bg-15-2251-2018, https://doi.org/10.5194/bg-15-2251-2018, 2018
Short summary
Short summary
We developed the model QUALity-NETwork (QUAL-NET) to simulate water quality variations in large drainage networks. This model is accurate enough to represent processes occurring over short periods of time such as storm events and helps to fully understand water quality variations in stream networks in the context of climate change and varying human pressures. It was tested on the Loire River and provided good performances and a new understanding of the functioning of the river.
Michael P. Schwab, Julian Klaus, Laurent Pfister, and Markus Weiler
Biogeosciences, 15, 2177–2188, https://doi.org/10.5194/bg-15-2177-2018, https://doi.org/10.5194/bg-15-2177-2018, 2018
Short summary
Short summary
We studied the diel fluctuations of dissolved organic carbon (DOC) concentrations in a small stream in Luxembourg. We identified an increased proportion of DOC from terrestrial sources as responsible for the peaks in DOC in the afternoon. Warmer water temperatures in the riparian zone in the afternoon increased the amount of water flowing towards the stream. Consequently, an increased amount of DOC-rich water from the riparian zone was entering the stream.
Trent R. Marwick, Fredrick Tamooh, Bernard Ogwoka, Alberto V. Borges, François Darchambeau, and Steven Bouillon
Biogeosciences, 15, 1683–1700, https://doi.org/10.5194/bg-15-1683-2018, https://doi.org/10.5194/bg-15-1683-2018, 2018
Short summary
Short summary
A 2-year biogeochemical record provides annual sediment and element flux estimates for the non-dammed Sabaki River, Kenya, establishing a baseline for future research in light of impending construction of the first major upstream reservoir. Over 80 % of material fluxes occur across the wet season, with annual yields comparable to the adjacent, and dammed, Tana River. Observations at low-flow periods suggest large mammalian herbivores may be vectors of terrestrial subsidies to the water column.
Loris Deirmendjian, Denis Loustau, Laurent Augusto, Sébastien Lafont, Christophe Chipeaux, Dominique Poirier, and Gwenaël Abril
Biogeosciences, 15, 669–691, https://doi.org/10.5194/bg-15-669-2018, https://doi.org/10.5194/bg-15-669-2018, 2018
Short summary
Short summary
Carbon leaching to streams represents a very small (~ 2 %) fraction of forest net ecosystem exchange (NEE). Such weak export of carbon from forest ecosystems, at least in temperate regions, is at odds with recent studies that attempt to integrate the contribution of inland waters in the continent carbon budget. Understanding why local and global carbon mass balances strongly diverge on the proportion of land NEE exported to aquatic systems is a major challenge for research in this field.
Katrin Magin, Celia Somlai-Haase, Ralf B. Schäfer, and Andreas Lorke
Biogeosciences, 14, 5003–5014, https://doi.org/10.5194/bg-14-5003-2017, https://doi.org/10.5194/bg-14-5003-2017, 2017
Short summary
Short summary
We analyzed the relationship between terrestrial net primary production (NPP) and the rate at which carbon is exported from catchments in a temperate stream network. The carbon exported by streams and rivers corresponds to 2.7 % of the terrestrial NPP. CO2 evasion and downstream transport contribute about equally to this flux. A review of existing studies suggests that the catchment-specific carbon export varies in a relatively narrow range across different study regions and spatial scales.
Rémi Dupas, Andreas Musolff, James W. Jawitz, P. Suresh C. Rao, Christoph G. Jäger, Jan H. Fleckenstein, Michael Rode, and Dietrich Borchardt
Biogeosciences, 14, 4391–4407, https://doi.org/10.5194/bg-14-4391-2017, https://doi.org/10.5194/bg-14-4391-2017, 2017
Short summary
Short summary
Carbon and nutrient export regimes were analyzed from archetypal headwater catchments to
downstream reaches. In headwater catchments, land use and lithology determine
land-to-stream C, N and P transfer processes. The crucial role of riparian
zones in C, N and P coupling was investigated. In downstream reaches,
point-source contributions and in-stream processes alter C, N and P export
regimes.
Rose M. Smith, Sujay S. Kaushal, Jake J. Beaulieu, Michael J. Pennino, and Claire Welty
Biogeosciences, 14, 2831–2849, https://doi.org/10.5194/bg-14-2831-2017, https://doi.org/10.5194/bg-14-2831-2017, 2017
Short summary
Short summary
Urban streams receive excess nitrogen from numerous sources. We hypothesized that variations in carbon availability and subsurface infrastructure influence emissions of N2O and other greenhouse gases (CH4 and CO2) as excess N is utilized by microbes. We sampled eight streams draining four categories of stormwater and sanitary infrastructure. Dissolved nitrogen concentration was the strongest predictor of CO2 and N2O concentrations, while C : N ratio was the strongest predictor of CH4 in streams.
Benjamin Kupilas, Daniel Hering, Armin W. Lorenz, Christoph Knuth, and Björn Gücker
Biogeosciences, 14, 1989–2002, https://doi.org/10.5194/bg-14-1989-2017, https://doi.org/10.5194/bg-14-1989-2017, 2017
Short summary
Short summary
Modern ecosystem restoration should consider a wide range of environmental characteristics, including functional ones, such as rates and patterns of ecosystem metabolism. We show that hydromorphological river restoration enhanced habitat availability and abundance of macrophytes, promoting river primary productivity and respiration. Incorporating ecosystem functioning into monitoring programs enables a more holistic assessment of river health and a better understanding of restoration effects.
Julia Vanessa Kunz, Michael D. Annable, Jaehyun Cho, Wolf von Tümpling, Kirk Hatfield, Suresh Rao, Dietrich Borchardt, and Michael Rode
Biogeosciences, 14, 631–649, https://doi.org/10.5194/bg-14-631-2017, https://doi.org/10.5194/bg-14-631-2017, 2017
Short summary
Short summary
The hyporheic zone, the subsurface region of streams, is a key compartment for in-stream nutrient retention. Knowledge on actual hyporheic processing rates is still limited due to methodological restrictions which are mainly related to the high local and temporal variability of subsurface flow patterns and nutrient transformation processes. We present a new device which allows quantitative assessment of hyporheic nutrient fluxes and demonstrate its advantages in an exemplary field testing.
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.
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, Glob. Change Biol., 15, 955–960, 2009.
Anesio, A. M., Sattler, B., Foreman, C., Telling, J., Hodson, A., Tranter, M., and Psenner, R.: Carbon fluxes through bacterial communities on glacier surfaces, Ann. Glaciol., 51, 32–40, https://doi.org/10.3189/172756411795932092, 2010.
Baker, A. and Lamont-BIack, J.: Fluorescence of dissolved organic matter as a natural tracer of ground water, Ground Water, 39, 745–750, 2001.
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, 2006.
Barker, J. D., Sharp, M., 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, 2009.
Bartholomew, I., Nienow, P., Sole, A., Mair, D., Cowton, T., Palmer, S., and Wadham, J.: Supraglacial forcing of subglacial drainage in the ablation zone of the Greenland ice sheet, Geophys. Res. Lett., 38, L08502, https://doi.org/10.1029/2011GL047063, 2011.
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. Ac., 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. Ac., 109, 329–344, https://doi.org/10.1016/j.gca.2013.02.006, 2013a.
Bhatia, M. P., Kujawinski, E. B., Das, S. B., Breier, C. F., Henderson, P. B., and Charette, M. A.: Greenland meltwater as a significant and potentially bioavailable source of iron to the ocean, Nat. Geosci., 6, 274–278, https://doi.org/10.1038/ngeo1746, 2013b.
Biersmith, A. and Benner, R.: Carbohydrates in phytoplankton and freshly produced dissolved organic matter, Mar. Chem., 63, 131–144, 1998.
Chandler, D., Wadham, J., Lis, G., Cowton, T., Sole, A., Bartholomew, I., Telling, J., Nienow, P., Bagshaw, E., and Mair, D.: Evolution of the subglacial drainage system beneath the Greenland Ice Sheet revealed by tracers, Nat. Geosci., 6, 195–198, 2013.
Chen, J., LeBoef, E. J., Dai, S. and Gu, B. H.: Fluorescence spectroscopic studies of natural organic matter fractions, Chemosphere 50, 639–647, 2003.
Cheng, S. M. and Foght, J. M.: Cultivation-independent and -dependent characterization of Bacteria resident beneath John Evans Glacier, FEMS Microbiol. Ecol., 59, 318–330, 2007.
Chillrud, S. N., Pedrozo, F. L., Temporetti, P. F., Planas, H. F., and Froelich, P. N.: Chemical-weathering of phosphate and germanium in glacial meltwater streams – effects of subglacial pyrite oxidation, Limnol. Oceanogr., 39, 1130–1140, 1994.
Christner, B., Skidmore, M., Priscu, J., Tranter, M., and Foreman, C.: Bacteria in subglacial environments, in: Psychrophiles: From Biodiversity to Biotechnology, edited by: Margesin, R., Schinner, F., Marx, J. C., and Gerday, C., Springer, Berlin, 51–71, 2009.
Coble, P. G.: Characterization of marine and terrestrial DOM in seawater using excitation emission matrix spectroscopy, Mar. Chem., 51, 325–346, 1996.
Cowton, T., Nienow, P., Bartholomew, I., Sole, A., and Mair, D.: Rapid erosion beneath the Greenland ice sheet, Geology 40, 343–346, 2012.
Cuevas, L. A., Egge, J. K., Thingstad, T. F., and Topper, B.: Organic carbon and mineral nutrient limitation of oxygen consumption, bacterial growth and efficiency in the Norwegian Sea, Polar Biol., 34, 871–882, 2011.
Das, S. B., Joughin, I., Behn, M. D., Howat, I. M., King, M. A., Lizarralde, D., and Bhatia, M. P.: Fracture propagation to the base of the Greenland Ice Sheet during supraglacial lake drainage, Science, 320, 778–781, 2008.
Dittmar, T. and Kattner, G.: The biogeochemistry of the river and shelf ecosystem of the Arctic Ocean: a review, Mar. Chem., 83, 103–120, 2003.
Escher, A. and Watt, W. S.: Geology of Greenland, Grønlands Geologiske undersøgelse, 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, Biogeochemistry, 88, 169–184, 2008.
Fellman, J. B., Hood, E., Edwards, R. T., and D'Amore, D. V.: Changes in the concentration, biodegradability, and fluorescent properties of dissolved organic matter during stormflows in coastal temperate watersheds, J. Geophys. Res., 114, G01021, https://doi.org/10.1029/2008JG000790, 2009.
Fellman, J. B., Spencer, R. G. M., Hernes, P. J., Edwards, R. T., D'Amore, D. V., and Hood, E.: The impact of glacier runoff on the biodegradability and biochemical composition of terrigenous dissolved organic matter in near-shore marine ecosystems, Mar. Chem., 121, 112–122, 2010.
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.
Fettweis, X., Tedesco, M., van den Broeke, M., and Ettema, J.: Melting trends over the Greenland ice sheet (1958–2009) from spaceborne microwave data and regional climate models, The Cryosphere, 5, 359–375, https://doi.org/10.5194/tc-5-359-2011, 2011.
Foreman, C., Sattler, B., Mikucki, J., Poranzinska, D., and Priscu, J.: Metabolic activity and diversity of cryoconites in the Taylor valley, Antarctica, J. Geophys. Res., 112, G04S32, https://doi.org/10.1029/2006JG000358, 2007.
Gurnell, A., Hannah, D., and Lawler, D.: Suspended sediment yield from glacier basins, IAHS-AISH P., 236, 97–104, 1996.
Hanna, E., Huybrechts, P., Steffen, K., Cappelen, J., Huff, R., Shuman, C., Irvine-Fynn, T., Wise, S., and Griffiths, M.: Increased runoff from melt from the Greenland Ice Sheet: a response to global warming, J. Climate, 21, 331–341, 2008.
Hawkings, J. R., Wadham, J. L., Tranter, M., Raiswell, R., Benning, L. G., Statham, P. J., Tedstone, A., Nienow, P., Lee, K., and Telling, J.: Ice sheets as a significant source of highly reactive nanoparticulate iron to the oceans, Nature Commun., 5, 3929, https://doi.org/10.1038/ncomms4929, 2014.
Hodson, A., Anesio, A.M., Tranter, M., Fountain, A., Osborn, M., Priscu, J., Laybourn-Parry, J., Sattler, B.: Glacial ecosystems. Ecol. Monogr., 78, 41-67, 2008.
Hodson, A., Boggild, C., Hanna, E., Huybrechts, P., Langford, H., Cameron, K., and Houldsworth, A.: The cryoconite ecosystem on the Greenland ice sheet, Ann. Glaciol., 51, 123–129, 2010.
Holmes, R. M., McClelland, J. W., Peterson, B. J., Tank, S. E., Bulygina, E., Eglinton, T. I., Gordeev, V. V., Gurtovaya, T. Y., Raymond, P. A., and Repeta, D. J.: Seasonal and annual fluxes of nutrients and organic matter from large rivers to the Arctic Ocean and surrounding seas: Estuaries and Coasts, 35, 369–382, https://doi.org/10.1007/s12237-011-9386-6, 2012.
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, 2009.
Jansen, K., Stupperich, E., and Fuchs, G.: Carbohydrate synthesis from acetyl CoA in the autotroph Methanobacterium thermoautotrophicum, Arch. Microbiol., 132, 355–364, 1982.
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, 2001.
Lafrenière, M. and Sharp, M.: The concentration and fluorescence of Dissolved Organic Carbon (DOC) in glacial and nonglacial catchments; interpreting hydrological flow routing and DOC sources, Arct. Antarct. Alp. Res., 36, 156–165, https://doi.org/10.1657/1523-0430(2004)036[0156:TCAFOD]2.0.CO;2, 2004.
Lanoil, B., Skidmore, M., Priscu, J. C., Han, S., Foo, W., Vogel, S. W., Tulaczyk, S., and Engelhardt, H.: Bacteria beneath the West Antarctic Ice Sheet, Environ, Microbiol., 11, 609–615, 2009.
Lewis, S. and Smith, L.: Hydrologic drainage of the Greenland Ice Sheet, Hydrol. Process., 23, 2004–2011, https://doi.org/10.1002/hyp.7343, 2009.
Lobbes, J. M., Fitznar, H. P., and Kattner, G.: Biogeochemical characteristics of dissolved and particulate organic matter in Russian rivers entering the Arctic Ocean, Geochim. Cosmochim. Ac., 64, 2973–2983, 2000.
Lombardi, A. T. and Jardim, W. F.: Fluorescence spectroscopy of high performance liquid chromatography fractionated marine and terrestrial organic materials, Water Res., 33, 512–520, 1999.
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, 2001.
Mernild, S. H., Liston, G. E., Hiemstra, C. A., and Christensen, J. H.: Greenland Ice Sheet surface mass-balance modeling in a 131-yr perspective, 1950–2080, J. Hydrometeorol., 11, 3–25, 2010.
Miano, T. M. and Senesi, N.: Synchronous excitation fluorescence spectroscopy applied to soil humic substances chemistry, Sci. Total. Environ., 118, 41–51, 1992.
Middelboe, M. and Lundsgaard, C.: Microbial activity in the Greenland Sea: role of DOC lability, mineral nutrients and temperature, Aquat. Microb. Ecol., 32, 151–163, 2003.
Mikucki, J. A., Pearson, A., Johnston, D. T., Turchyn, A. V., Farquhar, J., Schrag, D. P., Anbar, A. D., Priscu, J. C., and Lee, P. A.: A contemporary microbially maintained subglacial ferrous "Ocean", Science, 324, 397–400, 2009.
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.
Nienow, P., Sharp, M., and Willis, I.: Seasonal changes in the morphology of the subglacial drainage system, Haut Glacier d'Arolla, Switzerland, Earth Surf. Proc. Land., 23, 825–843, 1998.
Raiswell, R.: Chemical-models of solute acquisition in glacial melt waters, J. Glaciol., 30, 49–57, 1984.
Raymond, P. A., McClelland, J. W., Holmes, R. M., Zhulidov, A. V., Mull, K., Peterson, B. J., Striegl, R. G., Aiken, G. R., and Gurtovaya, T. Y.: Flux and age of dissolved organic carbon exported to the Arctic Ocean: A carbon isotopic study of the five largest arctic rivers. Global Biogeochem. Cy., 21, GB4011, https://doi.org/10.1029/2007GB002934, 2007.
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 Pt II, 44, 1645–1663, 1997.
Säwström, C., Mumford, P., Marshall, W., Hodson, A., and Laybourn-Parry, J.: The microbial communities and primary productivity of cryoconite holes in an Arctic glacier (Svalbard 79° N), Polar Biol., 25, 591–596, 2002.
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, 1999.
Singer, G. A., Fasching, C., Wilhelm, L., Niggemann, J., Steier, P., Dittmar, T., and Battin, T. J.: Biogeochemically diverse organic matter in Alpine glaciers and its downstream fate, Nat. Geosci., 5, 710–714, https://doi.org/10.1038/ngeo1581, 2012.
Skidmore, M. L., Foght, J. M., and Sharp, M. J.: Microbial life beneath a high Arctic glacier, Appl. Environ. Microb., 66, 3214–3220, 2000.
Souchez, R., Samyn, D., Lorrain, R., Pattyn, F., and Fitzsimons, S.: An isotopic model for basal freeze-on associated with subglacial upward flow of pore water, Geophys. Res. Lett., 31, L02401, https://doi.org/10.1029/2003GL01886, 2004.
Stibal, M. and Tranter, M.: Laboratory investigation of inorganic carbon uptake by cryoconite debris from Werenskioldbreen, Svalbard, J. Geophys. Res.-Biogeo., 112, G04S33, https://doi.org/10.1029/2007JG000429, 2007.
Stibal, M., Tranter, M., Benning, L. G., and Rehak, J.: Microbial primary production on an Arctic glacier is insignificant in comparison with allochthonous organic carbon input, Environ. Microbiol., 10, 2172–2178, 2008.
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, 2010.
Stibal, M., Telling, J., Cook, J., Mak, K., Hodson, A., and Anesio, A.: Environmental controls on microbial abundance and activity on the Greenland Ice Sheet: a multivariate analysis approach, Microb. Ecol., 63, 74–84, 2012a.
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, 2012b.
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, Nat. Geosci., 5, 198–201, https://doi.org/10.1038/ngeo1403, 2012.
Ten Brink, N. W. and Weidick, A.: Greenland ice sheet history since the last glaciation, Quaternary Res., 4, 429–440, 1974.
Tranter, M., Sharp, M. J., Lamb, H. R., Brown, G. H., Hubbard, B. P., and Willis, I. C.: Geochemical weathering at the bed of Haut Glacier d'Arolla, Switzerland – a new model, Hydrol. Process., 16, 959–993, 2002.
Turchenek, L. and Oades, J.: Fractionation of organo-mineral complexes by sedimentation and density techniques, Geoderma, 21, 311–343, 1979.
Wadham, J. L., Hodson, A. J., Tranter, M., and Dowdeswell, J. A.: The hydrochemistry of meltwaters draining a polythermal-based, high Arctic glacier, south Svalbard: I. The ablation season, Hydrol. Process., 12, 1825–1849, 1998.
Wadham, J. L., Tranter, M., Skidmore, M., Hodson, A. J., Priscu, J., Lyons, W. B., Sharp, M., Wynn, P., and Jackson, M.: Biogeochemical weathering under ice: size matters, Global Biogeochem. Cy., 24, GB3025, https://doi.org/10.1029/2009GB003688, 2010.
Wadham, J. L., Death, R., Monteiro, F., Tranter, M., Ridgwell, A., Raiswell, R., and Tulaczyk, S.: The potential role of the Antarctic Ice Sheet in global biogeochemical cycles, Earth Env. Sci. T. R. So., 104, 1–13, 2013.
Yamashita, Y. and Tanoue, E.: Chemical characterization of protein-like fluorophores in DOM in relation to aromatic amino acids, Mar. Chem., 82, 255–271, 2003.
Altmetrics
Final-revised paper
Preprint