Increasing River Discharge to the Arctic Ocean

Peterson, Bruce J.; Holmes, Robert M.; McClelland, J. W.; Vörösmarty, Charles J; Lammers, Richard B.; Shiklomanov, A. I.; Shiklomanov, I. A.; Rahmstorf, Stefan

doi:10.1126/science.1077445

Cited by 1,332 publications

(1,068 citation statements)

References 27 publications

Supporting

Mentioning

1,000

Contrasting

Unclassified

Order By: Relevance

“…A general picture of increasing runoff trends in the panArctic drainage basin has been established in recent years (Peterson et al 2002Dyurgerov and Carter 2004;McClelland et al 2006;Shiklomanov and Lammers 2009). Dyurgerov et al (2010) have further reported that river runoff to the Arctic Ocean has increased independently of, but with similar magnitude as the increase in freshwater input from glacier melting.…”

Section: Discussionmentioning

confidence: 99%

Relevance of Hydro-Climatic Change Projection and Monitoring for Assessment of Water Cycle Changes in the Arctic

Bring

Destouni

2010

AMBIO

View full text Add to dashboard Cite

Rapid changes to the Arctic hydrological cycle challenge both our process understanding and our ability to find appropriate adaptation strategies. We have investigated the relevance and accuracy development of climate change projections for assessment of water cycle changes in major Arctic drainage basins. Results show relatively good agreement of climate model projections with observed temperature changes, but high model inaccuracy relative to available observation data for precipitation changes. Direct observations further show systematically larger (smaller) runoff than precipitation increases (decreases). This result is partly attributable to uncertainties and systematic bias in precipitation observations, but still indicates that some of the observed increase in Arctic river runoff is due to water storage changes, for example melting permafrost and/or groundwater storage changes, within the drainage basins. Such causes of runoff change affect sea level, in addition to ocean salinity, and inland water resources, ecosystems, and infrastructure. Process-based hydrological modeling and observations, which can resolve changes in evapotranspiration, and groundwater and permafrost storage at and below river basin scales, are needed in order to accurately interpret and translate climate-driven precipitation changes to changes in freshwater cycling and runoff. In contrast to this need, our results show that the density of Arctic runoff monitoring has become increasingly biased and less relevant by decreasing most and being lowest in river basins with the largest expected climatic changes.

show abstract

Section: Discussionmentioning

confidence: 99%

Relevance of Hydro-Climatic Change Projection and Monitoring for Assessment of Water Cycle Changes in the Arctic

Bring

Destouni

2010

AMBIO

View full text Add to dashboard Cite

show abstract

“…Throughout the last 25 yr there has been a steady downward trend in the extent of summer sea ice in coastal arctic regions, with 3 consecutive years of record minima in the period from 2002 to 2004 (Stroeve et al 2005). The Arctic Ocean is strongly influenced by inflows from large rivers, and the discharge of these inputs appears to be increasing (Peterson et al 2002), with implications for the delivery of dissolved and particulate organic matter to inshore arctic seas. Moreover, permafrost melting in subarctic and arctic catch-ments (Payette et al 2004) may mobilize the large stocks of organic carbon contained within their soils and cause increased transfer of these materials to arctic rivers and ultimately to the ocean.…”

Section: Introductionmentioning

confidence: 99%

Prokaryotic community structure and heterotrophic production in a river-influenced coastal arctic ecosystem

Garneau

Vincent²,

Alonso‐Sáez³

et al. 2006

Aquat. Microb. Ecol.

129

105

View full text Add to dashboard Cite

Spatial patterns in prokaryotic biodiversity and production were assessed in the Mackenzie shelf region of the Beaufort Sea during open-water conditions. The sampling transect extended 350 km northwards, from upstream freshwater sites in the Mackenzie River to coastal and offshore sites, towards the edge of the perennial arctic ice pack. The analyses revealed strong gradients in community structure and prokaryotic cell concentrations, both of which correlated with salinity. Picocyanobacterial abundance was low (10 2 to 10 3 cells ml -1 ), particularly at the offshore stations that were least influenced by the river plume. Analysis by catalyzed reporter deposition for fluorescence in situ hybridization (CARD-FISH) showed that the dominant heterotrophic cell types were β-Proteobacteria at river sites, shifting to dominance by α-Proteobacteria offshore. Cells in the Cytophaga-Flavobacter-Bacteroides and γ-Proteobacteria groups each contributed < 5% of total counts in the river, but >10% of counts in the marine samples. Archaea were detected among the surface-water microbiota, contributing on average 1.3% of the total DAPI counts in marine samples, but 6.0% in turbid coastal and riverine waters. 3 H-leucine uptake rates were significantly higher at 2 stations influenced by the river (1.5 pmol l -1 h -1 ) than at other marine stations or in the river itself (≤0.5 pmol -1 h -1 ). Size-fractionation experiments at 2 coastal sites showed that > 65% of heterotrophic production was associated with particles > 3 µm. These results indicate the importance of particleattached prokaryotes, and imply a broad functional diversity of heterotrophic microbes that likely facilitates breakdown of the heterogeneous dissolved and particulate terrestrial materials discharged into arctic seas. KEY WORDS:Prokaryote diversity · Archaea · Proteobacteria · Cytophaga-FlavobacterBacteroides · Arctic Ocean · Mackenzie River estuary · Picocyanobacteria · CARD-FISH Resale or republication not permitted without written consent of the publisherAquat Microb Ecol 42: [27][28][29][30][31][32][33][34][35][36][37][38][39][40] 2006 ments (Payette et al. 2004) may mobilize the large stocks of organic carbon contained within their soils and cause increased transfer of these materials to arctic rivers and ultimately to the ocean. Heterotrophic microbiota are likely to play a major role in the response of coastal arctic ecosystems to ongoing change, but prokaryotic diversity and production in these cold ocean environments have been little explored (Amon 2004).In the western Canadian Arctic, the Mackenzie River discharges large quantities of freshwater, solutes and sediments into a vast shelf region of the Beaufort Sea that extends >100 km offshore and encompasses a total area of 63 600 km 2 (Carmack et al. 2004). The annual discharge of the Mackenzie River (330 km 3 yr -1 ; Macdonald et al. 1998) is the 4th highest in the Arctic Basin after the Siberian rivers Yenisei, Lena and Ob, with concomitantly large inputs of freshwater biota, terrestria...

show abstract

“…A growing amount of evidence shows that global runoff has already increased significantly since the beginning of the 20th century [Labat et al, 2004;Garcia and Mechoso, 2006;Peterson et al, 2002]. But did runoff really increase since 1950?…”

Section: Introductionmentioning

confidence: 99%

Relative contributions of climate change, stomatal closure, and leaf area index changes to 20th and 21st century runoff change: A modelling approach using the Organizing Carbon and Hydrology in Dynamic Ecosystems (ORCHIDEE) land surface model

Alkama¹,

Kageyama²,

Ramstein³

2010

J. Geophys. Res.

View full text Add to dashboard Cite

[1] The recent evolution of continental runoff is still an open question. A related and controversial question is the attribution of this change and its consequences on our predictions of the behavior of future runoff. Here, the Land Surface Model Organizing Carbon and Hydrology in Dynamic Ecosystems is used to perform a set of transient simulations of the runoff from 1900 to 2100. We first show that the model's simulated runoff increases for the 20th century from a global point of view as well as its geographical pattern changes are close to the observations made in this paper. Moreover this trend is simulated to increase further during the 21st century under the SRES A2 scenario. We have designed a set of simulations to test the impact on global runoff evolution of three factors: climate, stomatal conductance, and vegetation growth, all sensitive to CO 2 increase. A complete factor-separation analysis of the influence of these three factors and of their interactions shows that climate change largely drives the 20th and 21st century runoff increase. The other two factors (stomatal conductance and vegetation growth) play a minor role in the 20th century runoff trend but we show that these contributions increase for the 21st century simulations. Although the interactions between the factors also plays a negligible role in the 20th century global runoff increase, our results show that they become significant during the 21st century, usually reducing the direct effect of each factor. However, our study does not reveal any important negative feedback to counteract the effect of climate warming on the hydrological cycle.Citation: Alkama, R., M. Kageyama, and G. Ramstein (2010), Relative contributions of climate change, stomatal closure, and leaf area index changes to 20th and 21st century runoff change: A modelling approach using the Organizing Carbon and Hydrology in Dynamic Ecosystems (ORCHIDEE) land surface model,

show abstract

Increasing River Discharge to the Arctic Ocean

Cited by 1,332 publications

References 27 publications

Relevance of Hydro-Climatic Change Projection and Monitoring for Assessment of Water Cycle Changes in the Arctic

Relevance of Hydro-Climatic Change Projection and Monitoring for Assessment of Water Cycle Changes in the Arctic

Prokaryotic community structure and heterotrophic production in a river-influenced coastal arctic ecosystem

Relative contributions of climate change, stomatal closure, and leaf area index changes to 20th and 21st century runoff change: A modelling approach using the Organizing Carbon and Hydrology in Dynamic Ecosystems (ORCHIDEE) land surface model

Contact Info

Product

Resources

About