Transitions in Arctic ecosystems: Ecological implications of a changing hydrological regime

Journal of Geophysical Research Biogeosciences, Journal Year: 2016, Volume and Issue: 121(3), P. 650 - 674

Published: March 1, 2016

Abstract Numerous international scientific assessments and related articles have, during the last decade, described observed potential impacts of climate change as well other environmental stressors on Arctic ecosystems. There is increasing recognition that projected changes in freshwater sources, fluxes, storage will have profound implications for physical, biogeochemical, biological, ecological processes properties terrestrial However, a significant level uncertainty remains relation to forecasting an intensified hydrological regime cryospheric ecosystem structure function. As ecology component Freshwater Synthesis, we review these uncertainties recommend enhanced coordinated circumpolar research monitoring efforts improve quantification prediction how altered influences local, regional, circumpolar‐level responses systems. Specifically, evaluate (i) productivity; (ii) alterations ecosystem‐level biogeochemical cycling chemical transport; (iii) landscapes, successional trajectories, creation new habitats; (iv) seasonality phenological mismatches; (v) gains or losses species associated trophic interactions. We emphasize need developing process‐based understanding interecosystem interactions, along with improved predictive models. use catchment scale integrated unit study, thereby more explicitly considering chemical, fluxes across full continuum geographic region spatial range hydroecological units (e.g., stream‐pond‐lake‐river‐near shore marine environments).

Language: Английский

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Analysis of the Beaufort Gyre Freshwater Content in 2003–2018

Journal of Geophysical Research Oceans, Journal Year: 2019, Volume and Issue: 124(12), P. 9658 - 9689

Published: Dec. 1, 2019

Abstract Hydrographic data collected from research cruises, bottom‐anchored moorings, drifting Ice‐Tethered Profilers, and satellite altimetry in the Beaufort Gyre region of Arctic Ocean document an increase more than 6,400 km 3 liquid freshwater content 2003 to 2018: a 40% growth relative climatology 1970s. This fresh water accumulation is shown result persistent anticyclonic atmospheric wind forcing (1997–2018) accompanied by sea ice melt, wind‐forced redirection Mackenzie River discharge predominantly eastward westward flow, contribution low salinity waters Pacific origin via Bering Strait. Despite significant uncertainties different observations, this study has demonstrated synergistic value having multiple diverse datasets obtain comprehensive understanding variability. For example, Observational System (BGOS) surveys clearly show interannual content, but without or Profiler measurements, it not possible resolve seasonal cycle which fact larger year‐to‐year variability, subtle variations.

Language: Английский

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Land Ice Freshwater Budget of the Arctic and North Atlantic Oceans: 1. Data, Methods, and Results

Journal of Geophysical Research Oceans, Journal Year: 2018, Volume and Issue: 123(3), P. 1827 - 1837

Published: Feb. 21, 2018

Abstract The freshwater budget of the Arctic and sub‐polar North Atlantic Oceans has been changing due, primarily, to increased river runoff, declining sea ice enhanced melting land ice. Since mid‐1990s this latter component experienced a pronounced increase. We use combination satellite observations glacier flow speed regional climate modeling reconstruct flux from Greenland sheet glaciers caps for period 1958–2016. cumulative anomaly exceeded 6,300 ± 316 km 3 by 2016. This is roughly twice estimate previous analysis that did not include outside which extended only 2010. From 2010 onward, total about 1,300 /yr, equivalent 0.04 Sv, 40% estimated runoff same time period. Not all will reach areas deep convection or Sub‐Arctic seas. note, however, largest anomalies, grouped ocean basin, are located in Baffin Bay Davis Strait. displays strong seasonal cycle with summer values typically around five times larger than annual mean. be important understanding impact these fluxes on fjord circulation, stratification, biogeochemistry of, nutrient delivery to, coastal waters.

Language: Английский

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Recent changes to Arctic river discharge

Nature Communications, Journal Year: 2021, Volume and Issue: 12(1)

Published: Nov. 25, 2021

Arctic rivers drain ~15% of the global land surface and significantly influence local communities economies, freshwater marine ecosystems, climate. However, trusted public knowledge pan-Arctic is inadequate, especially for small across Eurasia, inhibiting understanding response to climate change. Here, we calculate daily streamflow in 486,493 river reaches from 1984-2018 by assimilating 9.18 million discharge estimates made 155,710 satellite images into hydrologic model simulations. We reveal larger more heterogenous total water export (3-17% greater) acceleration (factor 1.2-3.3 larger) than previously reported, with substantial differences basins, ecoregions, stream orders, human regulation, permafrost regimes. also find significant changes spring freshet summer intermittency. Ultimately, our results represent an updated, publicly available, accurate uniquely enabled recent advances modeling remote sensing.

Language: Английский

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Winter Arctic Sea Ice Thickness From ICESat‐2 Freeboards

Journal of Geophysical Research Oceans, Journal Year: 2020, Volume and Issue: 125(5)

Published: April 15, 2020

Abstract National Aeronautics and Space Administration's (NASA's) Ice, Cloud, land Elevation Satellite‐2 (ICESat‐2) mission was launched in September 2018 with the primary goal of monitoring our rapidly changing polar regions. The sole instrument onboard, Advanced Topographic Laser Altimeter System, is now providing routine, very high‐resolution, surface elevation data across globe, including Arctic Southern oceans. In this study, we demonstrate new processing chain for converting along‐track ICESat‐2 sea ice freeboard product (ATL10) into thickness, focusing initial efforts on Ocean. For conversion, primarily make use snow depth density from NASA Eulerian Snow Sea Ice Model. coarse resolution (~100 km) are redistributed onto high‐resolution (approximately 30–100 m) ATL10 freeboards using relationships obtained collected by NASA's Operation IceBridge mission. We present regional thickness distributions highlight their seasonal evolution through first winter season collection. include uncertainty estimates, while also acknowledging limitations these estimates. generate a gridded monthly compare various estimates European Agency's CryoSat‐2 satellite mission, showing consistently lower thicknesses. Finally, February/March 2019 to ICESat (19 February 21 March) 2008 same input assumptions, which show an ~0.37 m or ~20% thinning inner Ocean domain 11‐year time period.

Language: Английский

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Review article: Earth's ice imbalance

˜The œcryosphere, Journal Year: 2021, Volume and Issue: 15(1), P. 233 - 246

Published: Jan. 25, 2021

Abstract. We combine satellite observations and numerical models to show that Earth lost 28 trillion tonnes of ice between 1994 2017. Arctic sea (7.6 tonnes), Antarctic shelves (6.5 mountain glaciers (6.1 the Greenland sheet (3.8 (2.5 Southern Ocean (0.9 tonnes) have all decreased in mass. Just over half (58 %) loss was from Northern Hemisphere, remainder (42 Hemisphere. The rate has risen by 57 % since 1990s – 0.8 1.2 per year owing increased losses glaciers, Antarctica, shelves. During same period, grounded sheets raised global level 34.6 ± 3.1 mm. majority were driven atmospheric melting (68 ice, shelf calving surface mass balance), with remaining (32 discharge thinning) being oceanic melting. Altogether, these elements cryosphere taken up 3.2 energy imbalance.

Language: Английский

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The Transpolar Drift as a Source of Riverine and Shelf‐Derived Trace Elements to the Central Arctic Ocean

Journal of Geophysical Research Oceans, Journal Year: 2020, Volume and Issue: 125(5)

Published: April 8, 2020

Abstract A major surface circulation feature of the Arctic Ocean is Transpolar Drift (TPD), a current that transports river‐influenced shelf water from Laptev and East Siberian Seas toward center basin Fram Strait. In 2015, international GEOTRACES program included high‐resolution pan‐Arctic survey carbon, nutrients, suite trace elements isotopes (TEIs). The cruises bisected TPD at two locations in central basin, which were defined by maxima meteoric dissolved organic carbon concentrations spanned 600 km horizontally ~25–50 m vertically. Dissolved TEIs such as Fe, Co, Ni, Cu, Hg, Nd, Th, are generally particle‐reactive but can be complexed matter, observed much higher than expected for open ocean setting. Other element Al, V, Ga, Pb lower due to scavenging over productive seas. Using combination radionuclide tracers ice drift modeling, transport rate core was estimated 0.9 ± 0.4 Sv (10 6 3 s −1 ). This used derive mass flux enriched TPD, revealing importance lateral supplying materials beneath potentially North Atlantic via Continued intensification hydrologic cycle permafrost degradation will likely lead an increase into Ocean.

Language: Английский

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Human‐induced salinity changes impact marine organisms and ecosystems

Global Change Biology, Journal Year: 2023, Volume and Issue: 29(17), P. 4731 - 4749

Published: July 12, 2023

Abstract Climate change is fundamentally altering marine and coastal ecosystems on a global scale. While the effects of ocean warming acidification ecology ecosystem functions services are being comprehensively researched, less attention directed toward understanding impacts human‐driven salinity changes. The water cycle operates through fluxes expressed as precipitation, evaporation, freshwater runoff from land. Changes to these in turn modulate shape environment by affecting currents, stratification, oxygen saturation, sea level rise. Besides direct impact physical processes, changes biological with ecophysiological consequences poorly understood. This surprising may diversity, habitat structure loss, community shifts including trophic cascades. model future projections (of end century changes) indicate magnitudes that lead modification open plankton suitability coral reef communities. Such also capable diversity metabolic capacity microorganisms impairing photosynthetic (coastal ocean) phytoplankton, macroalgae, seagrass, downstream ramifications biogeochemical cycling. scarcity comprehensive data dynamic regions warrants additional attention. datasets crucial quantify salinity‐based function relationships project such ultimately link into carbon sequestration well food availability human populations around globe. It critical integrate vigorous high‐quality interacting key environmental parameters (e.g., temperature, nutrients, oxygen) for anthropogenically induced its health economy.

Language: Английский

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Copernicus Marine Service Ocean State Report

Journal of Operational Oceanography, Journal Year: 2018, Volume and Issue: 11(sup1), P. S1 - S142

Published: Aug. 24, 2018

Introduction — s1 Chapter 1: Essential Variables s4  1.1 Ocean temperature and salinity  Sandrine Mulet, Bruno Buongiorno Nardelli, Simon Good, Andrea Pisano, Eric Greiner, Maeva Monier, Emmanuel...

Language: Английский

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Physical constrains and productivity in the future Arctic Ocean

Frontiers in Marine Science, Journal Year: 2015, Volume and Issue: 2

Published: Oct. 20, 2015

Todays physical oceanography and primary secondary production was investigated for the entire Arctic Ocean with physical-biologically coupled SINMOD model. To obtain indications on effect of climate change in 21th century magnitude change, where when these may take place forced down-scaled trajectories International Panel Climate Change A1B scenario which appears to predict an average global atmospheric temperature increase 3.5 4 °C at end this century. It is projected that some surface water features adjacent regions will considerably. The largest changes occur along continuous domains Pacific particular regarding Atlantic Water advection inflow shelves. Withdrawal ice production, but stratification persist or, most, get stronger as a function ice-melt thermal warming Thus nutrient dependent new harvestable not proportionally increasing photosynthetic active radiation. greatest increases are found Eurasian perimeter (up 40 g C m-2 y-1) northern Barents Kara Seas (40-80 less ice-cover implies thus stratification. Along shelf break engirdling upwelling vertical mixing supplies nutrients euphotic zone withdraws northwards. copepods significantly by (2-4 y-1). Primary decrease southern sections due In central much stratification-induced limitation.

Language: Английский

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