scholarly journals Recent ice cap snowmelt in Russian High Arctic and anti-correlation with late summer sea ice extent

2014 ◽  
Vol 9 (4) ◽  
pp. 045009 ◽  
Author(s):  
Meng Zhao ◽  
Joan Ramage ◽  
Kathryn Semmens ◽  
Friedrich Obleitner
Keyword(s):  
Sea Ice ◽  
Late Summer ◽  
High Arctic ◽  
Sea Ice Extent ◽  
Ice Cap

scholarly journals Evidence Of Environmental Change Since The Last Glacial Maximum Inferred From Chemical Analysis Of An Ice Core From Law Dome, Antarctica

1990 ◽  
Vol 14 ◽  
pp. 365-365
Author(s):  
N.W. Young ◽  
M. De Angelis ◽  
D. Davies
Keyword(s):  
Sea Ice ◽  
Oxygen Isotope ◽  
Atmospheric Circulation ◽  
Ice Core ◽  
Open Water ◽  
Sea Ice Extent ◽  
Ice Cap ◽  
Low Concentrations ◽  
Chemical Content ◽  
The Law

An ice core, drilled near the margin of the Law Dome ice cap at Cape Folger, has been analysed for trace chemical content. The concentration of the major anions and cations has been measured on samples selected from the ice core to give information on the major environmental changes which have occurred in the period 6–26 ka B.P. The chemical species can be divided into two fractions representing the two major sources of trace chemicals; marine and continental sources. Four species are chosen to illustrate the main features in the record; aluminium as an indicator of the continental fraction, sodium and magnesium as indicators of the marine fraction and methane sulphonic acid (MSA). Sodium and magnesium concentrations in the Law Dome core are predominantly derived from marine sources, although they usually include also small contributions from the continental sources. MSA has a marine biogenic source and exhibits a pattern which is generally unrelated to the variations in the two main fractions. Measured oxygen isotope ratios provide an additional data source. Concentrations of the same species in the Dome C core (De Angelis and others, 1982; Saigne and Legrand, 1987) are used as indicators of the global background atmospheric chemical content, and by inter-comparison of the records from the two cores are used to derive a proxy chronology for the Law Dome core.The interval in each core corresponding to the final stages of the Last Glacial Maximum (LGM) can be identified from the oxygen isotope records (Budd and Morgan, 1977; Lorius and others, 1984). Both cores have high aluminium concentrations in this interval reducing to very low concentrations towards the end of the transition to the Holocene. A similar sharp change from high to very low concentration is also observed for MSA. Very low concentrations of other species are also observed in this interval in the transition period. By assuming that these changes in the two cores are contemporaneous, the age scale from the Dome C core (Lorius and others, 1984) can be applied to the Law Dome core. An age of 13 ka B.p. is assigned to the very clean interval near the end of the transition. Other, less obvious, events in the chemical and isotope records distinguish intervals corresponding to ages of approximately 7.5, 15.5, and 26 ka B.P. Ages for intermediate intervals are derived by interpolation and reference to a modelled age-depth relation.The records from each of the cores for MSA and the continental fraction, represented by aluminium, show similar features at the Law Dome site as at Dome C. But the records for the marine fraction show distinct differences. On Law Dome there is a clear trend of decreasing concentration with depth, consistent with the ice at greater depth having an origin at higher elevation further inland on the ice cap. Very low concentrations occur in the lower part of the core, which includes the interval corresponding to the LGM. By way of contrast, at Dome C the concentration of sodium in the interval corresponding to the Holocene is low, but relatively higher in the LGM interval. The concentrations during the LGM, of both the marine and continental fractions, are lower in Law Dome by a factor generally between 1 and 2 than those at Dome C as a result of dilution caused by the higher precipitation and snow accumulation rates near the coast.For interpretation of the records, the concentrations in the Dome C core are assumed to indicate changes in the global background atmospheric loading and atmospheric circulation. On Law Dome, the general trend of decreasing concentra- tion with depth for the marine fraction is modulated by variations in the background atmospheric loading, and the effect of variations in past ice sheet and sea ice extent and thus distance to the source. At about 11 ka B.P., sodium and magnesium concentrations increase sharply to about three times the background level, and are maintained till about 9.5 ka B.P. This event is not apparent in the Dome C record. During the period 6–8 ka B P., sodium and magnesium concentrations are higher by a factor between 1.5 and 2 in conjunction with colder (more negative) values of the oxygen isotope ratio. There is some evidence of similar variations in the Dome C record.This suggests two separate scenarios. For the period 9.5–11 ka B P., one or more of the following events probably occurred: a change in the seasonal pattern of variation in sea ice extent and distribution; lesser sea ice extent; more open water closer to the coast; increased storminess in the coastal region, each of which could lead to an increased supply of material with marine source (sodium and magnesium) by either more vigorous atmospheric circulation or less distance to the source. Coincidentally, increased storminess is consistent with an increased fraction of open water in the sea ice zone. But there is apparently no change in the concnetration of MSA above background levels during this period. This could provide a constraint on the possible mechanisms causing the observed event. For the more recent period, 6–8 ka B.P., the changes found in both cores probably reflect climatic variation on a broader hemispheric or global scale, involving lower temperatures in at least the high latitudes, probably increased zonal atmospheric circulation, and perhaps changes in the seasonal sea ice distribution and total extent.

scholarly journals Winter Carnivory and Diapause Counteract the Reliance on Ice Algae by Barents Sea Zooplankton

2021 ◽  
Vol 8 ◽  
Author(s):  
Doreen Kohlbach ◽  
Katrin Schmidt ◽  
Haakon Hop ◽  
Anette Wold ◽  
Amalia Keck Al-Habahbeh ◽  
...  
Keyword(s):  
Sea Ice ◽  
Barents Sea ◽  
Feeding Activity ◽  
Carbon Sources ◽  
Late Summer ◽  
Rapid Decline ◽  
Amphipod Species ◽  
Ice Algae ◽  
Sea Ice Extent ◽  
Sea Ice Algae

The Barents Sea is a hotspot for environmental change due to its rapid warming, and information on dietary preferences of zooplankton is crucial to better understand the impacts of these changes on food-web dynamics. We combined lipid-based trophic marker approaches, namely analysis of fatty acids (FAs), highly branched isoprenoids (HBIs) and sterols, to compare late summer (August) and early winter (November/December) feeding of key Barents Sea zooplankters; the copepods Calanus glacialis, C. hyperboreus and C. finmarchicus and the amphipods Themisto libellula and T. abyssorum. Based on FAs, copepods showed a stronger reliance on a diatom-based diet. Phytosterols, produced mainly by diatoms, declined from summer to winter in C. glacialis and C. hyperboreus, indicating the strong direct linkage of their feeding to primary production. By contrast, C. finmarchicus showed evidence of year-round feeding, indicated by the higher winter carnivory FA ratios of 18:1(n-9)/18:1(n-7) than its larger congeners. This, plus differences in seasonal lipid dynamics, suggests varied overwintering strategies among the copepods; namely diapause in C. glacialis and C. hyperboreus and continued feeding activity in C. finmarchicus. Based on the absence of sea ice algae-associated HBIs (IP25 and IPSO25) in the three copepod species during both seasons, their carbon sources were likely primarily of pelagic origin. In both amphipods, increased FA carnivory ratios during winter indicated that they relied strongly on heterotrophic prey during the polar night. Both amphipod species contained sea ice algae-derived HBIs, present in broadly similar concentrations between species and seasons. Our results indicate that sea ice-derived carbon forms a supplementary food rather than a crucial dietary component for these two amphipod species in summer and winter, with carnivory potentially providing them with a degree of resilience to the rapid decline in Barents Sea (winter) sea-ice extent and thickness. The weak trophic link of both zooplankton taxa to sea ice-derived carbon in our study likely reflects the low abundance and quality of ice-associated carbon during late summer and the inaccessibility of algae trapped inside the ice during winter.

scholarly journals Biogenic and anthropogenic sources of aerosols at the High Arctic site Villum Research Station

2019 ◽  
Vol 19 (15) ◽  
pp. 10239-10256 ◽  
Author(s):  
Ingeborg E. Nielsen ◽  
Henrik Skov ◽  
Andreas Massling ◽  
Axel C. Eriksson ◽  
Manuel Dall'Osto ◽  
...  
Keyword(s):  
Sea Ice ◽  
Organic Aerosol ◽  
High Arctic ◽  
Polar Front ◽  
Anthropogenic Sources ◽  
The Arctic ◽  
Research Station ◽  
Aerosol Formation ◽  
Sea Ice Extent ◽  
Arctic Haze

Abstract. There are limited measurements of the chemical composition, abundance and sources of atmospheric particles in the High Arctic To address this, we report 93 d of soot particle aerosol mass spectrometer (SP-AMS) data collected from 20 February to 23 May 2015 at Villum Research Station (VRS) in northern Greenland (81∘36′ N). During this period, we observed the Arctic haze phenomenon with elevated PM1 concentrations ranging from an average of 2.3, 2.3 and 3.3 µg m−3 in February, March and April, respectively, to 1.2 µg m−3 in May. Particulate sulfate (SO42-) accounted for 66 % of the non-refractory PM1 with the highest concentration until the end of April and decreasing in May. The second most abundant species was organic aerosol (OA) (24 %). Both OA and PM1, estimated from the sum of all collected species, showed a marked decrease throughout May in accordance with the polar front moving north, together with changes in aerosol removal processes. The highest refractory black carbon (rBC) concentrations were found in the first month of the campaign, averaging 0.2 µg m−3. In March and April, rBC averaged 0.1 µg m−3 while decreasing to 0.02 µg m−3 in May. Positive matrix factorization (PMF) of the OA mass spectra yielded three factors: (1) a hydrocarbon-like organic aerosol (HOA) factor, which was dominated by primary aerosols and accounted for 12 % of OA mass, (2) an Arctic haze organic aerosol (AOA) factor and (3) a more oxygenated marine organic aerosol (MOA) factor. AOA dominated until mid-April (64 %–81 % of OA), while being nearly absent from the end of May and correlated significantly with SO42-, suggesting the main part of that factor is secondary OA. The MOA emerged late at the end of March, where it increased with solar radiation and reduced sea ice extent and dominated OA for the rest of the campaign until the end of May (24 %–74 % of OA), while AOA was nearly absent. The highest O∕C ratio (0.95) and S∕C ratio (0.011) was found for MOA. Our data support the current understanding that Arctic aerosols are highly influenced by secondary aerosol formation and receives an important contribution from marine emissions during Arctic spring in remote High Arctic areas. In view of a changing Arctic climate with changing sea-ice extent, biogenic processes and corresponding source strengths, highly time-resolved data are needed in order to elucidate the components dominating aerosol concentrations and enhance the understanding of the processes taking place.

scholarly journals New observations of late summer bio-physical ice and snow conditions in the northwestern Weddell Sea

2020 ◽  
Author(s):  
Stefanie Arndt ◽  
Christian Haas ◽  
Ilka Peeken
Keyword(s):  
Sea Ice ◽  
Ice Cores ◽  
Late Summer ◽  
Weddell Sea ◽  
Sea Ice Extent ◽  
Snow Properties ◽  
Snow Conditions ◽  
Surface Ice ◽  
Remote Sensing Methods ◽  
The Antarctic

<p>Summer sea ice extent in the Weddell Sea has increased overall during the last four decades, with large interannual variations. However, the underlying causes and the related ice and snow properties are still poorly known. Here we present results of the interdisciplinary Weddell Sea Ice (WedIce) project carried out in the northwestern Weddell Sea on board the German icebreaker R/V Polarstern in February and March 2019, i.e. at the end of the summer ablation period. This is the region of the thickest, oldest ice in the Weddell Sea, at the outflow of the Weddell Gyre. Measurements included airborne ice thickness surveys and in-situ snow and ice sampling of mostly second- and third year ice. Preliminary results show mean ice thicknesses between 2.6 and 5.4 m, increasing from the Antarctic Sound towards the Larsen B region. The ice had mostly positive ice freeboard. Mean snow thicknesses ranged between 0.05 and 0.46 m. Snow was well below the melting temperature on most days and was highly metamorphic and icy, with melt-freeze forms as dominant snow type. In addition, as a result of the summer’s thaw, an average of 0.14 m of superimposed ice was found in all ice cores drilled during the cruise. Although there was rotten ice below a solid, ca. 30 cm thick surface ice layer, pronounced gap layers typical for late summer ice in the marginal ice zone were rare, and algal biomass was patchily distributed within individual sea ice cores. Overall, there was a strong gradient of increasing ice algal biomass from the Larsen B to the Antarctic Sound region. The presented results show that sea ice conditions in the northwestern Weddell Sea are still severe and have not changed significantly since the last observations carried out in 2004 and 2006. The presence of relatively thin, icy snow has strong implications for the ice and snow mass balance, for freshwater oceanography, and for the application of remote sensing methods. Overall sea ice properties strongly affect the biological productivity of this region and limit carbon fluxes to the seafloor in the northwestern Weddell Sea.</p>

Long time-series of export fluxes in the western Ross Sea (Antarctica)

2020 ◽  
Author(s):  
Patrizia Giordano ◽  
Federico Giglio ◽  
Mariangela Ravaioli ◽  
Marco Capello ◽  
Laura Cutroneo ◽  
...  
Keyword(s):  
Time Series ◽  
Sea Ice ◽  
Primary Production ◽  
Ross Sea ◽  
Late Summer ◽  
Sediment Traps ◽  
Sea Ice Extent ◽  
Particle Fluxes ◽  
Over Time ◽  
Western Ross Sea

<p>The export of particulate organic carbon (POC) from the sea surface is an essential part of the biological pump. Export fluxes are the result of what is produced in surface water and how much is consumed during particle sinking in the water column. In the Ross Sea, fluxes of POC and total mass are well correlated implying that particle fluxes are dominated by biogenic debris.</p><p>Here, we report new and reference data of vertical particle fluxes to below the productive layer obtained on decadal time scales (1990-2017) by automatic sediment traps tethered to moorings in the western Ross Sea (Antarctica). Compilation of all data available in the Ross Sea (23 sites, >1000 samples) shows that annual POC fluxes to below 200 m average 4.4±3.3 g C m<sup>-2</sup>  y<sup>-1</sup>. Particle fluxes are relatively low when primary production is high (spring-summer) followed by enhanced sedimentation in late summer-fall. The high degree of decoupling between production and sedimentation is unusual compared to records of Antarctic Peninsula and may represent low grazing rates. Furthermore, data exhibit a large interannual variability and a decreasing trend over time, with a clear shift after 2000. Do the reduced export fluxes depend on lower biological production, enhanced OM consumption, or other processes (e.g., lateral transfer of biogenic particles outside the study area)?</p><p>Satellite observations allow us to reconstruct the seasonal and interannual change of chlorophyll biomass, and sea ice extent and duration. Water temperature recorded at mid-depth is used to monitor the different intrusion over time of CDW, the main driver of temporal variability of Fe supply for the Ross Sea. Time series of particle fluxes, chlorophyll, sea ice cover and mid-depth temperature will be compared in order to test if the recent reduction of downward particle fluxes depend on primary production changes.</p>

scholarly journals Baffin Bay sea ice extent and synoptic moisture transport drive water vapor isotope (<i>δ</i><sup>18</sup>O, <i>δ</i><sup>2</sup>H, and deuterium excess) variability in coastal northwest Greenland

2020 ◽  
Vol 20 (22) ◽  
pp. 13929-13955
Author(s):  
Pete D. Akers ◽  
Ben G. Kopec ◽  
Kyle S. Mattingly ◽  
Eric S. Klein ◽  
Douglas Causey ◽  
...  
Keyword(s):  
Water Vapor ◽  
Sea Ice ◽  
Environmental Changes ◽  
Surface Wind ◽  
Local Environment ◽  
Sea Breeze ◽  
High Arctic ◽  
Deuterium Excess ◽  
Sea Ice Extent ◽  
Baffin Bay

Abstract. At Thule Air Base on the coast of Baffin Bay (76.51∘ N, 68.74∘ W), we continuously measured water vapor isotopes (δ18O, δ2H) at a high frequency (1 s−1) from August 2017 through August 2019. Our resulting record, including derived deuterium excess (dxs) values, allows an analysis of isotopic–meteorological relationships at an unprecedented level of detail and duration for high Arctic Greenland. We examine isotopic variability across multiple temporal scales from daily to interannual, revealing that isotopic values at Thule are predominantly controlled by the sea ice extent in northern Baffin Bay and the synoptic flow pattern. This relationship can be identified through its expression in the following five interacting factors: (a) local air temperature, (b) local marine moisture availability, (c) the North Atlantic Oscillation (NAO), (d) surface wind regime, and (e) land-based evaporation and sublimation. Each factor's relative importance changes based on the temporal scale and in response to seasonal shifts in Thule's environment. Winter sea ice coverage forces distant sourcing of vapor that is isotopically light from fractionation during transport, while preventing isotopic exchange with local waters. Sea ice breakup in late spring triggers a rapid isotopic change at Thule as the newly open ocean supplies warmth and moisture that has ∼10 ‰ and ∼70 ‰ higher δ18O and δ2H values, respectively, and ∼10 ‰ lower dxs values. Sea ice retreat also leads to other environmental changes, such as sea breeze development, that radically alter the nature of relationships between isotopes and many meteorological variables in summer. On synoptic timescales, enhanced southerly flow promoted by negative NAO conditions produces higher δ18O and δ2H values and lower dxs values. Diel isotopic cycles are generally very small as a result of a moderated coastal climate and the counteracting isotopic effects of the sea breeze, local evaporation, and convection. Future losses in Baffin Bay's sea ice extent will likely shift mean annual isotopic compositions toward more summer-like values, and local glacial ice could potentially preserve isotopic evidence of past reductions. These findings highlight the influence that the local environment can have on isotope dynamics and the need for dedicated, multiseason monitoring to fully understand the controls on water vapor isotope variability.

scholarly journals Attribution of sea ice model biases to specific model errors enabled by new induced surface flux framework

2018 ◽  
Author(s):  
Alex West ◽  
Mat Collins ◽  
Ed Blockley ◽  
Jeff Ridley ◽  
Alejandro Bodas-Salcedo
Keyword(s):  
Sea Ice ◽  
Climate Models ◽  
Climate Model ◽  
Late Summer ◽  
Surface Flux ◽  
Arctic Sea Ice ◽  
Onset Date ◽  
Model Errors ◽  
Sea Ice Extent ◽  
Ice Volume

Abstract. A new framework is presented for analysing the causes of model sea ice biases, demonstrated with the CMIP5 model HadGEM2-ES. Arctic sea ice extent has decreased over recent decades and has reached historic minima in late summer in recent years. Climate models project an ice-free Arctic in late summer during the 21st century, with wide-ranging implications for global climate and geopolitics. However, substantial spread remains in climate model projections of the rate of sea ice decline, with drivers poorly understood. In the framework described, the sea ice volume is treated as a consequence of the integrated surface energy balance. A system of simple models allows specific portions of the surface flux anomaly to be attributed to individual processes by calculating for each process an induced surface flux anomaly. The method allows detailed quantification of the role played by the surface albedo and ice thickness-growth feedbacks in causing anomalous sea ice melt and growth. It shows biases in the HadGEM2-ES sea ice volume simulation to be due to a bias in spring surface melt onset date, partly countered by a counteracting bias in winter downwelling longwave radiation. The framework is applicable in principle to any model and has the potential to greatly improve understanding of the reasons for ensemble spread in modelled sea ice state.

scholarly journals Biogenic and Anthropogenic sources of Arctic Aerosols

2019 ◽  
Author(s):  
Ingeborg E. Nielsen ◽  
Henrik Skov ◽  
Andreas Massling ◽  
Axel C. Eriksson ◽  
Manuel Dall'Osto ◽  
...  
Keyword(s):  
Sea Ice ◽  
Black Carbon ◽  
Organic Aerosol ◽  
High Arctic ◽  
Anthropogenic Sources ◽  
The Arctic ◽  
Research Station ◽  
Aerosol Formation ◽  
Sea Ice Extent ◽  
Arctic Haze

Abstract. There are limited measurements of the chemical composition, abundance, and sources of black carbon (BC) containing particles in the high Arctic. To address this, we report 93 days of Soot Particle Aerosol Mass Spectrometer (SP-AMS) data collected in the high Arctic. The period spans from February 20th until May 23rd 2015 at Villum Research Station (VRS) in Northern Greenland (81°36' N). Particulate sulfate (SO42−) accounted for 66 % of the non-refractory PM1, which amounted to 2.3 µg m−3 as an average value observed during the campaign. The second most abundant species was organic matter (24 %), averaging 0.55 µg m3. Both organic aerosol (OA) and PM1, estimated from the sum of all collected species, showed a marked decrease throughout May in accordance with Arctic haze leveling off. The refractory black carbon (rBC) concentration averaged 0.1 µg m−3 over the entire campaign. Positive Matrix Factorization (PMF) of the OA mass spectra yielded three factors: (1) a Hydrocarbon-like Organic Aerosol (HOA) factor, which was dominated by primary aerosols and accounted for 12 % of OA mass; (2) an Arctic haze Organic Aerosol (AOA) factor, which accounted for 64 % of the OA and dominated until mid-April while being nearly absent from the end of May; and (3) a more oxygenated Marine Organic Aerosol (MOA) factor, which accounted for 22 % of OA. AOA correlated significantly with SO42−, suggesting the main part of that factor being secondary OA. The MOA emerged late at the end of March, where it increased with solar radiation and reduced sea ice extent, and dominated OA for the rest of the campaign until the end of May. Important differences are observed among the factors, including the highest O/C ratio (0.95) and S/C ratio (0.011) for MOA – the marine related factor. Our data supports current understanding of the Arctic summer aerosols, driven mainly by secondary aerosol formation, but with an important contribution from marine emissions. In view of a changing Arctic climate with changing sea-ice extent, biogenic processes, and corresponding source strengths, highly time-resolved data are urgently needed in order to elucidate the components dominating aerosol concentrations.

scholarly journals Investigating the anomalous sea-ice conditions in the Canadian High Arctic (Queen Elizabeth Islands) during summer 1998

2001 ◽  
Vol 33 ◽  
pp. 507-512 ◽  
Author(s):  
Sharon Jeffers ◽  
Tom A. Agnew ◽  
Bea Taylor Alt ◽  
Roger de Abreu ◽  
Steve McCourt
Keyword(s):  
Time Series ◽  
Sea Ice ◽  
High Arctic ◽  
Canadian High Arctic ◽  
Sea Ice Extent ◽  
Ice Melt ◽  
Digital Database ◽  
Ice Conditions ◽  
Fast Ice ◽  
Thermal Preconditioning

AbstractThe Queen Elizabeth Islands of the Canadian Arctic Archipelago exhibit one of the most complex sea-ice regimes in the Northern Hemisphere. Time series of minimum monthly passive-microwave sea-ice area (1979−98), minimum sea-ice extent, melting degree-days (1961−98) and minimum sea ice from the new Canadian Ice Service digital database (1968−98) are examined. The extreme nature of the amount of sea-ice melt in the summers of 1998 and 1962 is evident in these time series. The 38 year record of minimum ice, to date, shows no significant trend. Details of the sea-ice behavior during summer 1998 were then examined within 13 individual sea-ice regimes. The multi-year fast-ice plugs in both Sverdrup Channel and Nansen Sound broke up and became truly mobile in 1998. Discussion focuses on the areas surrounding the multi-year plugs, relating sea-ice conditions to weather. Results emphasize the importance of the timing of synoptic events in combination with strong thermal preconditioning in determining the sea-ice conditions in this area during summer 1998.

scholarly journals Warmer–wetter climate drives shift in δD–δ18O composition of precipitation across the Queen Elizabeth Islands, Arctic Canada

2020 ◽  
pp. 1-22
Author(s):  
Luke Copland ◽  
Denis Lacelle ◽  
David Fisher ◽  
Frances Delaney ◽  
Laura Thomson ◽  
...  
Keyword(s):  
Sea Ice ◽  
Ice Cores ◽  
Atmospheric Temperature ◽  
Sea Ice Extent ◽  
Ice Caps ◽  
Ice Cap ◽  
Temperature And Precipitation ◽  
Vapour Flux ◽  
Zonal Average ◽  
Snow Samples

We examine how recent increases in air temperature and precipitation, together with reductions in sea ice extent, may have affected the regional δD–δ18O composition of precipitation. In spring 2014, 80 snow samples were collected from six glaciers and ice caps across the Queen Elizabeth Islands, and in 2009 and 2014, two shallow ice cores were collected from Agassiz Ice Cap and White Glacier, respectively. The snow samples showed average δ18O values from 2013 to 2014 to be approximately 2‰–3‰ higher than those recorded in 1973–1974 in nearby locations, with the ice cores showing similar trends in δ18O values. A zonal average water isotope model was used to help understand the causes of the increased δ18O values, using inputs calibrated for observed changes in temperature, vapour flux, and sea ice extent. Model results indicate that atmospheric temperature changes account for <1‰ of the observed change in δ18O values, and that changes in local water input and precipitation driven by changes in sea ice extent only have an effect in coastal regions. Enhanced meridional vapour flux to the Queen Elizabeth Islands is, therefore, also required to explain the observed increases in δ18O values, with fluxes ∼7% higher today than in the 1970s, consistent with the change in precipitation.

Sign in / Sign up

Export Citation Format

Share Document