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Author Pitout F, Marchaudon A, Blelly P-L, Bai X, Forme F, Buchert S C, Lorentzen D A, doi  openurl
  Title Swarm and ESR observations of the ionospheric response to a field-aligned current system in the high-latitude midnight sector Type Journal Article
  Year 2015 Publication Geophysical Research Letters Abbreviated Journal  
  Volume 42 Issue 11 Pages 4270-4279  
  Keywords  
  Abstract (down) We present a conjunction between the Swarm fleet and the European Incoherent Scatter Svalbard Radar (ESR) on 9 January 2014. The Swarm orbit in the early phase of the mission gives us the unique opportunity of sequencing the temporal evolution of the observed field-aligned current system in the nightside, near magnetic local midnight. These field-aligned currents are seen to move poleward through the radar field of view and to affect the observed ionosphere. The upward field-aligned current (FAC) is responsible, at least in part, for the heating of the ionospheric electrons. It is less clear whether the downward FAC cools the ionosphere. We use the TRANSCAR model of the ionosphere to quantify the thermoelectric effect that comes into play. Finally, we compare the plasma parameters measured by the Langmuir probe on board Swarm and the ESR and conclude on an agreement within the errors.  
  Programme 312  
  Campaign  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0094-8276 ISBN Medium  
  Area Expedition Conference  
  Notes Approved yes  
  Call Number Serial 6118  
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Author Wang Z, Chappellaz J, Park K, Mak J E, doi  openurl
  Title Large Variations in Southern Hemisphere Biomass Burning During the Last 650 Years. Type Journal Article
  Year 2010 Publication Science (New York, N.Y.) Abbreviated Journal Science  
  Volume 330 Issue 6011 Pages 1663 -1666  
  Keywords  
  Abstract (down) We present a 650-year Antarctic ice core record of concentration and isotopic ratios ((13)C and (18)O) of atmospheric carbon monoxide. Concentrations decreased by ~25% (14 ppbv) from mid-1300s to the 1600s, then recovered completely by the late 1800s. (13)C and (18)O decreased by about 2 and 4 respectively from mid-1300s to the 1600s, then increase by about 2.5 and 4 by the late 1800s. These observations and isotope mass balance model results imply that large variations in the degree of biomass burning in the Southern Hemisphere occurred during the last 650 years, with a decrease by about 50% in the 1600s, an increase of about 100% by the late 1800s, and another decrease by about 70% from the late 1800s to present day.
 
  Programme 458  
  Campaign  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0036-8075 ISBN Medium  
  Area Expedition Conference  
  Notes Approved yes  
  Call Number Serial 2421  
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Author Berthier Etienne, Le Bris Raymond, Mabileau Laure, Testut Laurent, Rmy Frdrique, doi  openurl
  Title Ice wastage on the Kerguelen Islands (49S, 69E) between 1963 and 2006 Type Journal Article
  Year 2009 Publication J. Geophys. Res. Abbreviated Journal J. Geophys. Res.  
  Volume 114 Issue F3 Pages F03005 -  
  Keywords ice caps, climate change, remote sensing, Kerguelen Islands, Southern Ocean, mass balance, 0720 Cryosphere: Glaciers, 0738 Cryosphere: Ice, 0776 Cryosphere: Glaciology, 0758 Cryosphere: Remote sensing, 0762 Cryosphere: Mass balance,  
  Abstract (down) We observed the wastage of ice masses on the Kerguelen Islands (Indian Ocean, 49S, 69E) using historical information and recent satellite data. Overall, the total ice-covered area on the islands declined from 703 to 552 km2 between 1963 and 2001, a reduction of 21%. The area of Cook ice cap (the main ice body) decreased asymmetrically from 501 to 403 km2. West flowing glaciers lost 11% of their area, while east flowing glaciers lost 28%. After 1991, the retreat rate accelerated from 1.9 km2/a (1963–1991) to 3.8 km2/a (1991–2003). Between 1963 and 2000, the ice volume loss was 25–30 km3, equivalent to an area-average ice-thinning rate of 1.4–1.7 m/a. The glacial retreat took place in the climatic context of a relatively low level of precipitation (compared to the 1950s) and a ~1C warming that occurred between 1964 and 1982. The acceleration of the ice losses since at least the 1990s indicates that the state of the ice bodies on the Kerguelen Islands is still far from balanced. Together with other studies in Patagonia, South Georgia, and Heard Island, our analysis is consistent with a pattern of strong and accelerated wastage of ice masses influenced by the Southern Ocean.
 
  Programme 688  
  Campaign  
  Address  
  Corporate Author Thesis  
  Publisher AGU Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0148-0227 ISBN Medium  
  Area Expedition Conference  
  Notes Approved yes  
  Call Number Serial 1858  
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Author Beine Harry, Anastasio Cort, Domine Florent, Douglas Thomas, Barret Manuel, France James, King Martin, Hall Sam, Ullmann Kirk, doi  openurl
  Title Soluble chromophores in marine snow, seawater, sea ice and frost flowers near Barrow, Alaska Type Journal Article
  Year 2012 Publication J. Geophys. Res. Abbreviated Journal  
  Volume 117 Issue Pages D00R15-  
  Keywords OASIS, chromophores, colored dissolved organic matter (CDOM), frost flowers, light absorption, marine, 0317 Atmospheric Composition and Structure: Chemical kinetic and photochemical properties, 0322 Atmospheric Composition and Structure: Constituent sources and sinks, 0736 Cryosphere: Snow (1827, 1863), 0750 Cryosphere: Sea ice (4540), 4807 Oceanography: Biological and Chemical: Chemical speciation and complexation,  
  Abstract (down) We measured light absorption in 42 marine snow, sea ice, seawater, brine, and frost flower samples collected during the OASIS field campaign between February 27 and April 15, 2009. Samples represented multiple sites between landfast ice and open pack ice in coastal areas approximately 5 km west of Barrow, Alaska. The chromophores that are most commonly measured in snow, H2O2, NO3-, and NO2-, on average account for less than 1% of sunlight absorption in our samples. Instead, light absorption is dominated by unidentified “residual” species, likely organic compounds. Light absorption coefficients for the frost flowers on first-year sea ice are, on average, 40 times larger than values for terrestrial snow samples at Barrow, suggesting very large rates of photochemical reactions in frost flowers. For our marine samples the calculated rates of sunlight absorption and OH production from known chromophores are (0.1–1.4) 1014 (photons cm-3 s-1) and (5–70) 10-12 (mol L-1 s-1), respectively. Our residual spectra are similar to spectra of marine chromophoric dissolved organic matter (CDOM), suggesting that CDOM is the dominant chromophore in our samples. Based on our light absorption measurements we estimate dissolved organic carbon (DOC) concentrations in Barrow seawater and frost flowers as approximately 130 and 360 μM C, respectively. We expect that CDOM is a major source of OH in our marine samples, and it is likely to have other significant photochemistry as well.
 
  Programme 1017  
  Campaign  
  Address  
  Corporate Author Thesis  
  Publisher AGU Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0148-0227 ISBN Medium  
  Area Expedition Conference  
  Notes Approved yes  
  Call Number Serial 989  
Permanent link to this record
 

 
Author Simpson, W.R.; Alvarez-Aviles, L.; Douglas, T.A.; Sturm, M.; Domine, F. doi  openurl
  Title Halogens in the coastal snow pack near Barrow, Alaska: Evidence for active bromine air-snow chemistry during springtime Type Journal Article
  Year 2005 Publication Geophysical research letters Abbreviated Journal  
  Volume 32 Issue Pages  
  Keywords 0312 Atmospheric Composition and Structure: Air/sea constituent fluxes; 0330 Atmospheric Composition and Structure: Geochemical cycles; 0365 Atmospheric Composition and Structure: Troposphere: composition and chemistry; 0368 Atmospheric Composition and Structure: Troposphere: constituent transport and chemistry; 1863 Hydrology: Snow and ice  
  Abstract (down) We measured halide concentrations of snow and frost flowers in the vicinity of Barrow, Alaska. We find that the ratio of bromide to sodium in frost flowers is slightly enhanced (?10%) as compared to sea water. In contrast, the ratio of bromide to sodium in some snow samples is more than an order of magnitude enhanced, and in other samples is more than an order of magnitude depleted. We interpret the bromide depleted snow as having been processed by heterogeneous chemistry and providing reactive halogen compounds to the atmosphere. The eventual end product of reactive bromine chemistry is HBr that is then deposited over a wide region, enhancing bromide in inland snow samples. Although frost flowers or open leads are likely to be the original source of halides that become reactive halogen gases, we find that the bromide release often occurs subsequent to production of aerosol from marine sources.  
  Programme 437  
  Campaign  
  Address  
  Corporate Author Thesis  
  Publisher American Geophysical Union Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0094-8276 ISBN Medium  
  Area Expedition Conference  
  Notes Approved yes  
  Call Number IPEV @ Thierry.Lemaire @ Serial 5598  
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Author Rolf Weller, Michel Legrand, Susanne Preunkert file  doi
isbn  openurl
  Title Size distribution and ionic composition of marine summer aerosol at the continental Antarctic site Kohnen Type Journal
  Year 2018 Publication Atmospheric Chemistry and Physics Abbreviated Journal  
  Volume 18 Issue 4 Pages 2413-2430  
  Keywords  
  Abstract (down) We Measured Aerosol Size Distributions And Conducted Bulk And Size-segregated Aerosol Sampling During Two Summer Campaigns In January 2015 And January 2016 At The Continental Antarctic Station Kohnen (Dronning Maud Land). Physical And Chemical Aerosol Properties Differ Conspicuously During The Episodic Impact Of A Distinctive Low-pressure System In 2015 (Lps15) Compared To The Prevailing Clear Sky Conditions. The Approximately 3-day Lps15 Located In The Eastern Weddell Sea Was Associated With The Following: Marine Boundary Layer Air Mass Intrusion; Enhanced Condensation Particle Concentrations (1400±700cm−3 Compared To 250±120cm−3 Under Clear Sky Conditions; Mean±sd); The Occurrence Of A New Particle Formation Event Exhibiting A Continuous Growth Of Particle Diameters (Dp) From 12 To 43nm Over 44h (Growth Rate 0.6nmh−1); Peaking Methane Sulfonate (Ms−), Non-sea-salt Sulfate (Nss–so42-), And Na+ Concentrations (190ngm−3ms−, 137ngm−3 Nss–so42-, And 53ngm−3na+ Compared To 24±15, 107±20, And 4.1±2.2ngm−3, Respectively, During Clear Sky Conditions); And Finally An Increased Ms−∕nss–so42- Mass Ratio βMs Of 0.4 Up To 2.3 (0.21±0.1 Under Clear Sky Conditions) Comparable To Typical Values Found At Coastal Antarctic Sites. Throughout The Observation Period A Larger Part Of Ms− Could Be Found In Super-micron Aerosol Compared To Nss–so42-, I.e., (10±2) % By Mass Compared To (3.2±2) %, Respectively. On The Whole, Under Clear Sky Conditions Aged Aerosol Characterized By Usually Mono-modal Size Distributions Around Dp=60nm Was Observed. Although Our Observations Indicate That The Sporadic Impacts Of Coastal Cyclones Were Associated With Enhanced Marine Aerosol Entry, Aerosol Deposition On-site During Austral Summer Should Be Largely Dominated By Typical Steady Clear Sky Conditions.  
  Programme 414  
  Campaign  
  Address  
  Corporate Author Thesis Bachelor's thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1680-7316 ISBN 1680-7316 Medium  
  Area Expedition Conference  
  Notes Approved yes  
  Call Number Serial 7361  
Permanent link to this record
 

 
Author L. Lescarmontier, B. Legresy, N. W. Young, R. Coleman, L. Testut, C. Mayet, P. Lacroix doi  isbn
openurl 
  Title Rifting processes and ice-flow modulation observed on Mertz Glacier, East Antarctica Type Journal
  Year 2015 Publication Journal of Glaciology Abbreviated Journal  
  Volume 61 Issue 230 Pages 1183-1193  
  Keywords Antarctic glaciology calving crevasses glacier flow glacier mechanics  
  Abstract (down) We investigated the evolution of two major rifts cutting across Mertz Glacier Tongue, East Antarctica, using a combination of satellite images and 60 day sets of GPS data from two stations deployed either side of the western rift in 2007. The eastern rift began to open in the early 1990s, and the western rift initiated in 2002 in conjunction with the collision of a large iceberg with the tongue. Velocity time series derived from the 2007 GPS data exhibited strong variations at tidal periods modulated by sea-surface height and sea-surface slope and reproduced here with a conceptually simple model. We found that opening of the western rift in 2002 leads to a dramatic change in behavior of the tongue as the large range in velocity (700–2400 m a−1) observed in 2000 was largely reduced (1075–1225 m a−1) in 2007. Opening of the western rift decoupled the glacier from the transverse loading on the tongue driven by east–west tidal circulation. This loading previously induced time-varying lateral drag, which caused the large velocity range. Our results suggest changes in the mechanical behavior of an ice tongue impact the dynamics of the outlet glacier system and should be considered in longer-term mass-balance evaluations.  
  Programme 688  
  Campaign  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0022-1430, 1727-5652 ISBN 0022-1430, 1727-5652 Medium  
  Area Expedition Conference  
  Notes Approved yes  
  Call Number Serial 7066  
Permanent link to this record
 

 
Author Bozda Ebru, Trampert Jeannot, doi  openurl
  Title Assessment of tomographic mantle models using spectral element seismograms Type Journal Article
  Year 2010 Publication Geophysical Journal International Abbreviated Journal 0956-540X  
  Volume 180 Issue 3 Pages 1187-1199  
  Keywords Body waves, Surface waves and free oscillations, Seismic tomography, Computational seismology, Wave propagation, Crustal structure,  
  Abstract (down) We investigated the agreement between real seismograms and those predicted by long wavelength mantle models by looking at phase and amplitude differences. We computed full synthetic seismograms using a spectral element method together with 3-D mantle models and the appropriate crustal model on top. We selected differently damped mantle models to see the effect of regularization on the computed seismograms. To check the phase agreement, we measured time-shifts between the real and synthetic surface waves and body wave phases such as P, S and SS using a cross-correlation technique. We also compared the amplitudes of the real and synthetic seismograms to understand how well the models explain not only the phases, but the whole waveforms. 3-D mantle models improve the phase agreement of surface waves in particular. The remaining misfit, however, is still so large that we cannot distinguish between different tomographic models. We suggest that this is mainly due to an imperfect modelling of the crust, and/or source location if body waves are included, which have to be addressed in future inversions. Amplitude mismatches are large, regardless which 3-D mantle model is used. We observe that 3-D scattering or focusing/defocusing effects can only explain half of the surface wave amplitudes whereas body wave amplitudes are dominated by scattering effects. 1-D Q models, particularly in the crust and upper-mantle, strongly affect surface wave amplitudes and have to be modelled properly.
 
  Programme 133  
  Campaign  
  Address  
  Corporate Author Thesis  
  Publisher Blackwell Publishing Ltd Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1365-246X ISBN Medium  
  Area Expedition Conference  
  Notes Approved yes  
  Call Number Serial 3225  
Permanent link to this record
 

 
Author Lecomte N., Kuntz G., Lambert N., Gendner J.P., Handrich Y., Le Maho Y., & Bost C.A. openurl 
  Title Alloparental feeding in the King penguin, Aptenodytes patagonicus. Type Journal Article
  Year 2006 Publication Animal behaviour Abbreviated Journal  
  Volume 71 Issue 2 Pages 457-462  
  Keywords  
  Abstract (down) We investigated allofeeding (feeding of offspring by adults other than their own parents) in the king penguin, Aptenodytes patagonicus, a long-lived pelagic bird that faces severe food shortages during its reproduction and in which parents leave their fasting chick in dense crèches. A 1-year monitoring of 103 breeding pairs and 70 chicks was carried out in a colony in the Crozet Archipelago. We examined whether allofeeding was common enough to alter survival costs or benefits for both the allofed chicks and the allofeeders. Twenty-two per cent of marked adults allofed more than 65% of all the chicks without repeatedly feeding the same chick. Allofeeding in king penguins benefited allofed chicks by increasing their survival, yet little or no fitness cost was detected among allofeeders. We identified proximal factors affecting allofeeding: (1) the breeding conditions of the population were not unusual; (2) allofeeding occurred mostly when parental provisioning was low; (3) alloparents did not respond to increased begging by regurgitating more meals; (4) allofeeders were mostly failed breeders, although successful breeders occasionally allofed; (5) when the colony was no longer organized into breeder territories, allofeeders preferentially fed chicks that had been reared by close neighbours at the time of brooding.  
  Programme 394  
  Campaign  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0003-3472 ISBN Medium  
  Area Expedition Conference  
  Notes Approved yes  
  Call Number Serial 3017  
Permanent link to this record
 

 
Author Feng W, Chipperfield M P, Dhomse S, Monge-Sanz B M, Yang X, Zhang K, Ramonet M, doi  openurl
  Title Evaluation of cloud convection and tracer transport in a three-dimensional chemical transport model Type Journal Article
  Year 2010 Publication Atmos. Chem. Phys. Discuss. Abbreviated Journal  
  Volume 10 Issue 10 Pages 22953 -22991  
  Keywords  
  Abstract (down) We investigate the performance of cloud convection and tracer transport in a global off-line 3-D chemical transport model. Various model simulations are performed using different meteorological (re)analyses (ERA-40, ECMWF operational and ECMWF Interim) to diagnose the updraft mass flux, convective precipitation and cloud top height.

The diagnosed upward mass flux distribution from TOMCAT agrees quite well with the ECMWF reanalysis data (ERA-40 and ERA-Interim) below 200 hPa. Inclusion of midlevel convection improves the agreement at mid-high latitudes. However, the reanalyses show strong convective transport up to 100 hPa, well into the tropical tropopause layer (TTL), which is not captured by TOMCAT. Similarly, the model captures the spatial and seasonal variation of convective cloud top height although the mean modelled value is about 2 km lower than observed.

The ERA-Interim reanalyses have smaller archived upward convective mass fluxes than ERA-40, and smaller convective precipitation, which is in better agreement with satellite-based data. TOMCAT captures these relative differences when diagnosing convection from the large-scale fields. The model also shows differences in diagnosed convection with the version of the operational analyses used, which cautions against using results of the model from one specific time period as a general evaluation.

We have tested the effect of resolution on the diagnosed modelled convection with simulations ranging from 5.6° × 5.6° to 1° × 1°. Overall, in the off-line model, the higher model resolution does not make a large change to the diagnosed convective tracer transport. Similarly, the resolution of the forcing winds in the higher resolution CTM does not make a large improvement compared to the archived mass fluxes.

Including a radon tracer in the model confirms the importance of convection for reproducing observed midlatitude profiles. The model run using archived mass fluxes transports significantly more radon to the upper troposphere but the available data does not strongly discriminate between the different model versions.
 
  Programme 416  
  Campaign  
  Address  
  Corporate Author Thesis  
  Publisher Copernicus Publications Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1680-7375 ISBN Medium  
  Area Expedition Conference  
  Notes Approved yes  
  Call Number Serial 2680  
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