| |
Records |
Links |
|
Author |
Mark A. Hindell, Clive R. McMahon, Ian Jonsen, Robert Harcourt, Fernando Arce, Christophe Guinet |
|
| |
Title |
Inter- and intrasex habitat partitioning in the highly dimorphic southern elephant seal |
Type |
Journal |
| |
Year |
2021 |
Publication |
Ecology and Evolution |
Abbreviated Journal |
|
|
| |
Volume |
11 |
Issue |
4 |
Pages |
1620-1633 |
|
| |
Keywords |
Antarctic Shelf foraging and diving behavior Kerguelen Plateau mid-year haul out predation risk Southern Ocean |
|
| |
Abstract |
Partitioning resources is a key mechanism for avoiding intraspecific competition and maximizing individual energy gain. However, in sexually dimorphic species it is difficult to discern if partitioning is due to competition or the different resource needs of morphologically distinct individuals. In the highly dimorphic southern elephant seal, there are intersexual differences in habitat use; at Iles Kerguelen, males predominantly use shelf waters, while females use deeper oceanic waters. There are equally marked intrasexual differences, with some males using the nearby Kerguelen Plateau, and others using the much more distant Antarctic continental shelf ( 2,000 km away). We used this combination of inter and intrasexual behavior to test two hypotheses regarding habitat partitioning in highly dimorphic species. (a) that intersexual differences in habitat use will not appear until the seals diverge in body size and (b) that some habitats have higher rates of energy return than others. In particular, that the Antarctic shelf would provide higher energy returns than the Kerguelen Shelf, to offset the greater cost of travel. We quantified the habitat use of 187 southern elephant seals (102 adult females and 85 subadult males). The seals in the two groups were the same size ( 2.4 m) removing the confounding effect of body size. We found that the intersexual differences in habitat use existed before the divergence in body size. Also, we found that the amount of energy gained was the same in all of the major habitats. This suggests that the use of shelf habitats by males is innate, and a trade-off between the need to access the large benthic prey available on shelf waters, against the higher risk of predation there. Intrasexual differences in habitat use are another trade-off; although there are fewer predators on the Antarctic shelf, it is subject to considerable interannual fluctuations in sea-ice extent. In contrast, the Kerguelen Plateau presents more consistent foraging opportunities, but contains higher levels of predation. Habitat partitioning in this highly dimorphic species is therefore the result of complex interplay of life history strategies, environmental conditions and predation pressure. |
|
| |
Programme |
109,1201 |
|
| |
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  |
2045-7758 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
|
Approved |
yes |
|
| |
Call Number |
|
Serial |
8243 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Eeva M. Soininen, Isabel C. Barrio, Ragnhild Bjørkås, Katrín Björnsdóttir, Dorothee Ehrich, Kelly Hopping, Elina Kaarlejärvi, Anders Lorentzen Kolstad, Svetlana Abdulmanova, Robert G. Björk, C. Guillermo Bueno, Isabell Eischeid, Rebecca Finger Higgens, Jennifer Sorensen Forbey, Charles Gignac, Olivier Gilg, Michael den Herder, Hildur Søndergaard Holm, Bernice C. Hwang, Jane Uhd Jepsen, Stefaniya Kamenova, Ilona Kater, Amanda M. Koltz, Jeppe Aagaard Kristensen, Chelsea J. Little, Petr Macek, Karen Marie Mathisen, Daniel Metcalfe, Jesper Bruun Mosbacher, Martin Alfons Mörsdorf, Taejin Park, Jeffrey Propster, Aradhana Roberts, Emmanuel Serrano Ferron, Marcus P. Spiegel, Mariana Tamayo, Maria W. Tuomi, Megha Verma, Katariina Elsa Maria Vuorinen, Maria Väisänen, René Van der Wal, Megan Wilcots, Nigel Yoccoz, James D. M. Speed |
|
| |
Title |
Location of studies and evidence of effects of herbivory on Arctic vegetation: a systematic map |
Type |
Journal |
| |
Year |
2021 |
Publication |
Environmental Evidence |
Abbreviated Journal |
|
|
| |
Volume |
10 |
Issue |
1 |
Pages |
25 |
|
| |
Keywords |
Browsing Defoliation Forest-tundra Grazing Grubbing Invertebrate Plant–herbivore interaction Tundra Vertebrate |
|
| |
Abstract |
Herbivores modify the structure and function of tundra ecosystems. Understanding their impacts is necessary to assess the responses of these ecosystems to ongoing environmental changes. However, the effects of herbivores on plants and ecosystem structure and function vary across the Arctic. Strong spatial variation in herbivore effects implies that the results of individual studies on herbivory depend on local conditions, i.e., their ecological context. An important first step in assessing whether generalizable conclusions can be produced is to identify the existing studies and assess how well they cover the underlying environmental conditions across the Arctic. This systematic map aims to identify the ecological contexts in which herbivore impacts on vegetation have been studied in the Arctic. Specifically, the primary question of the systematic map was: “What evidence exists on the effects of herbivores on Arctic vegetation?”. |
|
| |
Programme |
1036 |
|
| |
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 |
2047-2382 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
|
Approved |
yes |
|
| |
Call Number |
|
Serial |
8386 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Scott A. Shaffer, Pierre Blévin, Christophe Barbraud, Olivier Chastel, Henri Weimerskirch |
|
| |
Title |
Comparative egg attendance patterns of incubating polar petrels |
Type |
Journal |
| |
Year |
2021 |
Publication |
Animal Biotelemetry |
Abbreviated Journal |
|
|
| |
Volume |
9 |
Issue |
1 |
Pages |
17 |
|
| |
Keywords |
Biologging Cape petrel Egg neglect Egg temperatures Egg turning rates Snow petrel |
|
| |
Abstract |
The internal environment of eggs in most birds is regulated by transferring heat energy through contact incubation, maintaining nest microclimate, and frequent egg turning by the incubating parent on its nest. However, we lack information about egg attendance patterns in birds that breed in polar environments where variations in life history are expected to influence incubation behavior. Moreover, crevice/burrow nesting petrels in high-latitude regions are known for periodically leaving their egg unattended (hereafter ‘egg neglect’), but there is little reporting on the internal condition of unattended eggs. At Dumont d’Urville Station, Antarctica, we studied the incubation behavior of 24 snow (Pagodroma nivea) and 15 Cape (Daption capense) petrel pairs using egg loggers that recorded egg turning rates, orientation changes, and temperatures at 1 Hz for durations of 3–6 days. |
|
| |
Programme |
109 |
|
| |
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 |
2050-3385 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
|
Approved |
yes |
|
| |
Call Number |
|
Serial |
8091 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Alexander Kokhanovsky, Simon Gascoin, Laurent Arnaud, Ghislain Picard |
|
| |
Title |
Retrieval of Snow Albedo and Total Ozone Column from Single-View MSI/S-2 Spectral Reflectance Measurements over Antarctica |
Type |
Journal |
| |
Year |
2021 |
Publication |
Remote Sensing |
Abbreviated Journal |
|
|
| |
Volume |
13 |
Issue |
21 |
Pages |
4404 |
|
| |
Keywords |
albedo inverse problems light scattering radiative transfer snow snow grain size |
|
| |
Abstract |
We proposed a simple algorithm to retrieve the total ozone column and snow properties (spectral albedo and effective light absorption path) using the high spatial resolution single–view MSI/S-2 measurements over Antarctica. In addition, the algorithm allows the retrieval of the snow grain size on a scale of 10–20 m. This algorithm should be useful for the understanding of intra-pixel total ozone and snow albedo variability in complement to satellite observations performed on a much coarser spatial resolution scale (0.3–1 km and even larger spatial scales). |
|
| |
Programme |
1110 |
|
| |
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 |
2072-4292 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
|
Approved |
yes |
|
| |
Call Number |
|
Serial |
8305 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Stine Frey Laursen, Laura Skrubbeltrang Hansen, Simon Bahrndorff, Hanne Marie Nielsen, Natasja Krog Noer, David Renault, Goutam Sahana, Jesper Givskov Sørensen, Torsten Nygaard Kristensen |
|
| |
Title |
Contrasting Manual and Automated Assessment of Thermal Stress Responses and Larval Body Size in Black Soldier Flies and Houseflies |
Type |
Journal |
| |
Year |
2021 |
Publication |
Insects |
Abbreviated Journal |
|
|
| |
Volume |
12 |
Issue |
5 |
Pages |
380 |
|
| |
Keywords |
Hermetia illucens Musca domestica acclimation automated phenotyping heat and cold tolerance |
|
| |
Abstract |
Within ecophysiological and genetic studies on insects, morphological and physiological traits are commonly assessed and phenotypes are typically obtained from manual measurements on numerous individuals. Manual observations are, however, time consuming, can introduce observer bias and are prone to human error. Here, we contrast results obtained from manual assessment of larval size and thermal tolerance traits in black soldier flies (Hermetia illucens) and houseflies (Musca domestica) that have been acclimated under three different temperature regimes with those obtained automatically using an image analysis software (Noldus EthoVision XT). We found that (i) larval size estimates of both species, obtained by manual weighing or by using the software, were highly correlated, (ii) measures of heat and cold tolerance using manual and automated approaches provided qualitatively similar results, and (iii) by using the software we obtained quantifiable information on stress responses and acclimation effects of potentially higher ecological relevance than the endpoint traits that are typically assessed when manual assessments are used. Based on these findings, we argue that automated assessment of insect stress responses and largescale phenotyping of morphological traits such as size will provide new opportunities within many disciplines where accurate and largescale phenotyping of insects is required. |
|
| |
Programme |
136 |
|
| |
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 |
2075-4450 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
|
Approved |
yes |
|
| |
Call Number |
|
Serial |
8299 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Mike Lockwood, Carl Haines, Luke A. Barnard, Mathew J. Owens, Chris J. Scott, Aude Chambodut, Kathryn A. McWilliams |
|
| |
Title |
Semi-annual, annual and Universal Time variations in the magnetosphere and in geomagnetic activity: 4. Polar Cap motions and origins of the Universal Time effect |
Type |
Journal |
| |
Year |
2021 |
Publication |
Journal of Space Weather and Space Climate |
Abbreviated Journal |
|
|
| |
Volume |
11 |
Issue |
|
Pages |
15 |
|
| |
Keywords |
|
|
| |
Abstract |
We use the am, an, as and the aσ geomagnetic indices to the explore a previously overlooked factor in magnetospheric electrodynamics, namely the inductive effect of diurnal motions of the Earth’s magnetic poles toward and away from the Sun caused by Earth’s rotation. Because the offset of the (eccentric dipole) geomagnetic pole from the rotational axis is roughly twice as large in the southern hemisphere compared to the northern, the effects there are predicted to be roughly twice the amplitude of those in the northern hemisphere. Hemispheric differences have previously been discussed in terms of polar ionospheric conductivities generated by solar photoionization, effects which we allow for by looking at the dipole tilt effect on the time-of-year variations of the indices. The electric field induced in a geocentric frame is shown to also be a significant factor and gives a modulation of the voltage applied by the solar wind flow in the southern hemisphere that is typically a ±30% diurnal modulation for disturbed intervals rising to ±76% in quiet times. For the northern hemisphere these are 15% and 38% modulations. Motion away from/towards the Sun reduces/enhances the directly-driven ionospheric voltages and reduces/enhances the magnetic energy stored in the tail and we estimate that approximately 10% of the effect appears in directly driven ionospheric voltages and 90% in changes of the rate of energy storage or release in the near-Earth tail. The hemispheric asymmetry in the geomagnetic pole offsets from the rotational axis is shown to be the dominant factor in driving Universal Time (UT) variations and hemispheric differences in geomagnetic activity. Combined with the effect of solar wind dynamic pressure and dipole tilt on the pressure balance in the near-Earth tail, the effect provides an excellent explanation of how the observed Russell-McPherron pattern with time-of-year F and UT in the driving power input into the magnetosphere is converted into the equinoctial F-UT pattern in average geomagnetic activity (after correction is made for dipole tilt effects on ionospheric conductivity), added to a pronounced UT variation with minimum at 02–10 UT. In addition, we show that the predicted and observed UT variations in average geomagnetic activity has implications for the occurrence of the largest events that also show the nett UT variation. |
|
| |
Programme |
139 |
|
| |
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 |
2115-7251 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
|
Approved |
yes |
|
| |
Call Number |
|
Serial |
8076 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Mathilde Poirier, Dominique Fauteux, Gilles Gauthier, Florent Domine, Jean-François Lamarre |
|
| |
Title |
Snow hardness impacts intranivean locomotion of arctic small mammals |
Type |
Journal |
| |
Year |
2021 |
Publication |
Ecosphere |
Abbreviated Journal |
|
|
| |
Volume |
12 |
Issue |
11 |
Pages |
e03835 |
|
| |
Keywords |
Arctic burrowing behavior digging fossorial hardness lemming locomotion rain-on-snow rodent snow subnivean tunnel |
|
| |
Abstract |
Fossorial locomotion is often considered as the most energetically costly of all terrestrial locomotion. Small arctic rodents, such as lemmings, dig tunnels not only in the soil but also through the snowpack, which is present for over 8 months of the year. Lemmings typically dig in the softest snow layer called the depth hoar but with climate change, melt-freeze and rain-on-snow (ROS) events are expected to increase in the Arctic, leading to a higher frequency of hardened snowpacks. We assessed the impacts of snow hardness on the locomotion of two lemming species showing different morphological adaptations for digging. We hypothesized that an increase in snow hardness would (1) decrease lemming performance and (2) increase their effort while digging, but those responses would differ between lemming species. We exposed four brown lemmings (Lemmus trimucronatus) and three collared lemmings (Dicrostonyx groenlandicus) to snow of different hardness (soft, hard, and ROS) during 30-min trials (n = 63 trials) in a cold room and filmed their behavior. We found that the digging speed and tunnel length of both species decreased with snow hardness and density, underlining the critical role of snow properties in affecting lemming digging performance. During the ROS trials, time spent digging by lemmings increased considerably and they also started using their incisors to help break the hard snow, validating our second hypothesis. Overall, digging performance was higher in collared lemmings, the species showing more morphological adaptations to digging, than in brown lemmings. We conclude that the digging performance of lemming is highly dependent on snowpack hardness and that the anticipated increase in ROS events may pose a critical energetic challenge for arctic rodent populations. |
|
| |
Programme |
1042 |
|
| |
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 |
2150-8925 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
|
Approved |
yes |
|
| |
Call Number |
|
Serial |
8028 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Jonathan D. Wille, Vincent Favier, Irina V. Gorodetskaya, Cécile Agosta, Christoph Kittel, Jai Chowdhry Beeman, Nicolas C. Jourdain, Jan T. M. Lenaerts, Francis Codron |
|
| |
Title |
Antarctic Atmospheric River Climatology and Precipitation Impacts |
Type |
Journal |
| |
Year |
2021 |
Publication |
Journal of Geophysical Research: Atmospheres |
Abbreviated Journal |
|
|
| |
Volume |
126 |
Issue |
8 |
Pages |
e2020JD033788 |
|
| |
Keywords |
Antarctica atmospheric rivers climatology meteorology |
|
| |
Abstract |
The Antarctic ice sheet (AIS) is sensitive to short-term extreme meteorological events that can leave long-term impacts on the continent's surface mass balance (SMB). We investigate the impacts of atmospheric rivers (ARs) on the AIS precipitation budget using an AR detection algorithm and a regional climate model (Modèle Atmosphérique Régional) from 1980 to 2018. While ARs and their associated extreme vapor transport are relatively rare events over Antarctic coastal regions (∼3 days per year), they have a significant impact on the precipitation climatology. ARs are responsible for at least 10% of total accumulated snowfall across East Antarctica (localized areas reaching 20%) and a majority of extreme precipitation events. Trends in AR annual frequency since 1980 are observed across parts of AIS, most notably an increasing trend in Dronning Maud Land; however, interannual variability in AR frequency is much larger. This AR behavior appears to drive a significant portion of annual snowfall trends across East Antarctica, while controlling the interannual variability of precipitation across most of the AIS. AR landfalls are most likely when the circumpolar jet is highly amplified during blocking conditions in the Southern Ocean. There is a fingerprint of the Southern Annular Mode (SAM) on AR variability in West Antarctica with SAM+ (SAM−) favoring increased AR frequency in the Antarctic Peninsula (Amundsen-Ross Sea coastline). Given the relatively large influence ARs have on precipitation across the continent, it is advantageous for future studies of moisture transport to Antarctica to consider an AR framework especially when considering future SMB changes. |
|
| |
Programme |
411 |
|
| |
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 |
2169-8996 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
|
Approved |
yes |
|
| |
Call Number |
|
Serial |
8327 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
A. Barbero, J. Savarino, R. Grilli, C. Blouzon, G. Picard, M. M. Frey, Y. Huang, N. Caillon |
|
| |
Title |
New Estimation of the NOx Snow-Source on the Antarctic Plateau |
Type |
Journal |
| |
Year |
2021 |
Publication |
Journal of Geophysical Research: Atmospheres |
Abbreviated Journal |
|
|
| |
Volume |
126 |
Issue |
20 |
Pages |
e2021JD035062 |
|
| |
Keywords |
Antarctic Plateau flux chamber nitrate photolysis snowpack emissions |
|
| |
Abstract |
To fully decipher the role of nitrate photolysis on the atmospheric oxidative capacity in snow-covered regions, NOx flux must be determined with more precision than existing estimates. Here, we introduce a method based on dynamic flux chamber measurements for evaluating the NOx production by photolysis of snowpack nitrate in Antarctica. Flux chamber experiments were conducted for the first time in Antarctica, at the French-Italian station Concordia, Dome C (75°06'S, 123°20’E, 3233 m a.s.l) during the 2019–2020 summer campaign. Measurements were gathered with several snow samples of different ages ranging from newly formed drifted snow to 6-year-old firn. Contrary to existing literature expectations, the daily average photolysis rate coefficient, , did not significantly vary between differently aged snow samples, suggesting that the photolabile nitrate in snow behaves as a single-family source with common photochemical properties, where a = (2.37 0.35) × 10−8 s−1 (1) has been calculated from December 10th 2019 to January 7th 2020. At Dome C summer daily average NOx flux, , based on measured NOx production rates was estimated to be (4.3 1.2) × 108 molecules cm−2 s−1, which is 1.5–7 times less than the net NOx flux observed previously above snow at Dome C using the gradient flux method. Using these results, we extrapolated an annual continental snow sourced NOx budget of 0.017 0.003 TgN y−1, 2 times the nitrogen budget, (N-budget), of the stratospheric denitrification previously estimated for Antarctica. These quantifications of nitrate photolysis using flux chamber experiments provide a road-map toward a new parameterization of the product that can improve future global and regional models of atmospheric chemistry. |
|
| |
Programme |
1177 |
|
| |
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 |
2169-8996 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
|
Approved |
yes |
|
| |
Call Number |
|
Serial |
8393 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
S. Ishino, S. Hattori, M. Legrand, Q. Chen, B. Alexander, J. Shao, J. Huang, L. Jaeglé, B. Jourdain, S. Preunkert, A. Yamada, N. Yoshida, J. Savarino |
|
| |
Title |
Regional Characteristics of Atmospheric Sulfate Formation in East Antarctica Imprinted on 17O-Excess Signature |
Type |
Journal |
| |
Year |
2021 |
Publication |
Journal of Geophysical Research: Atmospheres |
Abbreviated Journal |
|
|
| |
Volume |
126 |
Issue |
6 |
Pages |
e2020JD033583 |
|
| |
Keywords |
aerosols Antarctica isotope methanesulfonate sulfate |
|
| |
Abstract |
17O-excess (Δ17O = δ17O − 0.52 × δ18O) of sulfate trapped in Antarctic ice cores has been proposed as a potential tool for assessing past oxidant chemistry, while insufficient understanding of atmospheric sulfate formation around Antarctica hampers its interpretation. To probe influences of regional specific chemistry, we compared year-round observations of Δ17O of non-sea-salt sulfate in aerosols (Δ17O(SO42−)nss) at Dome C and Dumont d'Urville, inland and coastal sites in East Antarctica, throughout the year 2011. Although Δ17O(SO42−)nss at both sites showed consistent seasonality with summer minima (∼1.0‰) and winter maxima (∼2.5‰) owing to sunlight-driven changes in the relative importance of O3 oxidation to OH and H2O2 oxidation, significant intersite differences were observed in austral spring–summer and autumn. The cooccurrence of higher Δ17O(SO42−)nss at inland (2.0‰ ± 0.1‰) than the coastal site (1.2‰ ± 0.1‰) and chemical destruction of methanesulfonate (MS–) in aerosols at inland during spring–summer (October–December), combined with the first estimated Δ17O(MS–) of ∼16‰, implies that MS– destruction produces sulfate with high Δ17O(SO42−)nss of ∼12‰. If contributing to the known postdepositional decrease of MS– in snow, this process should also cause a significant postdepositional increase in Δ17O(SO42−)nss over 1‰, that can reconcile the discrepancy between Δ17O(SO42−)nss in the atmosphere and ice. The higher Δ17O(SO42−)nss at the coastal site than inland during autumn (March–May) may be associated with oxidation process involving reactive bromine and/or sea-salt particles around the coastal region. |
|
| |
Programme |
1177 |
|
| |
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 |
2169-8996 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
|
Approved |
yes |
|
| |
Call Number |
|
Serial |
8412 |
|
| Permanent link to this record |
