Mineral dust variability in central West Antarctica associated with ozone depletion

Abstract. We present here data of mineral dust variability retrieved from an ice core of the central West Antarctic, spanning the last five decades. Main evidence provided by the geochemical analysis is that northerly air mass incursions to the coring site, tracked by insoluble dust microparticles, have declined over the past 50 yr. This result contrasts with dust records from ice cores reported to the coastal West Antarctic that show increases since mid-20th century. We attribute this difference to regional climatic changes due to the ozone depletion and its implications to westerly winds. We found that the diameters of insoluble microparticles in the central West Antarctica ice core are significantly correlated with cyclone depth (energy) and wind intensity around Antarctica.

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A 200 year sub-annual record of sulfate in West Antarctica, from 16 ice cores

Annals of Glaciology ◽

10.3189/172756404781814113 ◽

2004 ◽

Vol 39 ◽

pp. 545-556 ◽

Cited By ~ 34

Author(s):

Daniel Dixon ◽

Paul A. Mayewski ◽

Susan Kaspari ◽

Sharon Sneed ◽

Mike Handley

Keyword(s):

Ice Core ◽

Temporal Distribution ◽

Ice Cores ◽

Volcanic Eruptions ◽

Global Scale ◽

West Antarctica ◽

West Antarctic ◽

Volcanic Events ◽

Climate Transition ◽

Better Than

AbstractSixteen high-resolution ice-core records from West Antarctica and South Pole are used to examine the spatial and temporal distribution of sulfate for the last 200 years. The preservation of seasonal layers throughout the length of each record results in a dating accuracy of better than 1 year based on known global-scale volcanic events. A dual transport source for West Antarctic sea-salt (ss) SO42– and excess (xs) SO42– is observed: lower-tropospheric for areas below 1000m elevation and mid-/upper-tropospheric/stratospheric for areas located above 1000 m. Our xsSO42– records with volcanic peaks removed do not display any evidence of an anthropogenic impact on West Antarctic SO42– concentrations but do reveal that a major climate transition takes place over West Antarctica at ∼1940. Global-scale volcanic eruptions appear as significant peaks in the robust-spline residual xsSO42– records from sites located above 1000m elevation but do not appear in the residual records from sites located below 1000 m.

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The Ross Sea Dipole – temperature, snow accumulation and sea ice variability in the Ross Sea region, Antarctica, over the past 2700 years

Climate of the Past ◽

10.5194/cp-14-193-2018 ◽

2018 ◽

Vol 14 (2) ◽

pp. 193-214 ◽

Cited By ~ 19

Author(s):

Nancy A. N. Bertler ◽

Howard Conway ◽

Dorthe Dahl-Jensen ◽

Daniel B. Emanuelsson ◽

Mai Winstrup ◽

...

Keyword(s):

Sea Ice ◽

Ross Sea ◽

Ice Core ◽

Ice Cores ◽

Snow Accumulation ◽

Ice Age ◽

West Antarctica ◽

Isotopic Enrichment ◽

The Past ◽

Western Ross Sea

Abstract. High-resolution, well-dated climate archives provide an opportunity to investigate the dynamic interactions of climate patterns relevant for future projections. Here, we present data from a new, annually dated ice core record from the eastern Ross Sea, named the Roosevelt Island Climate Evolution (RICE) ice core. Comparison of this record with climate reanalysis data for the 1979–2012 interval shows that RICE reliably captures temperature and snow precipitation variability in the region. Trends over the past 2700 years in RICE are shown to be distinct from those in West Antarctica and the western Ross Sea captured by other ice cores. For most of this interval, the eastern Ross Sea was warming (or showing isotopic enrichment for other reasons), with increased snow accumulation and perhaps decreased sea ice concentration. However, West Antarctica cooled and the western Ross Sea showed no significant isotope temperature trend. This pattern here is referred to as the Ross Sea Dipole. Notably, during the Little Ice Age, West Antarctica and the western Ross Sea experienced colder than average temperatures, while the eastern Ross Sea underwent a period of warming or increased isotopic enrichment. From the 17th century onwards, this dipole relationship changed. All three regions show current warming, with snow accumulation declining in West Antarctica and the eastern Ross Sea but increasing in the western Ross Sea. We interpret this pattern as reflecting an increase in sea ice in the eastern Ross Sea with perhaps the establishment of a modern Roosevelt Island polynya as a local moisture source for RICE.

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Mineral dust variability in central West Antarctica associated with ozone depletion

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-12-12685-2012 ◽

2012 ◽

Vol 12 (5) ◽

pp. 12685-12714

Author(s):

M. Cataldo ◽

H. Evangelista ◽

J. C. Simões ◽

R. H. M. Godoi ◽

I. Simmonds ◽

...

Keyword(s):

Ozone Depletion ◽

Mineral Dust ◽

Regional Climate ◽

Ice Core ◽

Polar Vortex ◽

Southern Annular Mode ◽

Quadratic Functions ◽

West Antarctica ◽

Linear Quadratic ◽

Air Mass

Abstract. Here we show that mineral dust retrieved from an ice core in the central West Antarctic sector, spanning the last five decades, provides evidence that northerly air mass incursions into Antarctica, tracked by dust microparticles, have slightly declined. This result contrasts with dust in ice core records reported in West/coastal Antarctica, which show significant increases to the present day. We attribute that difference, in part, to changes in the regional climate regime triggered by the ozone depletion and its consequences for the polar vortex intensity. The vortex maintains the Antarctic central region relatively isolated from mid-latitude air mass incursions with implications to the intensification of the Westerlies and to a persistent positive phase of the Southern Annular Mode. We also show that variability of the diameter of insoluble microparticles in central West Antarctica can be modeled by linear/quadratic functions of both cyclone depth (energy) and wind intensity around Antarctica.

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A 200 year sulfate record from 16 Antarctic ice cores and associations with Southern Ocean sea-ice extent

Annals of Glaciology ◽

10.3189/172756405781813366 ◽

2005 ◽

Vol 41 ◽

pp. 155-166 ◽

Cited By ~ 14

Author(s):

Daniel Dixon ◽

Paul A. Mayewski ◽

Susan Kaspari ◽

Karl Kreutz ◽

Gordon Hamilton ◽

...

Keyword(s):

Sea Ice ◽

Ross Sea ◽

Ice Core ◽

Ice Cores ◽

South Pole ◽

West Antarctica ◽

The South ◽

Sea Ice Extent ◽

West Antarctic ◽

Low Latitudes

AbstractChemistry data from 16, 50–115m deep, sub-annually dated ice cores are used to investigate spatial and temporal concentration variability of sea-salt (ss) SO42– and excess (xs) SO42– over West Antarctica and the South Pole for the last 200 years. Low-elevation ice-core sites in western West Antarctica contain higher concentrations of SO42– as a result of cyclogenesis over the Ross Ice Shelf and proximity to the Ross Sea Polynya. Linear correlation analysis of 15 West Antarctic ice-core SO42– time series demonstrates that at several sites concentrations of ssSO42– are higher when sea-ice extent (SIE) is greater, and the inverse for xsSO42–. Concentrations of xsSO42– from the South Pole site (East Antarctica) are associated with SIE from the Weddell region, and West Antarctic xsSO42– concentrations are associated with SIE from the Bellingshausen–Amundsen–Ross region. The only notable rise of the last 200 years in xsSO42–, around 1940, is not related to SIE fluctuations and is most likely a result of increased xsSO42– production in the mid–low latitudes and/or an increase in transport efficiency from the mid–low latitudes to central West Antarctica. These high-resolution records show that the source types and source areas of ssSO42– and xsSO42– delivered to eastern and western West Antarctica and the South Pole differ from site to site but can best be resolved using records from spatial ice-core arrays such as the International Trans-Antarctic Scientific Expedition (ITASE).

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Variability in accumulation rates from GPR profiling on the West Antarctic plateau

Annals of Glaciology ◽

10.3189/172756404781814393 ◽

2004 ◽

Vol 39 ◽

pp. 238-244 ◽

Cited By ~ 71

Author(s):

Vandy B. Spikes ◽

Gordon S. Hamilton ◽

Steven A. Arcone ◽

Susan Kaspari ◽

Paul A. Mayewski

Keyword(s):

Accumulation Rate ◽

Ice Core ◽

Ice Cores ◽

Track Length ◽

Flow Profile ◽

Accumulation Rates ◽

West Antarctica ◽

West Antarctic ◽

Ground Penetrating ◽

Along Track

AbstractIsochronal layers in firn detected with ground-penetrating radar (GPR) and dated using results from ice-core analyses are used to calculate accumulation rates along a 100 km across-flow profile in West Antarctica. Accumulation rates are shown to be highly variable over short distances. Elevation measurements from global positioning system surveys show that accumulation rates derived from shallow horizons correlate well with surface undulations, which implies that wind redistribution of snow is the leading cause of this variability. Temporal changes in accumulation rate over 25–185 year intervals are smoothed to along-track length scales comparable to surface undulations in order to identify trends in accumulation that are likely related to changes in climate. Results show that accumulation rates along this profile have decreased in recent decades, which is consistent with core-derived time series of annual accumulation rates measured at the two ends of the radar profile. These results suggest that temporal variability observed in accumulation-rate records from ice cores and GPR profiles can be obscured by spatial influences, although it is possible to resolve temporal signals if the effects of local topography and ice flow are quantified and removed.

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Soluble/insoluble fractionation of elements in mineral dust from Antarctic samples

10.5194/egusphere-egu2020-15986 ◽

2020 ◽

Author(s):

Elena Di Stefano ◽

Giovanni Baccolo ◽

Paolo Gabrielli ◽

Aja Ellis ◽

Barbara Delmonte ◽

...

Keyword(s):

Rare Earth ◽

Rare Earth Elements ◽

Mineral Dust ◽

Ice Core ◽

Ice Cores ◽

Dust Particles ◽

Aeolian Dust ◽

The Past ◽

Icp Ms

Deposition of dust on the Antarctic continent is controlled by many factors, such as the primary supply of dust particles from the continents [1], the long range transport, the hydrological cycle and the snow accumulation rate [2, 3]. Thus, the study of mineral dust in ice cores gives the possibility to reconstruct past climatic and environmental conditions.Generally, when an ice core sample is melted, soluble elements dissolve in water, while insoluble elements remain in the solid phase. Other elements, such as iron, calcium, potassium and sulfur, typically partition between the soluble and the insoluble fractions. However recent studies have shown how the dust record may be chemically and physically altered in deep ice cores [4, 5], posing a challenge in the interpretation of the climatic signal that may lie within such samples. In particular, relative abundance of specific elements was shown to be different when comparing shallow and deep dust samples, suggesting that post depositional processes are taking place.In this study we present a comparison between samples belonging to the Talos Dome ice core analyzed through two different techniques: instrumental neutron activation analysis (INAA) and inductively coupled plasma mass spectrometry (ICP-MS). While the former is used to investigate only the insoluble fraction of dust, as it can only be applied to solid samples, the latter is used to assess the elemental composition of both the total and the soluble fraction of dust. We determined 45 elements through ICP-MS and 39 through INAA, with a good overlapping of the elements between the two techniques. Besides the determination of major elements, the high sensibility of both techniques also permitted the determination of trace elements. Among these, rare earth elements (REE) are of particular importance as they have been widely used as a geochemical tracer of aeolian dust sources [6]. We here present depth profiles for each analysed element, covering discrete portions of the entire ice core.&#160;Bibliography[1] Petit, Jean-Robert, et al. "Climate and atmospheric history of the past 420,000 years from the Vostok ice core, Antarctica." Nature 399.6735 (1999): 429-436.[2] Lambert, Fabrice, et al. "Dust-climate couplings over the past 800,000 years from the EPICA Dome C ice core." Nature 452.7187 (2008): 616.[3] Wegner, Anna, et al. "The role of seasonality of mineral dust concentration and size on glacial/interglacial dust changes in the EPICA Dronning Maud Land ice core." Journal of Geophysical Research: Atmospheres 120.19 (2015): 9916-9931.[4] Baccolo, Giovanni, et al. &#8220;The contribution of synchrotron light for the characterization of atmospheric mineral dust in deep ice cores: Preliminary results from the Talos Dome ice core (East Antarctica).&#8221; Condensed Matter 3, no. 3 (2018): 25.[5] De Angelis, Martine, et al. &#8220;Micro-investigation of EPICA Dome C bottom ice: Evidence of long term in situ processes involving acid-salt interactions, mineral dust, and organic matter.&#8221; Quaternary Science Reviews 78 (2013): 248-265.[6] Gabrielli, Paolo, et al. &#8220;A major glacial-interglacial change in aeolian dust composition inferred from Rare Earth Elements in Antarctic ice.&#8221; Quaternary Science Reviews 29, no. 1-2 (2010): 265-273.&#160;

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Synchronous volcanic eruptions and abrupt climate change ∼17.7 ka plausibly linked by stratospheric ozone depletion

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1705595114 ◽

2017 ◽

Vol 114 (38) ◽

pp. 10035-10040 ◽

Cited By ~ 26

Author(s):

Joseph R. McConnell ◽

Andrea Burke ◽

Nelia W. Dunbar ◽

Peter Köhler ◽

Jennie L. Thomas ◽

...

Keyword(s):

Southern Hemisphere ◽

Ozone Depletion ◽

Stratospheric Ozone ◽

Ice Core ◽

Ice Cores ◽

Volcanic Eruptions ◽

Climate Impacts ◽

Stratospheric Ozone Depletion ◽

Climate Conditions ◽

West Antarctic

Glacial-state greenhouse gas concentrations and Southern Hemisphere climate conditions persisted until ∼17.7 ka, when a nearly synchronous acceleration in deglaciation was recorded in paleoclimate proxies in large parts of the Southern Hemisphere, with many changes ascribed to a sudden poleward shift in the Southern Hemisphere westerlies and subsequent climate impacts. We used high-resolution chemical measurements in the West Antarctic Ice Sheet Divide, Byrd, and other ice cores to document a unique, ∼192-y series of halogen-rich volcanic eruptions exactly at the start of accelerated deglaciation, with tephra identifying the nearby Mount Takahe volcano as the source. Extensive fallout from these massive eruptions has been found >2,800 km from Mount Takahe. Sulfur isotope anomalies and marked decreases in ice core bromine consistent with increased surface UV radiation indicate that the eruptions led to stratospheric ozone depletion. Rather than a highly improbable coincidence, circulation and climate changes extending from the Antarctic Peninsula to the subtropics—similar to those associated with modern stratospheric ozone depletion over Antarctica—plausibly link the Mount Takahe eruptions to the onset of accelerated Southern Hemisphere deglaciation ∼17.7 ka.

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Improved estimates of preindustrial biomass burning reduce the magnitude of aerosol climate forcing in the Southern Hemisphere

Science Advances ◽

10.1126/sciadv.abc1379 ◽

2021 ◽

Vol 7 (22) ◽

pp. eabc1379

Author(s):

Pengfei Liu ◽

Jed O. Kaplan ◽

Loretta J. Mickley ◽

Yang Li ◽

Nathan J. Chellman ◽

...

Keyword(s):

Southern Hemisphere ◽

Radiative Forcing ◽

Ice Core ◽

Ice Cores ◽

Terrestrial Ecosystems ◽

Rapid Expansion ◽

Past Century ◽

Fire Emissions ◽

The Past ◽

Fire Activity

Fire plays a pivotal role in shaping terrestrial ecosystems and the chemical composition of the atmosphere and thus influences Earth’s climate. The trend and magnitude of fire activity over the past few centuries are controversial, which hinders understanding of preindustrial to present-day aerosol radiative forcing. Here, we present evidence from records of 14 Antarctic ice cores and 1 central Andean ice core, suggesting that historical fire activity in the Southern Hemisphere (SH) exceeded present-day levels. To understand this observation, we use a global fire model to show that overall SH fire emissions could have declined by 30% over the 20th century, possibly because of the rapid expansion of land use for agriculture and animal production in middle to high latitudes. Radiative forcing calculations suggest that the decreasing trend in SH fire emissions over the past century largely compensates for the cooling effect of increasing aerosols from fossil fuel and biofuel sources.

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The Amundsen Sea Low: Variability, Change, and Impact on Antarctic Climate

Bulletin of the American Meteorological Society ◽

10.1175/bams-d-14-00018.1 ◽

2016 ◽

Vol 97 (1) ◽

pp. 111-121 ◽

Cited By ~ 119

Author(s):

M. N. Raphael ◽

G. J. Marshall ◽

J. Turner ◽

R. L. Fogt ◽

D. Schneider ◽

...

Keyword(s):

Sea Ice ◽

Climate Model ◽

Ross Sea ◽

Ice Core ◽

Meridional Wind ◽

West Antarctica ◽

Sea Ice Extent ◽

Amundsen Sea ◽

West Antarctic ◽

Climate Model Simulations

Abstract The Amundsen Sea low (ASL) is a climatological low pressure center that exerts considerable influence on the climate of West Antarctica. Its potential to explain important recent changes in Antarctic climate, for example, in temperature and sea ice extent, means that it has become the focus of an increasing number of studies. Here, the authors summarize the current understanding of the ASL, using reanalysis datasets to analyze recent variability and trends, as well as ice-core chemistry and climate model projections, to examine past and future changes in the ASL, respectively. The ASL has deepened in recent decades, affecting the climate through its influence on the regional meridional wind field, which controls the advection of moisture and heat into the continent. Deepening of the ASL in spring is consistent with observed West Antarctic warming and greater sea ice extent in the Ross Sea. Climate model simulations for recent decades indicate that this deepening is mediated by tropical variability while climate model projections through the twenty-first century suggest that the ASL will deepen in some seasons in response to greenhouse gas concentration increases.

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Centennial-scale variability of the Southern Hemisphere westerly wind belt in the eastern Pacific over the past two millennia

Climate of the Past ◽

10.5194/cp-10-1125-2014 ◽

2014 ◽

Vol 10 (3) ◽

pp. 1125-1144 ◽

Cited By ~ 30

Author(s):

B. G. Koffman ◽

K. J. Kreutz ◽

D. J. Breton ◽

E. J. Kane ◽

D. A. Winski ◽

...

Keyword(s):

Particle Size ◽

Wind Speed ◽

Atmospheric Circulation ◽

Southern Hemisphere ◽

Zonal Wind ◽

Ice Core ◽

Eastern Pacific ◽

The Past ◽

West Antarctic ◽

Lower Elevation

Abstract. We present the first high-resolution (sub-annual) dust particle data set from West Antarctica, developed from the West Antarctic Ice Sheet (WAIS) Divide deep ice core (79.468° S, 112.086° W), and use it to reconstruct changes in atmospheric circulation over the past 2400 years. We find a background dust flux of ~4 mg m−2 year−1 and a mode particle size of 5–8 μm diameter. Through comparing the WAIS Divide record with other Antarctic ice core particle records, we observe that coastal and lower-elevation sites have higher dust fluxes and coarser particle size distributions (PSDs) than sites on the East Antarctic plateau, suggesting input from local dust sources at these lower-elevation sites. In order to explore the use of the WAIS Divide dust PSD as a proxy for past atmospheric circulation, we make quantitative comparisons between both mid-latitude zonal wind speed and West Antarctic meridional wind speed and the dust size record, finding significant positive interannual relationships. We find that the dust PSD is related to mid-latitude zonal wind speed via cyclonic activity in the Amundsen Sea region. Using our PSD record, and through comparison with spatially distributed climate reconstructions from the Southern Hemisphere (SH) middle and high latitudes, we infer that the SH westerlies occupied a more southerly position from circa 1050 to 1400 CE (Common Era), coinciding with the Medieval Climate Anomaly (MCA). Subsequently, at ca. 1430 CE, the wind belt shifted equatorward, where it remained until the mid-to-late twentieth century. We find covariability between reconstructions of El Niño–Southern Oscillation (ENSO) and the mid-latitude westerly winds in the eastern Pacific, suggesting that centennial-scale circulation changes in this region are strongly influenced by the tropical Pacific. Further, we observe increased coarse particle deposition over the past 50 years, consistent with observations that the SH westerlies have been shifting southward and intensifying in recent decades.

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