Review of the manuscript entitled “Mineral Dust Influence on the Glacial Nitrate Record from the RICE Ice Core, West Antarctica and Environmental Implications”

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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Mineral Dust Influence on the Glacial Nitrate Record from the RICE Ice Core, West Antarctica and Environmental Implications

10.5194/cp-2020-151 ◽

2020 ◽

Author(s):

Abhijith U. Venugopal ◽

Nancy A. N. Bertler ◽

Rebecca L. Pyne ◽

Helle A. Kjær ◽

V. Holly L. Winton ◽

...

Keyword(s):

Mineral Dust ◽

Ice Core ◽

Environmental Implications ◽

Long Distance ◽

Central Dome ◽

Long Distance Transport ◽

Depositional Processes ◽

Latitudinal Position ◽

Climate Evolution ◽

Polar Snow

Abstract. Nitrate (NO3−), an abundant aerosol in polar snow, is a complex environmental proxy to interpret owing to the variety of its sources and its susceptibility to post-depositional processes. During the last glacial period, when the dust level in the Antarctic atmosphere was higher than today by a factor up to ~25, mineral dust appears to have a stabilizing effect on the NO3− concentration. However, the exact mechanism remains unclear. Here, we present new and highly resolved records of NO3− and non-sea salt calcium (nssCa2+, a proxy for mineral dust) from the Roosevelt Island Climate Evolution (RICE) ice core for the period 26–40 kilo years Before Present (ka BP). This interval includes seven millennial-scale Antarctic Isotope Maxima (AIM) events, against the background of a glacial climate state. We observe a significant correlation between NO3− and nssCa2+ over this period and especially during AIM events. We put our observation into a spatial context by comparing the records to existing data from east Antarctic cores of EPICA Dome C (EDC), Vostok and central Dome Fuji. The data suggest that nssCa2+ is contributing to the effective scavenging of NO3− from the atmosphere through the formation of Ca(NO3)2. The geographic pattern implies that the process of Ca(NO3)2 formation occurs during the long-distance transport of mineral dust from the mid-latitude source regions by Southern Hemisphere Westerly Winds (SHWW) and most likely over the Southern Ocean. Since NO3− is dust-bound and the level of dust mobilized through AIM events is mainly regulated by the latitudinal position of SHWW, we suggest that NO3− may also have the potential to provide insights into paleo-westerly wind pattern during the events.

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Mineral dust variability in central West Antarctica associated with ozone depletion

Atmospheric Chemistry and Physics ◽

10.5194/acp-13-2165-2013 ◽

2013 ◽

Vol 13 (4) ◽

pp. 2165-2175 ◽

Cited By ~ 12

Author(s):

M. Cataldo ◽

H. Evangelista ◽

J. C. Simões ◽

R. H. M. Godoi ◽

I. Simmonds ◽

...

Keyword(s):

Ozone Depletion ◽

Mineral Dust ◽

Ice Core ◽

Ice Cores ◽

Geochemical Analysis ◽

West Antarctica ◽

The Past ◽

West Antarctic ◽

Westerly Winds ◽

Wind Intensity

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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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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Magmatic and phreatomagmatic volcanic activity at Mt. Takahe, West Antarctica, based on tephra layers in the Byrd ice core and field observations at Mt. Takahe

Journal of Volcanology and Geothermal Research ◽

10.1016/0377-0273(88)90025-x ◽

1988 ◽

Vol 35 (4) ◽

pp. 295-317 ◽

Cited By ~ 27

Author(s):

Julie M. Palais ◽

Philip R. Kyle ◽

William C. McIntosh ◽

Diane Seward

Keyword(s):

Volcanic Activity ◽

Ice Core ◽

Field Observations ◽

West Antarctica ◽

Tephra Layers

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Tephrochronology of the Siple Dome ice core, West Antarctica: correlations and sources

Quaternary Science Reviews ◽

10.1016/j.quascirev.2011.03.015 ◽

2011 ◽

Vol 30 (13-14) ◽

pp. 1602-1614 ◽

Cited By ~ 32

Author(s):

Nelia W. Dunbar ◽

Andrei V. Kurbatov

Keyword(s):

Ice Core ◽

West Antarctica ◽

Siple Dome

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Centennial mineral dust variability in high-resolution ice core data from Dome C, Antarctica

Climate of the Past ◽

10.5194/cp-8-609-2012 ◽

2012 ◽

Vol 8 (2) ◽

pp. 609-623 ◽

Cited By ~ 97

Author(s):

F. Lambert ◽

M. Bigler ◽

J. P. Steffensen ◽

M. Hutterli ◽

H. Fischer

Keyword(s):

High Resolution ◽

Southern Ocean ◽

Mineral Dust ◽

Ice Core ◽

Principal Component ◽

Dominant Factor ◽

Core Data ◽

The Past ◽

Dust Flux ◽

Soluble Calcium

Abstract. Ice core data from Antarctica provide detailed insights into the characteristics of past climate, atmospheric circulation, as well as changes in the aerosol load of the atmosphere. We present high-resolution records of soluble calcium (Ca2+), non-sea-salt soluble calcium (nssCa2+), and particulate mineral dust aerosol from the East Antarctic Plateau at a depth resolution of 1 cm, spanning the past 800 000 years. Despite the fact that all three parameters are largely dust-derived, the ratio of nssCa2+ to particulate dust is dependent on the particulate dust concentration itself. We used principal component analysis to extract the joint climatic signal and produce a common high-resolution record of dust flux. This new record is used to identify Antarctic warming events during the past eight glacial periods. The phasing of dust flux and CO2 changes during glacial-interglacial transitions reveals that iron fertilization of the Southern Ocean during the past nine glacial terminations was not the dominant factor in the deglacial rise of CO2 concentrations. Rapid changes in dust flux during glacial terminations and Antarctic warming events point to a rapid response of the southern westerly wind belt in the region of southern South American dust sources on changing climate conditions. The clear lead of these dust changes on temperature rise suggests that an atmospheric reorganization occurred in the Southern Hemisphere before the Southern Ocean warmed significantly.

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A 2700-year annual timescale and accumulation history for an ice core from Roosevelt Island, West Antarctica

10.5194/cp-2017-101 ◽

2017 ◽

Cited By ~ 8

Author(s):

Mai Winstrup ◽

Paul Vallelonga ◽

Helle A. Kjær ◽

Tyler J. Fudge ◽

James E. Lee ◽

...

Keyword(s):

Accumulation Rate ◽

Ice Core ◽

Early Period ◽

Volcanic Eruptions ◽

Snow Accumulation ◽

Atmospheric Methane ◽

Accumulation Rates ◽

West Antarctica ◽

Ross Ice Shelf ◽

Accumulation History

Abstract. We present a 2700-year annually resolved timescale for the Roosevelt Island Climate Evolution (RICE) ice core, and reconstruct a past snow accumulation history for the coastal sector of the Ross Ice Shelf in West Antarctica. The timescale was constructed by identifying annual layers in multiple ice-core impurity records, employing both manual and automated counting approaches, and constitutes the top part of the Roosevelt Island Ice Core Chronology 2017 (RICE17). The maritime setting of Roosevelt Island results in high sulfate influx from sea salts and marine biogenic emissions, which prohibits a routine detection of volcanic eruptions in the ice-core records. This led to the use of non-traditional chronological techniques for validating the timescale: RICE was synchronized to the WAIS Divide ice core, on the WD2014 timescale, using volcanic attribution based on direct measurements of ice-core acidity, as well as records of globally-synchronous, centennial-scale variability in atmospheric methane concentrations. The RICE accumulation history suggests stable values of 0.25 m water equivalent (w.e.) per year until around 1260 CE. Uncertainties in the correction for ice flow thinning of annual layers with depth do not allow a firm conclusion about long-term trends in accumulation rates during this early period but from 1260 CE to the present, accumulation rate trends have been consistently negative. The decrease in accumulation rates has been increasingly rapid over the last centuries, with the decrease since 1950 CE being more than 7 times greater than the average over the last 300 years. The current accumulation rate of 0.22 ± 0.06 m w.e. yr−1 (average since 1950 CE, ±1σ) is 1.49 standard deviations (86th percentile) below the mean of 50-year average accumulation rates observed over the last 2700 years.

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Ice Core Archives of Mineral Dust

Mineral Dust ◽

10.1007/978-94-017-8978-3_18 ◽

2014 ◽

pp. 463-485 ◽

Cited By ~ 5

Author(s):

Paul Vallelonga ◽

Anders Svensson

Keyword(s):

Mineral Dust ◽

Ice Core

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