scholarly journals Little Ice Age climate and oceanic conditions of the Ross Sea, Antarctica from a coastal ice core record

2012 ◽  
Vol 8 (4) ◽  
pp. 1223-1238 ◽  
Author(s):  
R. H. Rhodes ◽  
N. A. N. Bertler ◽  
J. A. Baker ◽  
H. C. Steen-Larsen ◽  
S. B. Sneed ◽  
...  
Keyword(s):  
Little Ice Age ◽  
Ross Sea ◽  
Global Climate ◽  
Ice Core ◽  
Ice Age ◽  
Katabatic Wind ◽  
Aeolian Transport ◽  
Katabatic Winds ◽  
Order Of Magnitude ◽  
Wind Events

Abstract. Increasing paleoclimatic evidence suggests that the Little Ice Age (LIA) was a global climate change event. Understanding the forcings and associated climate system feedbacks of the LIA is made difficult by the scarcity of Southern Hemisphere paleoclimate records. We use a new glaciochemical record of a coastal ice core from Mt. Erebus Saddle, Antarctica, to reconstruct atmospheric and oceanic conditions in the Ross Sea sector of Antarctica over the past five centuries. The LIA is identified in stable isotope (δD) and lithophile element records, which respectively demonstrate that the region experienced 1.6 ± 1.4 °C cooler average temperatures prior to 1850 AD than during the last 150 yr and strong (>57 m s−1) prevailing katabatic winds between 1500 and 1800 AD. Al and Ti concentration increases of an order of magnitude (>120 ppb Al) are linked to enhanced aeolian transport of complex silicate minerals and represent the strongest katabatic wind events of the LIA. These events are associated with three 12–30 yr intervals of cooler temperatures at ca. 1690 AD, 1770 AD and 1840 AD. Furthermore, ice core concentrations of the biogenic sulphur species MS− suggest that biological productivity in the Ross Sea polynya was ~80% higher prior to 1875 AD than at any subsequent time. We propose that cooler Antarctic temperatures promoted stronger katabatic winds across the Ross Ice Shelf, resulting in an enlarged Ross Sea polynya during the LIA.

scholarly journals Little Ice Age climate and oceanic conditions of the Ross Sea, Antarctica from a coastal ice core record

2012 ◽  
Vol 8 (1) ◽  
pp. 215-262 ◽  
Author(s):  
R. H. Rhodes ◽  
N. A. N. Bertler ◽  
J. A. Baker ◽  
H. C. Steen-Larsen ◽  
S. B. Sneed ◽  
...  
Keyword(s):  
Little Ice Age ◽  
Bottom Water ◽  
Ross Sea ◽  
Ice Core ◽  
Ice Age ◽  
Katabatic Wind ◽  
Katabatic Winds ◽  
Ross Ice Shelf ◽  
Order Of Magnitude ◽  
Wind Events

Abstract. The Little Ice Age (LIA) is the most recent abrupt climate change event. Understanding its forcings and associated climate system feedbacks is made difficult by a scarcity of Southern Hemisphere paleoclimate records. In this paper we utilise ice core glaciochemical records to reconstruct atmospheric and oceanic conditions in the Ross Sea sector of Antarctic, a region influenced by two contrasting meteorological regimes: katabatic winds and cyclones. Stable isotope (δD) and lithophile element concentration (e.g., Al) records indicate that the region experienced ~1.75 °C cooler temperatures and strong (>57 m s−1) prevailing katabatic winds during the LIA. We observe that the 1590–1875 record is characterised by high d-excess values and marine element (e.g., Na) concentrations, which are linked to the intrusion of cyclonic systems. The strongest katabatic wind events of the LIA, marked by Al, Ti and Pb concentration increases of an order of magnitude (>120 ppb Al), also occur during this interval. Furthermore, concentrations of the biogenic sulphur species MS− suggest that biological productivity in the Ross Sea Polynya was ~80% higher prior to 1875 than in the subsequent time. We propose that colder temperatures and intensified cyclonic activity in the Ross Sea promoted stronger katabatic winds across the Ross Ice Shelf, resulting in an enlarged polynya with increased sea ice and bottom water production. It is therefore hypothesised that increased bottom water formation during the LIA occurred in response to atmospheric circulation change.

scholarly journals A Paleoclimate Reconstruction of the Little Ice Age to Modern Era Climate Conditions in the Eastern Ross Sea, Antarctica as Captured in the RICE Ice Core

2021 ◽  
Author(s):  
◽  
Hannah Brightley
Keyword(s):  
Sea Ice ◽  
Little Ice Age ◽  
Ross Sea ◽  
Ice Core ◽  
Circulation Pattern ◽  
Ice Age ◽  
Biological Productivity ◽  
Atmospheric Circulation Pattern ◽  
Ion Chromatograph ◽  
Modern Era

<p>The Little Ice Age (LIA) (1400-1850 AD) represents one of the most significant climatic shifts over the past 5000 years. Previous studies from Antarctica indicate generally cooler and stormier conditions during this period, but this pattern shows distinct spatial and temporal variability. The Roosevelt Island Climate Evolution (RICE) ice core provides a new opportunity to study the drivers behind this variability at annual/seasonal resolution, in a relatively under-sampled and climatically sensitive region in the eastern Ross Sea. Contrary to previous studies, isotope measurements suggest warm conditions during the LIA at Roosevelt Island.  This study presents analysis of eight major ions (Na⁺, Mg²⁺, Ca²⁺, K⁺, MS⁻, Cl⁻, NO₃⁻, SO₄²⁻) using both Ion Chromatograph and ICP-MS data, in order to reconstruct the atmospheric circulation pattern, sea ice extent and marine primary productivity across this LIA to Modern Era (ME) at Roosevelt Island. The dataset is tied to a robust age model allowing annual dating and the opportunity to accurately reconstruct rates of change during this ME-LIA. Challenges revolving around the calibration of the Ion Chromatograph are also discussed. The major ion record determines whether the lack of cooling in the Roosevelt Island core implied by the stable isotopes represents a true temperature anomaly or whether the atmospheric circulation pattern caused an isotopic enrichment that masks an underlying cooling.  It was determined that Roosevelt Island experienced during the LIA (i) an increase in marine air mass intrusions along with weaker katabatic winds compared to the 200 years prior, (ii) decreased biological productivity and (iii) increased sea ice. From the 1850-1880s to 1992 AD, there is a shift to reduced marine winds, increased katabatics, increased biological productivity and decreased sea ice until 1992. In the wider Ross Sea context, this suggests an east-west divide in terms of the dominance of katabatics versus marine wind influence. This divide is attributed with the warming signal seen in the RICE record in the Eastern Ross Sea and the cooling in the Western Ross Sea records. It is also likely linked to the influence of climate indices on the depth/position of the Amundsen Sea Low.</p>

scholarly journals A Paleoclimate Reconstruction of the Little Ice Age to Modern Era Climate Conditions in the Eastern Ross Sea, Antarctica as Captured in the RICE Ice Core

2021 ◽  
Author(s):  
◽  
Hannah Brightley
Keyword(s):  
Sea Ice ◽  
Little Ice Age ◽  
Ross Sea ◽  
Ice Core ◽  
Circulation Pattern ◽  
Ice Age ◽  
Biological Productivity ◽  
Atmospheric Circulation Pattern ◽  
Ion Chromatograph ◽  
Modern Era

<p>The Little Ice Age (LIA) (1400-1850 AD) represents one of the most significant climatic shifts over the past 5000 years. Previous studies from Antarctica indicate generally cooler and stormier conditions during this period, but this pattern shows distinct spatial and temporal variability. The Roosevelt Island Climate Evolution (RICE) ice core provides a new opportunity to study the drivers behind this variability at annual/seasonal resolution, in a relatively under-sampled and climatically sensitive region in the eastern Ross Sea. Contrary to previous studies, isotope measurements suggest warm conditions during the LIA at Roosevelt Island.  This study presents analysis of eight major ions (Na⁺, Mg²⁺, Ca²⁺, K⁺, MS⁻, Cl⁻, NO₃⁻, SO₄²⁻) using both Ion Chromatograph and ICP-MS data, in order to reconstruct the atmospheric circulation pattern, sea ice extent and marine primary productivity across this LIA to Modern Era (ME) at Roosevelt Island. The dataset is tied to a robust age model allowing annual dating and the opportunity to accurately reconstruct rates of change during this ME-LIA. Challenges revolving around the calibration of the Ion Chromatograph are also discussed. The major ion record determines whether the lack of cooling in the Roosevelt Island core implied by the stable isotopes represents a true temperature anomaly or whether the atmospheric circulation pattern caused an isotopic enrichment that masks an underlying cooling.  It was determined that Roosevelt Island experienced during the LIA (i) an increase in marine air mass intrusions along with weaker katabatic winds compared to the 200 years prior, (ii) decreased biological productivity and (iii) increased sea ice. From the 1850-1880s to 1992 AD, there is a shift to reduced marine winds, increased katabatics, increased biological productivity and decreased sea ice until 1992. In the wider Ross Sea context, this suggests an east-west divide in terms of the dominance of katabatics versus marine wind influence. This divide is attributed with the warming signal seen in the RICE record in the Eastern Ross Sea and the cooling in the Western Ross Sea records. It is also likely linked to the influence of climate indices on the depth/position of the Amundsen Sea Low.</p>

Ice-Core Pollen Record of Climatic Changes in the Central Andes during the last 400 yr

2005 ◽  
Vol 64 (2) ◽  
pp. 272-278 ◽  
Author(s):  
Kam-biu Liu ◽  
Carl A. Reese ◽  
Lonnie G. Thompson
Keyword(s):  
Little Ice Age ◽  
Ice Core ◽  
Climatic Changes ◽  
Ice Age ◽  
Striking Similarity ◽  
Pollen Record ◽  
Dry Period ◽  
Proxy Records ◽  
Ice Cap ◽  
Ice Accumulation

AbstractThis paper presents a high-resolution ice-core pollen record from the Sajama Ice Cap, Bolivia, that spans the last 400 yr. The pollen record corroborates the oxygen isotopic and ice accumulation records from the Quelccaya Ice Cap and supports the scenario that the Little Ice Age (LIA) consisted of two distinct phases�"a wet period from AD 1500 to 1700, and a dry period from AD 1700 to 1880. During the dry period xerophytic shrubs expanded to replace puna grasses on the Altiplano, as suggested by a dramatic drop in the Poaceae/Asteraceae (P/A) pollen ratio. The environment around Sajama was probably similar to the desert-like shrublands of the Southern Bolivian Highlands and western Andean slopes today. The striking similarity between the Sajama and Quelccaya proxy records suggests that climatic changes during the Little Ice Age occurred synchronously across the Altiplano.

scholarly journals Little Ice Age (Neoglacial) Paleoenvironmental Conditions At Siple Station, Antarctica

1990 ◽  
Vol 14 ◽  
pp. 199-204 ◽  
Author(s):  
Ellen Mosley-Thompson ◽  
Lonnie G. Thompson ◽  
Pieter M. Grootes ◽  
N. Gundestrup
Keyword(s):  
Little Ice Age ◽  
Regional Differences ◽  
Meteorological Data ◽  
Ice Core ◽  
Observational Evidence ◽  
Ice Age ◽  
Temperature Pattern ◽  
South Pole ◽  
Atmospheric Conditions ◽  
Spatially Distributed

The 550-year records of δ18O and dust concentrations from Siple Station, Antarctica suggest warmer and less dusty atmospheric conditions from 1600 to 1830 A.D. which encompasses much of the northern hemisphere Little Ice Age (LIA). Dust and δ18O data from South Pole Station indicate that the opposite conditions (e.g. cooler and more dusty) were prevalent there during the LIA. Meteorological data from 1945–85 show that the LIA temperature opposition between Amundsen-Scott and Siple, inferred from δ18O, is consistent with the present spatial distribution of surface temperature. There is some observational evidence suggesting that under present conditions stronger zonal westerlies produce a temperature pattern similar to that of the LIA. These regional differences demonstrate that a suite of spatially distributed, high resolution ice-core records will be necessary to characterize the LIA in Antarctica

scholarly journals Tree-ring radiocarbon reveals reduced solar activity during Younger Dryas cooling

2020 ◽  
Author(s):  
Adam Sookdeo ◽  
Bernd Kromer ◽  
Florian Adolphi ◽  
Jürg Beer ◽  
Nicolas Brehm ◽  
...  
Keyword(s):  
Solar Activity ◽  
Tree Ring ◽  
North Atlantic ◽  
Little Ice Age ◽  
Ice Core ◽  
Younger Dryas ◽  
Ice Age ◽  
The North ◽  
Long Duration ◽  
Clear Sign

&lt;p&gt;The Younger Dryas stadial (YD) was a return to glacial-like conditions in the North Atlantic region that interrupted deglacial warming around 12900 cal BP (before 1950 AD). Terrestrial and marine records suggest this event was initiated by the interruption of deep-water formation arising from North American freshwater runoff, but the causes of the millennia-long duration remain unclear. To investigate the solar activity, a possible YD driver, we exploit the cosmic production signals of tree-ring radiocarbon (&lt;sup&gt;14&lt;/sup&gt;C) and ice-core beryllium-10 (&lt;sup&gt;10&lt;/sup&gt;Be). Here we present the highest temporally resolved dataset of &lt;sup&gt;14&lt;/sup&gt;C measurements (n = 1558) derived from European tree rings that have been accurately extended back to 14226 cal BP (&amp;#177;8, 2-&amp;#963;), allowing precise alignment of ice-core records across this period. We identify a substantial increase in &lt;sup&gt;14&lt;/sup&gt;C and &lt;sup&gt;10&lt;/sup&gt;Be production starting at 12780 cal BP is comparable in magnitude to the historic Little Ice Age, being a clear sign of grand solar minima. We hypothesize the timing of the grand solar minima provides a significant amplifying factor leading to the harsh sustained glacial-like conditions seen in the YD.&lt;/p&gt;

Pattern and Forcing of Northern Hemisphere Glacier Variations During the Last Millennium

1986 ◽  
Vol 26 (1) ◽  
pp. 27-48 ◽  
Author(s):  
Stephen C. Porter
Keyword(s):  
Northern Hemisphere ◽  
Little Ice Age ◽  
Ice Core ◽  
Volcanic Eruptions ◽  
Ice Age ◽  
Phase Lag ◽  
Mountain Glacier ◽  
Radiocarbon Dates ◽  
Glacier Fluctuations ◽  
Decadal Scale

Time series depicting mountain glacier fluctuations in the Alps display generally similar patterns over the last two centuries, as do chronologies of glacier variations for the same interval from elsewhere in the Northern Hemisphere. Episodes of glacier advance consistently are associated with intervals of high average volcanic aerosol production, as inferred from acidity variations in a Greenland ice core. Advances occur whenever acidity levels rise sharply from background values to reach concentrations ≥1.2 μequiv H+/kg above background. A phase lag of about 10–15 yr, equivalent to reported response lags of Alpine glacier termini, separates the beginning of acidity increases from the beginning of subsequent ice advances. A similar relationship, but based on limited and less-reliable historical data and on lichenometric ages, is found for the preceding 2 centuries. Calibrated radiocarbon dates related to advances of non-calving and non-surging glaciers during the earlier part of the Little Ice Age display a comparable consistent pattern. An interval of reduced acidity values between about 1090 and 1230 A.D. correlates with a time of inferred glacier contraction during the Medieval Optimum. The observed close relation between Noothern Hemisphere glacier fluctuations and variations in Greenland ice-core acidity suggests that sulfur-rich aerosols generated by volcanic eruptions are a primary forcing mechanism of glacier fluctuations, and therefore of climate, on a decadal scale. The amount of surface cooling attributable to individual large eruptions or to episodes of eruptions is simlar to the probable average temperature reduction during culminations of Little Ice Age alacier advances (ca. 0.5°–1.2°C), as inferred from depression of equilibrium-line altitudes.

Little Ice Age Evidence from a South-Central North American Ice Core, U.S.A.

1996 ◽  
Vol 28 (1) ◽  
pp. 35 ◽  
Author(s):  
D. L. Naftz ◽  
R. W. Klusman ◽  
R. L. Michel ◽  
P. F. Schuster ◽  
M. M. Reddy ◽  
...  
Keyword(s):  
North American ◽  
Little Ice Age ◽  
Ice Core ◽  
Ice Age ◽  
South Central

Oxygen isotope evidence of Little Ice Age aridity on the Caribbean slope of the Cordillera Central, Dominican Republic

2011 ◽  
Vol 75 (3) ◽  
pp. 461-470 ◽  
Author(s):  
Chad S. Lane ◽  
Sally P. Horn ◽  
Kenneth H. Orvis ◽  
John M. Thomason
Keyword(s):  
Climate Change ◽  
Dominican Republic ◽  
Oxygen Isotope ◽  
Little Ice Age ◽  
Global Climate ◽  
Ice Age ◽  
Energy Budgets ◽  
Cordillera Central ◽  
Climate Conditions ◽  
The Caribbean

AbstractClimate change during the so-called Little Ice Age (LIA) of the 15th to 19th centuries was once thought to be limited to the high northern latitudes, but increasing evidence reflects significant climate change in the tropics. One of the hypothesized features of LIA climate in the low latitudes is a more southerly mean annual position of the Intertropical Convergence Zone (ITCZ), which produced more arid conditions through much of the northern tropics. High-resolution stable oxygen isotope data and other sedimentary evidence from Laguna de Felipe, located on the Caribbean slope of the Cordillera Central of the Dominican Republic, support the hypothesis that the mean annual position of the ITCZ was displaced significantly southward during much of the LIA. Placed within the context of regional paleoclimate and paleoceanographic records, and reconstructions of global LIA climate, this shift in mean annual ITCZ position appears to have been induced by lower solar insolation and internal dynamical responses of the global climate system. Our results from Hispaniola further emphasize the global nature of LIA climate change and the sensitivity of circum-Caribbean climate conditions to what are hypothesized to be relatively small variations in global energy budgets.

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