Climatic Conditions and Hydrological Change Recorded in a High-Resolution Stable-Isotope Profile of a Recent Laminated Tufa on a Subtropical Island, Southern Japan

2007 ◽  
Vol 77 (1) ◽  
pp. 59-67 ◽  
Author(s):  
A. Kano ◽  
R. Hagiwara ◽  
T. Kawai ◽  
M. Hori ◽  
J. Matsuoka
Keyword(s):  
High Resolution ◽  
Stable Isotope ◽  
Climatic Conditions ◽  
Hydrological Change ◽  
Southern Japan ◽  
Isotope Profile

scholarly journals Surface mass balance and water stable isotopes derived from firn cores on three ice rises, Fimbul Ice Shelf, Antarctica

2016 ◽  
Vol 10 (6) ◽  
pp. 2763-2777 ◽  
Author(s):  
Carmen P. Vega ◽  
Elisabeth Schlosser ◽  
Dmitry V. Divine ◽  
Jack Kohler ◽  
Tõnu Martma ◽  
...  
Keyword(s):  
High Resolution ◽  
Stable Isotope ◽  
Mass Balance ◽  
Temporal Variability ◽  
Ice Cores ◽  
Surface Mass Balance ◽  
Ice Shelf ◽  
Climate Signal ◽  
Surface Mass ◽  
Water Stable Isotope

Abstract. Three shallow firn cores were retrieved in the austral summers of 2011/12 and 2013/14 on the ice rises Kupol Ciolkovskogo (KC), Kupol Moskovskij (KM), and Blåskimen Island (BI), all part of Fimbul Ice Shelf (FIS) in western Dronning Maud Land (DML), Antarctica. The cores were dated back to 1958 (KC), 1995 (KM), and 1996 (BI) by annual layer counting using high-resolution oxygen isotope (δ18O) data, and by identifying volcanic horizons using non-sea-salt sulfate (nssSO42−) data. The water stable isotope records show that the atmospheric signature of the annual snow accumulation cycle is well preserved in the firn column, especially at KM and BI. We are able to determine the annual surface mass balance (SMB), as well as the mean SMB values between identified volcanic horizons. Average SMB at the KM and BI sites (0.68 and 0.70 mw. e. yr−1) was higher than at the KC site (0.24 mw. e. yr−1), and there was greater temporal variability as well. Trends in the SMB and δ18O records from the KC core over the period of 1958–2012 agree well with other previously investigated cores in the area, thus the KC site could be considered the most representative of the climate of the region. Cores from KM and BI appear to be more affected by local meteorological conditions and surface topography. Our results suggest that the ice rises are suitable sites for the retrieval of longer firn and ice cores, but that BI has the best preserved seasonal cycles of the three records and is thus the most optimal site for high-resolution studies of temporal variability of the climate signal. Deuterium excess data suggest a possible effect of seasonal moisture transport changes on the annual isotopic signal. In agreement with previous studies, large-scale atmospheric circulation patterns most likely provide the dominant influence on water stable isotope ratios preserved at the core sites.

scholarly journals Climate Change Impacts Assessment on Wine-Growing Bioclimatic Transition Areas

Agriculture ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 605
Author(s):  
Alba Piña-Rey ◽  
Estefanía González-Fernández ◽  
María Fernández-González ◽  
Mª. Nieves Lorenzo ◽  
Fco. Javier Rodríguez-Rajo
Keyword(s):  
Climate Change ◽  
High Resolution ◽  
Climate Change Impacts ◽  
Mediterranean Area ◽  
Cultural Practice ◽  
Climatic Conditions ◽  
Study Region ◽  
Bioclimatic Indices ◽  
Northwestern Spain ◽  
The Mediterranean

Viticultural climatic indices were assessed for the evaluation of the meteorological variations in the requirements of wine cultivars. The applied bioclimatic indices have been widely used to provide an initial evaluation of climate change impacts on grapevine and to delineate wine regions and suitable areas for planting around the world. The study was carried out over a period of 16 years (from 2000 to 2015) in five Designation of Origin areas in Northwestern Spain located in the Eurosiberian region, the transition zone between the Eurosiberian and the Mediterranean areas, and in the Mediterranean area. In addition, the high-resolution meteorological dataset “Spain02” was applied to the bioclimatic indices for the period 1950–2095. To further assess the performance of “Spain02”, Taylor diagrams were elaborated for the different bioclimatic indices. A significant trend to an increase of the Winkler, Huglin, Night Cold Index and GSS Indices was detected in the North-western Spain, whereas slight negative trends for BBLI and GSP Indices were observed. To analyze future projections 2061–2095, data from the high-resolution dynamically downscaled daily climate simulations from EURO-CORDEX project were used. To further assess the performance of Spain02, Taylor diagrams were elaborated for the different bioclimatic indices. A trend to an increase of the Winkler, Huglin, Night Cold Index and GSP Indices was detected in Northwestern Spain, whereas slight negative trends for BBLI and GSP Indices were observed. Our results showed that climatic conditions in the study region could variate for the crop in the future, more for Mediterranean than Eurosiberian bioclimatic area. Due to an advance in the phenological events or the vintage data, more alcohol-fortified wines and variations in the acidity level of wines could be expected in Northwestern Spain, these processes being most noticeable in the Mediterranean area. The projections for the BBLI and GSP Indices will induce a decrease in the pressure of the mildew attacks incidence in the areas located at the Eurosiberian region and the nearest transition zones. Projections showed if the trend of temperature increase continues, some cultural practice variations should be conducted in order to preserve the grape cultivation suitability in the studied area.

Onset of Oceanic Anoxic Event 2 in the Lower Saxony Basin – Insights fromhigh-resolution stable isotope stratigraphy and geochemical modelling

2021 ◽  
Author(s):  
Pia Müller ◽  
Ulrich Heimhofer ◽  
Christian Ostertag-Henning
Keyword(s):  
Organic Matter ◽  
High Resolution ◽  
Stable Isotope ◽  
Carbon Cycle ◽  
Geochemical Modelling ◽  
Positive Anomaly ◽  
Lower Saxony ◽  
Data Set ◽  
Oceanic Anoxic Event ◽  
Anoxic Event

<p>The Oceanic Anoxic Event (OAE) 2 spanning the Cenomanian-Turonian boundary (93.5 Ma)<br>represents a major perturbation of the global carbon cycle and is marked by organic-rich<br>sediments deposited under oxygen-depleted conditions. In many studies the eruption of the<br>Caribbean LIP is considered to be the cause for rapidly increasing CO2 concentrations and<br>resulting global warming accompanied by widespread oceanic anoxia. In the Lower Saxony<br>Basin of northern Germany, the deposits of the OAE 2 are exposed in several industry drill<br>cores. In this study, the lower part of the OAE 2 has been studied in the HOLCIM 2011-3 drill<br>core. Sedimentary rocks are composed of limestones, marly limestones, marls and black<br>shales and have been analysed with a high-resolution stable isotope approach<br>(approximately one sample every 2 cm) combined with geochemical modelling. Using stable<br>carbon isotopes, bulk rock parameters and petrographic analysis, the onset of OAE 2 has<br>been investigated in detail. The high-resolution δ<sup>13</sup>C curve exhibits overall stable values<br>around 3 ‰ before the onset of the Plenus event. This background level is interrupted by<br>three short-lived and small but significant negative carbon isotope excursions (CIEs) down to<br>δ<sup>13</sup>C values of 2.5 ‰, 2.7 ‰ and 1.9 ‰. Immediately before the main rise in the Plenus bed,<br>a longer-lasting negative CIE down to 2.8 ‰ is observed, preceding the large positive CIE of<br>the OAE 2 to values of 5.2 ‰ over 33 ka. Thereafter, the δ<sup>13</sup>C values decrease to 3.5 ‰ over<br>a period of approximately 130 ka. The results can be correlated with the lower-resolution<br>data set of Voigt et al. (2008) but enable a more accurate characterization of the subtle<br>features of the CIE and hence events before and during this time interval. Carbon cycle<br>modelling with the modelling software SIMILE using a model based on Kump & Arthur (1999)<br>reveals that the negative excursion before the Plenus bed can be explained by a massive<br>volcanic pulse releasing of 0.95*10<sup>18</sup> mol CO2 within 14 ka. This amount corresponds to only<br>81 % of the calculated volume of CO<sub>2</sub> release during emplacement of the Caribbean LIP by<br>Joo et al. (2020). In the model the volcanic exhalation increases atmospheric CO<sub>2</sub><br>concentrations. This will increase global temperatures, intensify the hydrological cycle and<br>thus increase nutrient input into the ocean, resulting in an expansion of the oxygen minimum<br>zone, the development of anoxic conditions and an increase in the preservation potential for<br>organic material. In the model enhanced primary productivity and organic matter preservation<br>can be controlled by the implemented riverine phosphate input and the preservation factor for<br>organic matter. For the positive anomaly, the riverine phosphate input must be nearly<br>doubled (from 0.01 μmol/kg PO<sub>4 </sub>to 0.019 μmol/kg) for the period of the increasing δ<sup>13</sup>C<br>values (app. 33 ka), with a concomitant rise of the preservation factor from 1 % to 2 %. This<br>model scenario accurately reproduces the major features of the new high-resolution δ<sup>13</sup>C<br>record over the onset of the OAE 2 CIE.</p>

Paleoenvironmental reconstruction of the central Levantine Corridor during the Pliocene: insights from lacustrine settings 

2021 ◽  
Author(s):  
John Greenlee ◽  
Silas Dean ◽  
Nicolas Waldmann
Keyword(s):  
High Resolution ◽  
Data Science ◽  
Environmental Changes ◽  
Laser Diffraction ◽  
Climatic Conditions ◽  
Paleoenvironmental Reconstruction ◽  
Cosmogenic Isotopes ◽  
X Ray ◽  
Geochemical Proxies ◽  
Favorable Conditions

<p>This study aims to reconstruct the paleoenvironmental and climatic conditions affecting the Levantine corridor during the early Pliocene. For the purpose of this study, a ~20 m continuous core sequence was retrieved out of the ~200 m long, tilted Erk el Ahmar sequence previously dated by cosmogenic isotopes to ~3.5 Ma. The record include intercalating units consisting of sands, silts, and clays that were sampled in high resolution in order to analyze a variety of sedimentological and geochemical proxies of past climate and environmental changes. We present new preliminary, high-resolution sedimentological (laser diffraction granulometry), petrophysical (magnetic susceptibility) and compositional (X-ray fluorescence) data along with accompanying statistical analysis performed with an advanced suite of data-science tools. These results reveal new cycles of environmental change in the area, which appears to be orbitally controlled, and include dramatic changes also indicated by discrete strata of fossil fragments. Moreover, cycles of deposition can also provide hints on the major hydrological controlling mechanisms. This project provides new light into favorable conditions for the subsistence of perennial lake environments in the Levantine Corridor, which in turn may have facilitated faunal migration between Africa and Eurasia.</p>

scholarly journals Layer echoes in polar ice sheets

1975 ◽  
Vol 15 (73) ◽  
pp. 95-101 ◽  
Author(s):  
Gudmandsen Preben
Keyword(s):  
Stable Isotope ◽  
Ice Sheets ◽  
Polar Ice ◽  
Last Glaciation ◽  
Polar Ice Sheets ◽  
Isotope Profile

AbstractA multitude of extensive layers have been observed by radio-echo soundings in Greenland. By comparison with the stable isotope profile from Camp Century it is found that layering in the lop of the ice has been formed in the period since the last glaciation. Radio-echo layers observed at greater depths in central Greenland may have been created in the period of the interstadials and further down possibly in the period prior to the last glaciation. Further investigations are needed to prove this.

scholarly journals Layer echoes in polar ice sheets

1975 ◽  
Vol 15 (73) ◽  
pp. 95-101 ◽  
Author(s):  
Gudmandsen Preben
Keyword(s):  
Stable Isotope ◽  
Ice Sheets ◽  
Polar Ice ◽  
Last Glaciation ◽  
Polar Ice Sheets ◽  
Isotope Profile

AbstractA multitude of extensive layers have been observed by radio-echo soundings in Greenland. By comparison with the stable isotope profile from Camp Century it is found that layering in the lop of the ice has been formed in the period since the last glaciation. Radio-echo layers observed at greater depths in central Greenland may have been created in the period of the interstadials and further down possibly in the period prior to the last glaciation. Further investigations are needed to prove this.

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