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1,022 results on '"SPÖTL, Christoph"'

1. Sustained North Atlantic warming drove anomalously intense MIS 11c interglacial

Author

Hu, Hsun-Ming, Marino, Gianluca, Pérez-Mejías, Carlos, Spötl, Christoph, Yokoyama, Yusuke, Yu, Jimin, Rohling, Eelco, Kano, Akihiro, Ludwig, Patrick, Pinto, Joaquim G., Michel, Véronique, Valensi, Patricia, Zhang, Xin, Jiang, Xiuyang, Mii, Horng-Sheng, Chien, Wei-Yi, Tsai, Hsien-Chen, Sung, Wen-Hui, Hsu, Chia-Hao, Starnini, Elisabetta, Zunino, Marta, and Shen, Chuan-Chou

Published
2024
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6. Cryogenic cave carbonates

Author

Dublyansky, Yuri V., primary, Moseley, Gina E., additional, Koltai, Gabriella, additional, Töchterle, Paul, additional, and Spötl, Christoph, additional

Published
2024
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7. Tracking westerly wind directions over Europe since the middle Holocene.

Author

Hu, Hsun-Ming, Trouet, Valerie, Spötl, Christoph, Tsai, Hsien-Chen, Chien, Wei-Yi, Sung, Wen-Hui, Michel, Véronique, Yu, Jin-Yi, Valensi, Patricia, Jiang, Xiuyang, Duan, Fucai, Wang, Yongjin, Mii, Horng-Sheng, Chou, Yu-Min, Lone, Mahjoor Ahmad, Wu, Chung-Che, Starnini, Elisabetta, Zunino, Marta, Watanabe, Takaaki K, Watanabe, Tsuyoshi, Hsu, Huang-Hsiung, Moore, GWK, Zanchetta, Giovanni, Pérez-Mejías, Carlos, Lee, Shih-Yu, and Shen, Chuan-Chou

Subjects
Wind, Climate, Europe, Italy, Atlantic Ocean
Abstract

The variability of the northern westerlies has been considered as one of the key elements for modern and past climate evolution. Their multiscale behavior and underlying control mechanisms, however, are incompletely understood, owing to the complex dynamics of Atlantic sea-level pressures. Here, we present a multi-annually resolved record of the westerly drift over the past 6,500 years from northern Italy. In combination with more than 20 other westerly-sensitive records, our results depict the non-stationary westerly-affected regions over mainland Europe on multi-decadal to multi-centennial time scales, showing that the direction of the westerlies has changed with respect to the migrations of the North Atlantic centers of action since the middle Holocene. Our findings suggest the crucial role of the migrations of the North Atlantic dipole in modulating the westerly-affected domain over Europe, possibly modulated by Atlantic Ocean variability.

Published
2022

19. Coupled atmosphere-ice-ocean dynamics during Heinrich Stadial 2

Author

Dong, Xiyu, Kathayat, Gayatri, Rasmussen, Sune O, Svensson, Anders, Severinghaus, Jeffrey P, Li, Hanying, Sinha, Ashish, Xu, Yao, Zhang, Haiwei, Shi, Zhengguo, Cai, Yanjun, Pérez-Mejías, Carlos, Baker, Jonathan, Zhao, Jingyao, Spötl, Christoph, Columbu, Andrea, Ning, Youfeng, Stríkis, Nicolás M, Chen, Shitao, Wang, Xianfeng, Gupta, Anil K, Dutt, Som, Zhang, Fan, Cruz, Francisco W, An, Zhisheng, Lawrence Edwards, R, and Cheng, Hai

Subjects
Earth Sciences, Physical Geography and Environmental Geoscience, Geology, Climate Action
Abstract

Our understanding of climate dynamics during millennial-scale events is incomplete, partially due to the lack of their precise phase analyses under various boundary conditions. Here we present nine speleothem oxygen-isotope records from mid-to-low-latitude monsoon regimes with sub-centennial age precision and multi-annual resolution, spanning the Heinrich Stadial 2 (HS2) - a millennial-scale event that occurred at the Last Glacial Maximum. Our data suggests that the Greenland and Antarctic ice-core chronologies require +320- and +400-year adjustments, respectively, supported by extant volcanic evidence and radiocarbon ages. Our chronological framework shows a synchronous HS2 onset globally. Our records precisely characterize a centennial-scale abrupt "tropical atmospheric seesaw" superimposed on the conventional "bipolar seesaw" at the beginning of HS2, implying a unique response/feedback from low-latitude hydroclimate. Together with our observation of an early South American monsoon shift at the HS2 termination, we suggest a more active role of low-latitude hydroclimate dynamics underlying millennial events than previously thought.

Published
2022

20. Split westerlies over Europe in the early Little Ice Age

Author

Hu, Hsun-Ming, Shen, Chuan-Chou, Chiang, John CH, Trouet, Valerie, Michel, Véronique, Tsai, Hsien-Chen, Valensi, Patricia, Spötl, Christoph, Starnini, Elisabetta, Zunino, Marta, Chien, Wei-Yi, Sung, Wen-Hui, Chien, Yu-Tang, Chang, Ping, and Korty, Robert

Subjects
Earth Sciences, Physical Geography and Environmental Geoscience, Climate Change Science, Geology, Climate Action, Arctic Regions, Climate, Climate Change, Europe, Ice Cover
Abstract

The Little Ice Age (LIA; ca. 1450-1850 C.E.) is the best documented cold period of the past millennium, characterized by high-frequency volcanism, low solar activity, and high variability of Arctic sea-ice cover. Past studies of LIA Atlantic circulation changes have referenced the North Atlantic Oscillation (NAO), but recent studies have noted that LIA climate patterns appear to possess complexity not captured by an NAO analogue. Here, we present a new precipitation-sensitive stalagmite record from northern Italy that covers the past 800 years. We show that in the early LIA (1470-1610 C.E.), increased atmospheric ridging over northern Europe split the climatological westerlies away from central and northern Europe, possibly caused by concurrent Artic sea-ice reduction. With ongoing ice melting in the northern high latitudes and decreasing solar irradiance in the coming years, the early LIA may potentially serve as an analogue for European hydroclimatic conditions in the coming decades.

Published
2022

27. Relict soil features in cave sediments record periods of wet climate and dense vegetation over the last 100 kyr in a present-day semiarid region of northeast Brazil

Author

Vieira de Sousa, Daniel, Spinola, Diogo, dos Santos, Janaina C., Hatsui Tatumi, Sonia, Yee, Marcio, Aline Pessoa Oliveira, Raquel, Eltink, Estevan, do Vale Lopes, Davi, Spötl, Christoph, Cherkinsky, Alex, Figueirado Reis, Hilda, de Oliviera Silva, Jhonathan, Auler, Augusto, and William da Cruz, Francisco

Published
2023
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29. Timing and structure of the Younger Dryas event and its underlying climate dynamics

Author

Cheng, Hai, Zhang, Haiwei, Spötl, Christoph, Baker, Jonathan, Sinha, Ashish, Li, Hanying, Bartolomé, Miguel, Moreno, Ana, Kathayat, Gayatri, Zhao, Jingyao, Dong, Xiyu, Li, Youwei, Ning, Youfeng, Jia, Xue, Zong, Baoyun, Brahim, Yassine Ait, Pérez-Mejías, Carlos, Cai, Yanjun, Novello, Valdir F, Cruz, Francisco W, Severinghaus, Jeffrey P, An, Zhisheng, and Edwards, R Lawrence

Subjects
Climate Action, Younger Dryas, timing, structure, event phasing, climate dynamics
Abstract

The Younger Dryas (YD), arguably the most widely studied millennial-scale extreme climate event, was characterized by diverse hydroclimate shifts globally and severe cooling at high northern latitudes that abruptly punctuated the warming trend from the last glacial to the present interglacial. To date, a precise understanding of its trigger, propagation, and termination remains elusive. Here, we present speleothem oxygen-isotope data that, in concert with other proxy records, allow us to quantify the timing of the YD onset and termination at an unprecedented subcentennial temporal precision across the North Atlantic, Asian Monsoon-Westerlies, and South American Monsoon regions. Our analysis suggests that the onsets of YD in the North Atlantic (12,870 ± 30 B.P.) and the Asian Monsoon-Westerlies region are essentially synchronous within a few decades and lead the onset in Antarctica, implying a north-to-south climate signal propagation via both atmospheric (decadal-time scale) and oceanic (centennial-time scale) processes, similar to the Dansgaard-Oeschger events during the last glacial period. In contrast, the YD termination may have started first in Antarctica at ∼11,900 B.P., or perhaps even earlier in the western tropical Pacific, followed by the North Atlantic between ∼11,700 ± 40 and 11,610 ± 40 B.P. These observations suggest that the initial YD termination might have originated in the Southern Hemisphere and/or the tropical Pacific, indicating a Southern Hemisphere/tropics to North Atlantic-Asian Monsoon-Westerlies directionality of climatic recovery.

Published
2020

37. Reconstructing hydroclimate changes over the past 2500 years using speleothems from Pyrenean caves (NE Spain)

Author

Ministerio de Economía y Competitividad (España), Agencia Estatal de Investigación (España), Ministerio de Ciencia, Innovación y Universidades (España), CSIC - Unidad de Recursos de Información Científica para la Investigación (URICI), Bartolomé, Miguel [0000-0002-2924-6261], Moreno Caballud, Ana [0000-0001-7357-584X], Bartolomé, Miguel, Moreno Caballud, Ana, Sancho, Carlos, Cacho, Isabel, Stoll, Heather, Haghipour, Negar, Belmonte, Anchel, Spötl, Christoph, Hellstrom, John, Edwards, R. Lawrence, Cheng, Hai, Ministerio de Economía y Competitividad (España), Agencia Estatal de Investigación (España), Ministerio de Ciencia, Innovación y Universidades (España), CSIC - Unidad de Recursos de Información Científica para la Investigación (URICI), Bartolomé, Miguel [0000-0002-2924-6261], Moreno Caballud, Ana [0000-0001-7357-584X], Bartolomé, Miguel, Moreno Caballud, Ana, Sancho, Carlos, Cacho, Isabel, Stoll, Heather, Haghipour, Negar, Belmonte, Anchel, Spötl, Christoph, Hellstrom, John, Edwards, R. Lawrence, and Cheng, Hai

Abstract

Reconstructing of past hydroclimates at regional scales during the Common Era (CE) is necessary to place the current warming in the context of natural climate variability. Here we present a composite record of oxygen isotope variations during last 2500 years based on eight stalagmites from four caves in the central Pyrenees (NE Spain) dominated by temperature variations, with the amount of precipitation playing a minor role. The dataset is compared with other Iberian reconstructions that show a high degree of internal coherence with respect to variability at the centennial scale. The Roman Period (RP) (especially 0–200 CE), the Medieval Climate Anomaly (MCA), and part of the Little Ice Age (LIA) represent the warmest periods, while the coldest decades occurred during the Dark Ages (DA) and most of the LIA intervals (e.g., 520–550 CE and 1800–1850 CE). Importantly, the LIA cooling or the MCA warming were not continuous or uniform and exhibited high decadal variability. The Industrial Era (IE) shows an overall warming trend although with marked cycles and partial stabilization during the last 2 decades (1990–2010). The strong coherence between the speleothem data, European temperature reconstructions and global tree-ring data informs about the regional representativeness of this new record as Pyrenean past climate variations. Solar variability, likely through its impact on the North Atlantic Oscillation, and major volcanic eruptions appear to be the two main drivers of climate in southwestern Europe during the past 2.5 millennia.

Published
2024

50. Radiocarbon ages of microcrystalline authigenic carbonate in Lake Neusiedl (Austria) suggest millennial‐scale growth of Mg‐calcite and protodolomite.

Author

Neuhuber, Stephanie, Gier, Susanne, Draganits, Erich, Steier, Peter, Bolka, Monika, Ottner, Franz, Spötl, Christoph, Hippler, Dorothee, and Meister, Patrick

Subjects
CALCITE, DOLOMITE, LAST Glacial Maximum, CARBON isotopes, CARBONATE minerals, LAKE sediments, LAKES
Abstract

Authigenic Mg‐calcite and dolomite are frequently observed in restricted, evaporative environments, such as lagoon or lake systems, but their formation is difficult to capture due to slow growth rates. Lake Neusiedl, an alkaline and subhaline lake with a mean water depth of 0.7 m in Austria, offers a natural system to study the precipitation of Ca‐Mg‐carbonate phases, which occur as fine‐grained, unconsolidated and largely homogenized mud. To elucidate the timing and formation mechanisms of these authigenic carbonate phases, the mineralogical and isotopic composition and radiocarbon age of different sediment grain‐size fractions from <0.2 to >3.0 μm were analysed. X‐ray diffraction analyses show two broad peaks of Mg‐calcite and protodolomite (lacking ordering peaks), suggesting that the carbonates are authigenic rather than detrital in origin. Calibrated carbon‐14 ages range between 200 cal yr bp and 3700 cal yr bp. The linear correlation of age and grain size suggests a very slow growth rate of single crystals of 0.23 to 0.60 μm/ka. These rates suggest an extremely slow sedimentation rate in a shallow lake that existed during most of the Holocene. The higher abundance of protodolomite in older grain fractions, in contrast to the presence of high‐Mg calcite in the youngest fractions, suggests a growth succession where high‐Mg calcite develops first and subsequently transforms into protodolomite. Much higher ages of 6 cal ka bp to 15 cal ka bp are measured in carbonates of lake deposits exposed on land, in a section north‐west of the recent lake, suggesting a growth rate of those carbonate minerals of 0.13 μm/ka. These time constraints further suggest that some carbonate grains could already have nucleated from lake water before or during the last glacial maximum, although under slightly different hydrochemical conditions. [ABSTRACT FROM AUTHOR]

Published
2024
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