B–Tm Ash of a Catastrophic Eruption of Baitoushan Volcano in Terrestrial Deposits of Primorye as an Age Marker of the Medieval Warm Period in the Holocene

Abstract. The Amazon Basin is one of the major contributors to global biomass burning emissions. However, regional paleofire trends remain partially unknown. Due to their proximity to the Amazon Basin, Andean ice cores are suitable to reconstruct paleofire trends in South America and improve our understanding of the complex linkages between fires, climate and humans. Here we present the first refractory black carbon (rBC) ice-core record from the Andes as a proxy for biomass burning emissions in the Amazon Basin, derived from an ice core drilled at 6300 m a.s.l. from Illimani glacier in the Bolivian Andes and spanning the entire Holocene back to the last deglaciation 13 000 years ago. The Illimani rBC record displays a strong seasonality with low values during the wet season and high values during the dry season due to the combination of enhanced biomass burning emissions in the Amazon Basin and less precipitation at the Illimani site. Significant positive (negative) correlations were found with reanalyzed temperature (precipitation) data, respectively, for regions in Eastern Bolivia and Western Brazil characterized by a substantial fire activity. rBC long-term trends indirectly reflect regional climatic variations through changing biomass burning emissions as they show higher (lower) concentrations during warm/dry (cold/wet) periods, respectively, in line with climate variations such as the Younger Dryas, the 8.2 ka event, the Holocene Climatic Optimum, the Medieval Warm Period or the Little Ice Age. The highest rBC concentrations of the entire record occurred during the Holocene Climatic Optimum between 7000 and 3000 BC, suggesting that this outstanding warm and dry period caused an exceptional biomass burning activity, unprecedented in the context of the past 13 000 years. Recent rBC levels, rising since 1730 AD in the context of increasing temperatures and deforestation, are similar to those of the Medieval Warm Period. No decrease was observed in the 20th century, in contradiction with the global picture (broken fire hockey stick hypothesis).

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MEDIEVAL WARM PERIOD OF THE HOLOCENE AND ITS POSSIBLE CAUSES

THE LIFE OF THE EARTH ◽

10.29003/m1768.0514-7468.2020_42_4/395-405 ◽

2020 ◽

Vol 42 (4) ◽

pp. 395-405

Author(s):

Valeriy FEDOROV ◽

◽

Pavel GREBENNIKOV ◽

Keyword(s):

Heat Transfer ◽

Global Climate ◽

Medieval Warm Period ◽

Warm Period ◽

Meridional Transport ◽

The Holocene ◽

The Earth ◽

Winter Half ◽

History Of

A brief overview of reliably established global climate events in the Holocene is provided. On the basis of high-precision astronomical ephemeris with high spatial and temporal resolution, the annual and seasonal insolation of the Earth and hemispheres was calculated for the period 3000 BC-AD 2999. According to the results of calculations, the values of insolation contrast were obtained in a generalized manner (for the regions of the heat source and sink), reflecting the changes in the meridional insolation gradient that controls the meridional heat transfer in the hemispheres. The character of long-term variations of both the annual and seasonal arrival, and the annual and seasonal meridional transport of radiation heat in the hemispheres was obtained. The long-term distribution of insolation characteristics of the Earth and hemispheres (annual and seasonal insolation and insolation contrast in the hemispheres) is analyzed. The synchronicity of the extrema of the irradiation characteristics with the global climatic event in the history of the Earth (the Medieval Warm Period of the Holocene) was revealed. On the basis of the revealed synchronicity, the maximum insolation contrast in the winter half of the year in the Northern Hemisphere (the maximum of meridional heat transfer in the winter half of the year), as well as the maximum of interhemispheric heat transfer may be determined to be the reasons for the Medieval Warm Period.

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A Holocene black carbon ice-core record of biomass burning in the Amazon Basin from Illimani, Bolivia

Climate of the Past ◽

10.5194/cp-15-579-2019 ◽

2019 ◽

Vol 15 (2) ◽

pp. 579-592 ◽

Cited By ~ 9

Author(s):

Dimitri Osmont ◽

Michael Sigl ◽

Anja Eichler ◽

Theo M. Jenk ◽

Margit Schwikowski

Keyword(s):

Black Carbon ◽

Biomass Burning ◽

Amazon Basin ◽

Ice Core ◽

Medieval Warm Period ◽

Warm Period ◽

The Holocene ◽

Holocene Climatic Optimum ◽

Fire Activity ◽

Ice Core Record

Abstract. The Amazon Basin is one of the major contributors to global biomass burning emissions. However, regional paleofire trends remain particularly unknown. Due to their proximity to the Amazon Basin, Andean ice cores are suitable to reconstruct paleofire trends in South America and improve our understanding of the complex linkages between fires, climate and humans. Here we present the first refractory black carbon (rBC) ice-core record from the Andes as a proxy for biomass burning emissions in the Amazon Basin, derived from an ice core drilled at 6300 m a.s.l. from the Illimani glacier in the Bolivian Andes and spanning the entire Holocene back to the last deglaciation 13 000 years ago. The Illimani rBC record displays a strong seasonality with low values during the wet season and high values during the dry season due to the combination of enhanced biomass burning emissions in the Amazon Basin and less precipitation at the Illimani site. Significant positive (negative) correlations were found with reanalyzed temperature (precipitation) data for regions in eastern Bolivia and western Brazil characterized by substantial fire activity. rBC long-term trends indirectly reflect regional climatic variations through changing biomass burning emissions as they show higher (lower) concentrations during warm–dry (cold–wet) periods, in line with climate variations such as the Younger Dryas, the 8.2 ka event, the Holocene Climatic Optimum, the Medieval Warm Period and the Little Ice Age. The highest rBC concentrations of the entire record occurred during the Holocene Climatic Optimum between 7000 and 3000 BCE, suggesting that this exceptionally warm and dry period caused high levels of biomass burning activity, unprecedented in the context of the past 13 000 years. Recent rBC levels, rising since 1730 CE in the context of increasing temperatures and deforestation, are similar to those of the Medieval Warm Period. No decrease in fire activity was observed in the 20th century, in contradiction to global biomass burning reconstructions based on charcoal data.

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Climate Variability in Central Europe during the Last 2500 Years Reconstructed from Four High-Resolution Multi-Proxy Speleothem Records

Geosciences ◽

10.3390/geosciences11040166 ◽

2021 ◽

Vol 11 (4) ◽

pp. 166

Author(s):

Sarah Waltgenbach ◽

Dana F. C. Riechelmann ◽

Christoph Spötl ◽

Klaus P. Jochum ◽

Jens Fohlmeister ◽

...

Keyword(s):

Trace Elements ◽

High Resolution ◽

Climate Variability ◽

Little Ice Age ◽

Medieval Warm Period ◽

Warm Period ◽

Ice Age ◽

Cold Period ◽

Cave System ◽

Dark Ages

The Late Holocene was characterized by several centennial-scale climate oscillations including the Roman Warm Period, the Dark Ages Cold Period, the Medieval Warm Period and the Little Ice Age. The detection and investigation of such climate anomalies requires paleoclimate archives with an accurate chronology as well as a high temporal resolution. Here, we present 230Th/U-dated high-resolution multi-proxy records (δ13C, δ18O and trace elements) for the last 2500 years of four speleothems from Bunker Cave and the Herbstlabyrinth cave system in Germany. The multi-proxy data of all four speleothems show evidence of two warm and two cold phases during the last 2500 years, which coincide with the Roman Warm Period and the Medieval Warm Period, as well as the Dark Ages Cold Period and the Little Ice Age, respectively. During these four cold and warm periods, the δ18O and δ13C records of all four speleothems and the Mg concentration of the speleothems Bu4 (Bunker Cave) and TV1 (Herbstlabyrinth cave system) show common features and are thus interpreted to be related to past climate variability. Comparison with other paleoclimate records suggests a strong influence of the North Atlantic Oscillation at the two caves sites, which is reflected by warm and humid conditions during the Roman Warm Period and the Medieval Warm Period, and cold and dry climate during the Dark Ages Cold period and the Little Ice Age. The Mg records of speleothems Bu1 (Bunker Cave) and NG01 (Herbstlabyrinth) as well as the inconsistent patterns of Sr, Ba and P suggests that the processes controlling the abundance of these trace elements are dominated by site-specific effects rather than being related to supra-regional climate variability.

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Evidence for a ‘Medieval Warm Period’ in a 1,100 year tree-ring reconstruction of past austral summer temperatures in New Zealand

Geophysical Research Letters ◽

10.1029/2001gl014580 ◽

2002 ◽

Vol 29 (14) ◽

pp. 12-1-12-4 ◽

Cited By ~ 58

Author(s):

Edward R. Cook ◽

Jonathan G. Palmer ◽

Rosanne D. D'Arrigo

Keyword(s):

New Zealand ◽

Tree Ring ◽

Austral Summer ◽

Medieval Warm Period ◽

Warm Period ◽

Summer Temperatures ◽

Tree Ring Reconstruction

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Response of Siberian trees to climatic changes over the past 1500 years

10.5194/egusphere-egu21-8995 ◽

2021 ◽

Author(s):

Olga Churakova (Sidorova) ◽

Marina Fonti ◽

Rolf Siegwolf ◽

Tatyana Trushkina ◽

Eugene Vaganov ◽

...

Keyword(s):

Tree Ring ◽

Ice Core ◽

Climatic Changes ◽

Medieval Warm Period ◽

Warm Period ◽

Taimyr Peninsula ◽

Climate Conditions ◽

Northeastern Part ◽

The Past ◽

Tree Ring Cellulose

<p>We use an interdisciplinary approach combining stable isotopes in tree rings, pollen data, ice cores from temperature-limited environment in the Siberian north and developed a comprehensive description of the climatic changes over the past 1500 years. We found that the Climatic Optimum Period was warmer and drier compared to the Medieval one, but rather similar to the recent period. Our results indicate that the Medieval Warm period in the Taimyr Peninsula started earlier and was wetter compared to the northeastern part of Siberia (northeastern Yakutia). Summer precipitation reconstruction obtained from carbon isotopes in tree-ring cellulose from Taimyr Peninsula significantly correlated with the pollen data of the Lama Lake (Andreev et al. 2004) and oxygen isotopes of the ice core from Severnaya Zemlya (Opel et al. 2013) recording wetter climate conditions during the Medieval Warm period compared to the northeastern part of Siberia. Common large-scale climate variability was confirmed by significant relationship between oxygen isotope data in tree-ring cellulose from the Taimyr Peninsula and northeastern Yakutia, and oxygen isotope ice core data from Severnaya Zemlja during the Medieval Warm period and the recent one. Finally, we showed that the recent warming on the Taimyr Peninsula is not unprecedented in the Siberian north. Similar climate conditions were recorded by stable isotopes in tree rings, pollen, and ice core data 6000 years ago. On the northeastern part of Siberia newly developed a 1500-year summer vapor pressure deficit (VPD) reconstruction showed, that VPD increased recently, but does not yet exceed the maximum values reconstructed during the Medieval Warm period. The most humid conditions in the northeastern part of Siberia were recorded in the Early Medieval period and during the Little Ice Age. However, the increasing VPD under elevated air temperature in the last decades affects the hydrological regime of these sensitive ecosystems by greater evapotranspiration rates. Further VPD increase will significantly affect Siberian forests most likely leading to drought even under additional access of thawed permafrost water.</p><p>This work was supported by the FP7-PEOPLE-IIF-2008 - Marie Curie Action: "International Incoming Fellowships" 235122 and "Reintegration Fellowships" 909122 &#8220;Climatic and environmental changes in the Eurasian Subarctic inferred from tree-ring and stable isotope chronologies for the past and recent periods&#8221; and the Government of Krasnoyarsk Kray and Russian Foundation for Basic Research and Krasnoyarsk Foundation 20-44-240001 &#8220;Adaptation of conifer forests on the north of the Krasnoyarsk region (Taimyr Peninsula) to climatic changes after extreme events over the past 1500 years&#8220; awarded to Olga V. Churakova (Sidorova).</p>

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