Jan Esper
Dados Biográficos
| ID | 2738148 |
|---|---|
| NOME | Jan Esper |
| PRENOMES | Jan |
| SOBRENOME | Esper |
| ASSINATURA | ESPER J |
| AFILIAÇÕES | Johannes Gutenberg University Mainz |
| ORCID | 0000-0003-3919-014X |
| VERIFICADO | Sim |
| TOTAL DE OBRAS | 30 |
| TOTAL DE CITAÇÕES | 64 |
| TOTAL COMO AUTOR | 30 |
| TOTAL COMO EDITOR | 0 |
| PRIMEIRO ANO DE PUBLICAÇÃO | 2000 |
| ANO MAIS RECENTE DE PUBLICAÇÃO | 2026 |
| ÍNDICE H | 4 |
An absolutely dated mid-Holocene English yew chronology offers new opportunities for archaeological and palaeoenvironmental research
Research on Holocene climate variability and human history greatly benefits from annually resolved and absolutely dated tree-ring chronologies. The quality and quantity of such records, however, decline back in time, with little tree-ring evidence available for the Early and Middle Holocene. Here, we present a tree-ring width (TRW) chronology from 100 subfossil yews ( Taxus baccata L.) excavated from peat-rich soils in the Fenland region of easte…
Expanding the Yukon tree ring Blue Intensity network to assess divergence effects and enhance climate reconstructions
The Divergence Problem (DP) – classically defined as a breakdown in the relationship between tree growth and temperature in recent decades – poses a major challenge to developing robust tree-ring based climate reconstructions. This is particularly relevant in northwestern North America (NWNA), a climatically sensitive yet underrepresented region in dendroclimatological networks. To address this gap and the implications of the DP, we developed a n…
Multi-Proxy Tree-Ring Dating during the Younger Dryas
The world's longest tree-ring chronology comprises thousands of oak and pine series from Germany and continuously covers the Holocene back to 12,325 cal BP. A lack of relict wood from the Younger Dryas cold reversal ca. 12,900–11,700 cal BP, however, challenges the extension of this absolutely dated ring width record further back in time. Here, we combine 646 high-resolution stable oxygen isotope and 795 radiocarbon measurements from subfossil pi…
Tree-ring stable isotopes in cellulose and lignin methoxy groups reveal different age-related behaviour
Tree-ring stable isotopes (TRSI) have the unique ability to capture inter-annual to multi-millennial climate trends and extremes if the appropriate data and methods are combined. However, there is still an ongoing debate about age-related biases in TRSI measurements that potentially affect the fidelity of their chronologies and subsequent climate reconstructions. Here, we investigate carbon and oxygen TRSI measurements in cellulose (δ13Ccell and …
A frequency-optimised temperature record for the Holocene
Existing global mean surface temperature reconstructions for the Holocene lack high-frequency variability that is essential for contextualising recent trends and extremes in the Earth’s climate system. Here, we isolate and recombine archive-specific climate signals to generate a frequency-optimised record of interannual to multi-millennial temperature changes for the past 12 000 years. Average temperatures before ∼8000 years BP and after ∼4000 ye…
The significance of climate variability on early modern European grain prices
Grain was the most important food source in early modern Europe ( c . 1500–1800), and its price influenced the entire economy. The extent to which climate variability determined grain price variations remains contested, and claims of solar cycle influences on prices are disputed. We thoroughly reassess these questions, within a framework of comprehensive statistical analysis, by employing an unprecedentedly large grain price data set together wit…
Investigation of age trends in tree-ring stable carbon and oxygen isotopes from northern Fennoscandia over the past millennium
A millennium-long ‘Blue Ring’ chronology from the Spanish Pyrenees reveals severe ephemeral summer cooling after volcanic eruptions
‘ Blue Rings’ (BRs) are distinct wood anatomical anomalies recently discovered in several tree species from different sites. While it is evident that they are associated with a cooling-induced lack of cell wall lignification, BRs have yet to be evaluated systematically in paleoclimate studies. Here, we present a continuous wood anatomical assessment of 31 living and relict pine samples from a high-elevation site in the central Spanish Pyrenees th…
Illuminating Intcal During the Younger Dryas
As the worldwide standard for radiocarbon ( 14 C) dating over the past ca. 50,000 years, the International Calibration Curve (IntCal) is continuously improving towards higher resolution and replication. Tree-ring-based 14 C measurements provide absolute dating throughout most of the Holocene, although high-precision data are limited for the Younger Dryas interval and farther back in time. Here, we describe the dendrochronological characteristics …
European warm-season temperature and hydroclimate since 850 CE
The long-term relationship between temperature and hydroclimate has remained uncertain due to the short length of instrumental measurements and inconsistent results from climate model simulations. This lack of understanding is particularly critical with regard to projected drought and flood risks. Here we assess warm-season co-variability patterns between temperature and hydroclimate over Europe back to 850 CE using instrumental measurements, tre…
Annual 14 C Tree-Ring Data Around 400 AD
Two tree-ring series, one from a high-latitude pine tree (located in northern Scandinavia) and one from a mid-latitude oak tree (located in eastern Germany) were analyzed for radiocarbon ( 14 C) at annual resolution. The new records cover the calendar date ranges 290–460 AD and 382–486 AD, respectively, overlapping by 79 yr. The series show similar trends as IntCal13. However, some significant deviations around 400 AD are present with lower Δ 14 …
Warfare dendrochronology
A new archive of large volcanic events over the past millennium derived from reconstructed summer temperatures
Information about past volcanic impact on climate is mostly derived from historic documentary data and sulfate depositions in polar ice sheets. Although these archives have provided important insights into the Earth's volcanic eruption history, the climate forcing and exact dating of many events is still vague. Here we apply a new method of break detection to the first millennium-length maximum latewood density reconstruction of Northern Hemisphe…
Cooling and societal change during the Late Antique Little Ice Age from 536 to around 660 AD
European summer temperatures since Roman times
The spatial context is criticalwhen assessing present-day climate anomalies, attributing them to potential forcings and making statements regarding their frequency and severity in a long-term perspective. Recent international initiatives have expanded the number of high-quality proxy-records and developed new statistical reconstruction methods. These advances allow more rigorous regional past temperature reconstructions and, in turn, the possibil…
Diverse growth trends and climate responses across Eurasia’s boreal forest
The area covered by boreal forests accounts for 16% of the global and 22% of the Northern Hemisphere landmass. Changes in the productivity and functioning of this circumpolar biome not only have strong effects on species composition and diversity at regional to larger scales, but also on the Earth's carbon cycle. Although temporal inconsistency in the response of tree growth to temperature has been reported from some locations at the higher north…
Old World megadroughts and pluvials during the Common Era
An atlas of megadroughts in Europe and in the Mediterranean Basin during the Common Era provides insights into climate variability.
Modified climate with long term memory in tree ring proxies
Long term memory (LTM) scaling behavior in worldwide tree-ring proxies and subsequent climate reconstructions is analyzed for and compared with the memory structure inherent to instrumental temperature and precipitation data. Detrended fluctuation analysis is employed to detect LTM, and its scaling exponent a is used to evaluate LTM. The results show that temperature and precipitation reconstructions based on ring width measurements (mean α = 0.8…
Decadal climate variability of the North Sea during the last millennium reconstructed from bivalve shells ( Arctica islandica )
Uninterrupted, annually resolved paleoclimate records are crucial to contextualize the current global change. Such information is particularly relevant for the Europe realm for which weather and climate projections are still very challenging if not virtually impossible. This study presents the first precisely dated, annually resolved, multiregional Arctica islandica chronologies from the North Sea which cover the time interval ad 1040–2010 and co…
Continental-scale temperature variability during the past two millennia
The Palaeoanthropocene - The beginnings of anthropogenic environmental change
Comparison of stable carbon and oxygen isotopes in Picea glauca tree rings and Sphagnum fuscum moss remains from subarctic Canada
Stable isotope ratios from tree rings and peatland mosses have become important proxies of past climate variations. We here compare recent stable carbon and oxygen isotope ratios in cellulose of tree rings from white spruce ( Picea glauca ), growing near the arctic tree line; and cellulose of Sphagnum fuscum stems, growing in a hummock of a subarctic peatland, in west-central Canada. Results show that carbon isotopes in S. fuscum correlate signif…
Years of European Climate Variability and Human Susceptibility
Variability of central European temperature and precipitation shows correlations with some major historical changes.
A noodle, hockey stick, and spaghetti plate
The high‐resolution reconstruction of hemispheric‐scale temperature variation over the past‐millennium benchmarks recent warming against more naturally driven climate episodes, such as the Little Ice Age and the Medieval Warm Period, thereby allowing assessment of the relative efficacies of natural and anthropogenic forcing factors. Icons of past temperature variability, as featured in the Intergovernmental Panel on Climate Change (IPCC) reports …
Persistent Positive North Atlantic Oscillation Mode Dominated the Medieval Climate Anomaly
The Medieval Climate Anomaly (MCA) was the most recent pre-industrial era warm interval of European climate, yet its driving mechanisms remain uncertain. We present here a 947-year-long multidecadal North Atlantic Oscillation (NAO) reconstruction and find a persistent positive NAO during the MCA. Supplementary reconstructions based on climate model results and proxy data indicate a clear shift to weaker NAO conditions into the Little Ice Age (LIA…
The Palaeoanthropocene - The beginnings of anthropogenic environmental change
Years of climatic history for Western Central Asia inferred from tree-rings
More than 200 000 ring-width measurements from 384 trees were obtained for 20 individual sites ranging from the lower to upper local timber-lines in the Northwest Karakorum of Pakistan and the Southern Tien Shan of Kirghizia. Samples were obtained predominantly from juniper species (Juniperus) and were analysed to reconstruct regional climatic variation patterns in Western Central Asia since ad 618. Site distri bution represents diverse ecologica…
Illuminating Intcal During the Younger Dryas
As the worldwide standard for radiocarbon ( 14 C) dating over the past ca. 50,000 years, the International Calibration Curve (IntCal) is continuously improving towards higher resolution and replication. Tree-ring-based 14 C measurements provide absolute dating throughout most of the Holocene, although high-precision data are limited for the Younger Dryas interval and farther back in time. Here, we describe the dendrochronological characteristics …
A noodle, hockey stick, and spaghetti plate
The high‐resolution reconstruction of hemispheric‐scale temperature variation over the past‐millennium benchmarks recent warming against more naturally driven climate episodes, such as the Little Ice Age and the Medieval Warm Period, thereby allowing assessment of the relative efficacies of natural and anthropogenic forcing factors. Icons of past temperature variability, as featured in the Intergovernmental Panel on Climate Change (IPCC) reports …
Annual 14 C Tree-Ring Data Around 400 AD
Two tree-ring series, one from a high-latitude pine tree (located in northern Scandinavia) and one from a mid-latitude oak tree (located in eastern Germany) were analyzed for radiocarbon ( 14 C) at annual resolution. The new records cover the calendar date ranges 290–460 AD and 382–486 AD, respectively, overlapping by 79 yr. The series show similar trends as IntCal13. However, some significant deviations around 400 AD are present with lower Δ 14 …
Long-term tree-ring variations in Juniperus at the upper timber-line in the Karakorum (Pakistan)
Ring-width series of Juniperus excelsa M. Bieb and Juniperus turkestanica Kom. from six different sites, in the Hunza-Karakorum, were used in reconstructing modes of regional climate over the past 500 years. All reconstructions were derived from trees growing close to the upper timber-line (approx. 4000 m a.s.l.). Standardized site chronologies, derived from ring-width measurements, display common low-and high-frequency variation that is synchron…
Decadal climate variability of the North Sea during the last millennium reconstructed from bivalve shells ( Arctica islandica )
Uninterrupted, annually resolved paleoclimate records are crucial to contextualize the current global change. Such information is particularly relevant for the Europe realm for which weather and climate projections are still very challenging if not virtually impossible. This study presents the first precisely dated, annually resolved, multiregional Arctica islandica chronologies from the North Sea which cover the time interval ad 1040–2010 and co…
Long-term tree-ring variations in Juniperus at the upper timber-line in the Karakorum (Pakistan)
Ring-width series of Juniperus excelsa M. Bieb and Juniperus turkestanica Kom. from six different sites, in the Hunza-Karakorum, were used in reconstructing modes of regional climate over the past 500 years. All reconstructions were derived from trees growing close to the upper timber-line (approx. 4000 m a.s.l.). Standardized site chronologies, derived from ring-width measurements, display common low-and high-frequency variation that is synchron…
Interpretation of tree–ring chronologies
To interpret published tree-ring chronologies and to use these results for geographic studies, knowledge about essential aspects of chronology building is necessary. For example, most chronologies display climatic variation in the wavelengths of years to decades. Trends on longer time-scales, like century-scale variation, are generally more difficult to emphasize and often missing in tree-ring chronologies. Here we aim to explain such facts and t…
Low-Frequency Signals in Long Tree-Ring Chronologies for Reconstructing Past Temperature Variability
Preserving multicentennial climate variability in long tree-ring records is critically important for reconstructing the full range of temperature variability over the past 1000 years. This allows the putative “Medieval Warm Period” (MWP) to be described and to be compared with 20th-century warming in modeling and attribution studies. We demonstrate that carefully selected tree-ring chronologies from 14 sites in the Northern Hemisphere (NH) extrat…
Years of climatic history for Western Central Asia inferred from tree-rings
More than 200 000 ring-width measurements from 384 trees were obtained for 20 individual sites ranging from the lower to upper local timber-lines in the Northwest Karakorum of Pakistan and the Southern Tien Shan of Kirghizia. Samples were obtained predominantly from juniper species (Juniperus) and were analysed to reconstruct regional climatic variation patterns in Western Central Asia since ad 618. Site distri bution represents diverse ecologica…
Persistent Positive North Atlantic Oscillation Mode Dominated the Medieval Climate Anomaly
The Medieval Climate Anomaly (MCA) was the most recent pre-industrial era warm interval of European climate, yet its driving mechanisms remain uncertain. We present here a 947-year-long multidecadal North Atlantic Oscillation (NAO) reconstruction and find a persistent positive NAO during the MCA. Supplementary reconstructions based on climate model results and proxy data indicate a clear shift to weaker NAO conditions into the Little Ice Age (LIA…
Late Holocene climatic and environmental changes in arid central Asia
A noodle, hockey stick, and spaghetti plate
The high‐resolution reconstruction of hemispheric‐scale temperature variation over the past‐millennium benchmarks recent warming against more naturally driven climate episodes, such as the Little Ice Age and the Medieval Warm Period, thereby allowing assessment of the relative efficacies of natural and anthropogenic forcing factors. Icons of past temperature variability, as featured in the Intergovernmental Panel on Climate Change (IPCC) reports …
Years of European Climate Variability and Human Susceptibility
Variability of central European temperature and precipitation shows correlations with some major historical changes.
Comparison of stable carbon and oxygen isotopes in Picea glauca tree rings and Sphagnum fuscum moss remains from subarctic Canada
Stable isotope ratios from tree rings and peatland mosses have become important proxies of past climate variations. We here compare recent stable carbon and oxygen isotope ratios in cellulose of tree rings from white spruce ( Picea glauca ), growing near the arctic tree line; and cellulose of Sphagnum fuscum stems, growing in a hummock of a subarctic peatland, in west-central Canada. Results show that carbon isotopes in S. fuscum correlate signif…
Continental-scale temperature variability during the past two millennia
The Palaeoanthropocene - The beginnings of anthropogenic environmental change
Decadal climate variability of the North Sea during the last millennium reconstructed from bivalve shells ( Arctica islandica )
Uninterrupted, annually resolved paleoclimate records are crucial to contextualize the current global change. Such information is particularly relevant for the Europe realm for which weather and climate projections are still very challenging if not virtually impossible. This study presents the first precisely dated, annually resolved, multiregional Arctica islandica chronologies from the North Sea which cover the time interval ad 1040–2010 and co…
Old World megadroughts and pluvials during the Common Era
An atlas of megadroughts in Europe and in the Mediterranean Basin during the Common Era provides insights into climate variability.
Modified climate with long term memory in tree ring proxies
Long term memory (LTM) scaling behavior in worldwide tree-ring proxies and subsequent climate reconstructions is analyzed for and compared with the memory structure inherent to instrumental temperature and precipitation data. Detrended fluctuation analysis is employed to detect LTM, and its scaling exponent a is used to evaluate LTM. The results show that temperature and precipitation reconstructions based on ring width measurements (mean α = 0.8…
Cooling and societal change during the Late Antique Little Ice Age from 536 to around 660 AD
European summer temperatures since Roman times
The spatial context is criticalwhen assessing present-day climate anomalies, attributing them to potential forcings and making statements regarding their frequency and severity in a long-term perspective. Recent international initiatives have expanded the number of high-quality proxy-records and developed new statistical reconstruction methods. These advances allow more rigorous regional past temperature reconstructions and, in turn, the possibil…
Diverse growth trends and climate responses across Eurasia’s boreal forest
The area covered by boreal forests accounts for 16% of the global and 22% of the Northern Hemisphere landmass. Changes in the productivity and functioning of this circumpolar biome not only have strong effects on species composition and diversity at regional to larger scales, but also on the Earth's carbon cycle. Although temporal inconsistency in the response of tree growth to temperature has been reported from some locations at the higher north…
A new archive of large volcanic events over the past millennium derived from reconstructed summer temperatures
Information about past volcanic impact on climate is mostly derived from historic documentary data and sulfate depositions in polar ice sheets. Although these archives have provided important insights into the Earth's volcanic eruption history, the climate forcing and exact dating of many events is still vague. Here we apply a new method of break detection to the first millennium-length maximum latewood density reconstruction of Northern Hemisphe…
European warm-season temperature and hydroclimate since 850 CE
The long-term relationship between temperature and hydroclimate has remained uncertain due to the short length of instrumental measurements and inconsistent results from climate model simulations. This lack of understanding is particularly critical with regard to projected drought and flood risks. Here we assess warm-season co-variability patterns between temperature and hydroclimate over Europe back to 850 CE using instrumental measurements, tre…
Annual 14 C Tree-Ring Data Around 400 AD
Two tree-ring series, one from a high-latitude pine tree (located in northern Scandinavia) and one from a mid-latitude oak tree (located in eastern Germany) were analyzed for radiocarbon ( 14 C) at annual resolution. The new records cover the calendar date ranges 290–460 AD and 382–486 AD, respectively, overlapping by 79 yr. The series show similar trends as IntCal13. However, some significant deviations around 400 AD are present with lower Δ 14 …
Warfare dendrochronology
A millennium-long ‘Blue Ring’ chronology from the Spanish Pyrenees reveals severe ephemeral summer cooling after volcanic eruptions
‘ Blue Rings’ (BRs) are distinct wood anatomical anomalies recently discovered in several tree species from different sites. While it is evident that they are associated with a cooling-induced lack of cell wall lignification, BRs have yet to be evaluated systematically in paleoclimate studies. Here, we present a continuous wood anatomical assessment of 31 living and relict pine samples from a high-elevation site in the central Spanish Pyrenees th…
Illuminating Intcal During the Younger Dryas
As the worldwide standard for radiocarbon ( 14 C) dating over the past ca. 50,000 years, the International Calibration Curve (IntCal) is continuously improving towards higher resolution and replication. Tree-ring-based 14 C measurements provide absolute dating throughout most of the Holocene, although high-precision data are limited for the Younger Dryas interval and farther back in time. Here, we describe the dendrochronological characteristics …
The significance of climate variability on early modern European grain prices
Grain was the most important food source in early modern Europe ( c . 1500–1800), and its price influenced the entire economy. The extent to which climate variability determined grain price variations remains contested, and claims of solar cycle influences on prices are disputed. We thoroughly reassess these questions, within a framework of comprehensive statistical analysis, by employing an unprecedentedly large grain price data set together wit…
Investigation of age trends in tree-ring stable carbon and oxygen isotopes from northern Fennoscandia over the past millennium
Tree-ring climate responses (28 obras) · Geography (24 obras) · Climate change (21 obras) · Geology and Paleoclimatology Research (21 obras) · Climatology (20 obras) · Geology (19 obras) · Physical geography (18 obras) · Dendrochronology (15 obras) · Plant Water Relations and Carbon Dynamics (15 obras) · Oceanography (13 obras)