Seasonal climate signals (1990–2008) in a modern Soreq Cave stalagmite as revealed by high-resolution geochemical analysis

Abstract. Varved lake sediments are exceptional archives of paleoclimatic information due to their precise chronological control and annual resolution. However, quantitative paleoclimate reconstructions based on the biogeochemical composition of biochemical varves are extremely rare, mainly because the climate–proxy relationships are complex and obtaining biogeochemical proxy data at very high (annual) resolution is difficult. Recent developments in high-resolution hyperspectral imaging (HSI) of sedimentary pigment biomarkers combined with micro X-ray fluorescence (µXRF) elemental mapping make it possible to measure the structure and composition of varves at unprecedented resolution. This provides opportunities to explore seasonal climate signals preserved in biochemical varves and, thus, assess the potential for annual-resolution climate reconstruction from biochemical varves. Here, we present a geochemical dataset including HSI-inferred sedimentary pigments and µXRF-inferred elements at very high spatial resolution (60 µm, i.e. > 100 data points per varve year) in varved sediments of Lake Żabińskie, Poland, over the period 1966–2019 CE. We compare these data with local meteorological observations to explore and quantify how changing seasonal meteorological conditions influenced sediment composition and varve formation processes. Based on the dissimilarity of within-varve multivariate geochemical time series, we classified varves into four types. Multivariate analysis of variance shows that these four varve types were formed in years with significantly different seasonal meteorological conditions. Generalized additive models (GAMs) were used to infer seasonal climate conditions based on sedimentary variables. Spring and summer (MAMJJA) temperatures were predicted using Ti and total C (Radj2=0.55; cross-validated root mean square error (CV-RMSE) = 0.7 ∘C, 14.4 %). Windy days from March to December (mean daily wind speed > 7 m s−1) were predicted using mass accumulation rate (MAR) and Si (Radj2=0.48; CV-RMSE = 19.0 %). This study demonstrates that high-resolution scanning techniques are promising tools to improve our understanding of varve formation processes and climate–proxy relationships in biochemical varves. This knowledge is the basis for quantitative high-resolution paleoclimate reconstructions, and here we provide examples of calibration and validation of annual-resolution seasonal weather inference from varve biogeochemical data.

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Seasonal climate signals preserved in biochemical varves: insights from novel high-resolution sediment scanning techniques

10.5194/cp-2021-56 ◽

2021 ◽

Author(s):

Paul D. Zander ◽

Maurycy Żarczyński ◽

Wojciech Tylmann ◽

Shauna-kay Rainford ◽

Martin Grosjean

Keyword(s):

High Resolution ◽

Meteorological Conditions ◽

Additive Models ◽

Formation Processes ◽

Seasonal Climate ◽

Climate Proxy ◽

Climate Signals ◽

Paleoclimate Reconstructions ◽

Annual Resolution ◽

Very High

Abstract. Varved lake sediments are exceptional archives of paleoclimatic information due to their precise chronological control and annual resolution. However, quantitative paleoclimate reconstructions based on the biogeochemical composition of biochemical varves are extremely rare mainly because the climate-proxy relationships are complex, and obtaining biogeochemical proxy data at very high (annual) resolution is difficult. Recent developments in high-resolution hyperspectral imaging (HSI) of sedimentary pigment biomarkers combined with micro X-ray fluorescence (μXRF) elemental mapping make it possible to measure the structure and composition of varves at unprecedented resolution. This provides opportunities to explore (seasonal) climate signals preserved in biochemical varves and, thus, assess the potential for annual resolution climate reconstruction from biochemical varves. Here, we present a geochemical dataset including HSI-inferred sedimentary pigments and uXRF-inferred elements at very high spatial resolution (60 μm, i.e. > 100 data points per varve year) in varved sediments of Lake Żabińskie, Poland over the period 1966–2019 CE. We compare this data with local meteorological observations to explore and quantify how changing seasonal meteorological conditions influenced sediment composition and varve formation processes. Based on the dissimilarity of within-varve multivariate geochemical time series, we classified varves into four types. Multivariate analysis of variance shows that these four varve types were formed in years with significantly different seasonal meteorological conditions. Generalized additive models (GAMs) were used to infer seasonal climate conditions based on sedimentary variables. Spring and summer (MAMJJA) temperature were predicted using Ti and total C (R2adj = 0.55; cross-validated root mean square error (CV-RMSE) = 0.7 °C, 14.4%). Windy days from March to December (mean daily wind speed > 7 m/s) were predicted using mass accumulation rate (MAR) and Si (R2adj = 0.48; CV-RMSE = 19.0%). This study demonstrates that high-resolution scanning techniques are promising tools to improve our understanding of varve formation processes and climate-proxy relationships in biochemical varves. This knowledge is the basis for quantitative high-resolution paleoclimate reconstructions, and here we provide examples of calibration and validation of annual resolution seasonal weather inference from varve biogeochemical data.

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Tephra in the Greenland Ice cores: Insights into Icelandic volcano-climate impacts

10.5194/egusphere-egu21-9187 ◽

2021 ◽

Author(s):

Imogen Gabriel ◽

Gill Plunkett ◽

Peter Abbott ◽

Bergrún Óladóttir ◽

Joseph McConnell ◽

...

Keyword(s):

High Resolution ◽

Ice Core ◽

Ice Cores ◽

Volcanic Eruptions ◽

Climate Impacts ◽

Geochemical Analysis ◽

Volcanic Events ◽

Societal Impacts ◽

The Impact ◽

Ice Core Records

Volcanic eruptions are considered as one of the primary natural drivers for changes in the global climate system and understanding the impact of past eruptions on the climate is integral to adopt appropriate responses towards future volcanic eruptions.The Greenland ice core records are dominated by Icelandic eruptions, with several volcanic systems (Katla, Hekla, B&#225;r&#240;arbunga-Vei&#240;iv&#246;tn and Grimsv&#246;tn) being highly active throughout the Holocene. A notable period of increased Icelandic volcanic activity occurred between 500-1250 AD and coincided with climatic changes in the North Atlantic region which may have facilitated the Viking settlement of Greenland and Iceland. However, a number of these volcanic events are poorly constrained (duration and magnitude). Consequently, the Greenland ice cores offer the opportunity to reliably reconstruct past Icelandic volcanism (duration, magnitude and frequency) due to their high-resolution, the proximity of Iceland to Greenland and subsequent increased likelihood of volcanic fallout deposits (tephra particles and sulphur aerosols) being preserved. However, both the high frequency of eruptions between 500-1250 AD and the geochemical similarity of Iceland&#8217;s volcanic centres present challenges in making the required robust geochemical correlations between the source volcano and the ice core records and ultimately reliably assessing the climatic-societal impacts of these eruptions.To address this, we use two Greenland ice core records (TUNU2013 and B19) and undertake geochemical analysis on tephra from the volcanic events in the selected time window which have been detected and sampled using novel techniques (insoluble particle peaks and sulphur acidity peaks). Further geochemical analysis of proximal material enables robust correlations to be made between the events in the ice core records and their volcanic centres. The high-resolution of these polar archives provides a precise age for the event and when utilised alongside other proxies (i.e. sulphur aerosols), both the duration and magnitude of these eruptions can be constrained, and the climatic-societal impacts of these eruptions reliably assessed.

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Coupling forecast calibration and data‐driven downscaling for generating reliable, high‐resolution, multivariate seasonal climate forecast ensembles at multiple sites

International Journal of Climatology ◽

10.1002/joc.6346 ◽

2019 ◽

Vol 40 (4) ◽

pp. 2479-2496 ◽

Cited By ~ 1

Author(s):

Andrew Schepen ◽

Yvette Everingham ◽

Quan J. Wang

Keyword(s):

High Resolution ◽

Data Driven ◽

Climate Forecast ◽

Seasonal Climate Forecast ◽

Seasonal Climate

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Tracking climate signals in varved lake sediments: research strategy and key sites for comprehensive process studies in the Masurian Lakeland

Limnological Review ◽

10.1515/limre-2017-0015 ◽

2017 ◽

Vol 17 (3) ◽

pp. 159-166 ◽

Cited By ~ 2

Author(s):

Wojciech Tylmann ◽

Paulina Głowacka ◽

Agnieszka Szczerba

Keyword(s):

High Resolution ◽

Lake Sediments ◽

Sediment Cores ◽

Monitoring Program ◽

Sediment Traps ◽

Research Strategy ◽

Meteorological Conditions ◽

Lake Basin ◽

Climate Signals ◽

Process Studies

AbstractLake sediments are excellent archives of environmental and climate change. Especially important are varved sediments which can provide high-resolution (annual) records of those changes. Process studies including limnological measurements, particle flux monitoring and analyses of sediment structures give an opportunity to explain relationships between meteorological conditions, in-lake processes and varve formation. In our study, three lakes were selected in the Masurian Lakeland: Lake Żabińskie, Łazduny and Rzęśniki. These relatively small and deep lakes contain well preserved biogenic varves. The lakes are influenced by the same meteorological conditions but differ in terms of their catchment size, land use, hydrology, lake basin morphology and trophic status. To explore the relationships between different parameters and preservation/transformation of climate signals in the sediments we started systematic limnological measurements in the water column of these lakes, water sampling for hydrochemical analyses, monitoring of modern sedimentation using sediment traps and analysis of topmost varves from short sediment cores. With this comprehensive and high-resolution monitoring program scheduled for at least four years we are going to verify the potential of varves to track short-term meteorological phenomena in lake sediments.

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