Quantitative Reconstruction of Younger Dryas to Mid-Holocene Paleoclimates at Le Locle, Swiss Jura, Using Pollen and Lake-Level Data

2001 ◽  
Vol 56 (2) ◽  
pp. 170-180 ◽  
Author(s):  
Michel Magny ◽  
Joël Guiot ◽  
Patrick Schoellammer
Keyword(s):  
Lake Level ◽  
General Pattern ◽  
Younger Dryas ◽  
Growing Season ◽  
Summer Temperature ◽  
Annual Precipitation ◽  
Climatic Parameters ◽  
Cold Event ◽  
Level Data ◽  
Swiss Jura

AbstractPollen and lake-level data from Le Locle in the Swiss Jura were used to quantitatively reconstruct climatic parameters for the Younger Dryas event and the first half of the Holocene period. The Younger Dryas cold event at Le Locle was characterized by (i) a general trend toward a slight increase in summer temperature and a decrease in annual precipitation and (ii) a marked drying phase at ca. 11,900 cal yr B.P. that occurred between two wetter ones. Further phases of major deficit in moisture occured at ca. 11,500 cal yr B.P. (Younger Dryas-Holocene transition), 10,800 cal yr B.P., 8700 cal yr B.P., and 6500 cal yr B.P. Climatic parameters reconstructed here suggest that phases of higher lake level developing at ca. 12,500–12,000, 11,750–11,600, 11,200–10,900 (synchronous with the Preboreal oscillation), 10,400–8900, 8400–8300 (possibly related to the 8200 yr event), and 7800–7000 cal yr B.P. coincided with an increase in annual precipitation, a decrease in summer temperature, and a shorter growing season. Conversely, periods of low lake level corresponded to a decrease in annual precipitation, an increase in summer temperature, and a longer growing season. This general pattern could have resulted from alternate southward-northward displacements of the Atlantic Westerly Jet.

Quantitative estimates of temperature and precipitation changes over the last millennium from pollen and lake-level data at Lake Joux, Swiss Jura Mountains

2011 ◽  
Vol 75 (1) ◽  
pp. 45-54 ◽  
Author(s):  
Michel Magny ◽  
Odile Peyron ◽  
Emilie Gauthier ◽  
Boris Vannière ◽  
Laurent Millet ◽  
...  
Keyword(s):  
Lake Level ◽  
Summer Precipitation ◽  
Meridional Overturning Circulation ◽  
Ice Age ◽  
Last Millennium ◽  
Temperature Minimum ◽  
Jura Mountains ◽  
Level Data ◽  
Modern Analogue ◽  
Swiss Jura

AbstractThis paper presents quantitative climate estimates for the last millennium, using a multi-proxy approach with pollen and lake-level data from Lake Joux (Swiss Jura Mountains). The climate reconstruction, based on the Modern Analogue Technique, indicates warmer and drier conditions during the Medieval Warm Period (MWP). MWP was preceded by a short-lived cold humid event around AD 1060, and followed by a rapid return around AD 1400 to cooler and wetter conditions which generally characterize the Little Ice Age (LIA). Around AD 1450 (solar Spörer minimum), the LIA attained a temperature minimum and a summer precipitation maximum. The solar Maunder minimum around AD 1690 corresponded at Joux to rather mild temperatures but maximal annual precipitation. These results generally agree with other records from neighbouring Alpine regions. However, there are differences in the timing of the LIA temperature minimum depending on the proxy and/or the method used for the reconstruction. As a working hypothesis, the hydrological signal associated with the MWP and LIA oscillations at Lake Joux may have been mainly driven by a shift around AD 1400 from positive to negative NAO modes in response to variations in solar irradiance possibly coupled with changes in the Atlantic meridional overturning circulation.

scholarly journals Microbial Membrane Tetraether lipid-inferred paleohydrology and paleotemperature of Lake Chenghai during the Pleistocene-Holocene transition

2019 ◽  
Author(s):  
Weiwei Sun ◽  
Enlou Zhang ◽  
Jie Chang ◽  
James Shulmeister ◽  
Michael I. Bird ◽  
...  
Keyword(s):  
Relative Abundance ◽  
Lake Level ◽  
Southwest China ◽  
Transition Period ◽  
Younger Dryas ◽  
Lake Surface ◽  
Cold Event ◽  
The Past ◽  
Lake Chenghai ◽  
Temperature Records

Abstract. Over the past few decades, paleoenvironmental studies in the Indian Summer Monsoon (ISM) region have mainly focused on precipitation change, with few published terrestrial temperature records from the region. We analyzed the distribution of isoprenoid glycerol dialkyl glycerol tetraethers (isoGDGTs) in the sediments of Lake Chenghai in southwest China across the Pleistocene–Holocene transition, to extract both regional hydrological and temperature signals for this important transition period. Lake-level was reconstructed from the relative abundance of crenarchaeol in isoGDGTs (%cren) and the crenarchaeol'/crenarchaeol ratio. The %cren-inferred lake-level identified a single lowstand (15.4–14.4 cal ka BP), while the crenarchaeol'/crenarchaeol ratio suggests relatively lower lake-level between 15.4–14.4 cal ka BP and 12.5–11.7 cal ka BP, corresponding to periods of weakened ISM during the Heinrich 1 (H1) and Younger Dryas (YD) cold event. A filtered TetraEther indeX consisting of 86 carbon atoms (TEX86 index) revealed that lake surface temperature reached present-day values during the YD cold event, and suggests a substantial warming of ~ 4 °C from the early Holocene to the mid-Holocene. Our paleotemperature record is generally consistent with other records in southwest China, suggesting that the distribution of isoGDGTs in Lake Chenghai sediments has potential for quantitative paleotemperature reconstruction.

scholarly journals Lake-Level fluctuations at Le Locle, Swiss Jura, from the Younger Dryas to the Mid-Holocene: A high-resolution record of climate oscillations during the final deglaciation

2002 ◽  
Vol 53 (2) ◽  
pp. 183-197 ◽  
Author(s):  
Michel Magny ◽  
Patrick Schoellammer
Keyword(s):  
High Resolution ◽  
Lake Level ◽  
Environmental Changes ◽  
Younger Dryas ◽  
Greenland Ice Sheet ◽  
Climate Oscillations ◽  
Lake Level Fluctuations ◽  
High Lake Level ◽  
Swiss Jura ◽  
Holocene Period

Abstract On the basis of a high-resolution (10 cm / 110 years) lacustrine sequence from Le Locle, Swiss Jura, a fine-scale pattern of palaeohydrological changes is reconstructed for the late Younger Dryas (YD) and the early to mid-Holocene period. The late YD is characterized by a general trend of a fall in lake level and a large climatic instability. The early to mid-Holocene period shows a quasi-cyclic pattern of lake-level fluctuations. Large drops in lake level occurred at ca. 11 600-10 200 cal. BP and ca. 8 900-7 700 cal. BP. Each was interrupted by a short-term rise in lake-level and followed by a longer phase of high lake level respectively at ca. 10 200-8 900 cal. BP and ca. 7 700-6 600 cal. BP. The high lake-level periods at le Locle appear to be in phase with cold spells reconstructed in central Europe, in eastern North America and in the Greenland ice-sheet, or with cooling events and salinity anomalies recorded in the North Atlantic zone. They also coincide with rising residual Δ14C values. These data and the Lateglacial oxygen-isotope GISP2 record suggest three successive quasi-cycles of climatic and environmental changes showing strong similarities in their internal structure. These cycles suggest that large-scale climate oscillations developing from the Bølling warming to the mid-Holocene could have been associated with changes in ocean ventilation probably induced by three deglaciation steps. Finally, as a working hypothesis, a re-exami- nation of the YD event is proposed from a Holocene point of view.

Unstable ice stream in Greenland during the Younger Dryas cold event

Geology ◽  
2014 ◽  
Vol 42 (9) ◽  
pp. 759-762 ◽  
Author(s):  
Vincent Rinterknecht ◽  
Vincent Jomelli ◽  
Daniel Brunstein ◽  
Vincent Favier ◽  
Valérie Masson-Delmotte ◽  
...  
Keyword(s):  
Younger Dryas ◽  
Cold Event ◽  
Ice Stream

scholarly journals IMPACT OF CLIMATE CHANGE ON THE HYDRAULIC MODES OF OPERATION OF SURFACE RUNOFF DRAINAGE SYSTEMS

2020 ◽  
Vol 25 (4) ◽  
pp. 50-57
Author(s):  
V. S. Ignatchik ◽  
◽  
S. Y. Ignatchik ◽  
N. V. Kuznetsova ◽  
A. Y. Fes’kova ◽  
...  
Keyword(s):  
Climate Change ◽  
Linear Approximation ◽  
Surface Runoff ◽  
Annual Precipitation ◽  
Climatic Parameters ◽  
Modes Of Operation ◽  
Total Annual Precipitation ◽  
Rain Gauges ◽  
Drainage Networks ◽  
The Government

Introduction. Based on Resolution of the Government of the Russian Federation No. 782 “On water supply and wastewater disposal plans”, the volume of generated wastewater should be forecast for a period of at least 10 years. Along with this, it is also necessary to assess the hydraulic modes of operation of networks and collectors, specified earlier. However, the existing regulatory literature lacks data on the dynamics of calculated rain intensities and their prospective values. The analysis of the subject area showed that it is possible to determine the climatic parameters of an area, and thus establish the values for the characteristics of calculated rain, based on the data of long-term observations (from 20 years) with one self-recording rain gauge, or with a network of similar rain gauges, with a duration of observations of 5 years or more. A similar network of rain gauges is available in St. Petersburg. It makes it possible to assess the actual values of climatic parameters, but due to the lack of statistical data does not allow for assessing the dynamics of their changes. Therefore, the purpose of this article is to roughly estimate the dynamics of changes in climatic parameters in St. Petersburg and the degree of their impact on the hydraulic modes of operation of surface runoff drainage networks and collectors. Methods. In the course of the study, we analyzed the dynamics of changes in the total annual precipitation H and rain force in St. Petersburg and examined the influence of the dynamics of rain force changes on the operation of surface runoff drainage networks and collectors. Results. At the first stage of the study, we obtained the results of linear approximation of the H data, the calculated values of rain force changes Δ, and the results of linear approximation of the Δ data. The second stage of the study resulted in changes in the hydraulic modes of runoff input during the design period and in 50 years. Conclusion. We experimentally substantiated the possibility to determine the dynamics of rain force changes (at P = 0.33 and with acceptable accuracy) depending on the dynamics of changes in the total annual precipitation. For networks designed and laid 50 years ago, the actual rain force changes will be 9 %. As a result of climate change, water consumption in the calculation periods increased by about 26% with an increase in the total volume of discharged water by 9–10 %.

scholarly journals Late Pleistocene to present lake-level fluctuations at Pyramid and Winnemucca lakes, Nevada, USA

2019 ◽  
Vol 92 (1) ◽  
pp. 146-164 ◽  
Author(s):  
Kenneth D. Adams ◽  
Edward J. Rhodes
Keyword(s):  
Boundary Conditions ◽  
River Discharge ◽  
Lake Level ◽  
Late Holocene ◽  
Younger Dryas ◽  
Level Curve ◽  
Dry Period ◽  
Volume Changes ◽  
Hydrologic Variability ◽  
State Changes

AbstractA new lake-level curve for Pyramid and Winnemucca lakes, Nevada, is presented that indicates that after the ~15,500 cal yr BP Lake Lahontan high stand (1338 m), lake level fell to an elevation below 1200 m, before rising to 1230 m at the 12,000 cal yr BP Younger Dryas high stand. Lake level then fell to 1155 m by ~10,500 cal yr BP followed by a rise to 1200 m around 8000 cal yr BP. During the mid-Holocene, levels were relatively low (~1155 m) before rising to moderate levels (1190–1195 m) during the Neopluvial period (~4800–3400 cal yr BP). Lake level again plunged to about 1155 m during the late Holocene dry period (~2800–1900 cal yr BP) before rising to about 1190 m by ~1200 cal yr BP. Levels have since fluctuated within the elevation range of about 1170–1182 m except for the last 100 yr of managed river discharge when they dropped to as low as 1153 m. Late Holocene lake-level changes correspond to volume changes between 25 and 55 km3 and surface area changes between 450 and 900 km2. These lake state changes probably encompass the hydrologic variability possible under current climate boundary conditions.

scholarly journals Alpine Younger Dryas glaciers as palaeo-precipitation gauges

2000 ◽  
Vol 31 ◽  
pp. 80-84 ◽  
Author(s):  
Hanns Kerschner ◽  
Georg Kaser ◽  
Rudolf Sailer
Keyword(s):  
General Circulation ◽  
Climate Model ◽  
Younger Dryas ◽  
General Circulation Models ◽  
Summer Temperature ◽  
Equilibrium Line Altitude ◽  
The West ◽  
Temperature And Precipitation ◽  
Data Points ◽  
The Alps

AbstractMoraines of the Younger Dryas ˚Egesen Stadial", which are widespread features in the Alps, are a valuable terrestrial data source for quantitative palaeoclimatic studies. The depression of the early Younger Dryas (Egesen-I) equilibrium-line altitude (ELA) shows a distinct spatial pattern. It was greatest (about –450 to –500 m vs present day) m areas exposed towards the west and northwest. In the central, more sheltered valleys it was on the order of –300 m or less. Summer temperature depression, which can be derived from the Younger Dryas timberline depression, was on the order of –3.5 K. The stochastic glacier-climate model of Ohmura and others (1992), which relates summer temperature and precipitation at the ELA, is used to infer precipitation change. Results are compared with those obtained from the glacial-meteorological approach of Kuhn (1981a). The two models produce highly similar results. During the early Younger Dryas, climate in the central valleys of the Alps seems to have been considerably drier than today In areas open to the west and northwest, precipitation seems to have been the same as today or even slightly higher. These results, which are based on a rather dense network of data points, agree well with results from permafrost-climate studies and the more qualitative information from palaeobotanical research. They also support the results from atmospheric general circulation models for the Younger Dryas in Europe, which point towards a more zonal type of circulation.

Late-Quaternary summer temperature changes in the northern-European tree-line region

2008 ◽  
Vol 69 (03) ◽  
pp. 404-412 ◽  
Author(s):  
Heikki Seppä ◽  
Glen M. MacDonald ◽  
H. John B. Birks ◽  
Bruce R. Gervais ◽  
Jeffrey A. Snyder
Keyword(s):  
Kola Peninsula ◽  
Younger Dryas ◽  
Summer Temperature ◽  
The Arctic ◽  
Fossil Pollen ◽  
Tree Line ◽  
Temperature Changes ◽  
The Holocene ◽  
Northern European ◽  
Line Region

We present two new quantitative July mean temperature (Tjul) reconstructions from the Arctic tree-line region in the Kola Peninsula in north-western Russia. The reconstructions are based on fossil pollen records and cover the Younger Dryas stadial and the Holocene. The inferred temperatures are less reliable during the Younger Dryas because of the poorer fit between the fossil pollen samples and the modern samples in the calibration set than during the Holocene. The results suggest that the Younger Dryas Tjulin the region was 8.0–10.0°C, being 2.0–3.0°C lower than at present. The Holocene summer temperature maximum dates to 7500–6500 cal yr BP, with Tjulabout 1.5°C higher than at present. These new records contribute to our understanding of summer temperature changes along the northern-European tree-line region. The Holocene trends are consistent in most of the independent records from the Fennoscandian–Kola tree-line region, with the beginning of the Holocene thermal maximum no sooner than at about 8000 cal yr BP. In the few existing temperature-related records farther east in the Russian Arctic tree line, the period of highest summer temperature begins already at about 10,000 cal yr BP. This difference may reflect the strong influence of the Atlantic coastal current on the atmospheric circulation pattern and the thermal behaviour of the tree-line region on the Atlantic seaboard, and the more direct influence of the summer solar insolation on summer temperature in the region east of the Kola Peninsula.

scholarly journals A major hydrobiological change in Dasht-e Arjan Wetland (southwestern Iran) during the late glacial – early Holocene transition revealed by subfossil chironomids

2019 ◽  
Vol 56 (8) ◽  
pp. 848-856
Author(s):  
Cyril Aubert ◽  
Morteza Djamali ◽  
Matthew Jones ◽  
Hamid Lahijani ◽  
Nick Marriner ◽  
...  
Keyword(s):  
Lake Level ◽  
Regional Scale ◽  
Younger Dryas ◽  
Late Glacial ◽  
Early Holocene ◽  
Geochemical Data ◽  
The Holocene ◽  
Chironomus Plumosus ◽  
Subfossil Chironomids ◽  
Southwestern Iran

The late glacial – early Holocene transition is a key period in the earth’s history. However, although this transition is well studied in Europe, it is not well constrained in the Middle East and palaeohydrological records with robust chronologies remain scarce from this region. Here we present an interesting hydrobiological record showing a major environmental change occurring in the Dasht-e Arjan Wetland (southwestern Iran, near to Persepolis) during the late glacial – early Holocene transition (ca. 11 650 years cal BP). We use subfossil chironomids (Insecta: Diptera) as a proxy for hydrological changes and to reconstruct lake-level fluctuations. The Arjan wetland was a deep lake during the Younger Dryas marked by a dominance of Chironomus plumosus/anthracinus-type, taxa adapted to anoxic conditions of deep waters. At the beginning of the Holocene, a drastic decrease (more than 80% to less than 10%) of Chironomus plumosus/anthracinus-type, combined with diversification of littoral taxa such as Polypedilum nubeculosum-type, Dicrotendipes nervosus-type, and Glyptotendipes pallens-type, suggests a lake-level decrease and a more vegetalized aquatic environment. We compare and contrast the chironomid record of Arjan with a similar record from northwestern Iran. The palaeoclimatic significance of the record, at a local and regional scale, is subsequently discussed. The increase in Northern Hemisphere temperatures, inferred by geochemical data from NGRIP, at the beginning of the Holocene best explains the change from the Younger Dryas highstand to early Holocene lowstand conditions in the Dasht-e Arjan wetland. However, a contribution of the meltwater inflow from small local glaciers in the catchment basin is not excluded.

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