scholarly journals A Synoptic Scale Perspective on Greenland Ice Core δ18O Variability and Related Teleconnection Patterns

Atmosphere ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 294
Author(s):  
Norel Rimbu ◽  
Monica Ionita ◽  
Gerrit Lohmann
Keyword(s):  
Ice Core ◽  
Ice Cores ◽  
Synoptic Scale ◽  
Local Climate ◽  
Rossby Wave Breaking ◽  
Weather Patterns ◽  
Teleconnection Patterns ◽  
Climate Anomalies ◽  
The North ◽  
Oxygen Isotope Ratios

The variability of stable oxygen isotope ratios (δ18O) from Greenland ice cores is commonly linked to changes in local climate and associated teleconnection patterns. In this respect, in this study we investigate ice core δ18O variability from a synoptic scale perspective to assess the potential of such records as proxies for extreme climate variability and associated weather patterns. We show that positive (negative) δ18O anomalies in three southern and central Greenland ice cores are associated with relatively high (low) Rossby Wave Breaking (RWB) activity in the North Atlantic region. Both cyclonic and anticyclonic RWB patterns associated with high δ18O show filaments of strong moisture transport from the Atlantic Ocean towards Greenland. During such events, warm and wet conditions are recorded over southern, western and central part of Greenland. In the same time the cyclonic and anticyclonic RWB patterns show enhanced southward advection of cold polar air masses on their eastern side, leading to extreme cold conditions over Europe. The association between high δ18O winters in Greenland ice cores and extremely cold winters over Europe is partly explained by the modulation of the RWB frequency by the tropical Atlantic sea surface temperature forcing, as shown in recent modeling studies. We argue that δ18O from Greenland ice cores can be used as a proxy for RWB activity in the Atlantic European region and associated extreme weather and climate anomalies.

scholarly journals Spatial variations of local climate at Taylor Dome, Antarctica: implications for paleoclimate from ice cores

1994 ◽  
Vol 20 ◽  
pp. 219-225 ◽  
Author(s):  
E.D. Waddington ◽  
D.L. Morse
Keyword(s):  
Spatial Variability ◽  
Source Region ◽  
Ice Core ◽  
Ice Cores ◽  
Temperature Inversion ◽  
Related Factors ◽  
Local Climate ◽  
Air Masses ◽  
Air Temperatures ◽  
Inversion Strength

10m firn temperatures are commonly used on the Antarctic plateau to estimate mean annual air temperatures. 10m firn temperatures measured at Taylor Dome (also referred to as McMurdo Dome in the literature), Antarctica, are influenced by a factor other than altitude and latitude that varies systematically across Taylor Dome. Some inter-related factors possibly contributing to the modern temperature variability are differences in sensible heat from warm or cold air masses, differences in wind strength and source region, differences in temperature inversion strength and differences in cloudiness. Our preliminary data are compatible with spatially variable katabatic winds that could control the winter temperature inversion strength to provide a large part of the signal. This has implications for paleoclimate studies.(1) Variations of the stable isotopes δ18O and δD from ice cores are a proxy for paleotemperature. The isotope thermometer is calibrated by comparing local isotope ratios with corresponding measured temperatures. In order to derive a useful isotope-temperature calibration, we must understand the processes that control the modern spatial variability of temperature. (2) In order to quantify past changes in local climate, we must understand processes that influence local spatial variability. If those processes differed in the past, ice-core climate reconstruction would be affected in two ways: through alteration of the geochemical record and through alteration of deep ice and firn temperatures.

scholarly journals Impact of precipitation intermittency on NAO-temperature signals in proxy records

2013 ◽  
Vol 9 (2) ◽  
pp. 871-886 ◽  
Author(s):  
M. Casado ◽  
P. Ortega ◽  
V. Masson-Delmotte ◽  
C. Risi ◽  
D. Swingedouw ◽  
...  
Keyword(s):  
General Circulation ◽  
Ice Core ◽  
Circulation Model ◽  
Ice Cores ◽  
Stable Isotope Ratio ◽  
Global Network ◽  
Temporal Correlations ◽  
The North ◽  
The North Atlantic Oscillation ◽  
The Impact

Abstract. In mid and high latitudes, the stable isotope ratio in precipitation is driven by changes in temperature, which control atmospheric distillation. This relationship forms the basis for many continental paleoclimatic reconstructions using direct (e.g. ice cores) or indirect (e.g. tree ring cellulose, speleothem calcite) archives of past precipitation. However, the archiving process is inherently biased by intermittency of precipitation. Here, we use two sets of atmospheric reanalyses (NCEP (National Centers for Environmental Prediction) and ERA-interim) to quantify this precipitation intermittency bias, by comparing seasonal (winter and summer) temperatures estimated with and without precipitation weighting. We show that this bias reaches up to 10 °C and has large interannual variability. We then assess the impact of precipitation intermittency on the strength and stability of temporal correlations between seasonal temperatures and the North Atlantic Oscillation (NAO). Precipitation weighting reduces the correlation between winter NAO and temperature in some areas (e.g. Québec, South-East USA, East Greenland, East Siberia, Mediterranean sector) but does not alter the main patterns of correlation. The correlations between NAO, δ18O in precipitation, temperature and precipitation weighted temperature are investigated using outputs of an atmospheric general circulation model enabled with stable isotopes and nudged using reanalyses (LMDZiso (Laboratoire de Météorologie Dynamique Zoom)). In winter, LMDZiso shows similar correlation values between the NAO and both the precipitation weighted temperature and δ18O in precipitation, thus suggesting limited impacts of moisture origin. Correlations of comparable magnitude are obtained for the available observational evidence (GNIP (Global Network of Isotopes in Precipitation) and Greenland ice core data). Our findings support the use of archives of past δ18O for NAO reconstructions.

scholarly journals A 60 000 year Greenland stratigraphic ice core chronology

2008 ◽  
Vol 4 (1) ◽  
pp. 47-57 ◽  
Author(s):  
A. Svensson ◽  
K. K. Andersen ◽  
M. Bigler ◽  
H. B. Clausen ◽  
D. Dahl-Jensen ◽  
...  
Keyword(s):  
North Atlantic ◽  
Time Scale ◽  
Ice Core ◽  
Ice Cores ◽  
The North ◽  
Annual Layer ◽  
Zone Ii ◽  
Absolute Age ◽  
Age Estimates ◽  
New Time

Abstract. The Greenland Ice Core Chronology 2005 (GICC05) is a time scale based on annual layer counting of high-resolution records from Greenland ice cores. Whereas the Holocene part of the time scale is based on various records from the DYE-3, the GRIP, and the NorthGRIP ice cores, the glacial part is solely based on NorthGRIP records. Here we present an 18 ka extension of the time scale such that GICC05 continuously covers the past 60 ka. The new section of the time scale places the onset of Greenland Interstadial 12 (GI-12) at 46.9±1.0 ka b2k (before year AD 2000), the North Atlantic Ash Zone II layer in GI-15 at 55.4±1.2 ka b2k, and the onset of GI-17 at 59.4±1.3 ka b2k. The error estimates are derived from the accumulated number of uncertain annual layers. In the 40–60 ka interval, the new time scale has a discrepancy with the Meese-Sowers GISP2 time scale of up to 2.4 ka. Assuming that the Greenland climatic events are synchronous with those seen in the Chinese Hulu Cave speleothem record, GICC05 compares well to the time scale of that record with absolute age differences of less than 800 years throughout the 60 ka period. The new time scale is generally in close agreement with other independently dated records and reference horizons, such as the Laschamp geomagnetic excursion, the French Villars Cave and the Austrian Kleegruben Cave speleothem records, suggesting high accuracy of both event durations and absolute age estimates.

scholarly journals Precipitation record since AD 1600 from ice cores on the central Tibetan Plateau

2008 ◽  
Vol 4 (3) ◽  
pp. 175-180 ◽  
Author(s):  
T. Yao ◽  
K. Duan ◽  
B. Xu ◽  
N. Wang ◽  
X. Guo ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Ice Core ◽  
Ice Cores ◽  
The North ◽  
Northern Tibetan Plateau ◽  
Central Tibetan Plateau ◽  
Precipitation Record ◽  
Ice Field ◽  
The 19Th Century

Abstract. Lack of reliable long-term precipitation record from the northern Tibetan Plateau has constrained our understanding of precipitation variations in this region. We drilled an ice core on the Puruogangri Ice Field in the central Tibetan Plateau in 2000 to reveal the precipitation variations. The well dated part of the core extends back to AD 1600, allowing us to construct a 400-year annual accumulation record. This record shows that the central Tibetan plateau experienced a drier period with an average annual precipitation of ~300 mm in the 19th century, compared to ~450 mm in the wetter periods during 1700–1780 and the 20th century. This pattern agrees with precipitation reconstructions from the Dunde and Guliya ice cores on the northern Plateau but differs from that found in the Dasuopu ice cores from the southern Plateau The north-south contrasts in precipitation reconstruction reveals difference in moisture origin between the south Tibetan Plateau dominated by the Asian monsoon and the north Tibetan Plateau dominated by the continental recycling and the westerlies.

scholarly journals Spatial variations of local climate at Taylor Dome, Antarctica: implications for paleoclimate from ice cores

1994 ◽  
Vol 20 ◽  
pp. 219-225
Author(s):  
E.D. Waddington ◽  
D.L. Morse
Keyword(s):  
Spatial Variability ◽  
Source Region ◽  
Ice Core ◽  
Ice Cores ◽  
Temperature Inversion ◽  
Related Factors ◽  
Local Climate ◽  
Air Masses ◽  
Air Temperatures ◽  
Inversion Strength

10m firn temperatures are commonly used on the Antarctic plateau to estimate mean annual air temperatures. 10m firn temperatures measured at Taylor Dome (also referred to as McMurdo Dome in the literature), Antarctica, are influenced by a factor other than altitude and latitude that varies systematically across Taylor Dome. Some inter-related factors possibly contributing to the modern temperature variability are differences in sensible heat from warm or cold air masses, differences in wind strength and source region, differences in temperature inversion strength and differences in cloudiness. Our preliminary data are compatible with spatially variable katabatic winds that could control the winter temperature inversion strength to provide a large part of the signal. This has implications for paleoclimate studies.(1) Variations of the stable isotopes δ18O and δD from ice cores are a proxy for paleotemperature. The isotope thermometer is calibrated by comparing local isotope ratios with corresponding measured temperatures. In order to derive a useful isotope-temperature calibration, we must understand the processes that control the modern spatial variability of temperature. (2) In order to quantify past changes in local climate, we must understand processes that influence local spatial variability. If those processes differed in the past, ice-core climate reconstruction would be affected in two ways: through alteration of the geochemical record and through alteration of deep ice and firn temperatures.

scholarly journals Impact of the North Atlantic Oscillation on Transatlantic Flight Routes and Clear-Air Turbulence

2016 ◽  
Vol 55 (3) ◽  
pp. 763-771 ◽  
Author(s):  
Jung-Hoon Kim ◽  
William N. Chan ◽  
Banavar Sridhar ◽  
Robert D. Sharman ◽  
Paul D. Williams ◽  
...  
Keyword(s):  
New York ◽  
North Atlantic Oscillation ◽  
North Atlantic ◽  
Large Scale ◽  
Jet Streams ◽  
Weather Patterns ◽  
Teleconnection Patterns ◽  
The North ◽  
Air Turbulence ◽  
The North Atlantic Oscillation

AbstractThe variation of wind-optimal transatlantic flight routes and their turbulence potential is investigated to understand how upper-level winds and large-scale flow patterns can affect the efficiency and safety of long-haul flights. In this study, the wind-optimal routes (WORs) that minimize the total flight time by considering wind variations are modeled for flights between John F. Kennedy International Airport (JFK) in New York, New York, and Heathrow Airport (LHR) in London, United Kingdom, during two distinct winter periods of abnormally high and low phases of North Atlantic Oscillation (NAO) teleconnection patterns. Eastbound WORs approximate the JFK–LHR great circle (GC) route following northerly shifted jets in the +NAO period. Those WORs deviate southward following southerly shifted jets during the −NAO period, because eastbound WORs fly closely to the prevailing westerly jets to maximize tailwinds. Westbound WORs, however, spread meridionally to avoid the jets near the GC in the +NAO period to minimize headwinds. In the −NAO period, westbound WORs are north of the GC because of the southerly shifted jets. Consequently, eastbound WORs are faster but have higher probabilities of encountering clear-air turbulence than westbound ones, because eastbound WORs are close to the jet streams, especially near the cyclonic shear side of the jets in the northern (southern) part of the GC in the +NAO (−NAO) period. This study suggests how predicted teleconnection weather patterns can be used for long-haul strategic flight planning, ultimately contributing to minimizing aviation’s impact on the environment.

scholarly journals The Recurrence Time of Dansgaard–Oeschger Events and Limits on the Possible Periodic Component

2005 ◽  
Vol 18 (14) ◽  
pp. 2594-2603 ◽  
Author(s):  
Peter D. Ditlevsen ◽  
Mikkel S. Kristensen ◽  
Katrine K. Andersen
Keyword(s):  
Waiting Times ◽  
Ice Core ◽  
Ice Cores ◽  
Recurrence Time ◽  
Objective Criterion ◽  
Climate Signal ◽  
The North ◽  
Climate Shifts ◽  
Isotopic Records ◽  
Core Project

Abstract By comparing the high-resolution isotopic records from the Greenland Ice Core Project (GRIP) and the North Greenland Ice Core Project (NGRIP) ice cores, the common climate signal in the records has been approximately separated from local noise. From this, an objective criterion for defining Dansgaard–Oeschger (DO) events is achieved. The analysis identifies several additional short-lasting events, increasing the total number of DO events to 27 in the period 12–90 kyr before present (BP). The quasi-regular occurrence of the DO events could indicate a stochastic or coherent resonance mechanism governing their origin. From the distribution of waiting times, a statistical upper bound on the strength of a possible periodic forcing is obtained. This finding indicates that the climate shifts are purely noise driven with no underlying periodicity.

scholarly journals The NorthGRIP ice-core logging procedure: description and evaluation

2002 ◽  
Vol 35 ◽  
pp. 5-8 ◽  
Author(s):  
Christine Schøtt Hvidberg ◽  
Jørgen Peder Steffensen ◽  
Henrik B. Clausen ◽  
Hitoshi Shoji ◽  
Joseph Kipfstuhl
Keyword(s):  
Ice Core ◽  
Ice Cores ◽  
Depth Interval ◽  
Conductivity Measurements ◽  
The Core ◽  
The North ◽  
Core Logging ◽  
Independent Evaluation ◽  
The Difference ◽  
North Greenland

AbstractThe ice-core logging procedure used to log the North Greenland Icecore Project (NorthGRIP) ice cores is described. the existence of two deep ice cores, NorthGRIP 1and 2, drilled 25 mapart, allows an independent evaluation of the procedure. the logged depths of the NorthGRIP 1 and 2 cores deviate from the length of the unwound drill cable corrected for elongation of the cable when hanging in the hole, by 1.5‰ and 50.5‰ at depths of 1371 and 2931 m, respectively. Differences between logged depths of identified layers found in both cores are studied in the depth interval where they overlap. Layers are identified by electrical conductivity measurements and dielectric profiling. the difference between the logged depths of layers identified in both cores increases to 0.5 m close to the bottom of the NorthGRIP 1 core, which is <0.5 mm m–1 ice core. the comparison between the two cores shows that the NorthGRIP logging procedure is accurate and reproducible. Further, our results show that the temperature conditions and handling of the core during logging are important for obtaining a precise depth.

scholarly journals Lithium in Greenland ice cores measured by ion chromatography

2002 ◽  
Vol 35 ◽  
pp. 243-249 ◽  
Author(s):  
Marie-Louise Siggaard-Andersen ◽  
Jørgen Peder Steffensen ◽  
Hubertus Fischer
Keyword(s):  
Ion Chromatography ◽  
Ice Core ◽  
Ice Cores ◽  
Lithium Content ◽  
Seasonal Cycles ◽  
Ionic Component ◽  
Polar Ice ◽  
Cold Event ◽  
The North ◽  
Sample Preconcentration

AbstractIon chromatography (IC) is a widely used technique for analyzing ice cores for ions like Na+, NH4+, K+, Mg2+, Ca2+, F–, MSA–, Cl–, NO2– and SO42– that are present in polar ice cores at ppb level. By using sample preconcentration and an optimized separation technique, we have been able to detect Li+ in ice-core samples in concentrations as low as 0.0001 μeq kg–1 or 0.7 ppt by IC. During routine analysis of ions in ice cores, the lithium content has been evaluated and recorded. the IC technique used in these measurements and some exemplary IC data from the Greenland Icecore Project (GRIP) and the North Greenland Icecore Project (NorthGRIP) ice cores are presented. By these data we introduce Li+ concentration as a new parameter in the analysis of ice cores. Like other ions, Li+ reflects climatic changes and shows seasonal cycles. on the basis of the geochemistry of lithium, we suggest that Li+ measured in the Greenland ice cores is derived from mineral dust. However, data from the NorthGRIP ice core representing the 8.2 kyr BPHolocene cold event show a strong Li+ signal that does not correlate with any other ionic component measured. This means that the lithium content in ice cores is a signal with its own pattern, which is not yet understood.

scholarly journals Age ranges of the Tibetan ice cores with emphasis on the Chongce ice cores, western Kunlun Mountains

2018 ◽  
Vol 12 (7) ◽  
pp. 2341-2348 ◽  
Author(s):  
Shugui Hou ◽  
Theo M. Jenk ◽  
Wangbin Zhang ◽  
Chaomin Wang ◽  
Shuangye Wu ◽  
...  
Keyword(s):  
Ice Core ◽  
Ice Cores ◽  
High Elevation ◽  
The Other ◽  
Ice Cap ◽  
The North ◽  
Kunlun Mountains ◽  
Guliya Ice Core ◽  
Western Kunlun ◽  
Drilling Site

Abstract. An accurate chronology is the essential first step for a sound understanding of ice core records. However, dating ice cores drilled from the high-elevation glaciers is challenging and often problematic, leading to great uncertainties. The Guliya ice core, drilled to the bedrock (308.6 m in length) along the western Kunlun Mountains on the north-western Tibetan Plateau (TP) and widely used as a benchmark for palaeoclimate research, is believed to reach >500 ka (thousand years) at its bottom. Meanwhile other Tibetan ice cores (i.e. Dasuopu and East Rongbuk in the Himalayas, Puruogangri in the central TP and Dunde in the north-eastern TP) are mostly of Holocene origin. In this study, we drilled four ice cores into bedrock (216.6, 208.6, 135.8 and 133.8 m in length, respectively) from the Chongce ice cap ∼30 km to the Guliya ice core drilling site. We took measurements of 14C, 210Pb, tritium and β activity for the ice cores, and used these values in a two-parameter flow model to establish the ice core depth–age relationship. We suggested that the Chongce ice cores might be of Holocene origin, consistent with the other Tibetan ice cores except Guliya. The remarkable discrepancy between the Guliya and all the other Tibetan ice core chronology implies that more effort is necessary to explore multiple dating techniques to confirm the age ranges of the TP glaciers, including those from Chongce and Guliya.

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