scholarly journals A 70-yr record of oxygen-18 variability in accumulation from the Tanggula Mountains, central Tibetan Plateau

2009 ◽  
Vol 5 (4) ◽  
pp. 1929-1949
Author(s):  
D. R. Joswiak ◽  
T. Yao ◽  
G. Wu ◽  
B. Xu ◽  
W. Zheng
Keyword(s):  
Tibetan Plateau ◽  
Temperature Dependence ◽  
Ice Core ◽  
Warm Season ◽  
Ice Cores ◽  
Isotope Ratios ◽  
Significant Negative Correlation ◽  
Annual Average ◽  
The North ◽  
Central Tibetan Plateau

Abstract. A 33 m ice core was retrieved from the Tanggula Mtns, central Tibetan Plateau at 5743 m a.s.l. in August 2005. Annual average δ18O ratios were determined for the upper 17 m depth, representing the time series since the mid-1930's based on multi-parameter dating techniques. Data are compared to previous results (Kang et al., 2007) of an ice core from Mt. Geladaindong, 100 km to the northwest, for the period 1935–2003. During the time 1935–1960, δ18O ratios differed by 2–3‰ between the two ice cores, with generally lower ratios preserved in the Tanggula 2005 core. Differences in interannual variability and overall average ratios between the two study locations highlight the spatially variable climatic signals of ice core isotope ratios within the boundary of monsoon- and westerly-impacted regions of the central Tibetan Plateau. Average annual net accumulation was 261 mm w.eq. yr−1 for the period 1935–2004. Overall average δ18O ratio was −13.2‰ and exhibited a statistically significant increase from the 1935–1969 average (−413.7‰) to the 1970–2004 average (−12.6‰). Despite the observed increase in isotope ratios, temperature dependence was not found based on comparison with long-term data from meteorological stations to the north and southwest of the study location. Lack of temperature dependence is likely due monsoon influence, which results in relatively more depleted moisture arriving during the warm season. Evidence of monsoon impacts on precipitation in the central Tibetan Plateau has been previously documented, and statistically significant negative correlation (r=-0.37, p<0.01) between the annual average ice core δ18O ratio and N. India monsoon rainfall was observed for the period 1935–2004.

scholarly journals A 70-yr record of oxygen-18 variability in an ice core from the Tanggula Mountains, central Tibetan Plateau

2010 ◽  
Vol 6 (2) ◽  
pp. 219-227 ◽  
Author(s):  
D. R. Joswiak ◽  
T. Yao ◽  
G. Wu ◽  
B. Xu ◽  
W. Zheng
Keyword(s):  
Tibetan Plateau ◽  
Monsoon Rainfall ◽  
Ice Core ◽  
Warm Season ◽  
Ice Cores ◽  
Isotope Ratios ◽  
Rainfall Amount ◽  
North India ◽  
Annual Average ◽  
Central Tibetan Plateau

Abstract. A 33 m ice core was retrieved from the Tanggula Mts, central Tibetan Plateau at 5743 m a.s.l. in August 2005. Annual average δ18O values were determined for the upper 17 m depth (14.6 m w.eq.), representing the time series since the mid-1930s. Data are compared to previous results of an ice core from Mt. Geladaindong, 100 km to the northwest, for the period 1935–2003. During the time 1935–1960, δ18O values differed by 2–3‰ between the two ice cores, with generally lower ratios preserved in the Tanggula 2005 core. Differences in interannual variability and overall average ratios between the two study locations highlight the spatially variable climate controls on ice core isotope ratios within the boundary of monsoon- and westerly-impacted regions of the central Tibetan Plateau. Average annual net accumulation was 261 mm w.eq. for the period 1935–2004. The overall average δ18O value was −13.2‰ and exhibited a statistically significant increase from the 1935–1969 average (−13.7‰) to the 1970–2004 average (−12.6‰). Despite the observed increase in isotope ratios, isotopic temperature dependence was not evident, based on comparison with long-term data from meteorological stations to the north and southwest of the study location. Lack of correlation between average δ18O values and temperature is likely due to monsoon influence, which results in relatively greater isotopic depletion of moisture during the warm season. Evidence of monsoon impacts on precipitation in the central Tibetan Plateau has been previously documented, and statistically significant negative correlation (r=−0.37, p<0.01) between the annual average ice core δ18O values and North India monsoon rainfall was observed for the period 1935–2004. Although the δ18O data agree well with the monsoon rainfall amount, no significant correlation was observed between the core accumulation and the monsoon rainfall amount. Previous model and observational results suggest monsoon impact on δ18O in precipitation may extend beyond the immediate extent of heavy monsoon rainfall, reaching the central Tibetan Plateau. These results provide evidence that the δ18O variability at this study location may be sensitive to southern monsoon intensity.

scholarly journals Ice-core evidence of westerly and monsoon moisture contributions in the central Tibetan Plateau

2013 ◽  
Vol 59 (213) ◽  
pp. 56-66 ◽  
Author(s):  
Daniel R. Joswiak ◽  
Tandong Yao ◽  
Guangjian Wu ◽  
Lide Tian ◽  
Baiqing Xu
Keyword(s):  
Tibetan Plateau ◽  
Southern Oscillation ◽  
Ice Core ◽  
Ice Cores ◽  
Significant Negative Correlation ◽  
Climate Indices ◽  
Dipole Mode ◽  
Annual Average ◽  
Northern India ◽  
Central Tibetan Plateau

AbstractStable isotopes are a primary tool for inferring past temperature changes and atmospheric moisture variability from ice cores. A 33 m ice core representing the period 1850–2004 was retrieved from the Tanggula Mountains, central Tibetan Plateau (5743 m a.s.l.), in August 2005. Annual average stable isotope (δ18O, δD) values generally increase during the period, while the second-order parameter of deuterium excess (d-excess) generally decreases. High annual average d-excess values (18.2‰) throughout the ice core suggest a significant contribution of continental recycled moisture. d-excess values shift from relatively higher values during 1850–1940 to lower values since the 1940s. Annual isotope values and reconstructed accumulation are compared with climate indices, local station temperature records and northern India monsoon precipitation. Significant correlation is observed between δ18O and the Southern Oscillation, NINO3.4 and Dipole Mode indices. Annual average d-excess values revealed a significant negative correlation with the Dipole Mode index. Results suggest a relatively greater contribution of westerly-dominated continental moisture prior to the 1940s and an increase in the contribution of moisture evaporated under more humid conditions since the 1940s.

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 Ice core precipitation record in central Tibetan plateau since AD 1600

2008 ◽  
Vol 4 (1) ◽  
pp. 233-248 ◽  
Author(s):  
T. Yao ◽  
K. Duan ◽  
B. Xu ◽  
N. Wang ◽  
X. Guo ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Ice Core ◽  
Precipitation Amount ◽  
Ice Cores ◽  
The North ◽  
Temperature And Precipitation ◽  
Northern Tibetan Plateau ◽  
Central Tibetan Plateau ◽  
Precipitation Record ◽  
High Precipitation

Abstract. Lack of reliable long-term precipitation record from northern Tibetan Plateau has constrained the understanding of precipitation variation in this region. An ice core drilled from the Puruogangri Ice Field on central Tibetan Plateau in the year 2000 helped reveal the precipitation variations since AD 1600. Analysis of the annual accumulation data presented precipitation changes from AD 1600, indicative of wet and dry periods in the past 400 year in the central Tibetan Plateau. Accordingly, the 18th and 20th centuries experienced high precipitation period, whilst the 19th century experienced low precipitation period. Such a feature was consistent with precipitation recorded in ice cores from Dunde and Guliya Glaciers, northern Tibetan Plateau. Besides, the results also pointed to consistency in precipitation-temperature correlation on the northern Tibetan Plateau, in a way that temperature and precipitation were positively correlated. But this feature was contrary to the relationship revealed from Dasuopu ice cores, southern Tibetan Plateau, where temperature and precipitation were negatively correlated. The north-south contrast in precipitation amount and its relationship with temperature may shed light on the reconstruction of Asian monsoon since AD 1600.

scholarly journals Twentieth-century warming preserved in a Geladaindong mountain ice core, central Tibetan Plateau

2016 ◽  
Vol 57 (71) ◽  
pp. 70-80 ◽  
Author(s):  
Yulan Zhang ◽  
Shichang Kang ◽  
Bjorn Grigholm ◽  
Yongjun Zhang ◽  
Susan Kaspari ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
20Th Century ◽  
North Atlantic ◽  
Regional Climate ◽  
Source Region ◽  
Ice Core ◽  
Ice Age ◽  
The North ◽  
Central Tibetan Plateau ◽  
The North Atlantic

AbstractHigh-resolution δ18O records from a Geladaindong mountain ice core spanning the period 1477-1982 were used to investigate past temperature variations in the Yangtze River source region of the central Tibetan Plateau (TP). Annual ice-core δ18O records were positively correlated with temperature data from nearby meteorological stations, suggesting that the δ18O record represented the air temperature in the region. A generally increasing temperature trend over the past 500 years was identified, with amplified warming during the 20th century. A colder stage, spanning before the 1850s, was found to represent the Little Ice Age with colder periods occurring during the 1470s–1500s, 1580s–1660s, 1700s–20s and 1770s–1840s. Compared with other temperature records from the TP and the Northern Hemisphere, the Geladaindong ice-core record suggested that the regional climate of the central TP experienced a stronger warming trend during the 20th century than other regions. In addition, a positive relationship between the Geladaindong δ18O values and the North Atlantic Oscillation index, combined with a wavelet analysis of δ18O records, indicated that there was a potential atmospheric teleconnection between the North Atlantic and the central TP.

scholarly journals Dramatic loss of glacier accumulation area on the Tibetan Plateau revealed by ice core tritium and mercury records

2015 ◽  
Vol 9 (3) ◽  
pp. 1213-1222 ◽  
Author(s):  
S. Kang ◽  
F. Wang ◽  
U. Morgenstern ◽  
Y. Zhang ◽  
B. Grigholm ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Mass Loss ◽  
Mass Balance ◽  
Ice Core ◽  
Ice Cores ◽  
The Tibetan Plateau ◽  
Runoff Water ◽  
Sea Levels ◽  
Central Tibetan Plateau ◽  
High Elevations

Abstract. Two ice cores were retrieved from high elevations (~5800 m a.s.l.) at Mt. Nyainqêntanglha and Mt. Geladaindong in the southern and central Tibetan Plateau region. The combined tracer analysis of tritium (3H), 210Pb and mercury, along with other chemical records, provided multiple lines of evidence supporting that the two coring sites had not received net ice accumulation since at least the 1950s and 1980s, respectively. These results implied an annual ice loss rate of more than several hundred millimeter water equivalent over the past 30–60 years. Both mass balance modeling at the sites and in situ data from the nearby glaciers confirmed a continuously negative mass balance (or mass loss) in the region due to dramatic warming in recent decades. Along with a recent report on Naimona'nyi Glacier in the Himalayas, the findings suggest that the loss of accumulation area of glacier is a possibility from the southern to central Tibetan Plateau at high elevations, probably up to about 5800 m a.s.l. This mass loss raises concerns over the rapid rate of glacier ice loss and associated changes in surface glacier runoff, water availability, and sea levels.

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 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.

Sign in / Sign up

Export Citation Format

Share Document