scholarly journals Long-term climate variability over monsoon Asia as revealed by some proxy sources

MAUSAM ◽  
2021 ◽  
Vol 52 (1) ◽  
pp. 9-22
Author(s):  
H. P. BORGAONKAR ◽  
G. B. PANT
Keyword(s):  
Climate Variability ◽  
Monsoon Rainfall ◽  
Ice Cores ◽  
Monsoon Asia ◽  
Potential Source ◽  
Monsoon System ◽  
Monsoon Flow ◽  
Source Of Information ◽  
Contemporary Climate

Studies on climate variability over the region of monsoon Asia mostly during the Quaternary, based on various sources of proxy data have been reviewed. Increasing interest to understand the processes of monsoon system over the Asian region as well as the availability of data from variety of reliable proxy sources such as, ocean sediments, ice cores and historical documents have encouraged the palaeoclimatic studies in this region. Inferences drawn from the multiproxy sources indicate good association of glacial and inter-glacial phases with over all monsoon flow. Warm and wet periods are generally characterized by strong summer monsoon, where as, weak monsoonal activities were observed during cold and dry periods. All India monsoon rainfall since early 17th century based on dendroclimatic reconstructions shows trend-less nature with large interannual variability as seen in the instrumental record of recent century. Historical evidences over this region are a potential source of information on contemporary climate change.

scholarly journals Climate variability in West Antarctica derived from annual accumulation-rate records from ITASE firn/ice cores

2004 ◽  
Vol 39 ◽  
pp. 585-594 ◽  
Author(s):  
Susan Kaspari ◽  
Paul A. Mayewski ◽  
Daniel A. Dixon ◽  
Vandy Blue Spikes ◽  
Sharon B. Sneed ◽  
...  
Keyword(s):  
Climate Variability ◽  
Moisture Transport ◽  
Southern Oscillation ◽  
Accumulation Rate ◽  
Drainage System ◽  
Ice Cores ◽  
Cyclonic Activity ◽  
West Antarctica ◽  
Sea Level Pressure

AbstractThirteen annually resolved accumulation-rate records covering the last ~200 years from the Pine Island–Thwaites and Ross drainage systems and the South Pole are used to examine climate variability over West Antarctica. Accumulation is controlled spatially by the topography of the ice sheet, and temporally by changes in moisture transport and cyclonic activity. A comparison of mean accumulation since 1970 at each site to the long-term mean indicates an increase in accumulation for sites located in the western sector of the Pine Island–Thwaites drainage system. Accumulation is negatively associated with the Southern Oscillation Index (SOI) for sites near the ice divide, and periods of sustained negative SOI (1940–42, 1991–95) correspond to above-mean accumulation at most sites. Correlations of the accumulation-rate records with sea-level pressure (SLP) and the SOI suggest that accumulation near the ice divide and in the Ross drainage system may be associated with the mid-latitudes. The post-1970 increase in accumulation coupled with strong SLP–accumulation-rate correlations near the coast suggests recent intensification of cyclonic activity in the Pine Island– Thwaites drainage system.

Weihe Basin Drilling Project (WBDP): Cenozoic tectonic-monsoon interactions

2020 ◽  
Author(s):  
Zhisheng An ◽  
Peter Molnar ◽  
Peizhen Zhang ◽  
Hendrik Vogel ◽  
Mark Level ◽  
...  
Keyword(s):  
Climate Variability ◽  
Ice Cores ◽  
The Arctic ◽  
Second Phase ◽  
The Tibetan Plateau ◽  
Sedimentary Record ◽  
Weihe Basin ◽  
Drilling Project ◽  
Millennial Scale

<p>Earth’s climate underwent dramatic cooling throughout much of the Cenozoic, which has been linked to continental drift, mountain building, and the formation and expansion of ice-sheets in Antarctica and the Arctic. In particular, the India-Asia collision and uplift of the Tibetan Plateau (TP) have been posited as critical events responsible for increasing the rates of physical and chemical weathering on land, thereby decreasing the CO2 concentration of the atmosphere. The uplift of the TP ultimately led to the onset of the complexly coupled monsoon-arid environmental system in East Asia. Global-scale studies of Cenozoic deep-sea sediments and Quaternary ice cores indicate that, superimposed to the long-term cooling trend, climate variability at orbital-to-centennial time-scales is primarily induced by changing solar insolation and irradiance, and strongly modulated by complex internal land-air-ocean interactions. From the continental perspective, however, both the dynamics and impacts of long-term climate evolution and short-term climate variability remain poorly constrained due to the paucity of continuous terrestrial sequences spanning the entire Cenozoic.<br>The Weihe Basin is located in the monsoon-sensitive region to the north of the Qinling Mountains, a landform that constitutes the geographic and climatic boundary between northern and southern China. In the depocentre of this basin, a predominantly lacustrine sedimentary sequence with a thickness of >7 km, provides an unprecedented opportunity for: (1) reconstructing tectonic-to-millennial-scale climate changes from the Eocene to the present; (2) elucidating basin-mountain coupling processes; (3) assessing the effects of Cenozoic tectonic-climate interactions on the onset and evolution of the Asian paleomonsoon; and (4) investigating climatic/environmental impacts on the evolution of microbial communities. Importantly also, (5) sedimentary filling of the Weihe Basin can potentially yield unique high-resolution records of continental climate variability during high atmospheric CO2 periods of the Eocene, mid-Miocene, and Late Pliocene, and thus serve an analog for Earth’s near future climate.<br>The Weihe Basin Drilling Project (WBDP) proposes a two-phase drilling strategy to recover a complete as possible Cenozoic terrestrial sedimentary record from the eastern Weihe Basin depocenter. In the first phase (applied for here) we aim at producing a 3-km-long pilot sedimentary record (WBDP-1) to test the best suitable analytical approach and to reconstruct orbital-to-millennial-scale climate variability since the Late Miocene. In the second phase our aim is to produce a 7.5-km-long sedimentary record (WBDP-2) spanning the entire Cenozoic sedimentary infill of the Weihe Basin. The regional geological framework is well characterized through numerous exploration boreholes and detailed multichannel seismic reflection surveys. Scientific drilling operations will be accompanied by downhole logging, as well as on- and off-site analyses of the retrieved cores. The WBDP-1 borehole is expected to yield a world-class paleoclimate record for the last ~10 Ma and lead to fundamental advances in our understanding of multi-timescale climate variability and tectonic-climate monsoon linkages. The project will also enhance public awareness of human adaptation to Earth’s changing environment.</p>

scholarly journals Natural Climate Variability During the Holocene

Radiocarbon ◽  
2007 ◽  
Vol 49 (2) ◽  
pp. 837-854 ◽  
Author(s):  
V A Dergachev ◽  
O M Raspopov ◽  
F Damblon ◽  
H Jungner ◽  
G I Zaitseva
Keyword(s):  
Time Series ◽  
Climate Variability ◽  
Ice Cores ◽  
Cosmogenic Isotope ◽  
Radiocarbon Age ◽  
Earth’S Climate ◽  
Climatic Time Series ◽  
Natural Climate ◽  
Isotope Content

High-precision radiocarbon age calibration for different terrestrial samples allows us to establish accurate boundaries for many climatic time series. At the same time, the fluctuations of 14C content reflect solar variability. A bispectrum analysis of long-term series of the 14C content deduced from decadal measurements in tree rings demonstrates the existence of amplitude modulation, with a period of main modulation of ∼2400 yr. In 14C time series for the last 11 kyr, major oscillations are distinguished at 8.5–7.8, 5.4–4.7, 2.6–2.2, and 1.1–0.4 cal kyr BP with ∼2400-yr periodicity. High amplitudes in cosmogenic isotope content with a periodicity of about 2400 yr appear synchronous to cooling events documented in Greenland ice cores, to the timing of worldwide Holocene glacier expansion, and to the periods of lake-level changes. This paper focuses on revealing solar forcing on the Earth's climate and about the nature, significance, and impact of sharp Holocene climate variability on human societies and civilizations.

scholarly journals A debris-covered glacier at Kerguelen (49°S, 69°E) over the past 15 000 years

2020 ◽  
pp. 1-13
Author(s):  
Joanna Charton ◽  
Vincent Jomelli ◽  
Irene Schimmelpfennig ◽  
Deborah Verfaillie ◽  
Vincent Favier ◽  
...  
Keyword(s):  
Climate Variability ◽  
Late Holocene ◽  
Ice Cores ◽  
Cosmic Ray ◽  
Late Glacial ◽  
Temperature Changes ◽  
Precipitation Changes ◽  
The Antarctic ◽  
Exposure Ages

Abstract Debris-covered glaciers constitute a large part of the world's cryosphere. However, little is known about their long-term response to multi-millennial climate variability, in particular in the Southern Hemisphere. Here, we provide first insights into the response of a debris-covered glacier to multi-millennial climate variability in the sub-Antarctic Kerguelen Archipelago, which can be compared to that of recently investigated debris-free glaciers. We focus on the Gentil Glacier and present 13 new 36Cl cosmic-ray exposure ages from moraine boulders. The Gentil Glacier experienced at least two glacial advances: the first one during the Late Glacial (19.0–11.6 ka) at ~14.3 ka and the second one during the Late Holocene at ~2.6 ka. Both debris-covered and debris-free glaciers advanced broadly synchronously during the Late Glacial, most probably during the Antarctic Cold Reversal event (14.5–12.9 ka). This suggests that both glacier types at Kerguelen were sensitive to abrupt temperature changes recorded in Antarctic ice cores, associated with increased moisture. However, during the Late Holocene, the advance at ~2.6 ka was not observed in other glaciers and seems to be an original feature of the debris-covered Gentil Glacier, related to either distinct dynamics or to distinct sensitivity to precipitation changes.

scholarly journals The Effects of Multi-Scale Climate Variability on Biodiversity Patterns of Chinese Evergreen Broad-Leaved Woody Plants: Growth Form Matters

2021 ◽  
Vol 8 ◽  
Author(s):  
Yue Xu ◽  
Zehao Shen ◽  
Jinlong Zhang ◽  
Runguo Zang ◽  
Youxu Jiang
Keyword(s):  
Climate Change ◽  
Climate Variability ◽  
Woody Plants ◽  
Future Climate Change ◽  
Relative Importance ◽  
Growth Forms ◽  
Biodiversity Patterns ◽  
Short And Long Term ◽  
Contemporary Climate

Large-scale patterns of species diversity are thought to be linked to contemporary climate variability and Quaternary glacial–interglacial climate change. For plants, growth forms integrate traits related to competition or migration capacity, which determine their abilities to deal with the climate variability they face. Evergreen broad-leaved woody plants (EBWPs) are major components of numerous biomes in the subtropical and tropical regions. Hence, incorporating phylogenetic (temporal) and biogeographic (spatial) approaches, we assessed the relative importance of short- and long-term climate variability for biodiversity patterns of different growth forms (i.e., tree, shrub, liana, and bamboo) in EBWPs. We used a dated phylogeny and the distribution records for 6,265 EBWP species which are naturally occurred in China, and computed the corrected weighted endemism, standardized phylogenetic diversity and net relatedness index for the four growth forms, respectively. Ordinary least squares linear regressions, spatial error simultaneous autoregressive models, partial regression and hierarchical variation partitioning were employed to estimate the explanatory power of contemporary climate variability and climate-change velocity from the Last Glacial Maximum to the present. Our results showed that short- and long-term climate variability play complementary role in the biogeographic patterns of Chinese EBWPs. The former had larger effects, but the legacy effects of past climate changes were also remarkable. There were also differences in the effects of historical and current climate among the four growth forms, which support growth forms as a critical plant trait in predicting vegetation response to climate change. Compared to the glacial-interglacial climate fluctuation, seasonality as a unique feature of mid-latitude monsoon climate played a dominant role in the diversification and distribution of EBWP species at the macroscale. The results indicated that the relative importance of climate variability at different temporal scales may relate to distinct mechanisms. To understand effects of future climate change on species distribution more thoroughly, climate conditions in different time scales should be incorporated.

scholarly journals Long-term changes of river discharge regime in Latvia

2008 ◽  
Vol 39 (2) ◽  
pp. 133-141 ◽  
Author(s):  
Maris Klavins ◽  
Valery Rodinov
Keyword(s):  
Climate Variability ◽  
River Discharge ◽  
Water Resource Management ◽  
Regional Climate ◽  
Hydrological Regime ◽  
High Water ◽  
Regime Changes ◽  
Long Term Changes ◽  
Discharge Regime

The study of changes in river discharge is important for regional climate variability characterization and for development of an efficient water resource management system. The hydrological regime of rivers and their long-term changes in Latvia were investigated. Four major types of river hydrological regimes, which depend on climatic and physicogeographic factors, were characterized. These factors are linked to the changes observed in river discharge. Periodic oscillations of discharge, and low- and high-water flow years are common for the major rivers in Latvia. A main frequency of river discharge regime changes of about 20 and 13 years was estimated for the studied rivers. A significant impact of climate variability on the river discharge regime has been found.

Will Strategy Prevail over Economics? An Analysis of Charanka Solar Park in Gujarat

2016 ◽  
Vol 5 (2) ◽  
pp. 162-167
Author(s):  
Saif Siddiqui ◽  
Sumaira Jan
Keyword(s):  
Solar Energy ◽  
Solar Power ◽  
Power Production ◽  
Energy Crisis ◽  
Energy Sources ◽  
Potential Source ◽  
The World ◽  
Made In

The Charanka Solar Park, one of the world’s largest multi-developer and multi-beneficiary solar parks, is the hub of solar power production in India. It contributes about 6 per cent to the total solar power production in the country. Although solar power is more expensive than the traditional power in the country, its sheen is still not high to make it a potential source to eliminate energy crisis not just in India but all across the world. Researchers are continuously pushing their envelope to explore as to why solar energy should be adopted over traditional energy sources irrespective of the fact that it is more expensive. The war between its financial and strategic viability is going on. Efforts are being made in the direction of reducing its costs and making it as a financially viable and strategically active option. This case is an attempt in the same direction. We are using Charanka Solar Park as a base to explore if there is any future for such projects in the country. There are projects which are no doubt operational but their long-term viability is truly questionable.

Natural variability and recent warming in central Greenland ice cores

2021 ◽  
Author(s):  
Maria Hoerhold ◽  
Thomas Münch ◽  
Stefanie Weißbach ◽  
Sepp Kipfstuhl ◽  
Bo Vinther ◽  
...  
Keyword(s):  
Climate Variability ◽  
Ice Sheet ◽  
Greenland Ice Sheet ◽  
Ice Cores ◽  
Natural Variability ◽  
The Arctic ◽  
Last Millennium ◽  
Recent Warming ◽  
Temperature Reconstructions ◽  
Firn Core

<p>Climate variability of the Arctic region has been investigated by means of temperature reconstructions based on proxies from various climate archives around the Arctic, compiled over the last 2000a in the so called Arctic2k record. However, the representativeness of the Arctic2k reconstruction for central Greenland remains unclear, since only a few ice cores have been included in the reconstruction, and observations from the Greenland Ice Sheet (GIC) report ambiguous warming trends for the end of the 20th and the beginning of the 21st century which are not displayed by Arctic2k. Today, the GIC experiences periods with temperatures close to or above the freezing point at high elevations, area-wide melting and mass loss. In order to assess the recent warming as signature of global climate change, records of past climate changes with appropriate temporal and spatial coverage can serve as a benchmark for naturally driven climate variability. Instrumental records for Greenland are short and geographically sparse, and existing temperature reconstructions from single ice cores are noisy, leading to an inconclusive assessment of the recent warming for Greenland.</p><p>Here, we provide a Greenland firn-core stack covering the time span of the last millennium until the first decade of the 21<sup>st </sup>century in unprecedented quality by re-drilling as well as analyzing 16 existing firn core sites. We find a strong decadal to bi-decadal natural variability in the record, and, while the record exhibits several warming events with trends that show a similar amplitude as the recent one, we find that the recent absolute values of stable oxygen isotope composition are unprecedented for the last 1000 years.</p><p> </p><p>Comparing our Greenland record with the Arctic 2k temperature reconstruction shows that the correlation between the two records changes throughout the last millennium. While in the periods of 1200-1300 and 1400-1650 CE the records correlate positively, between 1300 and 1400 and 1650-1700 CE shorter periods with negative correlation are found. Since then the correlation is characterized by alternation between positive and zero correlation, with a drop towards negative values at the end of the 20<sup>th</sup> century. Including re-analysis data, we hypothesize that the climate on top of the GIC was decoupled from the surrounding Arctic for the last decades, leading to the observed mismatch in observations of warming trends.</p><p>We suggest that the recently observed Greenland temperatures are a superposition of a strong natural variability with an anthropogenic long-term trend. Our findings illustrate that global warming has reached the interior of the Greenland ice sheet, which will have implications for its surface mass balance and Greenland’s future contribution to sea level rise.</p><p>Our record complements the Arctic 2k record to a profound view on the Arctic climate variability, where regional compilations may not be representative for specific areas.</p>

Sign in / Sign up

Export Citation Format

Share Document