scholarly journals Causes of Greenland temperature variability over the past 4000 yr: implications for northern hemispheric temperature change

2012 ◽  
Vol 8 (5) ◽  
pp. 4817-4883 ◽  
Author(s):  
T. Kobashi ◽  
K. Kawamura ◽  
K. Goto-Azuma ◽  
J. E. Box ◽  
C.-C. Gao ◽  
...  
Keyword(s):  
Temperature Change ◽  
High Latitude ◽  
Ice Core ◽  
Volcanic Eruptions ◽  
Temperature Variability ◽  
Temperature Record ◽  
Average Temperature ◽  
The Past ◽  
Hemispheric Temperature ◽  
Climate Forcings

Abstract. A new Greenland temperature record reconstructed from argon and nitrogen isotopes from trapped air in a GISP2 ice core, provides high-resolution (<20 yr) and precise annual average temperature estimates for the past 4000 yr. Due to tight age-controls and abundant paleoclimatic information from the ice core, the temperature record provides an exceptional opportunity to investigate the late Holocene climate in a multi-decadal to millennial time scale. To investigate causes of Greenland temperature variability over the past 4000 yr, we calculated high latitude (70–80° N) temperature change using a one-dimensional energy balance model with reconstructed climate forcings including orbital, solar, volcanic, and greenhouse gas forcings. Greenland temperature was calculated from the high latitude temperature, considering Greenland's negative temperature responses to solar variability due to associated changes in atmospheric and oceanic circulations. The calculated Greenland temperature was significantly correlated with the ice-core-derived Greenland temperatures with the 97% confidence level. Therefore, the past variability of climate forcings can explain at least 10% of the multi-decadal to millennial variability in Greenland temperature over the past 4000 yr. An average temperature trend for the Northern Hemisphere (NH) over the past 4000 yr was also inferred from the ice-core derived Greenland temperatures. Lines of evidence indicate that the current decadal average temperature of NH is likely warmer than at any time over the past 4000 yr. Sequential cooling events starting around 800 B.C.E. (the 2.8 ka event), which were induced by several large volcanic eruptions as well as low solar activity, had similar magnitude with the Little Ice Age cooling.

scholarly journals Causes of Greenland temperature variability over the past 4000 yr: implications for northern hemispheric temperature changes

2013 ◽  
Vol 9 (5) ◽  
pp. 2299-2317 ◽  
Author(s):  
T. Kobashi ◽  
K. Goto-Azuma ◽  
J. E. Box ◽  
C.-C. Gao ◽  
T. Nakaegawa
Keyword(s):  
Confidence Interval ◽  
Early Period ◽  
Greenland Ice Sheet ◽  
Temperature Variability ◽  
Balance Model ◽  
Temperature Record ◽  
Average Temperature ◽  
The Past ◽  
Hemispheric Temperature ◽  
Northern Hemispheric

Abstract. Precise understanding of Greenland temperature variability is important in two ways. First, Greenland ice sheet melting associated with rising temperature is a major global sea level forcing, potentially affecting large populations in coming centuries. Second, Greenland temperatures are highly affected by North Atlantic Oscillation/Arctic Oscillation (NAO/AO) and Atlantic multidecadal oscillation (AMO). In our earlier study, we found that Greenland temperature deviated negatively (positively) from northern hemispheric (NH) temperature trend during stronger (weaker) solar activity owing to changes in atmospheric/oceanic changes (e.g. NAO/AO) over the past 800 yr (Kobashi et al., 2013). Therefore, a precise Greenland temperature record can provide important constraints on the past atmospheric/oceanic circulation in the region and beyond. Here, we investigated Greenland temperature variability over the past 4000 yr reconstructed from argon and nitrogen isotopes from trapped air in a GISP2 ice core, using a one-dimensional energy balance model with orbital, solar, volcanic, greenhouse gas, and aerosol forcings. The modelled northern Northern Hemisphere (NH) temperature exhibits a cooling trend over the past 4000 yr as observed for the reconstructed Greenland temperature through decreasing annual average insolation. With consideration of the negative influence of solar variability, the modelled and observed Greenland temperatures agree with correlation coefficients of r = 0.34–0.36 (p = 0.1–0.04) in 21 yr running means (RMs) and r = 0.38–0.45 (p = 0.1–0.05) on a centennial timescale (101 yr RMs). Thus, the model can explain 14 to 20% of variance of the observed Greenland temperature in multidecadal to centennial timescales with a 90–96% confidence interval, suggesting that a weak but persistent negative solar influence on Greenland temperature continued over the past 4000 yr. Then, we estimated the distribution of multidecadal NH and northern high-latitude temperatures over the past 4000 yr constrained by the climate model and Greenland temperatures. Estimated northern NH temperature and NH average temperature from the model and the Greenland temperature agree with published multi-proxy temperature records with r = 0.35–0.60 in a 92–99% confidence interval over the past 2000 yr. We found that greenhouse gases played two important roles over the past 4000 yr for the rapid warming during the 20th century and slightly cooler temperature during the early period of the past 4000 yr. Lastly, our analysis indicated that the current average temperature (1990–2010) or higher temperatures occurred at a frequency of 1.3 times per 1000 yr for northern high latitudes and 0.36 times per 4000 yr for NH temperatures, respectively, indicating that the current multidecadal NH temperature (1990–2010) is more likely unprecedented than not (p = 0.36) for the past 4000 yr.

scholarly journals A chironomid-based record of temperature variability during the past 4000 years in northern China and its possible societal implications

2017 ◽  
Author(s):  
Haipeng Wang ◽  
Jianhui Chen ◽  
Shengda Zhang ◽  
David D. Zhang ◽  
Zongli Wang ◽  
...  
Keyword(s):  
Temperature Change ◽  
Regional Scale ◽  
Northern China ◽  
Temperature Variability ◽  
Warm Period ◽  
Ice Age ◽  
Shanxi Province ◽  
Societal Implications ◽  
Temperature Record ◽  
The Past

Abstract. Long-term, high-resolution temperature records which combine an unambiguous proxy and precise dating are rare in China. In addition, the societal implications of past temperature change on regional scale have not been sufficiently assessed. Here, based on the modern relationship between chironomids and temperature, we use fossil chironomid assemblages in a precisely-dated sediment core from Gonghai Lake to explore temperature variability during the past 4000 years in northern China. Subsequently, we address the possible regional societal implications of temperature change through a statistical analysis of the occurrence of wars. Our results show that: (1) the mean annual temperature (TANN) was relatively high from 4000–2700 cal yr BP, decreased gradually from 2700–1270 cal yr BP, and then fluctuated drastically during the last 1270 years. (2) A cold climatic event in the Era of Disunity, the Sui-Tang Warm Period (STWP), the Medieval Warm Period (MWP) and the Little Ice Age (LIA) can all be recognized in the paleotemperature record, as well as in many other temperature reconstructions in China. This suggests that our chironomid-inferred temperature record for the Gonghai Lake region is representative. (3) Local wars in Shanxi Province, documented in the historical literature during the past 2700 years, are statistically significantly correlated with changes in temperature, and the relationship is a good example of the potential societal implications of temperature change on a regional scale.

Global and amplified land warming trends over the past 40+ years are entirely human-driven.

2021 ◽  
Author(s):  
Karsten Haustein
Keyword(s):  
Radiative Forcing ◽  
Volcanic Eruptions ◽  
Internal Variability ◽  
Forced Response ◽  
Global Temperature ◽  
Extreme Weather Events ◽  
Temperature Record ◽  
Model Framework ◽  
Anthropogenic Aerosol ◽  
The Past

&lt;p class=&quot;p1&quot;&gt;The role of external (radiative) forcing factors and internal unforced (ocean) low-frequency variations in the instrumental global temperature record are still hotly debated. More recent findings point towards a larger contribution from changes in external forcing, but the jury is still out. While the estimation of the human-induced total global warming fraction since pre-industrial times is fairly robust and mostly independent of multidecadal internal variability, this is not necessarily the case for key regional features such as Arctic amplification or enhanced warming over continental land areas. Accounting for the slow global temperature adjustment after strong volcanic eruptions, the spatially heterogeneous nature of anthropogenic aerosol forcing and known biases in the sea surface temperature record, almost all of the multidecadal fluctuations observed over at least the last 160+ years can be explained without a relevant role for internal variability. Using a two-box response model framework, I will demonstrate that not only multidecadal variability is very likely a forced response, but warming trends over the past 40+ years are entirely attributable to human factors. Repercussions for amplifed European (or D-A-CH for that matter) warming and associated implications for extreme weather events are discussed. Further consideration is given to the communications aspect of such critical results as well as the question of wider societal impacts.&lt;/p&gt;

scholarly journals Holocene temperature variations inferred from Antarctic ice cores

1994 ◽  
Vol 20 ◽  
pp. 427-436 ◽  
Author(s):  
P. Ciais ◽  
J. Jouzel ◽  
J. R. Petit ◽  
V. Lipenkov ◽  
J. W. C. White
Keyword(s):  
Late Holocene ◽  
Ice Core ◽  
Ice Cores ◽  
Temperature Fluctuations ◽  
Base Line ◽  
Temperature Changes ◽  
Average Temperature ◽  
The Past ◽  
Reconstructed Temperature ◽  
Line Temperature

We have reconstructed temperature changes over the past 15 000 years from ice-core data in Antarctica. We used measurements of the D/H isotope ratio in ice as a proxy of temperature for central sites (Vostok, Dome C and Komsomolskaya; as well as coastal sites (D47, D15 and D10). First, we examined the dating of each core and built up a common temporal framework for the ensemble of the data. Secondly, we addressed the problem of inferring small-amplitude temperature fluctuations from the isotope data, in the light of noise-generating mechanisms involved in snow deposition. Temperature was reconstructed so as to minimize distortion created by the sampling of ice cores in the field. The seven ice cores studied yield an average temperature curve which can be put in perspective with nearby paleoclimatic records. The early Holocene experienced climates warmer than today by 1-2°C. The late Holocene period shows more discernible, shorter-duration, temperature fluctuations, superimposed on a fairly stable "base-line" temperature.

scholarly journals The Influence On Atmospheric Composition of Volcanic Eruptions as Derived From Ice-Core Analysis

1985 ◽  
Vol 7 ◽  
pp. 125-129 ◽  
Author(s):  
C.U. Hammer
Keyword(s):  
Ice Core ◽  
Ice Sheets ◽  
Ice Cores ◽  
Volcanic Eruptions ◽  
Atmospheric Composition ◽  
Core Analysis ◽  
Polar Ice ◽  
Ice Caps ◽  
The Past ◽  
Polar Ice Sheets

Polar ice cores offer datable past snow deposits in the form of annual ice layers, which reflect the past atmospheric composition. Trace substances in the cores are related to the past mid-tropospheric impurity load, this being due to the vast extent of the polar ice sheets (or ice caps), their surface elevations and remoteness from most aerosol sources. Volcanic eruptions add to the rather low background impurity load via their eruptive products. This paper concentrates on the widespread influence on atmospheric impurity loads caused by the acid gas products from volcanic eruptions. In particular the following subjects are discussed: acid volcanic signals in ice cores, latitude of eruptions as derived by ice-core analysis, inter-hemispheric dating of the two polar ice sheets by equatorial eruptions, volcanic deposits in ice cores during the last glacial period and climatic implications.

scholarly journals A chironomid-based record of temperature variability during the past 4000 years in northern China and its possible societal implications

2018 ◽  
Vol 14 (3) ◽  
pp. 383-396 ◽  
Author(s):  
Haipeng Wang ◽  
Jianhui Chen ◽  
Shengda Zhang ◽  
David D. Zhang ◽  
Zongli Wang ◽  
...  
Keyword(s):  
Temperature Change ◽  
Regional Scale ◽  
Northern China ◽  
Temperature Variability ◽  
Warm Period ◽  
Ice Age ◽  
Shanxi Province ◽  
Societal Implications ◽  
Cold Event ◽  
The Past

Abstract. Long-term, high-resolution temperature records which combine an unambiguous proxy and precise dating are rare in China. In addition, the societal implications of past temperature change on a regional scale have not been sufficiently assessed. Here, based on the modern relationship between chironomids and temperature, we use fossil chironomid assemblages in a precisely dated sediment core from Gonghai Lake to explore temperature variability during the past 4000 years in northern China. Subsequently, we address the possible regional societal implications of temperature change through a statistical analysis of the occurrence of wars. Our results show the following. (1) The mean annual temperature (TANN) was relatively high during 4000–2700 cal yr BP, decreased gradually during 2700–1270 cal yr BP and then fluctuated during the last 1270 years. (2) A cold event in the Period of Disunity, the Sui-Tang Warm Period (STWP), the Medieval Warm Period (MWP) and the Little Ice Age (LIA) can all be recognized in the paleotemperature record, as well as in many other temperature reconstructions in China. This suggests that our chironomid-inferred temperature record for the Gonghai Lake region is representative. (3) Local wars in Shanxi Province, documented in the historical literature during the past 2700 years, are statistically significantly correlated with changes in temperature, and the relationship is a good example of the potential societal implications of temperature change on a regional scale.

scholarly journals The Influence On Atmospheric Composition of Volcanic Eruptions as Derived From Ice-Core Analysis

1985 ◽  
Vol 7 ◽  
pp. 125-129 ◽  
Author(s):  
C.U. Hammer
Keyword(s):  
Ice Core ◽  
Ice Sheets ◽  
Ice Cores ◽  
Volcanic Eruptions ◽  
Atmospheric Composition ◽  
Core Analysis ◽  
Polar Ice ◽  
Ice Caps ◽  
The Past ◽  
Polar Ice Sheets

Polar ice cores offer datable past snow deposits in the form of annual ice layers, which reflect the past atmospheric composition. Trace substances in the cores are related to the past mid-tropospheric impurity load, this being due to the vast extent of the polar ice sheets (or ice caps), their surface elevations and remoteness from most aerosol sources. Volcanic eruptions add to the rather low background impurity load via their eruptive products. This paper concentrates on the widespread influence on atmospheric impurity loads caused by the acid gas products from volcanic eruptions. In particular the following subjects are discussed: acid volcanic signals in ice cores, latitude of eruptions as derived by ice-core analysis, inter-hemispheric dating of the two polar ice sheets by equatorial eruptions, volcanic deposits in ice cores during the last glacial period and climatic implications.

scholarly journals Reconstruction of a continuous high-resolution CO<sub>2</sub> record over the past 20 million years

2011 ◽  
Vol 7 (4) ◽  
pp. 1459-1469 ◽  
Author(s):  
R. S. W. van de Wal ◽  
B. de Boer ◽  
L. J. Lourens ◽  
P. Köhler ◽  
R. Bintanja
Keyword(s):  
High Resolution ◽  
Sea Level ◽  
Northern Hemisphere ◽  
Climate Models ◽  
Ice Core ◽  
Co2 Concentration ◽  
Temperature Record ◽  
Absorption Bands ◽  
The Past

Abstract. The gradual cooling of the climate during the Cenozoic has generally been attributed to a decrease in CO2 concentration in the atmosphere. The lack of transient climate models and, in particular, the lack of high-resolution proxy records of CO2, beyond the ice-core record prohibit, however, a full understanding of, for example, the inception of the Northern Hemisphere glaciation and mid-Pleistocene transition. Here we elaborate on an inverse modelling technique to reconstruct a continuous CO2 series over the past 20 million year (Myr), by decomposing the global deep-sea benthic δ18O record into a mutually consistent temperature and sea level record, using a set of 1-D models of the major Northern and Southern Hemisphere ice sheets. We subsequently compared the modelled temperature record with ice core and proxy-derived CO2 data to create a continuous CO2 reconstruction over the past 20 Myr. Results show a gradual decline from 450 ppmv around 15 Myr ago to 225 ppmv for mean conditions of the glacial-interglacial cycles of the last 1 Myr, coinciding with a gradual cooling of the global surface temperature of 10 K. Between 13 to 3 Myr ago there is no long-term sea level variation caused by ice-volume changes. We find no evidence of change in the long-term relation between temperature change and CO2, other than the effect following the saturation of the absorption bands for CO2. The reconstructed CO2 record shows that the Northern Hemisphere glaciation starts once the long-term average CO2 concentration drops below 265 ppmv after a period of strong decrease in CO2. Finally, only a small long-term decline of 23 ppmv is found during the mid-Pleistocene transition, constraining theories on this major transition in the climate system. The approach is not accurate enough to revise current ideas about climate sensitivity.

A millennium-long 'Blue Ring' chronology from Bristlecone Pine as a record of volcanic forcing on climate

2021 ◽  
Author(s):  
Liliana Siekacz ◽  
Matthew Salzer ◽  
Charlotte Pearson ◽  
Marcin Koprowski
Keyword(s):  
Cell Wall ◽  
Time Resolution ◽  
High Latitude ◽  
Radial Growth ◽  
Ice Core ◽  
Ice Cores ◽  
Volcanic Eruptions ◽  
Climate Impact ◽  
Bristlecone Pine ◽  
Ice Core Records

&lt;p&gt;'Blue Rings' (BRs) are distinct wood anatomical anomalies recently discovered in several tree species. Previous studies connect their occurrence to lower than normal temperatures during the cell wall lignification phase of xylogenesis. Cell wall lignification usually continues after radial growth is completed, after the growth season. Therefore, systematic analysis of blue rings can add another level of time resolution to dendroclimatic studies. Additionally, BRs are more sensitive temperature recorders than frost rings which require freezing temperatures to form. We&amp;#160; present a continuous chronology of blue rings in North American bristlecone pine covering the last millennium and their connections to volcanic eruptions known both from historic and ice core records. Most recorded BR years coincide with cooling following large volcanic eruptions. The three most prominent events during the last 1000 years, with the highest share of blue rings in bristlecone pine from the White Mountains of California are at: 1453, 1601 and 1884CE (83%, 91%, 69% of blue rings respectively), attributed to known eruptions of Kuawe (attribution still debated) 1452CE -Vanuatu, Huaynaputina 1600CE &amp;#8211; Peru, and Krakatoa 1883CE - Indonesia. Fourth most prominent event with 58% of blue rings is noted in 1200CE. Acidity peak in 1200CE is so far recorded only in Greenland ice-cores suggesting northern hemisphere high latitude eruption, but strong BR signal would suggest a broader climatic significance of this event. It is interesting to note that BRs were indicated in 69% of samples in 1884, relating to the known eruption and associated climate impact of Krakatoa (1883), yet no BRs were observed in 1816, the so-called year without a summer which followed the largest historically noted and well described eruption of Tambora, Indonesia (1815). We did find a strong BR signal in 1809 (with BRs continuing in 1810 and 1811) following an unidentified but prominent eruption seen in ice core records. The 1809 and 1815 eruptions are thought to be responsible for the cold decade from 1810 to 1819 thought by some to be the coldest decade of the last 500ys. The source of 1809 eruption remains unknown and scientific debate over the scale of the eruption continues, but bipolar acidity peaks in ice cores point to a tropical eruption with widespread sulfate distribution to both hemispheres and tephra in ice cores points to two coinciding high latitude eruptions of only regional prominence. The BR record supports 1809 CE as an event of global climatic significance illustrating the capacity for BRs&amp;#160; to capture cooling events with even higher time resolution (after the radial growth is completed) and of smaller magnitude than frost rings, TRW or MXD studies to help better investigate and understand the impacts of volcanism on climate and society.&lt;/p&gt;

scholarly journals Inter-hemispheric temperature variability over the past millennium

2014 ◽  
Vol 4 (5) ◽  
pp. 362-367 ◽  
Author(s):  
Raphael Neukom ◽  
Joëlle Gergis ◽  
David J. Karoly ◽  
Heinz Wanner ◽  
Mark Curran ◽  
...  
Keyword(s):  
Temperature Variability ◽  
The Past ◽  
Hemispheric Temperature ◽  
Past Millennium
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