scholarly journals Tree-Ring-Based Summer Temperature Minimum Reconstruction for Taboshar, Sogd Province, Tajikistan, Since AD 1840: Linkages to the Oceans

2018 ◽  
Author(s):  
Zulfiyor Bakhtiyorov ◽  
Ruide Yu ◽  
Akylai Monoldorova ◽  
Zhijie Ta ◽  
Javhar Aminov
Keyword(s):  
Tree Ring ◽  
Minimum Temperature ◽  
Ring Width ◽  
Temperature Reconstruction ◽  
Forest Tree ◽  
Summer Temperature ◽  
Northwestern Part ◽  
Ocean Climate ◽  
High Asia ◽  
Ecological Importance

Despite the ecological importance of forest tree species, our study was motivated by scarce data on dendrochronology studies limited to the northwestern part of Tajikistan due to lack of access to such a part of the country which is difficult to access. Current studies on Junipers in the northwestern part of Tajikistan identified that tree ring-based climate reconstruction is possible. Cores of Juniperus Turkestanica from Taboshar area, Sogd province were developed into 176-year tree-ring width chronology. In the current study a summer (June-September) minimum temperature reconstruction spanning AD 1840–2016 was developed, which can explain 30.0% of the instrumental variableness for the period of 1940–2015. Five warmest (1856–1866, 1869–1871, 1907–1916, 1923–1935, 1988–2016) and four coldest time periods (1840–1855, 1872–1906, 1917–1922, 1940–1984) were identified. The developed reconstruction coincides with cold and warm periods with prior investigations from tree-rings in China, Mongolia, Kyrgyzstan, Kazakhstan and Tajikistan. Spatial correlation analysis with the gridded minimum temperature data shows that the temperature reconstruction covers geographical representation over High Asia. Significant correlation was found between temperature reconstruction with summer SST, which suggests strong linkages of regional temperature variability with Indian-Ocean climate system. The obtained spectral peaks from the spectral analysis of the summer temperature reconstruction were significantly at 84.7-year (90%), 2.9-year (99%), 2.6-year (99%), 2.5-year (99%), 2.4-year (99%) and 2.2-year (99%).

Four Centuries of Summer Temperature Changes in Tierra Del Fuego: Atmospheric Drivers and Tree-Ring Reconstruction From the Southernmost Forests of the World

2021 ◽  
Author(s):  
Vladimir Matskovsky ◽  
Fidel A. Roig ◽  
Mauricio Fuentes ◽  
Irina Korneva ◽  
Diego Araneo ◽  
...  
Keyword(s):  
Tree Ring ◽  
Ring Width ◽  
Temperature Reconstruction ◽  
Summer Temperature ◽  
Temperature Variability ◽  
Tierra Del Fuego ◽  
Climate Modelling ◽  
Least Squares Regression ◽  
Nothofagus Pumilio ◽  
The World

Abstract Proxy climate records, such as those derived from tree rings, are necessary to extend relatively short instrumental meteorological observations into the past. Tierra del Fuego is the most austral territory with forests in the world, situated close to the Antarctic Peninsula, which makes this region especially interesting for paleoclimatic research. However, high-quality, high-resolution summer temperature reconstruction are lacking in the region. In this study we used 63 tree-ring width chronologies of Nothofagus pumilio and Nothofagus betuloides and partial least squares regression (PLSR) to produce annually resolved December-to-February temperature reconstruction since AD 1600 which explains up to 65% of instrumental temperature variability. We also found that observed summer temperature variability in Tierra del Fuego is primarily driven by the fluctuations of atmospheric pressure systems both in the South Atlantic and South Pacific, while it is insignificantly correlated to major hemispheric modes: ENSO and SAM. This fact makes our reconstruction important for climate modelling experiments, as it represents specific regional variability. Our reconstruction can be used for direct comparison with model outputs to better understand model limitations or to tune a model or contribute to larger scale reconstructions based on paleoclimatic data assimilation. Moreover, we showed that PLSR has improved performance over principal component regression (PCR) in the case of multiple tree-ring predictors. According to these results, PLSR may be a preferable method over PCR for the use in automated tree-ring based reconstruction approaches, akin widely used point-by-point regression.

scholarly journals Tree-ring based temperature reconstruction for the west Qinling Mountains (China): linkages to the High Asia, solar activity and Pacific-Atlantic Ocean

2014 ◽  
Vol 41 (3) ◽  
pp. 234-244 ◽  
Author(s):  
Feng Chen ◽  
Yujiang Yuan ◽  
Wenshou Wei ◽  
Shulong Yu ◽  
Huaming Shang ◽  
...  
Keyword(s):  
Spatial Correlation ◽  
Tree Ring ◽  
Climatic Variability ◽  
Ring Width ◽  
Volcanic Eruptions ◽  
Temperature Reconstruction ◽  
Qinling Mountains ◽  
Western Qinling ◽  
Abies Faxoniana ◽  
High Asia

Abstract We developed a Faxon fir (Abies faxoniana) tree-ring width chronology at the timberline in the western Qinling Mountains, China. Herein February–July mean temperature was reconstructed for Zhouqu in the western Qinling Mountains back to AD 1650 based on the standard chronology. The climate/tree-growth model accounts for 43.5% of the instrumental temperature variance during the period 1972–2006. Spatial correlation analyses with the gridded temperature data shows that the temperature reconstruction captures regional climatic variations over central and southeast China, and strong teleconnections with the nearby High Asia. There is a good agreement with cold and warm periods previously estimated from tree-rings in Nepal, India and southwest China. The temperature re-construction indicates that there was pronounced cooling in Zhouqu during the Maunder Minimum (late 1600s to early 1700s). The cold period (1813–1827) of the temperature reconstruction coincide with the volcanic eruptions. Significant spectral peaks are found at 56.9, 22.3, 11.4, 2.9, 2.8, 2.6, 2.2 and 2.0 years. The spatial correlation patterns between our temperature reconstruction and SSTs of the Atlantic and Pacific Oceans suggest a connection between regional temperature variations and the atmospheric circulations. It is thus revealed that the chronology has enough potential to reconstruct the climatic variability further into the past.

scholarly journals Tree-ring reconstruction of seasonal mean minimum temperature at Mt. Yaoshan, China, since 1873 and its relevance to 20th-century warming

2014 ◽  
Vol 10 (2) ◽  
pp. 859-894 ◽  
Author(s):  
Y. Liu ◽  
Y. Zhang ◽  
H. Song ◽  
Y. Ma ◽  
Q. Cai ◽  
...  
Keyword(s):  
Spatial Correlation ◽  
20Th Century ◽  
Tree Ring ◽  
Minimum Temperature ◽  
Current Knowledge ◽  
Southern Oscillation ◽  
Ring Width ◽  
Temperature Reconstruction ◽  
Grid Data ◽  
Central Plains

Abstract. It is very important to comprehend the climate variations in the vast regions of Central Plains of China. Current knowledge about climate changes of the past few hundred years in this region is primarily based on historical documents, and lack of evidences from the natural archives. However, these documents had somewhat artificially effects caused by the recorders, and not sufficient to fully understand natural climatic changes. In this paper, based on a significant correlation between the tree-ring width of Chinese Pine and observed instrumental data in the Mt. Yaoshan, China, we formulated a transfer function to reconstruct the mean minimum temperature (MMinT) from the previous December to the current June (Tmin_DJ) for the period 1873–2011. The reconstruction explained 39.8% of the instrumental variance during the calibration period of 1958–2011. High Tmin_DJ intervals with values greater than the 139 year average occurred in 1932–1965 and 1976–2006. The intervals 1878–1894 and 1906–1931 experienced a Tmin_DJ lower than the 139 year average. The ten highest Tmin_DJ years occurred after the 1950s, especially after 1996. A distinct upward trend in the Tmin_DJ series beginning in the 1910s was apparent, and the highest value occurred around 2000. The 20th-century warming signal was captured well by the Yaoshan Tmin_DJ temperature reconstruction, indicating that the temperature rise in the sensitive Central Plains of China region reflected the global temperature change. The Tmin_DJ reconstruction also matched several other temperature series in China with similar warm-cold patterns. The distinct spatial correlation between both observed and reconstructed series and CRU TS3.10 grid data indicates that our results may represent Tmin_DJ changes on a larger scale. The spatial correlation with sea surface temperature (SST) indicated that observed and reconstructed Tmin_DJ temperatures in the Mt. Yaoshan are closely linked to the West Pacific, Indian and North Atlantic Oceans as well as El Niño-Southern Oscillation (ENSO).

scholarly journals Multiproxy records of climate variability for Kamchatka for the past 400 years

2007 ◽  
Vol 3 (1) ◽  
pp. 119-128 ◽  
Author(s):  
O. Solomina ◽  
G. Wiles ◽  
T. Shiraiwa ◽  
R. D'Arrigo
Keyword(s):  
Climate Variability ◽  
Tree Ring ◽  
Ice Core ◽  
Ring Width ◽  
Summer Temperature ◽  
Positive Anomaly ◽  
Temperature Decrease ◽  
Positive Mass ◽  
The Past ◽  
Tree Ring Data

Abstract. Tree ring, ice core and glacial geologic histories for the past several centuries offer an opportunity to characterize climate variability and to identify the key climate parameters forcing glacier expansion in Kamchatka over the past 400 years. A newly developed larch ring-width chronology (AD 1632–2004) is presented that is sensitive to past summer temperature variability. Individual low growth years in the larch record are associated with several known and proposed volcanic events from the Northern Hemisphere. The comparison of ring width minima and those of Melt Feature Index of Ushkovsky ice core helps confirm a 1–3 year dating accuracy~for this ice core series over the late 18th to 20th centuries. Decadal variations of low summer temperatures (tree-ring record) and high annual precipitation (ice core record) are broadly consistent with intervals of positive mass balances measured and estimated at several glaciers in 20th century, and with moraine building. According to the tree-ring data the 1860s–1880s were the longest coldest interval in the last 350 years. The latest part of this period (1880s) coincided with the positive anomaly in accumulation. This coincidence led to a positive mass balance, which is most likely responsible for glacier advances and moraine deposition of the end of 19th-early 20th centuries. As well as in some other high latitude regions (Spitsbergen, Polar Urals, Franz Jozef Land etc.) in Kamchatka these advances marked the last millennium glacial maximum. In full agreement with subsequent summer warming trend, inferred both from instrumental and tree ring data, glacier advances since 1880s have been less extensive. The late 18th century glacier expansion coincides with the inferred summer temperature decrease recorded by the ring width chronology. However, both the advance and the summer temperature decrease were less prominent that in the end of 19th century. Comparisons of the glacier history in Kamchatka with records from Alaska and the Canadian Rockies suggests broadly consistent intervals of glacier expansion and inferred summer cooling during solar irradiance minima.

Weakening climatic signal since mid-20th century in European larch tree-ring chronologies at different altitudes from the Adamello-Presanella Massif (Italian Alps)

2012 ◽  
Vol 77 (3) ◽  
pp. 344-354 ◽  
Author(s):  
Anna Coppola ◽  
Giovanni Leonelli ◽  
Maria Cristina Salvatore ◽  
Manuela Pelfini ◽  
Carlo Baroni
Keyword(s):  
Tree Ring ◽  
Function Analysis ◽  
Ring Width ◽  
Negative Influence ◽  
Summer Temperature ◽  
Central Alps ◽  
European Larch ◽  
Climatic Signal ◽  
Temperature Signal ◽  
Over Time

Tree rings from temperature-limited environments are highly sensitive climate proxies, widely used to reconstruct past climate parameters for periods prior to the availability of instrumental data and to analyse the effect of recent global warming on tree growth. An analysis of the climatic signal in five high-elevation tree-ring width chronologies of European larch (Larix decidua Mill.) from the tops of five different glacial valleys in the Italian Central Alps revealed that they contain a strong summer-temperature signal and that tree-ring growth is especially influenced by June temperatures. However, a moving correlation function analysis revealed a recent loss of the June temperature signal in the tree-ring chronologies. This signal reduction primarily involves the two lowest-altitude chronologies. It is probable that the observed increasing importance of late-summer temperature for tree-ring growth over the past 50 yr is an effect of the lengthening growing season and of the variations in the climate/tree-ring relationship over time. All the chronologies considered, especially those at the highest altitudes, show an increasing negative influence of June precipitation on tree-ring growth. The climatic signal recorded in tree-ring chronologies from the Italian Central Alps varies over time and is also differentially influenced by climatic parameters according to site elevation.

scholarly journals Tree-ring reconstruction of June-July mean temperatures in the northern Daxing’an Mountains, China

2020 ◽  
Vol 47 (1) ◽  
pp. 13-22
Author(s):  
Yangao Jiang ◽  
Yu Wang ◽  
Junhui Zhang ◽  
Shijie Han ◽  
Cassius E.O. Coombs ◽  
...  
Keyword(s):  
Tree Ring ◽  
Southern Oscillation ◽  
Regional Climate ◽  
Ring Width ◽  
Temperature Reconstruction ◽  
Global Scale ◽  
Spatial Correlations ◽  
Regional Study ◽  
Average Value ◽  
Daxing’An Mountains

AbstractIn this study, the mean temperature of June to July was reconstructed for the period of 1880 to 2014 by using the Larix gmelinii tree-ring width data for the Mangui region in the northern Daxing’an Mountains, China. The reconstruction accounts for 43.6% of the variance in the temperature observed from AD 1959–2014. During the last 134 years, there were 17 warm years and 17 cold years, which accounted for 12.7% of the total reconstruction years, respectively. Cold episodes occurred throughout 1887–1898 (average value is 14.2°C), while warm episodes occurred during 1994–2014 (15.9°C). Based on this regional study, the warmer events coincided with dry periods and the colder events were consistent with wet conditions. The spatial correlation analyses between the reconstructed series and gridded temperature data revealed that the regional climatic variations were well captured by this study and the reconstruction represented a regional temperature signal for the northern Daxing’an Mountains. In addition, Multi-taper method spectral analysis revealed the existence of significant periodicities in our reconstruction. Significant spectral peaks were found at 29.7, 10.9, 2.5, and 2.2 years. The significant spatial correlations between our temperature reconstruction and the El Niño–Southern Oscillation (ENSO), Pacific Decadal Oscillation (PDO) and Solar activity suggested that the temperature in the Daxing’an Mountains area indicated both local-regional climate signals and global-scale climate changes.

scholarly journals Evaluating the dendroclimatological potential of blue intensity on multiple conifer species from Australasia

2021 ◽  
Author(s):  
Rob Wilson ◽  
Kathy Allen ◽  
Patrick Baker ◽  
Sarah Blake ◽  
Gretel Boswijk ◽  
...  
Keyword(s):  
New Zealand ◽  
Tree Ring ◽  
High Frequency ◽  
Ring Width ◽  
Signal Strength ◽  
Summer Temperature ◽  
Weak Signal ◽  
Conifer Species ◽  
Blue Intensity ◽  
Blue Reflectance

Abstract. We evaluate a range of blue intensity (BI) tree-ring parameters in eight conifer species (12 sites) from Tasmania and New Zealand for their dendroclimatic potential, and as surrogate wood anatomical proxies. Using a dataset of ca. 10–15 trees per site, we measured earlywood maximum blue reflectance intensity (EWB), latewood minimum blue reflectance intensity (LWB) and the associated delta blue intensity (DB) parameter for dendrochronological analysis. No resin extraction was performed, impacting low frequency trends. Therefore, we focused only on the high frequency signal by detrending all tree-ring and climate data using a 20-year cubic smoothing spline. All BI parameters express low relative variance and weak signal strength compared to ring-width. Correlation analysis and principal component regression experiments identified a weak and variable climate response for most ring-width chronologies. However, for most sites, the EWB data, despite weak signal strength, expressed strong calibrations with summer temperatures. Significant correlations for LWB were also noted, but the sign of the relationship for most species is opposite to that reported for all conifer species in the Northern Hemisphere. DB performed well for the Tasmanian sites but explained minimal temperature variance in New Zealand. Using the full multi-species/parameter network, excellent summer temperature calibration was identified for both Tasmania and New Zealand ranging from 52 % to 78 % explained variance, with equally robust independent validation (Coefficient of Efficiency = 0.41 to 0.77). Comparison of the Tasmanian BI reconstruction with a wood anatomical reconstruction shows that these parameters record essentially the same strong high frequency summer temperature signal. Despite these excellent results, a substantial challenge exists with the capture of potential secular scale climate trends. Although DB, band-pass and other signal processing methods may help with this issue, substantially more experimentation is needed in conjunction with comparative analysis with ring density and quantitative WA measurements.

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