Restoration of Age and Gain Curves in the Tree-Ring Chronologies of Coniferous Plants in the North of the Western Siberia

Author(s):  
Vladimir R. Tsibulsky ◽  
Aleksandr A. Konovalov ◽  
Stanislav P. Arefyev
Keyword(s):  
Author(s):  
V. R. Tsibulsky ◽  
I. G. Solovyev ◽  
D. A. Govorkov

The subject of this research is conifer growth model based on time-series of annual rings width. The article addresses processing of data and model update in respect of forest dendrology. The purpose of study is to update the conifer growth model due to expansion of time-series of tree-rings width in regards to conifer forests in Western Siberia. The method represents expansion of time-series due to the fact that some growth phases had not been taken into account. When measurements were taken at the height of 1.3 meters, the following phases were not considered: seedling, juvenile, immature and beginning of virginile phase. The authors carried out examination of a number of scans and core samples, as well as time-series received by other scientists and which are contained in the International Tree-Ring Data Bank. Based on the results of field studies, the authors recommend to add some zeroes to the beginning of time-series within the range of 10-15 years for pine-trees in the south of Western Siberia, depending on growth conditions; the range of 15-30 years in the north for larch-trees and pine-trees depending on soil and climate conditions and latitude. The sequence of data pre-processing operations for time-series, received by means of core sampling, is as follows: averaging out of radius gain in 2 (3) mutually perpendicular directions for one specimen, graphing of radius gain curve, adding to the beginning of time-series, its normalization, approximation by specified growth function. It is possible to build area growth function for the scans. For averaging out a group of model trees, the sequence of operations is as follows: synchronization of time-series by cross-correlation method, approximation by specified growth function. Methods and results of studies can be applied in forest sectors and oil and gas industries for monitoring of forest health conditions. The proposed method of curve growth model update will allow to define more precisely time intervals for efficient forest exploitation as well as to reconstruct digital models of conifer populations in the north of Western Siberia.


Author(s):  
I. Zolnikov ◽  
◽  
A. Vybornov ◽  
A. Anoikin ◽  
A. Postnov ◽  
...  

In the course of studies conducted by IAET SB RAS in the Lower Ob in 2016–2019, the understanding of the conditions for settlement of the Paleolithic population in the north of Western Siberia was significantly supplemented. Dating of a series of paleontological finds was carried out at the "Accelerated mass spectrometer of the Budker Institute of Nucle- ar Physics of SB RAS". The dates obtained show the distribution of the main representatives of the Upper Pleistocene fauna of Subarctica: Mammuthus primigenius – 50,000–15,000 BP, Coelodonta antiquitatis – 43,000–38,000 BP and 27,000–25,000 BP, Rangifer tarandus, Equus ferus – 40,000–10,000 BP, Bison sp. – 50,000–40,000 BP, Ovibos moschatus – 41,000–32,000 BP.


2020 ◽  
pp. 54-62
Author(s):  
A. B. Tulubaev ◽  
E. V. Panikarovskii

In the article, we analyze types of drilling mud, which are used to drilling intervals of permafrost rocks; the importance of wellbore stability is noted. Wedescribethemain technologies, which have been being applied in the north of Western Siberia; these technologies are aimed at minimizing the loss wellbore stability due to violation of the temperature conditions in the well. We also analyze hydrocarbon systems, taking into account foreign experience, which is based on prospecting and exploratory drilling of ice deposits in Greenland and Antarctica. The article draws your attention to using synthetic fluids, monoesters and chladones. The difficulties of the existing technology and the disadvantages of the hydrocarbon systems are highlighted. We propose to apply a new cryogenic drilling technology, which consists in the use of synthetic fluorine-containing agents as flushing fluid at low temperatures. The text gives valuable information on composition of the proposed flushing fluid and the prospects of using the technology to prevent complications. Much attention is given to issue of manufacturing the main chemical reagent with the reduction of the generalized production chain of its production from the starting material, it is fluorspar.


2020 ◽  
Vol 162 (1) ◽  
pp. 127-143 ◽  
Author(s):  
Grant L. Harley ◽  
R. Stockton Maxwell ◽  
Bryan A. Black ◽  
Matthew F. Bekker
Keyword(s):  

2021 ◽  
Author(s):  
Helen Mackay ◽  
Gill Plunkett ◽  
Britta Jensen ◽  
Thomas Aubry ◽  
Christophe Corona ◽  
...  

Abstract. The 852/3 CE eruption of Mount Churchill, Alaska, was one of the largest first millennium volcanic events, with a magnitude of 6.7 (VEI 6) and a tephra volume of 39.4–61.9 km3 (95 % confidence). The spatial extent of the ash fallout from this event is considerable and the cryptotephra (White River Ash east; WRAe) extends as far as Finland and Poland. Proximal ecosystem and societal disturbances have been linked with this eruption; however, wider eruption impacts on climate and society are unknown. Greenland ice-core records show that the eruption occurred in winter 852/3 ± 1 CE and that the eruption is associated with a relatively moderate sulfate aerosol loading, but large abundances of volcanic ash and chlorine. Here we assess the potential broader impact of this eruption using palaeoenvironmental reconstructions, historical records and climate model simulations. We also use the fortuitous timing of the 852/3 CE Churchill eruption and its extensively widespread tephra deposition of the White River Ash (east) (WRAe) to examine the climatic expression of the warm Medieval Climate Anomaly period (MCA; ca. 950–1250 CE) from precisely linked peatlands in the North Atlantic region. The reconstructed climate forcing potential of 852/3 CE Churchill eruption is moderate compared with the eruption magnitude, but tree-ring-inferred temperatures report a significant atmospheric cooling of 0.8 °C in summer 853 CE. Modelled climate scenarios also show a cooling in 853 CE, although the average magnitude of cooling is smaller (0.3 °C). The simulated spatial patterns of cooling are generally similar to those generated using the tree-ring-inferred temperature reconstructions. Tree-ring inferred cooling begins prior to the date of the eruption suggesting that natural internal climate variability may have increased the climate system’s susceptibility to further cooling. The magnitude of the reconstructed cooling could also suggest that the climate forcing potential of this eruption may be underestimated, thereby highlighting the need for greater insight into, and consideration of, the role of halogens and volcanic ash when estimating eruption climate forcing potential. Precise comparisons of palaeoenvironmental records from peatlands across North America and Europe, facilitated by the presence of the WRAe isochron, reveal no consistent MCA signal. These findings contribute to the growing body of evidence that characterizes the MCA hydroclimate as time-transgressive and heterogeneous, rather than a well-defined climatic period. The presence of the WRAe isochron also demonstrates that no long-term (multidecadal) climatic or societal impacts from the 852/3 CE Churchill eruption were identified beyond areas proximal to the eruption. Historical evidence in Europe for subsistence crises demonstrate a degree of temporal correspondence on interannual timescales, but similar events were reported outside of the eruption period and were common in the 9th century. The 852/3 CE Churchill eruption exemplifies the difficulties of identifying and confirming volcanic impacts for a single eruption, even when it is precisely dated.


Sign in / Sign up

Export Citation Format

Share Document