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We analyzed the dynamics of Lake Teletskoye water level and attempted to use data on bottom sediment geochemistry in combination with Siberian larch (Larix sibirica) treering width chronology to reconstruct it for late Holocene. In particular, we studied the links among the water level characteristics, precipitation amount, bottom sediment geochemistry, and tree-ring width chronology available for Russian Altai. A correlation analysis revealed the annual water level fluctuations to correlate closely with mean annual temperature and annual precipitation (67% and 33%, respectively). The fluctuations exhibited a negative correlation with the regional tree-ring width chronology. As for the bottom sediments, two components were identified, one of which correlated closely with air temperature and the other with precipitation. Combining these three components, including tree-ring width chronology, provides new possibilities for a complex reconstruction of the lake water level fluctuations occurred during middle and late Holocene based on a regression model. A regression reconstruction model of the dynamics of the Lake Teletskoye water level was calculated for the last millennium. We defined ~60-, ~100-, ~200-year cycles of water level variability in Teletskoye Lake and supposed that the observed fluctuations are due to long-term climatic changes. Of the greatest interest are the identified interdecadal and decadal climate-caused water level fluctuations, since they will enable to estimate indirectly, in the long term, climatic changes in southern Siberia for the past 2-5 thousand years. [ABSTRACT FROM AUTHOR]

To better understand past climate variability of vast terrestrial regions, reconstructions of different climate parameters are needed. Different types of climate proxy data may provide season-, time resolution-, and longevity-specific information. In this paper, we present a reconstruction of summer temperature and ablation of Malii Aktru glacier variability, Altay Mountains, for the past four centuries inferred from lake Teletskoe sediments and the maximum density of the tree-rings of Siberian larch trees found at the upper timberline. The Teletskoe lake is situated close to both the Malii Aktru glacier and the tree-ring-maximum-density-chronology site (approxinately 50.29N, 87.39E). Lake Teletskoe sediments provided seasonal climatic information for the late Holocene, especially regarding summer and annual temperature variations. Ablation of the Malii Aktru glacier was also clearly sensitive to summer temperature (correlation was 0.8; p=0.05; n=32). The tree-ring maximum density chronology was well correlated with summer temperature (r=+0.65-0.72; n = 60). Ablation of Malii Aktru glacier was reconstructed using the linear regression from the tree-ring maximum density chronology (r=+0.68; n=32; p=0.05 for the calibration period) for the period since 1601 AD. The summer temperature reconstructed from the data on the lake sediments was compared with the reconstructed ablation of Malii Aktru glacier for 1601-1994. A common low-frequency variability (100-200-year long cycles) was identified in the summer temperature and ablation for the reconstructed series. For example, a decrease in ablation of Malii Aktru coincided well with a temperature decrease that was found around 1700 AD and middle of 1850AD. The cold periods during LIA (Little Ice Age) were clearly pronounced in Altai Mountains climate reconstructions obtained from different climate proxies. Our study showed that various sources (tree-rings, glaciers and lake sediments) may be based upon to extract common information on climate low frequency variables, which helps better understand regional climate changes. [ABSTRACT FROM AUTHOR]

Meromictic Shira Lake is situated in the semi-arid climatic area of South Siberia. The lake has a size of 5 x 9 km and a maximum depth of 24 m. A sediment column of 155 cm in length was retrieved in the deepest part of the lake. The sediment has thin laminated structure, where black clay carbonate organic-bearing layers are coupled with white organic free ones. Thickness of coupled rhythms varied from 2 mm in the uppermost 20 cm of core to 0.4 mm close to the bottom. For calculation of the layers were used pictures of wet core, optical thin sections and geochemical indicators, marking each annual layer. For dating the depth of the core were used AMS data 14C content, the activity of 137Cs and 210Pb. Comparison of age model, obtained by counting annual layers with radiocarbon data, showed that the «reservoir effect» in Lake Shira is equal 1275 years. Radiocarbon data reduction by this amount gives a good coincidence all results. [ABSTRACT FROM AUTHOR]

Meromictic Shira Lake is a good representative object for detail climate modeling due to its local hydroclimatic information and annually laminated bottom sediments. For geochemical research was used method of scanning microanalysis with synchrotron radiation. We used a one dimensional scanner and a system for collimating and focusing the beam that allowed us to perform measurements of more than 20 minor elements with detection limits of ~1-5 ppm in cores of bottom sediments with a spatial resolution of 100 µm. The applied experimental apparatus allowed us to reach a new quality of paleoclimatic reconstructions with annual time resolution. [ABSTRACT FROM AUTHOR]

The bottom sediments were studied as a source material for the mathematical treatment. 10 geochemical parameters: Ca, Ti, Mn, Fe, Br, Br / Rb, Br / Sr, Br / Y, Co / Inc, Sr / Rb were considered. The elements content were measured by X-ray fluorescence analysis on synchrotron radiation (SR XRF, BINP) along the entire length of the sediment core (1974 mm) with 1mm step. Matrix of the geochemical time series was built taking into account continuous sedimentation at an average accumulation rate of 1.06 mm/year in the time interval AD 530-2010 years. Reconstruction of target parameters (temperature, precipitation and "climate type", lake level) made by three methods - regression, discrimination and nearest neighbor realizing different approaches to the problem to be solved. [ABSTRACT FROM AUTHOR]

Amur Bay, Sea of Japan is one of the most studied areas in relation to seasonal anoxia in the estuarine-shelf basins, induced by the water inflow increase (Razdolnaya-Suifun River) during the summer monsoon. Eutrophication is associated with stratification of the water column due to warm fresh water entry, and also to synchronous increase of the phytoplankton productivity in July and August. To identify the causes of anoxia, sediment layers accumulated over the past 200 years near the mouth of the Razdolnaya River in the Amur Bay were tested. A new approach to the study of sediment records has appeared due to an automatic technique for scanning microanalysis along cores in situ. X-ray fluorescence analysis on synchrotron radiation (XRF SR) in the Institute of Nuclear Physics (Novosibirsk, Russia) was used to determine more than 35 elements in freshly opened cores and in solid preparates with steps of 0.1-1 mm. Tracing of sediment composition along the river-sea profile showed a reduction of carbonate-organophilic elements (Ca, Br, and Sr) closer to the river mouth. Respectively, high values of Fe, Rb, Y, Th and Rb/Sr ratio represent the flooding accumulation of clay material and hydroxides in that shallow freshened zone. High Br content, Mo/Mn and Rb/Sr and low Mn and Ca are observed within the axial part of the bay with seasonally anoxic bottom waters. The results suggest the increase of seasonal anoxia in bottom waters north of the Amur Bay and the Razdolnaya estuary in dry summer periods. Yearly drops of Br content mark extremal floods during typhoon events 1-3 times per decade. Zn, Ni, Cu, as well as Hg, most probably indicate the degree of technogenic contamination in sediments, together with an increase in eutrophication and organic matter content for the last 50 years. High-resolution studies of the element composition show alternating periods of marine or more dilute waters. The subdivision into layers was based on statistical models (cluster analysis, discriminant analysis), whilst the chronological framework was established using the 210 Pb and 137 Cs technique. [ABSTRACT FROM AUTHOR]

A solar-terrestrial relations were examined using millennium-scale paleoclimatic data from the Central Asia mountain region. The paleoclimatic data were based on non-varved lake sediments of the Teletskoye lake and temperature-sensitive long tree-ring width chronologies from the Altai region (Altai Mountains, South Siberia, Russia) in the late Holocene (2000 years). Also a solar-activity during late Holocene was used to analyze. Core of the bottom sediments from the Teletskoe lake (Altai Mountains) were investigated using scanning X-ray fluorescent analysis method with synchrotron radiation (spatial resolution is 0.1 mm). A method ensemble empirical mode decomposition (EEMD) was used to extract low-frequency variability from all presented paleoarchives. The results obtained for paleodata indicate palaeoclimatic oscillations in the range of the de Vries (Suess) (~200-year) solar cycles through the late Holocene. Evidence of the influence of solar activity on global climatic processes and terrestrial ecosystems is discussed. [ABSTRACT FROM AUTHOR]

The method analytical microstratigraphy of lacustrine sediments allows to obtain paleoclimatic information fundamentally new quality was tested on a model object - Lake Teletskoe (Gorny Altai). Teletskoe lake bottom sediments were studied by scanning X-ray microprobe using synchrotron radiation from VEPP-3 (INP SB RAS, Novosibirsk) with an annual time resolution on the time interval of 1500 years. Data on the distribution of isotopes Cs-137, Pb-210, C-14 were used to create an age model: core depth - age. Using this model were constructed time series of sediment cores composition changes. To obtain the time series used a scanning X-ray analysis on synchrotron radiation with 100 micron spatial resolution. At each point of the core at the same time determines the content of more than 20 trace elements: K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Ga, As, Se, Br, Rb, Sr, Y, Zr, Nb, Mo, Ba, Pb, Th, U. Terrigenous elements (Ti, V, Cr, Rb, Y, Th) reflect changes in precipitation in the catchment. Organogenic elements (Br, Zn, U) are more associated with regional temperature changes. The ratio of Rb/Sr shows the size of the particles and associated with spring flooding dynamics. The resulting time series were processed by mathematical methods, including the Hilbert-Huang transformation. Was found a set of cyclical changes in litho-geochemical indicators in the Lake Teletskoe sediments with periods of 3.5±0.3; 8.8±0.9; 18.9±2.0; 37.8±1.6; 86±10; 164±15; 346±30; 596±71 and 993 years. Found cycles can be used to predict climate change in nearest decades [ABSTRACT FROM AUTHOR]

Geochemical study of bottom sediments from several Siberian and Mongolian lakes (Teletskoye, Kucherla, Baikal, Arachlei, Telmen, and Shira) allows reconstructing of environmental parameters such as air temperature, precipitation, lake level, runoff, tree ring growth index, pressure, wind direction and others on annual scale. The new approach to study sediment records appeared due to automatic technique for scanning microanalysis of cores in situ. X-ray fluorescence analysis on synchrotron radiation (XRF SR) in the Institute of Nuclear Physics, Novosibirsk was adapted. More than 35 elements with step of measurement > 0.05 mm along fresh opened cores and in solid preparates were determined. Variations of several microelements content appeared to be well correlated with environmental parameters, which were used as a geochemical proxies for statistical treatment and modeling. Elements composing organic component of sediments (Br, I, U) are correlative with mean annual temperature variations because of changes vegetation productivity content in catchment and in waterbody. And elements from clastic mineral part (Rb, Sr, Ti, Y, Zr) reflect annual precipitation, runoff and the proportion of the unweathered terrestrial fraction. X-ray density (XRD) indicates water yield regime and sediment flux. Clastic varves are well-known all over the world, they are formed in glacial and non-glacial lakes, for example, Kucherla, Teletskoe lakes in Altai a.o. Analysis shows graded structure from lower mid-grained material (silt) to upper fine-grained part as usual. The last one contains more weathered (clay) material with a touch of organics. Correspondingly Rb and Br content increase, but XRD, Ti, Sr, Zr and other clastic components decrease upward. Carbonate varves are presented in saline lakes Telmen, Shira and other. Carbonate matter, as Ca, Mg and Sr content, evidences seasonal and long-term salinity fluctuation connected with lake level and aridity. Equilibrium thermodynamic modeling allows to quantify the atmosphere - water - sediment - pore solution system for saline lakes. Computer physicochemical simulation adapted for natural rock-water-gas multisystem of Shira lake is executed by "Selector" software, which used method of thermodynamic potentials minimization under local equilibrium state. For example, estimated salinity effect on Sr concentration proves positive correlation between strontianite content and evaporation/ice cover periods. Time series of lithological-geochemical indicators of climate change, based on counting of annual layers and isotope dating, are calibrated by hydrometeorological data to obtain the functions of variability for relevant parameters beyond instrumental and tree ring limits in the past [ABSTRACT FROM AUTHOR]

The bottom sediments of the meromictic lake Shira have annually laminated layers with thickness of 0.5 - 2.0 mm. A sediment column of 155 cm in length was retrieved by hammer corer in the deepest (24 m) central part of the lake. Solid samples were prepared from the wet cores by freeze drying and impregnating with epoxy resin. The inter annual and inter seasonal variations in the trace element composition of annual layers are studied by means of X-ray scanning microanalysis with synchrotron radiation on the VEPP-3 (Novosibirsk) and BESSY-II (Berlin) storage rings. Profiles of minor element distribution were obtained for K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Ga, As, Br, Rb, Sr, Y, Zr and Nb along the upper 180 mm of bottom sediments with a spatial resolution from 100 to 20 μm, using excitation energies of 12 and 20 keV. Were found geochemical indicators marking the beginning (Ca/Sr ratio) and end (Br/Rb ratio) of the annual cycle of sedimentation. Detailed experimental investigations of the internal structure of annual layers allowed us to create a lithological-geochemical model of sedimentation in Lake Shira, and to find climatically correlated minor elements. This model of the annual cycle of sedimentation was used to explain the periodic white layers with high Sr contents in the core. Thick 3-5 cm light carbonate Sr-enriched intervals correspond to an extremely low level of the lake and are repeated every 450-550 years [ABSTRACT FROM AUTHOR]

Now investigation of environmental dynamics is focusing to study high resolution - annual and seasonal time series. But annual quantitative reconstructions by lake deposits are scarce because discrete sampling and analysis. The new approach to study sediment records appeared due to scanning microanalysis of cores in situ. X-ray fluorescence analysis on synchrotron radiation in the Institute of Nuclear Physics, Novosibirsk, appeared to be the most effective. Sub-millimeter layered structures of bottom sediments from Siberian lakes as well as tree ring series in surrounded areas are studied. Elements composing organic component of sediments (Br, I, U) are usually responding to temperature. And elements from clastic mineral part (Rb, Sr, Ti, Y, Zr) more reflect annual precipitation and runoff. On this base air temperature, precipitation and lake level are restored on annual scale for the last two millennia. Climate variability reconstructed by geochemistry of lake sediments and dendrochronology reveals similar trends. Availability of several basic series of geochemical indices extends the scope for quantitative reconstructions of sought quantity. That becomes in the line of extrapolation, interpolation (detailed elaboration) and combination. Geochemical time series allowed estimating regression equations for tree ring width and extrapolating these short chronologies. Specifically, aridization trend is revealed in Transbaikalia for the last 2000 yrs (Arachlei Lake) by growth index, which is not conflict with palinological data. Also rare sampled palinological series, transferred to biomes, are worked out in detail to annual chronologies by training transfer function on element content in the same samples (Teletskoe Lake). Combined reconstruction of summer temperature is made for Altai mountain region using both geochemical parameters of lake sediments and independent biological series in multiple regression estimations. [ABSTRACT FROM AUTHOR]