Top PDF Pliocene to Pleistocene climate and environmental history of Lake El'gygytgyn, Far East Russian Arctic, based on high-resolution inorganic geochemistry data

Pliocene to Pleistocene climate and environmental history of Lake El'gygytgyn, Far East Russian Arctic, based on high-resolution inorganic geochemistry data

Pliocene to Pleistocene climate and environmental history of Lake El'gygytgyn, Far East Russian Arctic, based on high-resolution inorganic geochemistry data

Compared to titanium, potassium shows a smaller variability over the Lake El’gygytgyn sediment record (Fig. 3). Intensities range between 15 000 and 21 000 ct, except for some distinct lows during peak interglacials due to opal diution (e.g., MIS 11.3; ca. 3400 ct). The long-term trend yield rather constant K values back to ca. 2.0 Ma, whereas in the older sediments, two periods with significantly reduced K counts

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Pliocene to Pleistocene climate and environmental history of Lake El'gygytgyn, Far East Russian Arctic, based on high-resolution inorganic geochemistry data

Pliocene to Pleistocene climate and environmental history of Lake El'gygytgyn, Far East Russian Arctic, based on high-resolution inorganic geochemistry data

Although being a minor element in Lake El’gygytgyn sedi- ments, titanium has proven to be a useful indicator of the cli- matic history of the lake and its catchment of the past ca. 250 and 340 kyr (Minyuk et al., 2007, 2014). Throughout the en- tire lake sediment record, Ti exhibits highly variable signal amplitudes with typically lower values between ca. 5000 and 9000 ct during normal interglacials, peak minima down to ca. 3000 ct during peak interglacials, and maxima between 12 000 and 18 000 ct during cold stages (Figs. 3, 4). As a relatively immobile element, titanium occurs as an abundant component in a variety of mineral phases (e.g., rutile, sphen, titano-magnetite), and thus is commonly linked to detrital in- put (e.g., Haug et al., 2001; Yancheva et al., 2007). Therefore, it has been used in lacustrine sediments to reconstruct the in- tensities of catchment erosion and detrital input (Panizzo et al., 2008; Whitlock et al., 2008). In Lake El’gygytgyn sedi- ments, correlation analyses of Ti intensities to grain-size re- sults by Francke et al. (2013) yield a moderate to high cor- respondence to the fine silt fraction (R = 0.68; n = 858), but a weaker or even anticorrelation to other grain-size classes (Table 1). A similar enrichment of Ti in the fine fraction has been reported for the last 440 kyr of the record and ex- plained by enhanced deposition of Ti-bearing chlorite during glacial conditions (Minyuk et al., 2014). In interglacial sed- iments, in contrast, the clay mineralogy is rather dominated by smectite and illite (Asikainen et al., 2007). The Ti occur- rence in these sediments has been primarily attributed to the presence of titanomagnetite (Murdock et al., 2013), whose generally low abundance likely explains the Ti depletion dur- ing warm stages. In addition, simultaneous minima in Ti, K, and Ca, as well as in most other elements, during peak inter- glacials strongly suggest a significant dilution effect by bio- genic opal especially in peak interglacial sediments (Melles et al., 2012). Although also notable, this dilution effect on the Ti signal is less severe in conventional XRF data (Minyuk et al., 2014), thus suggesting that it is amplified by matrix ef- fects in untreated sediment due to higher water contents of the opal-rich sediment, leading to further scattering of the primary X radiation.
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A 350 ka record of climate change from Lake El'gygytgyn, Far East Russian Arctic: refining the pattern of climate modes by means of cluster analysis

A 350 ka record of climate change from Lake El'gygytgyn, Far East Russian Arctic: refining the pattern of climate modes by means of cluster analysis

Abstract. Rock magnetic, biochemical and inorganic records of the sediment cores PG1351 and Lz1024 from Lake El’gygytgyn, Chukotka peninsula, Far East Russian Arctic, were subject to a hierarchical agglomerative cluster analysis in order to refine and extend the pattern of climate modes as defined by Melles et al. (2007). Cluster analysis of the data obtained from both cores yielded similar results, dif- ferentiating clearly between the four climate modes warm, peak warm, cold and dry, and cold and moist. In addition, two transitional phases were identified, representing the early stages of a cold phase and slightly colder conditions during a warm phase. The statistical approach can thus be used to resolve gradual changes in the sedimentary units as an indi- cator of available oxygen in the hypolimnion in greater de- tail. Based upon cluster analyses on core Lz1024, the pub- lished succession of climate modes in core PG1351, cov- ering the last 250 ka, was modified and extended back to 350 ka. Comparison to the marine oxygen isotope (δ 18 O)
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Dynamic diatom response to changing climate 0–1.2 Ma at Lake El'gygytgyn, Far East Russian Arctic

Dynamic diatom response to changing climate 0–1.2 Ma at Lake El'gygytgyn, Far East Russian Arctic

The low-plankton events are not evenly distributed through the lake record. None has yet been observed from 225 to 550 ka in the low-resolution sampling completed, and none is anticipated based on the apparent stability of the dominant Cyclotella. The interval 680–920 ka also lacks low- plankton zones with a consistent dominance of Pliocaeni- cus. These intervals both correspond to a time of lower- amplitude summer insolation variability (e.g., Laskar et al., 2004), suggesting that these events may be triggered by con- ditions unique to summer insolation lows. This observation is similar to the interval of sustained high diatom concen- tration in the Lake Baikal record 370–580 ka (Prokopenko et al., 2002). The lake system and the regional climate are sensi- tive to intervals of extreme insolation lows, perhaps inducing extended periods of light limitation in planktonic habitats. Careful observations of diatom assemblages provide clues to the nature of exceptional cold events only subtlety expressed in other proxies.
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An operational approach to high resolution agro-ecological zoning in West-Africa

An operational approach to high resolution agro-ecological zoning in West-Africa

We also generated a set of precipitation and temperature data to represent the conditions typically observed in a dry year. These conditions were inferred based on historical drought observations from two reliable weather stations in the study region (Pirada and Bafata´, see location in Fig 1) and on the issue of a delayed wet season onset reported by the population during the field survey [28,29]. Rather than computing a statistical representation of historical droughts (e.g. average), monthly anomalies were manually adjusted to produce a simple but realistic dry year (Fig 4). In this case, annual rainfall was decreased by 42.5%, with higher per- centages at the onset of the wet season (May, June and July), and temperature were increased by 2˚C for all months. These dry year data can be adjusted, for example according to drought intensity expected from seasonal forecasts such as those provided by AGRHYMET.
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Braz. J. Geol.  vol.46 suppl.1

Braz. J. Geol. vol.46 suppl.1

Sedimentary rocks of the Camaquã Basin have ages between 600 Ma and 540 Ma (Paim et al. 2000, Chemale Jr. 2000, Oliveira et al. 2014). he basin is formed by diferent sedimentary and volcano-sedimentary units, with associated plutonic rocks, and separated from each other by angular or erosional unconformities of regional character. he basin was illed and deformed during the late stages of the Brasiliano orogeny. he deposition is believed to have evolved from marine environments (Maricá Group), through transitional between marine and lacustrine conditions (Bom Jardim and Santa Barbara Groups) to luvial and lacustrine environ- ments (Guaritas Group) (Figs. 4, 5, 7, 8 and 9). he irst two cycles are controlled by NE-SW shear zones associated with transcurrent compressive tectonics under ruptile-duc- tile conditions. he last three depositional episodes started with the eruption of volcanic rocks with tholeiitic, high-K calc-alkaline to shoshonitic characteristics (Hilário Formation, Bom Jardim Group), changing later to bimodal tholeiitic to sodic alkaline nature (Acampamento Velho Formation, Santa Barbara Group) and inishing with alkaline basaltic volcanics (Rodeio Velho Formation, Guaritas Group) (Wildner et al. 2002, Sommer et al. 2005, Janikian et al. 2012).
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PALINOLOGIA DA FORMAÇÃO SOLIMÕES, NEÓGENO DA BACIA DO SOLIMÕES, ESTADO DO AMAZONAS, BRASIL: IMPLICAÇÕES PALEOAMBIENTAIS E BIOESTRATIGRÁFICAS

PALINOLOGIA DA FORMAÇÃO SOLIMÕES, NEÓGENO DA BACIA DO SOLIMÕES, ESTADO DO AMAZONAS, BRASIL: IMPLICAÇÕES PALEOAMBIENTAIS E BIOESTRATIGRÁFICAS

samples were processed at the Instituto de Geociencias, University of Brasília (UnB) as well as in the Institute for Biodiversity and Ecosystem Dynamics (IBED), at the University of Amsterdam. The palynomorphs were identified, counted to a minimum of 100 grains (pollen and spores) and separated into three size fractions: < 20 m; 20 m / < 30 m; 30 m. The results were plotted in graphics and subjected to statistical analysis. Although there are evident differences, in terms of diversity both analyzed methods seem to be efficient, or better to say, equally inefficient. The biodiversity of Amazonia is so impressive that even when the pollen sum reached more than 500 grains, less than half of the identified taxa were common to both techniques. It indicates that either method gives a complete spectra of the paleovegetation, but provides enough information that enables the palynologist to draw paleonvironmental conclusions. The palynological associations of the four samples are in general similar, corresponding to the fluvial system paleoenvironmental model. Therefore it is possible to compare palynological spectra obtained through the two different methods despite the dissimilarities. The present study is restricted to a specific case with just a few samples and does not intend to generalize the conclusions, but shows the necessity of more detailed analysis with larger sampling.
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Lake surface water temperatures of European Alpine lakes (1989–2013) based on the Advanced Very High Resolution Radiometer (AVHRR) 1 km data set

Lake surface water temperatures of European Alpine lakes (1989–2013) based on the Advanced Very High Resolution Radiometer (AVHRR) 1 km data set

Abstract. Lake water temperature (LWT) is an important driver of lake ecosystems and it has been identified as an indicator of climate change. Consequently, the Global Climate Observing System (GCOS) lists LWT as an essential climate variable. Although for some European lakes long in situ time series of LWT do exist, many lakes are not observed or only on a non-regular basis making these observations insufficient for climate monitoring. Satellite data can provide the information needed. However, only few satellite sensors offer the possibility to analyse time series which cover 25 years or more. The Advanced Very High Resolution Radiometer (AVHRR) is among these and has been flown as a heritage instrument for almost 35 years. It will be carried on for at least ten more years, offering a unique opportunity for satellite-based climate studies. Herein we present a satellite- based lake surface water temperature (LSWT) data set for European water bodies in or near the Alps based on the extensive AVHRR 1 km data record (1989–2013) of the Remote Sensing Research Group at the University of Bern. It has been compiled out of AVHRR/2 (NOAA-07, -09, -11, -14) and AVHRR/3 (NOAA-16, -17, -18, -19 and MetOp-A) data. The high accuracy needed for climate related studies requires careful pre-processing and consideration of the atmospheric state. The LSWT retrieval is based on a simulation-based scheme making use of the Radiative Transfer for TOVS (RTTOV) Version 10 together with ERA-interim reanalysis data from the European Centre for Medium-range Weather Forecasts. The resulting LSWTs were extensively compared with in situ measurements from lakes with various sizes between 14 and 580 km 2 and the resulting biases and
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Palaeontological data about the climatic trends from Chattian to present along the Northeastern Atlantic frontage

Palaeontological data about the climatic trends from Chattian to present along the Northeastern Atlantic frontage

(early Pliocene, Anjou), and Circomphalus plicatus (late Pliocene, South of the gulf) are mixed with numerous taxa indicative of warm temperate climate (of mediterranean type) including.[r]

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Sensitivity of the Amazon biome to high resolution climate change projections

Sensitivity of the Amazon biome to high resolution climate change projections

The leaf area index (LAI) and the net primary production (NPP) of each PFT depends on the quantity of carbon absorbed by the vegetation during the year. Therefore, these are good parameters to indicate the impact of climate change in the rainforest biome. Figure 7 shows the 5-year mean variation of LAI and NPP for the PFTs that exist in the nine grid points surrounding the Santarem-k83 site. A 5-year average was applied to the time series to reduce the interannual variability signal and to show more clearly the trend. The linear negative trends of LAI and NPP in tropical broadleaf evergreen trees and tropical broadleaf drought-deciduous trees in both scenarios have statistical significance of 99,9%. The RCP8.5 scenario has a more pronounced decreasing trend than RCP4.5 scenario. However, for the functional type of warm (c4) grasses, increasing trend has statistical significance of 99,9% in the RCP4.5 and no statistical significance in the RCP8.5 scenario. The decrease of LAI and NPP in forest PFTs is due to the neutralization of CO 2 fertilization effect caused by reduced rainfall (Figure 6) and soil humidity simulated by the Eta-HadGEM2-ES in this area.
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Stride Search: a general algorithm for storm detection in high-resolution climate data

Stride Search: a general algorithm for storm detection in high-resolution climate data

Our results show that the storm track statistics associated with a particular climate data set can depend not only on the storm identification criteria, as is widely reported in the liter- ature (e.g., Bracegirdle and Gray, 2008; Raible et al., 2008; Horn et al., 2014), but also on the spatial search algorithm used to produce the storm tracks. Since the Stride Search al- gorithm is defined independently of data layout and resolu- tion, we posit that it may provide a more objective analysis tool and be less sensitive to differences in spatial discretiza- tions between data sets. Further experiments are necessary to investigate this claim; they should include variable resolution data, data defined on different types of spherical meshes, and sensitivity analyses covering a range of identification criteria and threshold values.
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VEGETATION AND ENVIRONMENTAL HISTORY OF LAKE DIAMOND, SOUTH GEORGIA – ANTARCTICA COMPARED TO NORTHEASTERN BRAZIL

VEGETATION AND ENVIRONMENTAL HISTORY OF LAKE DIAMOND, SOUTH GEORGIA – ANTARCTICA COMPARED TO NORTHEASTERN BRAZIL

The peaks of pollen accumulative rates calculated for naturalized/native species occurred in two different periods: ca. 1000 cal. years BP and around 2750 to 2450 cal. years BP. The two peaks on loss-on-ignition values (Figure 6) were observed at the same periods, supporting the evidences that the conditions at the time were favorable to higher organic matter occurrence in the surrounding areas and therefore higher deposition. Considering that some of the species, such as Acaena magellanica, Deschampsia antarctica and Phleum alpinum are commonly found in moraines (Galbraith, 2011), the peaks of deposition could relate to wetter or warmer conditions that would result in higher glacier transport, bringing pollen grains further on, until they reached Lake Diamond. As discussed before, the period around 2750 cal. years BP presented evidence of a wetter environment.
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Hominin responses to environmental changes during the Middle Pleistocene in Central and Southern Italy

Hominin responses to environmental changes during the Middle Pleistocene in Central and Southern Italy

selected the faunal species offering the most economically profitable volume of muscu- lar masse (Cassoli et al., 1999; Thun Hohenstein et al., 2009). These studies have also demonstrated that hominins had already acquired active predation behaviors, includ- ing specimen selections, with only occasional scavenging. It is then possible to deduce the hominin main predation strategies and to identify the environments they preferably

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«Consider it Possible to Return the Balkars...»: the Restoration of the Statehood (Documents returned) 1950s

«Consider it Possible to Return the Balkars...»: the Restoration of the Statehood (Documents returned) 1950s

The documentary publication deals with the problem of forced return links Balkars in the 1950s. Long 12 years of residence in Kazakhstan and the Central Asian republics, doubtless, have postponed their mark on this ethnic community. However, Balkars carefully treated their customs and traditions, preserved their original culture. 1950s opened up the possibility for the Balkars return to their homeland. The very process of return creates new difficulties. But Balkars together with representatives of other nations – Russian, Ukrainians, Kabardinians relying on their help to overcome these difficulties. In the first place, it has been resolved the main issue – the restoration of the Balkar national statehood. Presented publication of archival documents reveals a set of measures that are taken by the Balkars return to their former places of residence in the North Caucasus.
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Arq. NeuroPsiquiatr.  vol.58 número2B

Arq. NeuroPsiquiatr. vol.58 número2B

ABSTRACT - Objectives: The industrialization process and nervous system cancer (NSC) mortality in a urban region of Brazil. Method: From registries of the State System of Data Analysis Foundation (SEADE), 103 males deaths by NSC (ICD-9) in Baixada Santista (BS), from 1980 to 1993 were selected. Mortality ratios were calculated comparing the standardized mortality rate for ages over 10 years old (G1) and for the age group from 35 to 64 years old, in the industrialized and non-industrialized areas in three periods: 1980-1993, 1980-86, 1987-93. Results: A statiscally significant high mortality was observed in the industrialized area, for ages over 10 in all periods and only from 1980 to 1993 for ages from 34 to 64. The highest mortality ratio occurred from 1980-86 for ages over 10 - 4.12 (CI 1.79-9.42). Conclusion: High mortality was probably related to the environmental and occupational exposure to many organic and inorganic chemical substances, considered carcinogenics, such as aliphatic and aromatic hydrocarbons, organochlorinated, formaldehyde, nitrogenated compounds and heavy metals, found in the port and industrial complex. We discuss the importance of case-control studies in characterizing the association of these and other risk factors in the determination of NSC.
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Macrophyte-Based Assessment of the Ecological Status  of Lakes in Bulgaria

Macrophyte-Based Assessment of the Ecological Status of Lakes in Bulgaria

The total number of aquatic macrophyte species observed in a single lake ranged between 1 and 27. Twenty-six were registered indicator species, while number of accompanying species was 44 (Table 2). A number of indicator species were specifically occurring in one or two lakes only, such as Lemna trisulca, Nymphaea alba and Stratiotes aloides (Srebarna lake), Nuphar lutea (Shabla lake), Potamogeton pusillus (Ovchi kladenets), Myriophyllum verticillatum and Elodea canadensis (Batak reservoir, Choklyovo swamp), Spirodela polyrrhiza (Pchelina reservoir, Srebarna lake), Zannichellia palustris (Kovachitsa and Aleksandrovo reservoirs). Of the more common indicator species (Myriophyllum spicatum, Ceratophyllum demersum, Potamogeton pectinatus, etc.), most species showed high abundance.
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Late Holocene environmental reconstructions and their implications on flood events, typhoon, and agricultural activities in NE Taiwan

Late Holocene environmental reconstructions and their implications on flood events, typhoon, and agricultural activities in NE Taiwan

The Ilan Plain, located in northeastern Taiwan, is situ- ated under the main paths of TCs from the western Pacific (Fig. 1). It is an ideal area for a paleo-typhoon study, but very little investigation has been done so far, despite its im- portance (Chen et al., 2012). In addition, the interaction be- tween human activity and environment is a topic in paleoe- cology. Lin et al. (2007) suggested that the archeological hia- tus in the Ilan Plain during the late Holocene correlated to frequent typhoons and landslides. However, direct evidence and precise agricultural-activity duration are lacking. There- fore, this study used the pollen and diatom records from high- resolution lake sediments to detect the paleo-environment and anthropogenic impacts on NE Taiwan during the late Holocene. We assessed the role of frequent natural hazards on settlements during the past. We compared our data with other paleoclimatological records to understand the relation- ship between the precipitation in Ilan Plain and the typhoon activity in the West Pacific coastal area.
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How representative are instantaneous evaporative fraction measurements for daytime fluxes?

How representative are instantaneous evaporative fraction measurements for daytime fluxes?

EF obviously went down as compared to clear skies. Poorer RMSD were also obtained at the same time. This is because cloudiness could induce a decrease in the available energy and the latent heat flux, which further causes the increase in both instantaneous EF and daytime EF. But these increases are probably in different degrees. Thus, the EF tends to be more unstable during cloudy skies. Nevertheless, the above results have

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BIOCHEMICAL RESPONSES OF TWO ERYTHRINIDAE FISH TO ENVIRONMENTAL AMMONIA

BIOCHEMICAL RESPONSES OF TWO ERYTHRINIDAE FISH TO ENVIRONMENTAL AMMONIA

Both species, traíra and jeju, probably arose in the Jurassic (Godoy, 1975), and are presently living in similar environments (Nelson, 1984). Traíra and jeju usually feed on fish and insects respectively, which are both rich in protein. This kind of rich protein nourishment was proposed to induce changes in nitrogen catabolism (Cvancara, 1969). Among the OUC enzymes, ARG activity is supposed to increase under rich protein diets supporting nitrogen excretion (Cvancara, 1969). The compartimentalization of OUC enzymes of erythrinidae were previously studied by Polez et al. (1998) under usual environmental conditions. However, the ammonia exposure induced differential changes in the enzyme kinetic characteristics. This suggests distinct roles of OUC enzymes for the species in coping with ammonia. The enzyme kinetics of ARG and OCT presented interesting features. The ARG characte- ristics for both species appear very similar. In spite of the hypothesis supporting a direct relationship between ARG activity and dietary protein level (Cvancara, 1969), a large range of enzyme activities with very similar values for distinct species could be observed. Jeju and traíra feeding high protein diets should result in increase of amino nitrogen wasting through ARG.
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Climate Change Communication in Portugal

Climate Change Communication in Portugal

developed these policies since the early 1990s, mostly in response to EU determinations. The first milestone was the ratification of the United Nations Framework Convention on Climate Change (1992), followed by the signing of the Kyoto Protocol (1998). Due to the country’s comparatively low greenhouse gas emissions and gross domestic product, Portugal benefited from the Burden Sharing Agreement (2002) settled between the EU countries and thus was allowed to increase its emissions within limits. However, given the stage of development of the Portuguese economy, those limitations in the increase of emissions represented a considerable effort, which was further accentuated by a lack of integration in climate-relevant policies (Dessai & Michaelowa, 2001 ). In the 2000s, again
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