anthropogenic and natural CO2

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The role of ocean transport in the uptake of anthropogenic CO2

The role of ocean transport in the uptake of anthropogenic CO2

Fig. 3. Model-simulated oceanic uptake of CO 2 in response to an emission pulse of 590.2 Pg C plotted against their simulated natural radiocarbon (permil) of the global ocean, Circumpolar Deep Water (CDW, 90–45 ◦ S, 1500–5000 m), North Pacific Deep Water (NPDW, Equator-60 ◦ N, 1500–5000 m), and North Atlantic Deep Water (NADW, Equator-60 ◦ N, 1000–3500 m). The results are shown for years 30, 100, 300, and 1000 (following logarithmic distributions) after emission pulse. Vertical lines in each panel represent observational data (solid lines) from Global Data Analysis Project (GLODAP) (Key et al., 2004) and associated uncertainties (two standard deviation, dashed lines). Analysis of Matsumoto et al. (2004) using the GLODAP bottle data is represented by blue lines, and our analysis using regridded GLODAP data are represented by black lines. Also shown in each panel is the trend line and correlation coefficient r. Two correlation coefficients are shown for each panel: one with the regression taken for all models (the numbers outside the brackets) and the other with the regression taken only for models whose radiocarbon simulation fall within the range of observational estimates (the numbers inside the brackets).
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A  case study of anthropogenic impact on the CO2 levels in low-volume profile of the Balcarka Cave (Moravian Karst, Czech Republic)

A case study of anthropogenic impact on the CO2 levels in low-volume profile of the Balcarka Cave (Moravian Karst, Czech Republic)

Influence of visitor respiration The anthropogenic impact of visitor breathing on CO 2 level in the Small Chamber is clearly visible (Fig. 2a). The CO 2 increases are represented by disturbances superim- posed on the roughly smooth “natural” CO 2 level. Based on model results, the anthropogenic CO 2 fluxes during the individual visiting periods of the monitoring cam- paign varied between 4.42 × 10 –4 and 2.45 × 10 –3 mol s -1 (first period) or 1.96 × 10 –4 and 7.35 × 10 –4 mol s –1 (sec- ond period). The CO 2 flux related to one person, j (AP) ~ 4.90 × 10 –5 mol s –1 person –1 (Tab. 1), is consistent with the value of 5.35 × 10 –5 mol s -1 person -1 measured by Lang et al. (2015) in the Balcarka Cave earlier. Howev- er, this value is lower in comparison with the values of 2.90 × 10 –4 mol s –1 person –1 presented by Faimon et al. (2006), 3.35 × 10 –4 mol s –1 person –1 given by Milanolo & Gabrovšek (2009), or 1.49 × 10 –3 mol s –1 person –1 reported by Dragovich & Grose (1990). The relatively wide range of CO 2 exhalation rate in caves may be given by different human activity (Iwamoto et al. 1994), gender (Sciacca et
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Seasonal and mesoscale variability of oceanic transport of anthropogenic CO2

Seasonal and mesoscale variability of oceanic transport of anthropogenic CO2

To reduce computational costs, we used the offline model to simulate anthropogenic CO 2 . The offline model is a tracer- transport version of OPA (OPA Tracer 8.5) that was driven by 5-day fields of advection and vertical turbulent diffusion that were computed previously by the dynamic (online) version of the model. Furthermore, we used a perturbation approach to model anthropogenic CO 2 in order to further reduce the exhorbitant computational time and memory that would oth- erwise be needed to make long global carbon simulations at eddy-permitting resolution to near-steady state conditions. Typically, such simulations would need to be integrated for several thousand years. This perturbation approach was in- troduced by Siegenthaler and Joos (1992) and first used in a 3-D model by Sarmiento et al. (1992). It assumes that the natural ocean carbon cycle is not affected directly by the an- thropogenic perturbation, which means we can treat anthro- pogenic CO 2 as a passive transient tracer. For further details about these anthropogenic CO 2 simulations, including their boundary conditions, see Lachkar et al. (2007).
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Anthropogenic Space Weather

Anthropogenic Space Weather

Since this report by the Stanford group, a considerable number of ground- and space-based studies have been published that have examined the poten- tial effects of these harmonics in the VLF range on the electron population of the magnetosphere. The published discussions have ranged from “control” of the magnetosphere through actions on, or production of, chorus emissions; (e.g. Bullough, 1983; Luette et al., 1979; Park and Helliwell, 1977; Parrot, 1994) to considerable skepticism (e.g. Tsurutani et al., 1979; Tsurutani and Thorne, 1981). The possible effects on the space environment of human activ- ities via use of electrical power sources in industrial activities have also been reported from statistical analyses of weekly variations in geomagnetic activity (e.g. Fraser-Smith, 1979; Park and Miller, 1979), and refuted from other anal- yses (e.g. Karinen et al., 2002). While it is agreed that anthropogenic power line harmonic radiation does exist in the magnetosphere, the magnitude of any effects of this radiation on the trapped electron populations remains uncertain. Another persistent anthropogenic radiation in the magnetosphere is that produced by the widespread distribution of VLF and RF transmitters around the world. The radiation from these transmitters, used for navigation and com- munications, is known to disturb the trapped electron population of the mag- netosphere. In addition, over several decades, purposeful VLF transmissions in the form of controlled experiments have been conducted from spacecraft and from the ground (one of the more notable and long-lasting set of ground ex- periments was from Siple Station, beginning in the early 1970s and extending to the late 1980s). These topics are addressed in Section 8.
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Electrocarboxylation in supercritical CO2 and CO2-expanded liquids

Electrocarboxylation in supercritical CO2 and CO2-expanded liquids

a b s t r a c t In this study, the electrocarboxylation of benzyl chloride in pressurized CO 2 , or pressurized mixtures of dimethylformamide (DMF) and CO 2 , was investigated in order to synthesize phenylacetic acid. A stainless steel cathode was used as the working electrode, whereas a sacrificial massive magnesium rod or a platinized platinum grid was used as the anode, tetrabutylammonium perchlorate (TBAP) or tetrakis(decyl)ammonium tetraphenylborate (TDATPhB) being the supporting electrolyte. The electrocar- boxylation was carried out at 40 ◦ C, at operating pressures of 1, 6, 7, 8, 9 and 12 MPa, using current densities ranging from 0.1 to 150 mA cm −2 . It was found that a small amount of DMF was necessary to ensure the solubility of the supporting electrolyte, to obtain sufficient electrical conductivity of the medium. The best results were obtained using the magnesium sacrificial anode, at 6 MPa. After consumption of the the- oretical amount of electrical current (2F mol −1 ), 65.7% benzyl chloride conversion was reached, together with an 82.4% phenylacetic acid selectivity and a 54.2% faradaic yield. Detected by-products were toluene, bibenzyle, benzyl alcohol and benzaldehyde.
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Combination of surfactants and organic compounds for boosting CO2 separation from natural gas by clathrate hydrate formation

Combination of surfactants and organic compounds for boosting CO2 separation from natural gas by clathrate hydrate formation

rate was found to be enhanced by the presence of SDS in concen- trations ranging from 500 to 4800 ppm: (dn/dt)/n o increased with the SDS concentration, reached a plateau between 1600 and 3000 ppm and decreased at higher concentrations. With SDBS, several differences were noted: (i) no effect was obtained at the lowest concentrations tested (600 and 1930 ppm); (ii) from 3000 to 5800 ppm, the enhancement effect was obtained and the result- ing enclathration rate was nearly constant. One interesting point is that the enclathration rates obtained using SDS are always superior to those obtained with SDBS. However, the hydrate morphologies observed during the experiment were identical (i.e. hydrates grew along the reactor window, and dark efflorescences in the bulk cor- related with a dramatic drop in the reactor pressure). The appear- ance of the bulk at the end of the experiment was consequently very similar to these two additives shown previously in Fig. 3 (e). These two anionic surfactants probably have a similar mechanism for enhancing hydrate formation.
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Role of Natural Climate Variability in the Detection of Anthropogenic Climate Change Signal for Mean and Extreme Precipitation at Local and Regional Scales.

Role of Natural Climate Variability in the Detection of Anthropogenic Climate Change Signal for Mean and Extreme Precipitation at Local and Regional Scales.

To convince policy makers of the importance of adapting infrastructures to climate change, it is crucial to better understand and explain the influence of natural variability on the climate system. However, the ability to assess natural variability is strongly hampered by the short length of available historical records for key weather variables. An alternative approach is to study it through simulations of a general circulation model (GCM) or an Earth system model (ESM). Most pub- lished studies use many GCMs and/or ESMs [e.g., models from phase 5 of the Coupled Model In- tercomparison Project (CMIP5); Taylor et al. 2012] to gather a large enough ensemble of models to perform such analyses (Fischer et al. 2014; Giorgi and Bi 2009; Hawkins and Sutton 2012; IPCC 2013; King et al. 2015; Maraun 2013; Mora et al. 2013). In many such studies, the concept of time of emergence (TOE) is defined to assess the moment when the climate change signal emerges from natural variability (Giorgi and Bi 2009; Hawkins and Sutton 2012; IPCC 2013; King et al. 2015; Maraun 2013). Generally, it is defined through a signal- to-noise (S/N) ratio based on a measure of the anthro- pogenic climate change signal (S) and some measure of natural variability (i.e., noise; N). The TOE is then es- timated for each simulation (either from an individual model or from different models), and then some mea- sure of the TOE distribution over all simulations (e.g., mean or median TOE) is used.
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Laterites and paleoclimates. Weathering processes and anthropogenic impact

Laterites and paleoclimates. Weathering processes and anthropogenic impact

Anthropogenic Contaminants in Aquatic and Sedi- mentary EnÕironments, and another has been offered independently by the authors. The four first papers are devoted to the study of weathering processes in different hydroclimatic con- ditions and during different geological periods. The first one addresses the dating of kaolinization pro- cesses in sedimentary kaolins since the Late Triassic from the western border of the Bohemian Massif

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Anthropogenic and natural drivers of gene flow in a temperate wild fruit tree: a basis for conservation and breeding programs in apples

Anthropogenic and natural drivers of gene flow in a temperate wild fruit tree: a basis for conservation and breeding programs in apples

species, particularly in temperate fruit trees. The cultivated apple (Malus domestica) is the one of the most important fruit tree crop in terms of worldwide production (http:// faostat.fao.org/). It was introduced into Europe 1500 years ago and has been subject to the introgression of genes from the local wild European apple, Malus sylvestris, to the extent that M. domestica is now more closely related to M. sylvestris than to its primary progenitor in the Tian Shan, M. sieversii (Cornille et al. 2012). Reciprocally, crop- to-wild introgressions have been reported in the European wild apple M. sylvestris (Coart et al. 2006; Larsen et al. 2006; Gross et al. 2012; Cornille et al. 2013b). Investiga- tions of the demographic history of the European wild apple have revealed the existence of three main genetic groups shaped by past climate change during the Pleisto- cene (Cornille et al. 2013a). However, both a sampling gap in the distribution of M. sylvestris in France and a lack of information about the pollination ecology of this species have limited our understanding of the structure of the pop- ulation and the identification of drivers of intra- and interspecies gene flow. Yet, cultivated and wild apples in Europe, with their high levels of gene flow from crop-to- wild species and within wild species, easily detectable due to relatively recent secondary contact, constitute an ideal model for investigations of the anthropogenic and natural drivers of gene flow in fruit trees at large geographic scales.
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Distinguishing Natural from Anthropogenic Sources of Acid Extractable Organics in Groundwater near Oil Sands Tailings Ponds.

Distinguishing Natural from Anthropogenic Sources of Acid Extractable Organics in Groundwater near Oil Sands Tailings Ponds.

406 prey. 46 Since this parameter is not applicable to our dataset, TEF values were set to zero. The 407 number of model iterations was set at 1500 for the mixing polygon assessment and 500,000 for 408 the SIAR model. 409 As illustrated in Figure S2, groundwater samples fell predominantly within the area 410 corresponding to the 95% mixing region, demonstrating that the selected source end-members are 411 able to explain the isotopic variability at both sites. Proceeding with the SIAR model, the 412 credibility intervals (CIs) for the proportion of each source in groundwater monitoring wells at 413 Sites 1 and 2 were determined (Figure 4). As illustrated here, the majority of groundwater samples 414 were comprised predominantly of non-bitumen- and MFGW-derived AEOs, with OSPW generally 415 comprising a smaller component, particularly at Site 1 (0-34%; 95% CIs). An exception were four 416 samples from Site 2 (GW2-2-2015, GW2-2-2016, DP-02-2017, DP-10-17), for which the upper 417 95% CIs for OSPW ranged from 57-99% of AEOs. Wider 95% CIs were found for OSPW and 418 MFGW compared to non-bitumen proportions, reflecting the smaller differences in isotope ratios 419 between the two bitumen-derived AEO sources. Nonetheless, for the majority of groundwater 420 monitoring wells, the ranges of estimated proportions for OSPW and MFGW were reasonably 421 narrow; for instance, the differences between upper and lower 95% CIs were ≤ 40% in 19 out of 422 32 wells for MFGW and 23 out of 32 wells for OSPW (Figure 4). The results of the SIAR model 423 provided a quantitative estimate of OSPW in groundwater at two different mining operations, and 424 revealed that at one of these sites (TP2), OSPW-derived NAs were the dominant source in several 425 wells.
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Natural and anthropogenic particulate-bound aliphatic and polycyclic aromatic hydrocarbons in surface waters of the Gulf of Gabes (Tunisia, southern Mediterranean Sea)

Natural and anthropogenic particulate-bound aliphatic and polycyclic aromatic hydrocarbons in surface waters of the Gulf of Gabes (Tunisia, southern Mediterranean Sea)

Abstract Particulate-bound aliphatic and polycyclic aromatic hydrocarbons AHs and PAHs were investigated in the surface waters of the Gulf of Gabès Tunisia, southern Mediterranean Sea.. [r]

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Natural natural disasters and economic disruption

Natural natural disasters and economic disruption

C. Descriptive statistics Figure F2 and F3 show the geographic dispersion of affected countries for both cyclones and earthquakes. Earthquakes essentially occur along the faults existing between tectonic plates. As they result from deformations caused by major irregu- larities in the fault trace, the zone in which the probability of occurrence is non nil remains quite restricted. To sum up, the eastern part of the ring of fire, threaten the whole coast going from Alaska to Chile while the western counterpart provoke frequent tremors in Japan, China, Philippines, Indonesia. Finally, the eurasian fault affect mainly India, Pakistan, Iran, central Asia, Turkey, Greece. Cyclones, hur- ricanes or typhoons develop mainly in 5 basins: the extremely active West-Pacific basin where typhoons threaten the whole east-asian coast from Philippines and Viet- nam to the borders of Russia, the East-Pacific basin (Hawaii and Mexico), the Indian basin (Madagascar, Mozambique, Mauritius for the southern Indian ocean, India, Bangladesh for the northern part), the Australian basin (Australia, small islands of the southern Pacific ocean) and the active Atlantic basin (Caribbean countries, Central America and United States). Overall, the dataset cover almost 100 countries for both type of events, and between 1 and a dozen of events per country per year. The intersection of the sets of countries affected by cyclones and earthquakes is far from being empty.
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Magnetic particle characterization in the Seine river system: Implications for the determination of natural versus anthropogenic input

Magnetic particle characterization in the Seine river system: Implications for the determination of natural versus anthropogenic input

used as a proxy parameter, to the first order, for anthropogenic pollution and more specifically as a tracer of Sb-rich particle concentrations in the Seine river system. Since the EDS’s lower limit of detection is 0.5 wt %, we can assume the abundance of Sb containing magnetite is higher than observed, changing the slope of the linear regression line while not reducing the positive correlation coefficient. This assumption is also supported by the Sb elemental data, obtained from Instrumental Neutron Activation Analyses (INAA) performed on the respective bulk sediment samples [Tessier and Bonte´, 2002]. Moreover, the high correlation (r 2 = 0.85) between the normalized Sb/Sc ratio (bulk sediments) and the Sb/Ti ratio from the magnetic fraction (Figure 9c) suggests that the major proportion of Sb is actually present within the magnetic (heavy mineral) fraction. Fur- ther detailed electron microscopic and geochemical investigations of these specific particles will cer- tainly offer a more complete understanding of these (and other) anthropogenic particle types.
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Disentangling climatic and anthropogenic controls on global terrestrial evapotranspiration trends

Disentangling climatic and anthropogenic controls on global terrestrial evapotranspiration trends

To predict future changes in ET patterns, process- based simulation and understanding of the magni- tudes, mechanisms and interactions that control his- torical ET dynamics will be required and should be within uncertainty of both historical and present-day observations. Mechanistic land surface models (LSMs), driven by measurement-based environmental properties, are useful tools for the detection and attri- bution of natural and anthropogenic effects on ET dynamics. For the past decade, global factorial LSM experiments have been conducted and analyzed by dif- ferent modeling groups to investigate the separate effects of environmental stresses on land surface and subsurface runoff, river flow, ET and water use effi- ciency (Gedney et al 2006 , 2014 , Piao et al 2007 , Shi et al 2011 , 2013 , Tian et al 2011 , Liu et al 2012 , Tao et al 2014 ). The role of climate impacts on these hydro-
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Anthropogenic effects in landscapes: Historical context and spatial pattern

Anthropogenic effects in landscapes: Historical context and spatial pattern

and diversification of the plant communities (Gupta 2004 ; Sheaffer and Moncada 2009 ). It is appealing to detail these links between the start of husbandry, the founding of settlements, the development of villages, and the origin of cities. Increasing agricultural productivity is suggested as a key concept in this sequence. While agricultural production itself refers to the total quantity of biomass produced, the productivity concept expresses this quantity as a function of the production factors used (e.g., Van Zanden 1991 ). These factors can be numerous and heterogeneous, such as the time between the preparation of the land and the final yield, the number of farmers involved in production, the production surface used, energy inputs, or the quantities and types of fertilizers used. The nomadic lifestyle of Man before the development of agriculture and its dependence on natural rhythms and production had taught Man to observe and understand its environment. Through this necessity to adapt his life style to nature, Man acquired knowledge on the production of biomass in nature (Braidwood 1979 ; Sheaffer and Moncada 2009 ). Later on, agricultural productivity was increased, e.g. by use of energy provided by domes- ticated animals (Demangeon 1933 ; Childe 1950 ; Davis 1955 ; Kohl and Wright
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Climatic and Anthropogenic Impacts on African Ecosystems "CLANIMAE" - Final Report

Climatic and Anthropogenic Impacts on African Ecosystems "CLANIMAE" - Final Report

Paleoenvironmental calibration of non-pollen palynomorph microfossils (NPPs), including fossil fungal spores. Non-pollen palynomorph microfossils (NPPs) are much used as paleo-ecological indicators in Europe and North America, but prior to this project their value as such in tropical Africa had not been thoroughly explored. We calibrated the ecological indicator value of African NPPs in relation to landscape variables (vegetation, land use, erosion, burning practices) and lake characteristics (depth, productivity), again through analysis of surface sediments in 24 Ugandan crater lake basins located along environmental gradients of vegetation (moist evergreen and semi-deciduous forest, wooded and open grass savanna), land use (pastoralism, crop agriculture, plantations) and lake characteristics (basin morphometry, water chemistry and aquatic production). For this purpose the CLANIMAE land-cover classification (Table 6) was supplemented by data on domestic herbivore abundance. This analysis produced 311 distinct types of NPP, for a large part (230 types) spores and other remains of fungi. About 31% of these could be identified at the family, genus or species level, but the affinity of the majority of NPP types, specifically fungal spores, remains unknown. This high biodiversity coupled with a restricted distribution of NPP types among sites suggests high ecological specificity of the fungal species producing the NPPs. Direct gradient analysis of the distribution of 30 major terrestrial NPP morphotypes showed that the distribution of fungi generally associated with human landscape disturbance indeed correlates with anthropogenic land- cover variables such as crop agriculture and pasture. For example, Glomus (a mycorrhizal fungus living symbiotically in plant roots) is positively related to soil erosion from agricultural activity. Redundancy Analysis (RDA) was used to determine which environmental variables most strongly structure the fungal community. The first two RDA axes captured 33.8% of the variance in the species data, and 49.3% of the cumulative species-environment relation (Fig. 30). RDA axes 1 and 2 appeared to be strongly oriented by the Anthropic Impact index, perennial agriculture and natural vegetation (plus plantations). These three variables accounted for a statistically significant portion of the variance in the NPP data (11.5%, 12.8% and 12.2%, respectively), together with Chl a (8.8%). The distribution of Delitschia sp. (T1066), cf. Sordaria sp. (T1178),
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Hydrochemical characterization of transfers in karst aquifers by natural and anthropogenic tracers. Example of a Mediterranean karst system, the Lez karst aquifer (Southern France).

Hydrochemical characterization of transfers in karst aquifers by natural and anthropogenic tracers. Example of a Mediterranean karst system, the Lez karst aquifer (Southern France).

Spatial variability of groundwater chemistry and general groundwater flow A similar water stable isotopes fingerprinting was observed for the various springs that correspond to the outlets of the Lez aquifer catchment: Lez, Lirou, Restinclières and Fleurettes, indicating that they share the same recharge area. However, the great disparity observed in their hydrochemistry indicates that they have distinct water flowpaths within the aquifer. This shows that despite belonging to the same aquifer, those springs’ waters are more distinguished by solute masses than by the water isotopic signature. The hydrochemical characteristics of Restinclières and Fleurettes springs seem to be mostly associated to limestones and marly-limestones from Upper Jurassic and Early Cretaceous, i.e. shallower circulations. Furthermore, they have a complete absence of the evaporites fingerprinting that was observed at the Lez spring. Among these springs, the Lirou is an exception since its waters present a singular and very low mineralization characterized by a short residence time and a high participation of rapid infiltration waters. The isotopic content of Lirou waters highlights the significant reactivity of this spring, indicating that Lirou is effectively under a stronger influence of recent rainfalls than the other springs.
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Dissociation conditions and Raman spectra of CO2 + SO2 and CO2 + H2S hydrates

Dissociation conditions and Raman spectra of CO2 + SO2 and CO2 + H2S hydrates

enclathrated, the peak at 1151.5 cm −1 shifts to a lower frequency at 1147.1 cm −1 . For enclathrated CO 2 the higher- frequency peak of the Fermi dyad blue shifts to 1380.8 cm −1 . The Raman peaks for CO 2 + SO 2 hydrate also agree very well with those in the literature. 5 There are two types of cages in CO 2 + SO 2 sI hydrate, a small cage (5 12 ) and a large cage (5 12 6 2 ). Some Raman peaks have been observed to split to distinguish guests in small and large cages, allowing estimates of cage occupancies. For the Raman spectrum of CO2 + SO2 hydrate, splitting of the peaks is not observed for either CO 2 or SO2. According to the intensity of the SO2 peak in the CO2 + SO 2 hydrate spectrum, the 1147.1 cm −1 peak should be assigned to SO2 in the large cage. Although SO2 can occupy both large and small cages in pure sI hydrate, 8 we think that SO2 occupies only the large cage in the CO2 + SO2 hydrate because the observed peaks are not peaks attributable to SO 2 in small cages. CO2 can occupy both large and small cages in sI, but spectra do not show splitting of the Fermi doublet. An explanation has been proposed in the literature. 19
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Decadal-Scale SST and Salinity Variations in the Central Tropical Pacific: Signatures of Natural and Anthropogenic Climate Change

Decadal-Scale SST and Salinity Variations in the Central Tropical Pacific: Signatures of Natural and Anthropogenic Climate Change

which accounts for lag-one serial autocorrelation in the two time series as outlined by Bretherton et al. (1999). The estimation of uncertainty in the coral Sr/Ca-based SST proxy reconstruction takes into account contribu- tions of uncertainties from the analytical precision of Sr/Ca measurements and the Sr/Ca–SST calibration. Analytical uncertainty accounts for 60.078C (1s), and the uncertainty associated with the intercept and slope of the SST–Sr/Ca relationship translates into a large er- ror of 67.858C (1s) (s [ standard deviation). Taken together, the compounded error bar for the reconstructed SST record is conservatively reported as 67.858C (1s) via an additive error propagation, highlighting that the uncertainties in the Sr/Ca–SST calibration dominate the total error (see the appendix). It is important to note that this large error is associated with the calculation of absolute SST only. Relative changes in SST, upon which the results of this study are based, are associated with a much smaller error of 60.108C (1s) (see the appen- dix). In other words, large uncertainties in the slope and intercept of the Sr/Ca–SST relationship do not change the character of the coral-based SST nor the d 18 O SW
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Anthropogenic effects in landscapes: quantification and ecological effects

Anthropogenic effects in landscapes: quantification and ecological effects

Data show the role of anthropogenic pressure in landscape dynamics in Kisangani, the degradation of the Giant Panda habitat in China, the (low) impact of agricultural policy [r]

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