Monte Carlo uncertainty calculation of 210Pb chronologies and accumulation rates of sediments and peat bogs

2014 ◽  
Vol 23 ◽  
pp. 80-93 ◽  
Author(s):  
Joan-Albert Sanchez-Cabeza ◽  
Ana Carolina Ruiz-Fernández ◽  
Jorge Feliciano Ontiveros-Cuadras ◽  
Libia Hascibe Pérez Bernal ◽  
Carolina Olid
Keyword(s):  
Monte Carlo ◽  
Peat Bogs ◽  
Accumulation Rates ◽  
Uncertainty Calculation

scholarly journals Post-pyrogenic dynamics of the vegetation cover of the Barskoe raised bog (Vologda Region, Russia)

2021 ◽  
Vol 4 (1) ◽  
pp. 35-52
Author(s):  
Anzhelika A. Malashchuk ◽  
Dmitriy A. Philippov
Keyword(s):  
Species Richness ◽  
Vegetation Cover ◽  
Biomass Accumulation ◽  
Fold Increase ◽  
Peat Bogs ◽  
Accumulation Rates ◽  
Raised Bog ◽  
Dry Biomass ◽  
Ground Fire ◽  
Pyrogenic Transformation

The study deals with the issues of restoration of peat bogs exposed to the pyrogenic factor. The work was carried out in the Barskoe raised bog, at sites unaffected and directly affected by the ground fire of 2002. A decade later, these sites differed in species composition, phytocoenosis structure, and biomass accumulation rates. Post-pyrogenic changes in the vegetation cover of the raised bog were associated with a slight decrease in species richness, loss of moisture-demanding bog species and an increase of mesophyte’s and xerophyte’s roles, simplification of the mire sites structure towards the loss of complexity, reduction of phytocoenotic diversity, as well as an increase in the dry biomass stocks with a 1.3–1.4-fold decrease in the photosynthetic phytomass and a 6.4–6.7-fold increase in the mortmass. The restoration rate of the mire exposed to pyrogenic transformation can be accelerated by increasing its water table and the prevention of new fires.

Historical accumulation rates of mercury in four Scottish ombrotrophic peat bogs over the past 2000years

2009 ◽  
Vol 407 (21) ◽  
pp. 5578-5588 ◽  
Author(s):  
John G. Farmer ◽  
Peter Anderson ◽  
Joanna M. Cloy ◽  
Margaret C. Graham ◽  
Angus B. MacKenzie ◽  
...  
Keyword(s):  
Peat Bogs ◽  
Accumulation Rates ◽  
The Past ◽  
Ombrotrophic Peat

Historial thallium deposition trends as recorded in peat bogs - examples from Czech sites with contrasting pollution histories

2020 ◽  
Author(s):  
Martin Mihaljevic ◽  
Vojtech Ettler ◽  
Ales Vanek
Keyword(s):  
Czech Republic ◽  
Power Plants ◽  
Accumulation Rate ◽  
Enrichment Factors ◽  
Peat Bogs ◽  
Accumulation Rates ◽  
Mountain Areas ◽  
The Czech Republic ◽  
Gas Cleaning ◽  
Pristine Area

<p>The purpose of this study is to investigate the Tl distribution and accumulation rates in Czech peatbogs with contrasting anthropogenic loads. Nine peat cores were sampled in the mountain areas of the Czech Republic (6 cores in the northern part affected by emissions from coal-burning power plants and 3 in the pristine southern part). In addition, 3 cores were collected close to the Pb mining and smelting area of Pribram. Cores were 210-Pb dated and trace metals/metalloids were measured in the digests by ICP-MS. Maximum Tl concentrations in peat were significantly higher in the polluted northern areas (1.16 mg/kg) and close to the Pb smelter (0.83 mg/kg) than in the pristine area (0.45 mg/kg). Thallium distribution well correlated with other metals (Pb, Hg) and metalloids (As, Sb). Thallium enrichment factors (EFs) calculated against Sc reached the maximum value of 17 indicating significant input of anthropogenic Tl. Thallium accumulation rates in peat varied between 20 and 50 µg/m2/y until 1930s, followed by a significant increase related to industrial activities in the northern part of the Czech Republic (up to 290 µg/m2/y in 1980s). In contrast, maximum Tl accumulation rate at the pristine site was 88 µg/m2/y. Data from the vicinity of Pb mines/smelter indicated higher accumulation rates even in the second half of the 19th century (between 50 and 200 µg/m2/y) followed by a significant decrease in late 1970s as a result of more efficient flue gas cleaning technology installed in the smelter during this period. </p>

Evaluating fossil charcoal representation in small peat bogs: Detailed Holocene fire records from southern Sweden

The Holocene ◽  
2020 ◽  
Vol 30 (11) ◽  
pp. 1540-1551
Author(s):  
Qiao-Yu Cui ◽  
Marie-José Gaillard ◽  
Boris Vannière ◽  
Daniele Colombaroli ◽  
Geoffrey Lemdahl ◽  
...  
Keyword(s):  
Fire History ◽  
Source Area ◽  
Fire Regimes ◽  
Continuous Series ◽  
Peat Bogs ◽  
Accumulation Rates ◽  
Southern Sweden ◽  
Highly Correlated ◽  
Study Sites ◽  
In Fire

In this study, we assess how representative a single charcoal record from a peat profile in small bogs (1.5–2 ha in area) is for the reconstruction of Holocene fire history. We use high-resolution macrocharcoal (>250 μm) analysis of continuous series of 2 cm3 samples from two small bogs in southern Sweden. We compare (1) duplicate charcoal records from the same core, (2) duplicate charcoal records from profiles in the same site (10 m apart), and (3) charcoal records from two sites within the same region (15 km apart). Comparisons are made for charcoal counts and area expressed as accumulation rates. The results suggest that (a) charcoal counts and area are highly correlated in all records; (b) duplicate charcoal records within the same core are very similar, although some charcoal peaks are found in only one of the two records; (c) although long-term trends in fire regimes are similar between duplicate charcoal records from nearby profiles within the same site and between charcoal records from sites within the same region, some individual charcoal peaks/fire events are asynchronous between records. The known historical fires of the town of Växjö (1570 and 1612 CE) are recorded at the two study sites, which indicates a macrocharcoal source area of minimum 15 km in diameter. The 2 cm3 peat samples contained relatively low amounts of macrocharcoal; we therefore recommend to analyse larger samples from small peat bogs with comparable peat accumulation rates. This will improve the reliability of the macrocharcoal record and its interpretation.

scholarly journals Are Uncertainty Categories in a Wind Farm Annual Energy Production Estimate Actually Uncorrelated?

2019 ◽  
Author(s):  
Nicola Bodini ◽  
Mike Optis
Keyword(s):  
Monte Carlo ◽  
Uncertainty Quantification ◽  
Interannual Variability ◽  
Energy Production ◽  
Wind Farm ◽  
Wind Farms ◽  
The United States ◽  
Monte Carlo Approach ◽  
Uncertainty Calculation ◽  
Wind Resource

Abstract. Calculations of annual energy production (AEP) from a wind farm – whether based on preconstruction or operational data – are critical for wind farm financial transactions. The uncertainty in the AEP calculation is especially important in quantifying risk and is a key factor in determining financing terms. Standard industry practice assumes that different uncertainty categories within an AEP calculation are uncorrelated and can therefore be combined through a sum of squares approach. In this analysis, we assess the rigor of this assumption by performing operational AEP estimates for over 470 wind farms in the United States. We contrast the standard uncertainty assumption with a Monte Carlo approach to uncertainty quantification in which no assumptions of correlation between uncertainty categories are made. Results show that several uncertainty categories do, in fact, show weak to moderate correlations, namely: wind resource interannual variability and the windiness correction (positive correlation), wind resource interannual variability and regression (negative), and wind speed measurement uncertainty and regression (positive). The sources of these correlations are described and illustrated in detail in this paper, and the effect on the total AEP uncertainty calculation is investigated. Based on these results, we conclude that a Monte Carlo approach to AEP uncertainty quantification is more robust and accurate than the industry standard approach.

Outbursts of comet Schwassmann-Wachmann 1, and the cloud of interplanetary boulders

1974 ◽  
Vol 22 ◽  
pp. 307 ◽  
Author(s):  
Zdenek Sekanina
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Method ◽  
Interplanetary Space ◽  
Porous Matrix ◽  
Maximum Diameter ◽  
Expansion Velocity ◽  
Solid Constituent ◽  
Meteoric Material ◽  
Periodic Comet

AbstractIt is suggested that the outbursts of Periodic Comet Schwassmann-Wachmann 1 are triggered by impacts of interplanetary boulders on the surface of the comet’s nucleus. The existence of a cloud of such boulders in interplanetary space was predicted by Harwit (1967). We have used the hypothesis to calculate the characteristics of the outbursts – such as their mean rate, optically important dimensions of ejected debris, expansion velocity of the ejecta, maximum diameter of the expanding cloud before it fades out, and the magnitude of the accompanying orbital impulse – and found them reasonably consistent with observations, if the solid constituent of the comet is assumed in the form of a porous matrix of lowstrength meteoric material. A Monte Carlo method was applied to simulate the distributions of impacts, their directions and impact velocities.

Sign in / Sign up

Export Citation Format

Share Document