scholarly journals Application of the asymptotic theory of extreme values to risk simulation of breaking-out of large forest fires

2021 ◽  
Vol 34 (02) ◽  
pp. 1021-1031
Author(s):  
Vladimir Yu. Kosygin ◽  
Viktor D. Katin ◽  
Midkhat H. Akhtyamov ◽  
Mihail V. Ilyavin
Keyword(s):  
General Population ◽  
Probability Distribution ◽  
Forest Fires ◽  
Asymptotic Theory ◽  
Extreme Values ◽  
Original Material ◽  
Distribution Analysis ◽  
Sample Analysis ◽  
The South ◽  
Risk Simulation

Issues of applying the asymptotic theory of extreme values to the risks analysis of breaking-out of the largest-area yearly forest fires, were considered. As original material, the paper authors used data on areas of the forest fires occurring in the south of Russia’s Khabarovsk Territory from 1968 to 2017. For each year, the largest-area forest fire was selected from the considered period of time. In all, 50 fires were selected for this period of time (according to quantity of the years in the period). This sample analysis showed that the general population of these fires areas (where the sample was selected) has probability distribution of extreme values of the first type. An analytical expression for the probability distribution function of this general population was received. On the basis of this distribution analysis, a forecast was made concerning risks of the breaking-out and the average recurrence periods of such fires for various values of the burning area. The conducted analysis showed that in 87.5% of cases, in the south of Khabarovsk territory, the largest-area yearly forest fires, with an area of from 50 to 400 km2, will break out with the 1.2 years recurrence interval. In other words, almost every year, with the exception of these rare events when fires with other areas will occur.  It was supposed that the probability distribution of extreme values of the first type can be applied not only to the forest area of Russia’s Khabarovsk territory, but also to other zones in the world with large forest areas.

Galectin-3 is inversely associated with cardiorespiratory fitness in the general population

2021 ◽  
Vol 28 (Supplement_1) ◽  
Author(s):  
M Haid ◽  
M Bahls ◽  
M Doerr ◽  
S Felix ◽  
S Zylla ◽  
...  
Keyword(s):  
General Population ◽  
Oxygen Uptake ◽  
Cardiorespiratory Fitness ◽  
Extreme Values ◽  
Cardiopulmonary Exercise Testing ◽  
Left Ventricular ◽  
Left Ventricular Ejection ◽  
Linear Regression Models ◽  
Ventricular Ejection Fraction ◽  
Galectin 3

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Low cardiorespiratory fitness (CRF) is associated with high mortality and morbidity. Galectin-3 (Gal-3) is a prognostic biomarker for fibrosis, different cancers, renal impairment and, in particular, for heart failure. Further, higher Gal-3 levels are associated with increased cardiovascular mortality. Whether Gal-3 is related with the protective effects of a high CRF is unclear. Purpose The present study examined the relation between Gal-3 and CRF as determined by body weight adjusted peak oxygen uptake (VO2peak/kg), oxygen uptake at the anaerobic threshold (VO2@AT) and maximal workload (Wmax). Methods We used data of the population-based Study of Health in Pomerania (SHIP-TREND) from Northeast Germany. A total of n = 1,483 participants with a median age of 49 (IQR: 39 – 59 years, male 48%) were included in the analysis. CRF parameters were measured using standardized cardiopulmonary exercise testing on a bicycle ergometer. Plasma galectin-3 concentrations were determined using a quantitative sandwich enzyme immunoassay. Individuals with left ventricular ejection fraction < 40%, previous myocardial infarction, atrial fibrillation, chronic lung disease, severe renal disease (eGFR < 30 ml/min/mm2), a history of cancer, and extreme values for Gal-3 were excluded. Linear regression models adjusted for age, sex and lean mass were used to analyze the association between Gal-3 and CRF. Results A one ml/min/kg greater VO2peak was related to a 0.32 ng/ml (95% confidence interval [CI] -0.45 to -0.18, p <.001) lower Gal-3. Further, a one Watt larger power output was also associated with a 1.32 ng/ml (95% CI -2.10 to – 0.54, p <.001) lesser Gal-3. VO2@AT was not related to Gal-3 (β: -3.31 95% CI -8.68 to 2.05, p = .23). Conclusions In the general population Gal-3 is inversely associated with CRF. Further studies should investigate whether lower Gal-3, beyond its importance as a biomarker for heart disease, may even play a role in the protective effect of the CRF.

scholarly journals Environmental controls on the increasing GPP of terrestrial vegetation across northern Eurasia

2016 ◽  
Vol 13 (1) ◽  
pp. 45-62 ◽  
Author(s):  
P. Dass ◽  
M. A. Rawlins ◽  
J. S. Kimball ◽  
Y. Kim
Keyword(s):  
Forest Fires ◽  
Environmental Control ◽  
Negative Impact ◽  
Positive Impact ◽  
Terrestrial Ecosystems ◽  
Northern Eurasia ◽  
Terrestrial Vegetation ◽  
The South ◽  
Environmental Controls ◽  
Significant Negative Impact

Abstract. Terrestrial ecosystems of northern Eurasia are demonstrating an increasing gross primary productivity (GPP), yet few studies have provided definitive attribution for the changes. While prior studies point to increasing temperatures as the principle environmental control, influences from moisture and other factors are less clear. We assess how changes in temperature, precipitation, cloudiness, and forest fires individually contribute to changes in GPP derived from satellite data across northern Eurasia using a light-use- efficiency-based model, for the period 1982–2010. We find that annual satellite-derived GPP is most sensitive to the temperature, precipitation and cloudiness of summer, which is the peak of the growing season and also the period of the year when the GPP trend is maximum. Considering the regional median, the summer temperature explains as much as 37.7 % of the variation in annual GPP, while precipitation and cloudiness explain 20.7 and 19.3 %. Warming over the period analysed, even without a sustained increase in precipitation, led to a significant positive impact on GPP for 61.7 % of the region. However, a significant negative impact on GPP was also found, for 2.4 % of the region, primarily the dryer grasslands in the south-west of the study area. For this region, precipitation positively correlates with GPP, as does cloudiness. This shows that the south-western part of northern Eurasia is relatively more vulnerable to drought than other areas. While our results further advance the notion that air temperature is the dominant environmental control for recent GPP increases across northern Eurasia, the role of precipitation and cloudiness can not be ignored.

scholarly journals Shipborne And Ground-Based Lidar Monitoring of the Atmosphere Over the Lake Baikal in 2018

2020 ◽  
Vol 237 ◽  
pp. 02032
Author(s):  
Yurii S. Balin ◽  
Marina G. Klemasheva ◽  
Grigorii P. Kokhanenko ◽  
Sergey V. Nasonov ◽  
Ioganes E. Penner
Keyword(s):  
Spatial Structure ◽  
Lake Baikal ◽  
Forest Fires ◽  
Atmospheric Pollution ◽  
Atmospheric Aerosol ◽  
Baikal Region ◽  
Physical Models ◽  
The South ◽  
Ground Based Lidar ◽  
Background Area

The paper presents the results of studies aimed at the analysis and assessment of atmospheric pollution over the Lake Baikal in the summer. This information is necessary to create physical models of the formation and transfer of atmospheric aerosol fields, taking into account the physical and geographical features of the Baikal region. Measurements were carried out by a lidar «LOSA-A2» installed on the scientific-research vessel «Academician V.A. Koptyug». The vessel’s route passed along the South, Middle and Northern Baikal, from July 15, 2018 to July 26, 2018. At the same time, observations were conducted using lidar «LOSA-M2». It was located in the background area at Boyarsky stationary site (51.84° N, 106.06° E), in the south-eastern part of the lake. The results of changes in the spatial structure of atmospheric aerosol fields in background conditions and during forest fires are shown.

scholarly journals A weather regime characterisation of winter biomass aerosol transport from southern Africa

2021 ◽  
Author(s):  
Marco Gaetani ◽  
Benjamin Pohl ◽  
Maria del Carmen Alvarez Castro ◽  
Cyrille Flamant ◽  
Paola Formenti
Keyword(s):  
Spatial Distribution ◽  
Southern Africa ◽  
Forest Fires ◽  
South Atlantic ◽  
Austral Winter ◽  
The South ◽  
Predictive Tool ◽  
Weather Regime ◽  
Synoptic Variability

Abstract. During austral winter, a compact low cloud deck over South Atlantic contrasts with clear sky over southern Africa, where forest fires triggered by dry conditions emit large amount of biomass burning aerosols (BBA) in the free troposphere. Most of the BBA burden crosses South Atlantic embedded in the tropical easterly flow. However, midlatitude synoptic disturbances can deflect part of the aerosol from the main transport path towards southern extratropics. In this study, a characterisation of the synoptic variability controlling the spatial distribution of BBA in southern Africa and South Atlantic during austral winter (August to October) is presented. By analysing atmospheric circulation data from reanalysis products, a 6-class weather regime (WR) classification of the region is constructed. The classification reveals that the synoptic variability is composed by four WRs representing disturbances travelling at midlatitudes, and two WRs accounting for pressure anomalies in the South Atlantic. The WR classification is then successfully used to characterise the aerosol spatial distribution in the region in the period 2003–2017, in both reanalysis products and station data. Results show that the BBA transport towards southern extratropics is controlled by weather regimes associated with midlatitude synoptic disturbances. In particular, depending on the relative position of the pressure anomalies along the midlatitude westerly flow, the BBA transport is deflected from the main tropical route towards southern Africa or the South Atlantic. This paper presents the first objective classification of the winter synoptic circulation over South Atlantic and southern Africa. The classification shows skills in characterising the BBA transport, indicating the potential for using it as a diagnostic/predictive tool for aerosol dynamics, which is a key component for the full understanding and modelling of the complex radiation-aerosol-cloud interactions controlling the atmospheric radiative budget in the region.

scholarly journals Preliminary study on the case of black rain in Rio Grande do Sul, Brazil: A synoptic point of view

2021 ◽  
Vol 14 (3) ◽  
pp. 1268
Author(s):  
Maicon Moraes Santiago ◽  
Gabriel Borges dos Santos ◽  
Iulli Pitone Cardoso ◽  
André Becker Nunes
Keyword(s):  
Forest Fires ◽  
General Circulation ◽  
Rio Grande ◽  
Reanalysis Data ◽  
Point Of View ◽  
Rio Grande Do Sul ◽  
The South ◽  
Low Level ◽  
Suspended Particulate ◽  
South Of Brazil

Particles of soot from forest fires are transported by the wind, reaching distant locations and being deposited on the soil through precipitation, which clears the atmosphere, taking suspended particulate matter into its drops. The general circulation over South America indicates the possibility of soot from forest fires in the Amazon and Pantanal to be transported to southern Brazil. The event called “black rain” was observed in the period from 11 to 13 September 2020 at São Francisco de Assis City, in Rio Grande do Sul State (RS), and so this work aims to analyze if there were any anomalies of the flow that favored the occurrence of this event, given that there was a large number of fires in this period. Through ERA5 reanalysis data and GOES-16 satellite images, it was observed that on the three days under study low-level flow to the south of Brazil was more intense than normal, with the Low Level Jet occurrences, and on days 12 and 13 such flow to the south was also observed at 500 hPa. The precipitation was due to the instability of an extended trough from the Northwestern Argentinean Low. Thus, it is believed that there was a contribution from circulation at low and mid levels in the occurrence of black rain over RS.

Extreme Values of Waves and Ship Responses Subject to the Markov Chain Condition

1979 ◽  
Vol 23 (03) ◽  
pp. 188-197
Author(s):  
Michel K. Ochi
Keyword(s):  
Distribution Function ◽  
Markov Chain ◽  
Probability Distribution ◽  
Random Process ◽  
Probability Distribution Function ◽  
Extreme Values ◽  
Random Processes ◽  
Chain Condition ◽  
Extreme Value ◽  
Spectral Bandwidth

This paper discusses the effect of statistical dependence of the maxima (peak values) of a stationary random process on the magnitude of the extreme values. A theoretical analysis of the extreme values of a stationary normal random process is made, assuming the maxima are subject to the Markov chain condition. For this, the probability distribution function of maxima as well as the joint probability distribution function of two successive maxima of a normal process having an arbitrary spectral bandwidth are applied to Epstein's theorem for evaluating the extreme values in a given sample under the Markov chain condition. A numerical evaluation of the extreme values is then carried out for a total of 14 random processes, including nine ocean wave records, with various spectral bandwidth parameters ranging from 0.11 to 0.78. From the results of the computations, it is concluded that the Markov concept is applicable to the maxima of random processes whose spectral bandwidth parameter, ɛ, is less than 0.5, and that the extreme values with and without the Markov concept are constant irrespective of the e-value, and the former is approximately 10 percent greater than the latter. It is also found that the sample size for which the extreme value reaches a certain level with the Markov concept is much less than that without the Markov concept. For example, the extreme value will reach a level of 4.0 (nondimensional value) in 1100 observations of the maxima with the Markov concept, while the extreme value will reach the same level in 3200 observations of the maxima without the Markov concept.

Risk Planning with Discrete Distribution Analysis Applied to Petroleum Spills

2013 ◽  
Vol 2 (4) ◽  
pp. 61-78 ◽  
Author(s):  
Roy L. Nersesian ◽  
Kenneth David Strang
Keyword(s):  
Probability Distribution ◽  
Probability Distributions ◽  
Low Cost ◽  
Discrete Distribution ◽  
Distribution Model ◽  
Distribution Analysis ◽  
Distribution Models ◽  
Discrete Probability ◽  
Nonparametric Statistical ◽  
Spreadsheet Software

This study discussed the theoretical literature related to developing and probability distributions for estimating uncertainty. A theoretically selected ten-year empirical sample was collected and evaluated for the Albany NY area (N=942). A discrete probability distribution model was developed and applied for part of the sample, to illustrate the likelihood of petroleum spills by industry and day of week. The benefit of this paper for the community of practice was to demonstrate how to select, develop, test and apply a probability distribution to analyze the patterns in disaster events, using inferential parametric and nonparametric statistical techniques. The method, not the model, was intended to be generalized to other researchers and populations. An interesting side benefit from this study was that it revealed significant findings about where and when most of the human-attributed petroleum leaks had occurred in the Albany NY area over the last ten years (ending in 2013). The researchers demonstrated how to develop and apply distribution models in low cost spreadsheet software (Excel).

scholarly journals Camera-based single-molecule FRET detection with improved time resolution

2015 ◽  
Vol 17 (41) ◽  
pp. 27862-27872 ◽  
Author(s):  
Shazia Farooq ◽  
Johannes Hohlbein
Keyword(s):  
Probability Distribution ◽  
Single Molecule ◽  
Time Resolution ◽  
Laser Excitation ◽  
Single Molecule Detection ◽  
Distribution Analysis ◽  
Single Molecule Fret ◽  
Alternating Laser Excitation

Here the authors report on significant improvements in time-resolution and throughput in camera-based single-molecule detection by combining stroboscopic alternating-laser excitation with dynamic probability distribution analysis.

Sign in / Sign up

Export Citation Format

Share Document