scholarly journals Impacts of Global Climate Change on Duration of Logging Season in Siberian Boreal Forests

Forests ◽  
2020 ◽  
Vol 11 (7) ◽  
pp. 756 ◽  
Author(s):  
Anna V. Chugunkova ◽  
Anton I. Pyzhev
Keyword(s):  
Boreal Forests ◽  
Global Climate ◽  
Moving Average ◽  
Warming Trend ◽  
Climatic Data ◽  
Krasnoyarsk Krai ◽  
Start Date ◽  
Long Run ◽  
Frost Period ◽  
Almost All

In Siberia, most boreal forests are located in an area with relatively moist forest soils, which makes logging activities possible exclusively during the frost period with a permanent snow cover and stable sub-zero temperatures. As the global climate is experiencing a trend towards warming, it is reasonable to suppose that the duration of the logging season might shorten over time, influencing the economic potential of Siberian forests. To test this hypothesis, we created a concept for calculating the duration of the logging season, taking into account the economic and climatic peculiarities of doing forest business in these territories. Using the long-run daily-observed climatic data, we calculated the duration of the logging season for eight representative stations in Krasnoyarsk Krai (Yeniseysk, Boguchany, Achinsk, and Minusinsk) and Irkutsk Oblast (Bratsk, Kirensk, Tulun, and Yerbogachen) in 1966–2018. We found strong evidence of logging season duration shortening for almost all considered stations, with an uneven effect on the start and end boundaries of the season. Climate warming has almost no effect on the start date of the season in winter, but it significantly shifts the boundaries of the season end in spring. Using the autoregressive-integrated-moving average modeling (ARIMA) models, we demonstrated that, in the near future, the trends of the gradual shortening of the logging season will hold for the most part of the considered stations. The most pronounced effect is observed for the Achinsk station, where the logging season will shorten from 148.4 ± 17.3 days during the historical sample (1966–2018) to 136.2 ± 30 days in 2028, which reflects global warming trend patterns. From an economic perspective, a shorter duration of the logging season means fewer wood stocks available for cutting, which would impact the ability of companies to enact their logging plans and lead them to suffer losses in the future. To avoid losses, Siberian forest firms will have to adapt to these changes by redefining their economic strategies in terms of intensifying logging operations.

Climate Dynamics as a Nonlinear Brownian Motion

1998 ◽  
Vol 08 (04) ◽  
pp. 799-803 ◽  
Author(s):  
D. M. Sonechkin
Keyword(s):  
Time Series ◽  
Brownian Motion ◽  
Global Climate ◽  
Surface Air Temperature ◽  
Warming Trend ◽  
Climate System ◽  
Temperature Oscillations ◽  
Almost All ◽  
Temperature Time ◽  
The Heat Balance

Based on the heat balance equation of the global climate system the well-known surface air temperature time series of the Northern and Southern hemispheres were analyzed as realizations of a fractional Brownian motion. The technique of the so-called wavelet transform was used for this purpose. The technique easily admits splitting time series of interest to statistically stationary oscillations and a trend. Such temperature oscillations were extracted which include within themselves almost all differences between both hemispheric time series. As a result of subtraction of the oscillations from the primary hemispheric series a residual trend-like component was evaluated. The latter evidences a single warming trend of the global climate system that was started from the early 20th century.

ADAPTATION TO CYCLONE RISK: EVIDENCE FROM THE GLOBAL CROSS-SECTION

2012 ◽  
Vol 03 (02) ◽  
pp. 1250011 ◽  
Author(s):  
SOLOMON M. HSIANG ◽  
DAIJU NARITA
Keyword(s):  
Tropical Cyclones ◽  
Cross Section ◽  
Strong Evidence ◽  
Global Climate ◽  
Cost Effective ◽  
Adaptive Responses ◽  
Long Run ◽  
Almost All

Understanding the feasibility and cost of adaptation is essential to management of the global climate. Unfortunately, we lack general estimates of adaptive responses to almost all climatological processes. To address this for one phenomenon, we estimate the extent of adaptation to tropical cyclones (TCs) using the global cross-section of countries. We reconstruct every TC observed during 1950–2008 to parameterize countries' TC climate and year-to-year TC exposure. We then look for evidence of adaptation by comparing deaths and damages from physically similar TC events across countries with different TC climatologies. We find that countries with more intense TC climates suffer lower marginal losses from an actual TC event, indicating that adaptation to this climatological risk occurs but that it is costly. Overall, there is strong evidence that it is both feasible and cost-effective for countries with intense TC climatologies to invest heavily in adaptation. However, marginal changes from countries' current TC climates generate persistent losses, of which only ~3% is "adapted away" in the long run.

Application of Natural Dye Obtained from Sweet Indrajao on Fabrics

2020 ◽  
Vol 6 (3) ◽  
pp. 180-191
Author(s):  
Kavitha Chandrasekaran
Keyword(s):  
Potassium Dichromate ◽  
Bacterial Pathogens ◽  
Ultrasonic Method ◽  
Ferrous Sulphate ◽  
Fine Powder ◽  
Cost Effective ◽  
Metal Salts ◽  
Cow Dung ◽  
Long Run ◽  
Almost All

Background:: In the long run, synthetic tints were found to be harmful to the chemicals. As a result natural tints have come to be used for their many intrinsic values. The main reason being, then availability of local plants as the main source of natural colorants. Their easy availability in the country being zero cost – effective and planted for other purposes are the main reasons for utilizing them as natural tints. Almost all the parts of the plants, namely stem, leaves, fruits, seeds, barks etc. are used for extracting natural colour. In addition, they are antimicrobial antifungal, insect – repellant deodorant, disinfectant having medicinal values. Methods:: Sweet Indrajao leaves were cleaned by washing with water and dried under direct sunlight and ground as fine powder. A fine strainer was used to remove the wastages. After all these processes, 1-kilogram leaves weighed 318 grams. Then, it is put in 75% ethanol 25% water and heated in a breaker which in kept over a water bath for 2 hours. After this, the contents were filtered and kept in a separate beaker. Bleached fleece draperies stained with stain extract were made to become wet and put into different stain baths which contain the required amount of stain extract and water. Acetic acid was added to it after 20 minutes. The fleece drapery was stained for about one hour at 60oC. The draperies thus stained were removed, squeezed, and put to treatment with metal salts without washing. Different metal salts were used for the treatment using 3% of any one of the chemical mordants like alum, stannous chloride, potassium dichromate, ferrous sulphate, nickel sulphate, copper sulphate and natural mordants such as myrobolan, turmeric, cow dung, Banana sap juice at 60oC for 30 minutes with MLR of 1:30. The stained draperies were washed repeatedly in all the three methods in water and dried in air. At last, the stained draperies were put to soap with soap solution at 60oC for 10 minutes. The draperies were repeatedly washed in water and dried under the sun. Results:: Sweet Indrajao leaves discharged colour easily in alcoholic water. The fleece draperies were stained with chemical and natural mordants. It was observed that the stain uptake was found to be good in post-mordanting method. Ultrasonication has clearly improved the stainability of the draperies at pH 3 and 3.5 values. The pH decreases the stain ability under both Conventional and Ultrasonic conditions. The colour strength increases with an increase in staining temperature in both cases of US and CH methods. Conclusion:: Sweet Indrajao.L has been found to have good ultrasonic potential as a stain plant. The stain uptake as well as the fastness properties of the fleece drapery were found to enhance when metal mordant was used in conjugation with ultra-sonication for the extract of Sweet Indrajao. It was also found that the enhancement of staining ability was better without mordant draperies. The dye extract showed good antibacterial activity against the three bacterial pathogens. Among the three bacterial pathogens, dye extract showed more effective against Escherichia coli pathogens and dye extract showed more effective against Aspergillus pathogens. Hence, the ultrasonic method of drapery staining may be appropriate and beneficial for society at large in future.

Multivariate Markov-switching score-driven models: an application to the global crude oil market

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Szabolcs Blazsek ◽  
Alvaro Escribano ◽  
Adrian Licht
Keyword(s):  
Crude Oil ◽  
Moving Average ◽  
Local Level ◽  
Markov Switching ◽  
Impulse Response Functions ◽  
Common Trends ◽  
Vector Autoregressive ◽  
Oil Market ◽  
Long Run ◽  
Special Cases

Abstract A new class of multivariate nonlinear quasi-vector autoregressive (QVAR) models is introduced. It is a Markov switching score-driven model with stochastic seasonality for the multivariate t-distribution (MS-Seasonal-t-QVAR). As an extension, we allow for the possibility of having common-trends and nonlinear co-integration. Score-driven nonlinear updates of local level and seasonality are used, which are robust to outliers within each regime. We show that VAR integrated moving average (VARIMA) type filters are special cases of QVAR filters. Using exclusion, sign, and elasticity identification restrictions in MS-Seasonal-t-QVAR with common-trends, we provide short-run and long-run impulse response functions for the global crude oil market.

scholarly journals Economic fluctuations and crime: temporary and persistent effects

2016 ◽  
Vol 43 (4) ◽  
pp. 609-623 ◽  
Author(s):  
Keith Bender ◽  
Ioannis Theodossiou
Keyword(s):  
Design Methodology ◽  
Economic Fluctuations ◽  
Strong Positive Correlation ◽  
Dynamic Interactions ◽  
Content Type ◽  
Persistent Effect ◽  
Long Run ◽  
Unemployment And Crime ◽  
Ambiguous Effect ◽  
Almost All

Purpose Since the literature on the effect of the unemployment rate as reflection of economic fluctuations on crime shows an empirically ambiguous effect, the purpose of this paper is to argue that a new way of modeling the dynamics of unemployment and crime by focussing on the transitory and persistent effect of unemployment on crime helps resolve this ambiguity. Design/methodology/approach Panel data for US states from 1965 to 2006 are examined using the Mundlak (1978) methodology to incorporate the dynamic interactions between crime and unemployment into the estimation. Findings After decomposing the unemployment effect on crime into a transitory and persistent effect, evidence of a strong positive correlation between unemployment and almost all types of crime rates is unearthed. This evidence is robust to endogeneity and the controlling for cross-panel correlation and indicators for state imprisonment. Originality/value The paper is the first to examine the dynamics of the interaction of crime and economic fluctuations using the temporary and persistent effects framework of Mundlak (1978). In one set of estimates, one can evaluation both the short- and long-run effects of changes of unemployment on crime.

Simulated and Observed Preindustrial to Modern Vegetation and Climate Changes*

2005 ◽  
Vol 18 (17) ◽  
pp. 3650-3671 ◽  
Author(s):  
Michael Notaro ◽  
Zhengyu Liu ◽  
Robert Gallimore ◽  
Stephen J. Vavrus ◽  
John E. Kutzbach ◽  
...  
Keyword(s):  
Land Surface ◽  
Boreal Forests ◽  
Ring Width ◽  
Warming Trend ◽  
Physiological Effect ◽  
Co2 Fertilization ◽  
Vegetation Growth ◽  
Fully Coupled ◽  
Global Surface ◽  
Vegetation And Climate

Abstract Rising levels of carbon dioxide since the preindustrial era have likely contributed to an observed warming of the global surface, and observations show global greening and an expansion of boreal forests. This study reproduces observed climate and vegetation trends associated with rising CO2 using a fully coupled atmosphere–ocean–land surface GCM with dynamic vegetation and decomposes the effects into physiological and radiative components. The simulated warming trend, strongest at high latitudes, was dominated by the radiative effect, although the physiological effect of CO2 on vegetation (CO2 fertilization) contributed to significant wintertime warming over northern Europe and central and eastern Asia. The net global greening of the model was primarily due to the physiological effect of increasing CO2, while the radiative and physiological effects combined to produce a poleward expansion of the boreal forests. Observed and simulated trends in tree ring width are consistent with the enhancement of vegetation growth by the physiological effect of rising CO2.

scholarly journals Long Run Returns Predictability and Volatility with Moving Averages

Risks ◽  
2018 ◽  
Vol 6 (4) ◽  
pp. 105 ◽  
Author(s):  
Chia-Lin Chang ◽  
Jukka Ilomäki ◽  
Hannu Laurila ◽  
Michael McAleer
Keyword(s):  
Financial Performance ◽  
Stock Returns ◽  
Moving Average ◽  
Long Run ◽  
Returns Predictability ◽  
Rolling Window ◽  
Risk Free Rate ◽  
Data Frequency ◽  
Predictability Of Returns ◽  
Free Rate

This paper examines how the size of the rolling window, and the frequency used in moving average (MA) trading strategies, affects financial performance when risk is measured. We use the MA rule for market timing, that is, for when to buy stocks and when to shift to the risk-free rate. The important issue regarding the predictability of returns is assessed. It is found that performance improves, on average, when the rolling window is expanded and the data frequency is low. However, when the size of the rolling window reaches three years, the frequency loses its significance and all frequencies considered produce similar financial performance. Therefore, the results support stock returns predictability in the long run. The procedure takes account of the issues of variable persistence as we use only returns in the analysis. Therefore, we use the performance of MA rules as an instrument for testing returns predictability in financial stock markets.

scholarly journals Co-integration with score-driven models: an application to US real GDP growth, US inflation rate, and effective federal funds rate

2021 ◽  
pp. 1-21
Author(s):  
Szabolcs Blazsek ◽  
Alvaro Escribano ◽  
Adrian Licht
Keyword(s):  
Inflation Rate ◽  
Predictive Accuracy ◽  
Moving Average ◽  
Impulse Response Functions ◽  
Federal Funds ◽  
Federal Funds Rate ◽  
Vector Autoregressive ◽  
Autoregressive Moving Average Model ◽  
Long Run ◽  
The Us

Abstract Nonlinear co-integration is studied for score-driven models, using a new multivariate dynamic conditional score/generalized autoregressive score model. The model is named t-QVARMA (quasi-vector autoregressive moving average model), which is a location model for the multivariate t-distribution. In t-QVARMA, I(0) and co-integrated I(1) components of the dependent variables are included. For t-QVARMA, the conditions of the maximum likelihood estimator and impulse response functions (IRFs) are presented. A limiting special case of t-QVARMA, named Gaussian-QVARMA, is a Gaussian-VARMA specification with I(0) and I(1) components. As an empirical application, the US real gross domestic product growth, US inflation rate, and effective federal funds rate are studied for the period of 1954 Q3 to 2020 Q2. Statistical performance and predictive accuracy of t-QVARMA are superior to those of Gaussian-VAR. Estimates of the short-run IRF, long-run IRF, and total IRF impacts for the US data are reported.

scholarly journals Robust increase of Indian monsoon rainfall and its variability under future warming in CMIP-6 models

2020 ◽  
Author(s):  
Anja Katzenberger ◽  
Jacob Schewe ◽  
Julia Pongratz ◽  
Anders Levermann
Keyword(s):  
Climate Change ◽  
Global Warming ◽  
Climate Models ◽  
Monsoon Rainfall ◽  
Global Climate ◽  
Coupled Model ◽  
Global Climate Models ◽  
Future Climate Change ◽  
Global Mean Temperature ◽  
Almost All

Abstract. The Indian summer monsoon is an integral part of the global climate system. As its seasonal rainfall plays a crucial role in India's agriculture and shapes many other aspects of life, it affects the livelihood of a fifth of the world's population. It is therefore highly relevant to assess its change under potential future climate change. Global climate models within the Coupled Model Intercomparison Project Phase 5 (CMIP-5) indicated a consistent increase in monsoon rainfall and its variability under global warming. Since the range of the results of CMIP-5 was still large and the confidence in the models was limited due to partly poor representation of observed rainfall, the updates within the latest generation of climate models in CMIP-6 are of interest. Here, we analyse 32 models of the latest CMIP-6 exercise with regard to their annual mean monsoon rainfall and its variability. All of these models show a substantial increase in June-to-September (JJAS) mean rainfall under unabated climate change (SSP5-8.5) and most do also for the other three Shared Socioeconomic Pathways analyzed (SSP1-2.6, SSP2-4.5, SSP3-7.0). Moreover, the simulation ensemble indicates a linear dependence of rainfall on global mean temperature with high agreement between the models and independent of the SSP; the multi-model mean for JJAS projects an increase of 0.33 mm/day and 5.3 % per degree of global warming. This is significantly higher than in the CMIP-5 projections. Most models project that the increase will contribute to the precipitation especially in the Himalaya region and to the northeast of the Bay of Bengal, as well as the west coast of India. Interannual variability is found to be increasing in the higher-warming scenarios by almost all models. The CMIP-6 simulations largely confirm the findings from CMIP-5 models, but show an increased robustness across models with reduced uncertainties and updated magnitudes towards a stronger increase in monsoon rainfall.

scholarly journals The Status of Contaminants in Bald Eagles and Wildland Firefighters in the Teton Ecosystem

2008 ◽  
Vol 31 ◽  
pp. 117-124
Author(s):  
George Montopoli ◽  
Hank Harlow ◽  
W. Smith, MD ◽  
A. Wheeler, MD ◽  
Andy Byerly ◽  
...  
Keyword(s):  
Climate Change ◽  
Boreal Forests ◽  
Global Climate ◽  
Small Sample ◽  
Bald Eagle ◽  
Bald Eagles ◽  
Clear Cutting ◽  
Lead Ammunition ◽  
The Status ◽  
Small Sample Sizes

Advancing global climate change and associated desiccation of temperate and boreal forests, exacerbated by extensive clear-cutting, may increase poisoning of aquatic ecosystems with high levels of contaminants, especially Hg. We report on contaminants identified in nestling bald eagles and wildland firefighters of the Teton Ecosystem (Grand Teton National Park (GTNP) and the Snake River Unit (SRU), Wyoming) during summers of 2006, 2007 and 2008. In bald eagles, we focus primarily on mercury (Hg), lead (Pb), and selenium (Se) because each was detected in all nestlings during all summers at moderate levels. In wildland firefighters, we report primarily on Hg due to potential contamination from Hg when fighting fires and ingesting smoke and particulates produced by those fires. We feel that studying Hg both in the eagles and humans simultaneously is a better indicator of the general health of the environment than studying them separately. Both humans and bald eagles occupy top tiers on the food web, and intricately reflect the status of the environment. Results of the bald eagle analyses showed trends indicating increases in Hg and Pb from 2006 to 2007, and decreases from 2007 to 2008. Selenium essentially remained constant from 2006 to 2007 and increased from 2007 to 2008. In wildland firefighters, Hg appears to be elevated in those firefighters who are exposed to significant levels of smoke and particulates, both in 2007 and 2008. Conjectures about firefighters, however, are not statistically significant due to small sample sizes and logistical problems. Encouraging trends in bald eagle contaminant levels from 2007 to 2008 suggest reduction (or stabilization) of contaminant concentrations in the Teton Ecosystem. We also encourage the continued elimination of Pb attributable to humans (lead ammunition, lead shot, etc.) from the Teton Ecosystem. We encourage periodic monitoring of contaminants in the Teton Ecosystem, minimally at five-year intervals (Harmata 1996), unless unexpected events mandate more immediate monitoring. In wildland firefighters, we suggest a well-designed, comprehensive research study for summer 2009, to immediately address future ecological issues that are emerging due to climate change.

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