scholarly journals Detecting hotspots of atmosphere–vegetation interaction via slowing down – Part 1: A stochastic approach

2013 ◽  
Vol 4 (1) ◽  
pp. 63-78 ◽  
Author(s):  
S. Bathiany ◽  
M. Claussen ◽  
K. Fraedrich
Keyword(s):  
Climate Models ◽  
Stochastic Approach ◽  
General Context ◽  
Grid Cells ◽  
Climate System Model ◽  
Local Loss ◽  
Slowing Down ◽  
Current State ◽  
Long Time ◽  
Sudden Transition

Abstract. An analysis of so-called early warning signals (EWS) is proposed to identify the spatial origin of a sudden transition that results from a loss in stability of a current state. EWS, such as rising variance and autocorrelation, can be indicators of an increased relaxation time (slowing down). One particular problem of EWS-based predictions is the requirement of sufficiently long time series. Spatial EWS have been suggested to alleviate this problem by combining different observations from the same time. However, the benefit of EWS has only been shown in idealised systems of predefined spatial extent. In a more general context like a complex climate system model, the critical subsystem that exhibits a loss in stability (hotspot) and the critical mode of the transition may be unknown. In this study we document this problem with a simple stochastic model of atmosphere–vegetation interaction where EWS at individual grid cells are not always detectable before a vegetation collapse as the local loss in stability can be small. However, we suggest that EWS can be applied as a diagnostic tool to find the hotspot of a sudden transition and to distinguish this hotspot from regions experiencing an induced tipping. For this purpose we present a scheme which identifies a hotspot as a certain combination of grid cells which maximise an EWS. The method can provide information on the causality of sudden transitions and may help to improve the knowledge on the susceptibility of climate models and other systems.

scholarly journals Detecting hotspots of atmosphere-vegetation interaction via slowing down – Part 1: A stochastic approach

2012 ◽  
Vol 3 (2) ◽  
pp. 643-682 ◽  
Author(s):  
S. Bathiany ◽  
M. Claussen ◽  
K. Fraedrich
Keyword(s):  
Climate Models ◽  
Stochastic Approach ◽  
General Context ◽  
Grid Cells ◽  
Climate System Model ◽  
Local Loss ◽  
Slowing Down ◽  
Current State ◽  
Long Time ◽  
Sudden Transition

Abstract. An analysis of so-called Early Warning Signals (EWS) is proposed to identify the spatial origin of a sudden transition that results from a loss in stability of a current state. EWS, such as rising variance and autocorrelation, can be indicators of an increased relaxation time (slowing down). One particular problem of EWS-based predictions is the requirement of sufficiently long time series. Spatial EWS have been suggested to alleviate this problem by combining different observations from the same time. However, the benefit of EWS has only been shown in idealized systems of predefined spatial extent. In a more general context like a complex climate system model, the critical subsystem that exhibits a loss in stability (hotspot) and the critical mode of the transition may be unknown. In this study we document this problem with a simple stochastic model of atmosphere vegetation interaction where EWS at individual grid cells are not always detectable before a vegetation collapse as the local loss in stability can be small. However, we suggest that EWS can be applied as a diagnostic tool to find the hotspot of a sudden transition and to distinguish this hotspot from regions experiencing an induced tipping. For this purpose we present a scheme which identifies a hotspot as a certain combination of grid cells which maximize an EWS. The method can provide information on the causality of sudden transitions and may help to improve the knowledge on the susceptibility of climate models and other systems.

scholarly journals Detecting hotspots of atmosphere–vegetation interaction via slowing down – Part 2: Application to a global climate model

2013 ◽  
Vol 4 (1) ◽  
pp. 79-93 ◽  
Author(s):  
S. Bathiany ◽  
M. Claussen ◽  
K. Fraedrich
Keyword(s):  
Climate Models ◽  
Climate Model ◽  
Global Climate ◽  
Global Climate Model ◽  
Grid Cell ◽  
Physical Explanation ◽  
Vegetation Model ◽  
Statistical Tool ◽  
Slowing Down ◽  
Sudden Transition

Abstract. Early warning signals (EWS) have become a popular statistical tool to infer stability properties of the climate system. In Part 1 of this two-part paper we have presented a diagnostic method to find the hotspot of a sudden transition as opposed to regions that experience an externally induced tipping as a mere response. Here, we apply our method to the atmosphere–vegetation model PlanetSimulator (PlaSim) – VECODE using a regression model. For each of two vegetation collapses in PlaSim-VECODE, we identify a hotspot of one particular grid cell. We demonstrate with additional experiments that the detected hotspots are indeed a particularly sensitive region in the model and give a physical explanation for these results. The method can thus provide information on the causality of sudden transitions and may help to improve the knowledge on the vulnerability of certain subsystems in climate models.

scholarly journals Detecting hotspots of atmosphere-vegetation interaction via slowing down – Part 2: Application to a global climate model

2012 ◽  
Vol 3 (2) ◽  
pp. 683-713
Author(s):  
S. Bathiany ◽  
M. Claussen ◽  
K. Fraedrich
Keyword(s):  
Climate Models ◽  
Climate Model ◽  
Global Climate ◽  
Global Climate Model ◽  
Grid Cell ◽  
Physical Explanation ◽  
Vegetation Model ◽  
Statistical Tool ◽  
Slowing Down ◽  
Sudden Transition

Abstract. Early Warning Signals (EWS) have become a popular statistical tool to infer stability properties of the climate system. In Part 1 of this two-part paper we have presented a diagnostic method to find the hotspot of a sudden transition as opposed to regions that experience an externally induced tipping as a mere response. Here, we apply our method to the atmosphere-vegetation model PlanetSimulator (PlaSim) – VECODE using a surrogate stochastic toy model. For each of two vegetation collapses in PlaSim-VECODE we find a hotspot of one particular grid cell. We demonstrate with additional experiments that the detected hotspots are indeed a particularly sensitive region in the model and give a physical explanation for these results. The method can thus provide information on the causality of sudden transitions and may help to improve the knowledge on the vulnerability of certain subsystems in climate models.

scholarly journals A Review of Hybrid Electric Architectures in Construction, Handling and Agriculture Machines

2021 ◽  
Author(s):  
Francesco Mocera ◽  
Aurelio Somà
Keyword(s):  
Pollutant Emissions ◽  
Valuable Alternative ◽  
Specific Field ◽  
Current State ◽  
Long Time ◽  
Hybrid Electric ◽  
Application Fields ◽  
Work Done ◽  
Aftertreatment Systems ◽  
Alternative Solutions

Recent regulations on pollutant emissions have pushed working machines manufacturers towards research and development efforts to meet the strict limits imposed. For a long time, the use of gas aftertreatment systems have been the most widely accepted solution to reduce the amount of pollutants produced per unit of work done. However, lower emissions limits lead to larger systems and consequently higher difficulties in vehicle integration. Thus, alternative solutions have been studied in the last years to solve the emissions problem using wisely the on-board space. Hybrid electric technologies represent a valuable alternative in this direction. In this work, a review of the current state of the art in the adoption of hybrid and electric technologies on working vehicles is proposed. Due to the high amount of application fields and concepts for special applications, the analysis focused on the three major fields which however includes most of the working machines: Construction, Handling and Agriculture. This work highlights how the requirements of each specific field, strongly affects the design of an optimal hybrid electric architectures.

scholarly journals Issues on the problem of determining priorities and contents of interaction of school and parents in the modern situation and in the general context of education modernization.

2020 ◽  
Vol 3 (2) ◽  
pp. 41-45
Author(s):  
Svetlana S. Ignatovich ◽  
Keyword(s):  
Social Order ◽  
Comprehensive School ◽  
General Context ◽  
Specific Question ◽  
Children's Education ◽  
Long Time ◽  
Children’S Education

The article discusses the issues of determining and substantiating the priorities and content of interaction between the school and parents in the modern situation and in the general context of modernization of education. It is shown that the position taken by parents in the process of educating their children is contradictory. There has been an increase in the number of parents who do not connect the prospects of children's education with the fact of a child attending a comprehensive school. The reason for this contradiction is explained, consisting in the fact that for a long time, parents were virtually deprived of the opportunity to influence the education of the child in school. Shown are two options that exist for parents interested in educating their children. The specific question is posed: where should one look for a social order for education? A way out of this situation is presented – a dialogue between the school and parents, and also the reason for the unpreparedness of the school and parents for such a dialogue is shown. The basis of the bilateral dialogue with the school is the lack of subjective position of parents. It can be formed if they are included in the design of new ed-ucational practices. Parenthood should be formed as an influential civic educational in-stitution.

scholarly journals On the Dynamical Mechanisms Governing El Niño–Southern Oscillation Irregularity

2018 ◽  
Vol 31 (20) ◽  
pp. 8401-8419 ◽  
Author(s):  
Judith Berner ◽  
Prashant D. Sardeshmukh ◽  
Hannah M. Christensen
Keyword(s):  
El Niño ◽  
Time Scale ◽  
Climate Models ◽  
El Nino ◽  
Southern Oscillation ◽  
El Niño Southern Oscillation ◽  
El Nino Southern Oscillation ◽  
Short Time Scale ◽  
Time Step ◽  
Climate System Model

This study investigates the mechanisms by which short time-scale perturbations to atmospheric processes can affect El Niño–Southern Oscillation (ENSO) in climate models. To this end a control simulation of NCAR’s Community Climate System Model is compared to a simulation in which the model’s atmospheric diabatic tendencies are perturbed every time step using a Stochastically Perturbed Parameterized Tendencies (SPPT) scheme. The SPPT simulation compares better with ECMWF’s twentieth-century reanalysis in having lower interannual sea surface temperature (SST) variability and more irregular transitions between El Niño and La Niña states, as expressed by a broader, less peaked spectrum. Reduced-order linear inverse models (LIMs) derived from the 1-month lag covariances of selected tropical variables yield good representations of tropical interannual variability in the two simulations. In particular, the basic features of ENSO are captured by the LIM’s least damped oscillatory eigenmode. SPPT reduces the damping time scale of this eigenmode from 17 to 11 months, which is in better agreement with the 8 months obtained from reanalyses. This noise-induced stabilization is consistent with perturbations to the frequency of the ENSO eigenmode and explains the broadening of the SST spectrum (i.e., the greater ENSO irregularity). Although the improvement in ENSO shown here was achieved through stochastic physics parameterizations, it is possible that similar improvements could be realized through changes in deterministic parameterizations or higher numerical resolution. It is suggested that LIMs could provide useful insight into model sensitivities, uncertainties, and biases also in those cases.

Legislative Politics

2017 ◽  
Author(s):  
Olivier Costa
Keyword(s):  
Comparative Literature ◽  
Political Regime ◽  
Legislative Politics ◽  
New Work ◽  
Legislative Studies ◽  
Current State ◽  
French Case ◽  
Long Time ◽  
French Political Science ◽  
Over Time

This chapter proposes an assessment of the state of the study of legislative politics in France. It starts with a review of how the study of legislative politics has developed comparatively over time and identifies the major current debates in the comparative literature. Then it turns to the French case, explaining its weaknesses and peculiarities, and assessing the current state of legislative studies in France. We see that, for a long time, legislative studies were rare in the landscape of French political science. Things, though, have evolved since the end of the 1990s, when there was a renewed scholarly interest in central institutions and actors of the French political regime as well as the emergence of new work that was better connected with the methods, theories, and topics of mainstream legislative studies. Finally, we underline some dimensions of the agenda for the future study of legislative politics in France.

Strengthening and performance assessing historical cinema hall balcony according to new Turkish Earthquake Code

2021 ◽  
Vol 7 (1) ◽  
pp. 27
Author(s):  
Memduh Karalar ◽  
Murat Çavuşli
Keyword(s):  
Performance Analysis ◽  
Three Dimensional ◽  
Performance Evaluations ◽  
Current Status ◽  
Current State ◽  
Long Time ◽  
History Of ◽  
And Performance ◽  
Special Computer Program ◽  
Study Performance

Strengthening historical buildings and evaluating their performances make great contributions to both the history of the country and the tourism of the country. In this study, performance analysis and evaluations of the historical cinema hall balcony, which was built in 1933 by a French company and served to Zonguldak province for a long time, are presented in detail. This cinema hall was frequently used by local people between 1933 and 1999 and hosted many Yeşilçam movies. Firstly, examinations were performed in the historical cinema hall and the areas (columns, beams and floors) that were damaged in time were identified. According to the obtained information, it was determined that there were significant damages in the carrier system of the building and there were visible cracks and damages in the columns of the cinema hall. It was also observed that explosions occurred in one of the main carrier columns of the balcony. After the core samples taken from the balcony were tested in the laboratory, the current status of the carrier elements and reinforcements were determined with the help of an x-ray rebar scanner. After all these processes, the structure was modeled as three dimensional (3D) using a special computer program and performance evaluations were performed regarding the current state of the structure. As a result of the performance evaluation, it was determined that the balcony of the historical cinema hall could not survive anymore and would collapse over time. It was concluded that there were great damages especially on the balcony columns and a reinforcement should be made on a total of 6 columns. Strengthening was made to 4 different main columns and a performance analysis was performed again in strengthened structure. After strengthening, it was understood that the columns of the balcony of the cinema hall could survive for a long time.

Current state of heart surgery in relation to some views on modern surgical science

1927 ◽  
Vol 23 (3) ◽  
pp. 340-347
Author(s):  
V. L. Bogolyubov
Keyword(s):  
Internal Medicine ◽  
Gastrointestinal Tract ◽  
Biliary Tract ◽  
Heart Surgery ◽  
Surgical Intervention ◽  
Progressive Movement ◽  
Current State ◽  
Long Time ◽  
Sphere Of Influence

Modern surgery is taking over more and more organs, recapturing more and more areas of internal medicine. We see that in its great progressive movement surgery gradually involves within its sphere of influence a whole range of diseases that previously belonged exclusively to the sphere of internal medicine, such as some diseases of the gastrointestinal tract, biliary tract, lungs, etc. We see that even those organs, which until so recently were considered inaccessible to the art of the surgeon, are beginning to be subject to surgical intervention. Such last inviolable organ, on which the hand of the surgeon has not encroached for a long time, is the heart.

scholarly journals Impact of ocean circulation on regional polar climate simulations using the Arctic Region Climate System Model

1997 ◽  
Vol 25 ◽  
pp. 203-207 ◽  
Author(s):  
David A. Bailey ◽  
Amanda H. Lynch ◽  
Katherine S. Hedström
Keyword(s):  
Sea Ice ◽  
Mixed Layer ◽  
Climate Models ◽  
Regional Climate ◽  
The Arctic ◽  
Water Runoff ◽  
Polar Regions ◽  
Ice Dynamics ◽  
Climate System Model ◽  
Ice Model

Global climate models have pointed to the polar regions as very sensitive areas in response to climate change. However, these models often do not contain representations of processes peculiar to the polar regions such as dynamic sea ice, permafrost, and Arctic stratus clouds. Further, global models do not have the resolution necessary to model accurately many of the important processes and feedbacks. Thus, there is a need for regional climate models of higher resolution. Our such model (ARCSy M) has been developed by A. Lynch and W. Chapman. This model incorporates the NCAR Regional Climate Model (RegCM2) with the addition of Flato–Hibler cavitating fluid sea-ice dynamics and Parkinson–Washington ice thermodynamic formulation. Recently work has been conducted to couple a mixed-layer ocean to the atmosphere–ice model, and a three-dimensional (3-D) dynamical ocean model, in this case the S-Coordinate Primitive Equation Model (SPEM), to the ice model. Simulations including oceanic circulation will allow investigations of the feedbacks involved in fresh-water runoff from sea-ice melt and sea-ice transport. Further, it is shown that the definition of the mixed-layer depth has significant impact on ice thermodynamics.

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