scholarly journals Ongoing solution reproducibility of earth system models as they progress toward exascale computing

Author(s):  
Salil Mahajan ◽  
Katherine J Evans ◽  
Joseph H Kennedy ◽  
Min Xu ◽  
Mathew R Norman ◽  
...  

We present a methodology for solution reproducibility for the Energy Exascale Earth System Model during its ongoing software infrastructure development to prepare for exascale computers. The nonlinear chaotic nature of climate system simulations precludes traditional model verification approaches since machine precision differences—resulting from code refactoring, changes in software environment, and so on—grow exponentially to a different weather state. Here, we leverage the nature of climate as a statistical description of the atmosphere in order to establish model reproducibility. We evaluate the degree to which two-sample equality of distribution tests can confidently detect the change in climate from minor tuning parameter changes on model output variables in order to establish the level of difference that indicates a new climate. To apply this (baselined test), we target a section of the model’s development cycle wherein no intentional science changes have been applied to its source code. We compare an ensemble of short simulations that were conducted using a verified model configuration against a new ensemble with the same configuration but with the latest software infrastructure (Common Infrastructure for Modeling the Earth, CIME5.0), compiler versions, and software libraries. We also compare these against ensemble simulations conducted using the original version of the software infrastructure (CIME4.0) of the earlier model configuration, but with the latest compilers and software libraries, to test the impact of new compilers and libraries in isolation from additional software infrastructure. The two-sample equality of distribution tests indicates that these ensembles indeed represent the same climate.

2020 ◽  
pp. 108-115 ◽  
Author(s):  
Vladimir P. Budak ◽  
Anton V. Grimaylo

The article describes the role of polarisation in calculation of multiple reflections. A mathematical model of multiple reflections based on the Stokes vector for beam description and Mueller matrices for description of surface properties is presented. On the basis of this model, the global illumination equation is generalised for the polarisation case and is resolved into volume integration. This allows us to obtain an expression for the Monte Carlo method local estimates and to use them for evaluation of light distribution in the scene with consideration of polarisation. The obtained mathematical model was implemented in the software environment using the example of a scene with its surfaces having both diffuse and regular components of reflection. The results presented in the article show that the calculation difference may reach 30 % when polarisation is taken into consideration as compared to standard modelling.


2020 ◽  
Vol 18 (6) ◽  
pp. 1063-1078
Author(s):  
T.N. Skorobogatova ◽  
I.Yu. Marakhovskaya

Subject. This article discusses the role of social infrastructure in the national economy and analyzes the relationship between the notions of Infrastructure, Service Industry and Non-Productive Sphere. Objectives. The article aims to outline a methodology for development of the social infrastructure of Russia's regions. Methods. For the study, we used the methods of statistical and comparative analyses. The Republic of Crimea and Rostov Oblast's social infrastructure development was considered as a case study. Results. The article finds that the level of social infrastructure is determined by a number of internal and external factors. By analyzing and assessing such factors, it is possible to develop promising areas for the social sphere advancement. Conclusions. Assessment and analysis of internal factors largely determined by the region's characteristics, as well as a comprehensive consideration of the impact of external factors will help ensure the competitiveness of the region's economy.


2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Masruchin Masruchin

Corporate Social Responsibilityis a concept that a company has various forms of responsibility to all stakeholders including consumers, employees, shareholders, communities and the environment in all aspects of the company's operations that include economic, social, and environmental aspects. Therefore CSR is closely related to "sustainable development", in which a company, in carrying out its activities must base its decisions not only on the impact on economic aspects, such as the level of profits or dividends (profits), but also must consider the social and environmental impacts that arise from that decision, both for the short term and the longer term.Pondok Modern Darussalam Gontor (PMDG), in managing its Productive Waqf by establishing business units which mostly involve workers from the local society around PMDG. They are employed according to their skills. This is a form of implementing CSR in order to help advance and improve the welfare of the local society. The existence of these various business units is one of the educational facilities and as a form of CSR application which is actually intended to educate in the fields of independence, entrepreneurship, sincerity and sacrifice.PMDG involvement in social activities that are useful for the local society such as infrastructure development and village facilities, regeneration of students who are from around PMDG to be able to get higher education with funding from the PMDG, doing guidance to the local society through various religious activities, educational and economic activities is a form of PMDG responsibility to the local society environment and also to all stakeholders such as students, Ustadz, employees, so as to provide social and environmental impacts for the short term and the longer term.Keywords: Corporate Social Responsibilityandproductive waqf.


Author(s):  
Pranjal Kumar ◽  
Ashutosh Mishra

Jharkhand is popular for tribal culture and uniqueness of its inherent natural beauty attributing significantly on Tourism Industry of Jharkhand. There has been visible change and impact on socio-economic factor because of tourist influx in the Jharkhand state. The inherent beauty and nature has made the state popular for tourism. The attraction towards various important tourist spots revolves mostly within the domestic tourism. The paper attempts to ascertain the impact of tourism traits, like economic Development, Cost of living, Infrastructure Development, Socio-Cultural and the Environment affect through primary data collected from the responses of residents of six dominant tourist circuits of Jharkhand. The respondent’s views were ascertained on five point Likert Scale. The data so collected was subjected to analysis for identifying the impact of various tourism traits on the prospects of Jharkhand Tourism.


2010 ◽  
Vol 67 (8) ◽  
pp. 2537-2546 ◽  
Author(s):  
John F. Scinocca ◽  
Bruce R. Sutherland

Abstract A new effect related to the evaluation of momentum deposition in conventional parameterizations of orographic gravity wave drag (GWD) is considered. The effect takes the form of an adjustment to the basic-state wind about which steady-state wave solutions are constructed. The adjustment is conservative and follows from wave–mean flow theory associated with wave transience at the leading edge of the wave train, which sets up the steady solution assumed in such parameterizations. This has been referred to as “self-acceleration” and it is shown to induce a systematic lowering of the elevation of momentum deposition, which depends quadratically on the amplitude of the wave. An expression for the leading-order impact of self-acceleration is derived in terms of a reduction of the critical inverse Froude number Fc, which determines the onset of wave breaking for upwardly propagating waves in orographic GWD schemes. In such schemes Fc is a central tuning parameter and typical values are generally smaller than anticipated from conventional wave theory. Here it is suggested that self-acceleration may provide some of the explanation for why such small values of Fc are required. The impact of Fc on present-day climate is illustrated by simulations of the Canadian Middle Atmosphere Model.


2021 ◽  
Vol 13 (10) ◽  
pp. 5355
Author(s):  
Vilém Pechanec ◽  
Ondřej Cudlín ◽  
Miloš Zapletal ◽  
Jan Purkyt ◽  
Lenka Štěrbová ◽  
...  

Global and regional biodiversity loss is caused by several drivers including urban development, land use intensification, overexploitation of natural resources, environmental pollution, and climate change. The main aim of our study was to adapt the GLOBIO3 model to the conditions of the Czech Republic (CR) to assess loss of naturalness and biodiversity vulnerability at the habitat level on a detailed scale across the entire CR. An additional aim was to assess the main drivers affecting the biodiversity of habitat types. The GLOBIO3 model was adapted to CZ-GLOBIO by adapting global to local scales and using habitat quality and naturalness data instead of species occurrence data. The total mean species abundance (MSA) index of habitat quality, calculated from the spatial overlay of the four MSA indicators by our new equation, reached the value 0.62. The total value of MSA for natural and near-natural habitats was found to be affected mainly by infrastructure development and fragmentation. Simultaneously, intensity of land use change and atmospheric nitrogen deposition contributed primarily to the low total value of MSA for distant natural habitats. The CZ-GLOBIO model can be an important tool in political decision making to reduce the impact of the main drivers on habitat biodiversity in the CR.


Symmetry ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1159
Author(s):  
B. Günay ◽  
Praveen Agarwal ◽  
Juan L. G. Guirao ◽  
Shaher Momani

Eco-epidemiological can be considered as a significant combination of two research fields of computational biology and epidemiology. These problems mainly take ecological systems into account of the impact of epidemiological factors. In this paper, we examine the chaotic nature of a computational system related to the spread of disease into a specific environment involving a novel differential operator called the Atangana–Baleanu fractional derivative. To approximate the solutions of this fractional system, an efficient numerical method is adopted. The numerical method is an implicit approximate method that can provide very suitable numerical approximations for fractional problems due to symmetry. Symmetry is one of the distinguishing features of this technique compared to other methods in the literature. Through considering different choices of parameters in the model, several meaningful numerical simulations are presented. It is clear that hiring a new derivative operator greatly increases the flexibility of the model in describing the different scenarios in the model. The results of this paper can be very useful help for decision-makers to describe the situation related to the problem, in a more efficient way, and control the epidemic.


2019 ◽  
Vol 16 (19) ◽  
pp. 3883-3910 ◽  
Author(s):  
Lina Teckentrup ◽  
Sandy P. Harrison ◽  
Stijn Hantson ◽  
Angelika Heil ◽  
Joe R. Melton ◽  
...  

Abstract. Understanding how fire regimes change over time is of major importance for understanding their future impact on the Earth system, including society. Large differences in simulated burned area between fire models show that there is substantial uncertainty associated with modelling global change impacts on fire regimes. We draw here on sensitivity simulations made by seven global dynamic vegetation models participating in the Fire Model Intercomparison Project (FireMIP) to understand how differences in models translate into differences in fire regime projections. The sensitivity experiments isolate the impact of the individual drivers on simulated burned area, which are prescribed in the simulations. Specifically these drivers are atmospheric CO2 concentration, population density, land-use change, lightning and climate. The seven models capture spatial patterns in burned area. However, they show considerable differences in the burned area trends since 1921. We analyse the trajectories of differences between the sensitivity and reference simulation to improve our understanding of what drives the global trends in burned area. Where it is possible, we link the inter-model differences to model assumptions. Overall, these analyses reveal that the largest uncertainties in simulating global historical burned area are related to the representation of anthropogenic ignitions and suppression and effects of land use on vegetation and fire. In line with previous studies this highlights the need to improve our understanding and model representation of the relationship between human activities and fire to improve our abilities to model fire within Earth system model applications. Only two models show a strong response to atmospheric CO2 concentration. The effects of changes in atmospheric CO2 concentration on fire are complex and quantitative information of how fuel loads and how flammability changes due to this factor is missing. The response to lightning on global scale is low. The response of burned area to climate is spatially heterogeneous and has a strong inter-annual variation. Climate is therefore likely more important than the other factors for short-term variations and extremes in burned area. This study provides a basis to understand the uncertainties in global fire modelling. Both improvements in process understanding and observational constraints reduce uncertainties in modelling burned area trends.


2019 ◽  
Vol 15 (1) ◽  
pp. 70 ◽  
Author(s):  
Warsilan Warsilan

As the capital of the province of East Kalimantan, Samarinda City developments has a rapid progress from year to year. Samarinda City Development has a tendency oriented towards infrastructure development without regard to the existence of the quality of the existing environment. Imbalance of development in Samarinda city is to start decreasing the water catchment area, so its make increasing intensity of flood in the Samarinda City. The purpose of this study was to analyze the impact of changes in land use in the Samarinda city on the ability of the water catchment area. This research method using descriptive approach, the data collection system of primary and secondary. Intensity flood in the Samarinda city  is increasing from year to year, this condition happened as a problem that always occurs during the rainy season. Current development trends, always take an area that should be an infiltration  area for Samarinda City. Culture and inadequate infrastructure conditions such as lack of system of drainage and polder, was another factor causing the high intensity of flood  in Samarinda City. Therefore, the relevant regulations development guidelines for Samarinda  City must consider all aspects of planning, in this case especially the important of a balance of cultivated land and protected areas or zones.Keywords: Changes in land use; intensity of puddles; Samarinda


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