scholarly journals Grid-stretching capability for the GEOS-Chem 13.0.0 atmospheric chemistry model

2021 ◽  
Vol 14 (10) ◽  
pp. 5977-5997
Author(s):  
Liam Bindle ◽  
Randall V. Martin ◽  
Matthew J. Cooper ◽  
Elizabeth W. Lundgren ◽  
Sebastian D. Eastham ◽  
...  

Abstract. Modeling atmospheric chemistry at fine resolution globally is computationally expensive; the capability to focus on specific geographic regions using a multiscale grid is desirable. Here, we develop, validate, and demonstrate stretched grids in the GEOS-Chem atmospheric chemistry model in its high-performance implementation (GCHP). These multiscale grids are specified at runtime by four parameters that offer users nimble control of the region that is refined and the resolution of the refinement. We validate the stretched-grid simulation versus global cubed-sphere simulations. We demonstrate the operation and flexibility of stretched-grid simulations with two case studies that compare simulated tropospheric NO2 column densities from stretched-grid and cubed-sphere simulations to retrieved column densities from the TROPOspheric Monitoring Instrument (TROPOMI). The first case study uses a stretched grid with a broad refinement covering the contiguous US to produce simulated columns that perform similarly to a C180 (∼ 50 km) cubed-sphere simulation at less than one-ninth the computational expense. The second case study experiments with a large stretch factor for a global stretched-grid simulation with a highly localized refinement with ∼10 km resolution for California. We find that the refinement improves spatial agreement with TROPOMI columns compared to a C90 cubed-sphere simulation of comparable computational demands. Overall, we find that stretched grids in GEOS-Chem are a practical tool for fine-resolution regional- or continental-scale simulations of atmospheric chemistry. Stretched grids are available in GEOS-Chem version 13.0.0.

2020 ◽  
Author(s):  
Liam Bindle ◽  
Randall V. Martin ◽  
Matthew J. Cooper ◽  
Elizabeth W. Lundgren ◽  
Sebastian D. Eastham ◽  
...  

Abstract. Modeling atmospheric chemistry at fine resolution globally is computationally expensive; the capability to focus on specific geographic regions using a multiscale grid is desirable. Here, we develop, validate, and demonstrate stretched-grids in the GEOS-Chem atmospheric chemistry model in its high performance implementation (GCHP). These multiscale grids are specified at runtime by four parameters that offer users nimble control of the region that is refined and the resolution of the refinement. We validate the stretched-grid simulation versus global cubed-sphere simulations. We demonstrate the operation and flexibility of stretched-grid simulations with two case studies that compare simulated tropospheric NO2 column densities from stretched-grid and cubed-sphere simulations to retrieved column densities from the TROPOspheric Monitoring Instrument (TROPOMI). The first case study uses a stretched-grid with a broad refinement covering the contiguous US to produce simulated columns that perform similarly to a C180 (~50 km) cubed-sphere simulation at less than one-ninth the computational expense. The second case study experiments with a large stretch-factor for a global stretched-grid simulation with a highly localized refinement with ~10 km resolution for California. We find that the refinement improves spatial agreement with TROPOMI columns compared to a C90 cubed-sphere simulation of comparable computational demands, despite conducting the simulation at a finer resolution than parent meteorological fields. Overall we find that stretched-grids in GEOS-Chem are a practical tool for fine resolution regional- or continental-scale simulations of atmospheric chemistry. Stretched-grids are available in GEOS-Chem version 13.0.0.


2014 ◽  
Vol 7 (1) ◽  
pp. 203-210 ◽  
Author(s):  
A. Colette ◽  
B. Bessagnet ◽  
F. Meleux ◽  
E. Terrenoire ◽  
L. Rouïl

Abstract. The first pan-European kilometre-scale atmospheric chemistry simulation is introduced. The continental-scale air pollution episode of January 2009 is modelled with the CHIMERE offline chemistry transport model with a massive grid of 2 million horizontal points, performed on 2000 CPU of a high-performance computing system hosted by the Research and Technology Computing Center at the French Alternative Energies and Atomic Energy Commission (CCRT/CEA). Besides the technical challenge, we find that model biases are significantly reduced, especially over urban areas. The high-resolution grid also allows revisiting of the contribution of individual city plumes to the European burden of pollution, providing new insights to target the appropriate geographical level of action when designing air pollution mitigation strategies.


2021 ◽  
pp. 643-665
Author(s):  
Marco Tamborini

Abstract This paper investigates the mechanisms of knowledge production of twenty-first century robotics-inspired morphology. How robotics influences investigations into the structure, development, and change of organic forms? Which definition of form is presupposed by this new approach to the study of form? I answer these questions by investigating how robots are used to understand and generate new questions about the locomotion of extinct animals in the first case study and in high-performance fishes in the second case study. After having illustrated the landscape of twentieth-century morphology, I will reflect on the definition of form adopted in twenty-first century robotics-inspired morphology as well as on the differences between this approach to the study of form and the so-called nature-inspired disciplines, such as bionics or biomimetics. In the conclusion, I suggest that we are now in a material turn in morphology, characterized by the coexistence of the robotic, the virtual, and the real, which enables an understanding of how the structures and dynamics of shapes change over time.


2015 ◽  
Vol 7 (2) ◽  
pp. 443-457 ◽  
Author(s):  
Wanghui Jing ◽  
Ru Yan ◽  
Yitao Wang

A MIM-IDA-EPI-based strategy was proposed as a practical tool for the comprehensive characterization of the chemical profile of Mori Cortex.


Author(s):  
Ciro A. Rodriguez ◽  
Horacio Ahuett ◽  
Alex Elias ◽  
Arturo Molina ◽  
Carlos Ortega ◽  
...  

This paper describes an undergraduate research program recently established at the Instituto Tecnolo´gico y de Estudios Superiores de Monterrey (ITESM). The motivation, structure and expected benefits of this program are presented. Early results are illustrated through case studies. The first case study focuses on the evaluation of cycle time and contouring error in high performance machining centers. Contouring error measurement is conducted with a Heidenhain Grid Encoder on several high performance machining centers and tool path shapes. The second case study focuses on the development of an experimental micro-positioning systems based on compliant mechanisms and smart materials for actuation.


2013 ◽  
Vol 6 (3) ◽  
pp. 4189-4205
Author(s):  
A. Colette ◽  
B. Bessagnet ◽  
F. Meleux ◽  
L. Rouïl

Abstract. The first pan-European kilometre-scale atmospheric chemistry simulation is introduced. The continental-scale air pollution episode of January 2009 is modelled with the CHIMERE offline chemistry-transport model with a massive grid of 2 million horizontal points, performed on 2000 CPU of a high performance computing system hosted by the Research and Technology Computing Center at the French Alternative Energies and Atomic Energy Commission (CCRT/CEA). Besides the technical challenge, we find that model biases are significantly reduced, especially over urban areas. The high resolution grid also allows revisiting the contribution of individual city plumes to the European burden of pollution, providing new insights for designing air pollution control strategies.


2019 ◽  
pp. 123-130

The scientific research works concerning the field of mechanical engineering such as, manufacturing machine slate, soil tillage, sowing and harvesting based on the requirements for the implementation of agrotechnical measures for the cultivation of plants in its transportation, through the development of mastering new types of high-performance and energy-saving machines in manufacturing machine slate, creation of multifunctional machines, allowing simultaneous soil cultivation, by means of several planting operations, integration of agricultural machine designs are taken into account in manufacturing of the local universal tractor designed basing on high ergonomic indicators. For this reason, this article explores the use of case studies in teaching agricultural terminology by means analyzing the researches in machine building. Case study method was firstly used in 1870 in Harvard University of Law School in the United States. Also in the article, we give the examples of agricultural machine-building terms, teaching terminology and case methods, case study process and case studies method itself. The research works in the field of mechanical engineering and the use of case studies in teaching terminology have also been analyzed. In addition, the requirements for the development of case study tasks are given in their practical didactic nature. We also give case study models that allow us analyzing and evaluating students' activities.


Author(s):  
Kathryn M. de Luna

This chapter uses two case studies to explore how historians study language movement and change through comparative historical linguistics. The first case study stands as a short chapter in the larger history of the expansion of Bantu languages across eastern, central, and southern Africa. It focuses on the expansion of proto-Kafue, ca. 950–1250, from a linguistic homeland in the middle Kafue River region to lands beyond the Lukanga swamps to the north and the Zambezi River to the south. This expansion was made possible by a dramatic reconfiguration of ties of kinship. The second case study explores linguistic evidence for ridicule along the Lozi-Botatwe frontier in the mid- to late 19th century. Significantly, the units and scales of language movement and change in precolonial periods rendered visible through comparative historical linguistics bring to our attention alternative approaches to language change and movement in contemporary Africa.


Author(s):  
A.C.C. Coolen ◽  
A. Annibale ◽  
E.S. Roberts

This chapter reviews graph generation techniques in the context of applications. The first case study is power grids, where proposed strategies to prevent blackouts have been tested on tailored random graphs. The second case study is in social networks. Applications of random graphs to social networks are extremely wide ranging – the particular aspect looked at here is modelling the spread of disease on a social network – and how a particular construction based on projecting from a bipartite graph successfully captures some of the clustering observed in real social networks. The third case study is on null models of food webs, discussing the specific constraints relevant to this application, and the topological features which may contribute to the stability of an ecosystem. The final case study is taken from molecular biology, discussing the importance of unbiased graph sampling when considering if motifs are over-represented in a protein–protein interaction network.


1989 ◽  
Vol 170 ◽  
Author(s):  
Benjamin S. Hsiao ◽  
J. H. Eric

AbstractTranscrystallization of semicrystalline polymers, such as PEEK, PEKK and PPS, in high performance composites has been investigated. It is found that PPDT aramid fiber and pitch-based carbon fiber induce a transcrystalline interphase in all three polymers, whereas in PAN-based carbon fiber and glass fiber systems, transcrystallization occurs only under specific circumstances. Epitaxy is used to explain the surface-induced transcrystalline interphase in the first case. In the latter case, transcrystallization is probably not due to epitaxy, but may be attributed to the thermal conductivity mismatch. Plasma treatment on the fiber surface showed a negligible effect on inducing transcrystallization, implying that surface-free energy was not important. A microdebonding test was adopted to evaluate the interfacial strength between the fiber and matrix. Our preliminary results did not reveal any effect on the fiber/matrix interfacial strength of transcrystallinity.


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