scholarly journals fv3gfs-wrapper: a Python wrapper of the FV3GFS atmospheric model

2021 ◽  
Vol 14 (7) ◽  
pp. 4401-4409
Author(s):  
Jeremy McGibbon ◽  
Noah D. Brenowitz ◽  
Mark Cheeseman ◽  
Spencer K. Clark ◽  
Johann P. S. Dahm ◽  
...  
Keyword(s):  
Model Performance ◽  
Atmospheric Model ◽  
Simulation Software ◽  
Storage Model ◽  
High Productivity ◽  
Global Atmospheric Model ◽  
Performance Requirements ◽  
Wide Range ◽  
Stringent Performance ◽  
Cubed Sphere

Abstract. Simulation software in geophysics is traditionally written in Fortran or C++ due to the stringent performance requirements these codes have to satisfy. As a result, researchers who use high-productivity languages for exploratory work often find these codes hard to understand, hard to modify, and hard to integrate with their analysis tools. fv3gfs-wrapper is an open-source Python-wrapped version of the NOAA (National Oceanic and Atmospheric Administration) FV3GFS (Finite-Volume Cubed-Sphere Global Forecast System) global atmospheric model, which is coded in Fortran. The wrapper provides simple interfaces to progress the Fortran main loop and get or set variables used by the Fortran model. These interfaces enable a wide range of use cases such as modifying the behavior of the model, introducing online analysis code, or saving model variables and reading forcings directly to and from cloud storage. Model performance is identical to the fully compiled Fortran model, unless routines to copy the state in and out of the model are used. This copy overhead is well within an acceptable range of performance and could be avoided with modifications to the Fortran source code. The wrapping approach is outlined and can be applied similarly in other Fortran models to enable more productive scientific workflows.

scholarly journals fv3gfs-wrapper: a Python wrapper of the FV3GFS atmospheric model

2021 ◽  
Author(s):  
Jeremy McGibbon ◽  
Noah D. Brenowitz ◽  
Mark Cheeseman ◽  
Spencer K. Clark ◽  
Johann Dahm ◽  
...  
Keyword(s):  
Cloud Storage ◽  
Model Performance ◽  
Atmospheric Model ◽  
Simulation Software ◽  
Storage Model ◽  
High Productivity ◽  
Global Atmospheric Model ◽  
Performance Requirements ◽  
Wide Range ◽  
Stringent Performance

Abstract. Simulation software in geophysics is traditionally written in Fortran or C++ due to the stringent performance requirements these codes have to satisfy. As a result, these codes are often hard to understand, hard to modify and hard to interface with high-productivity languages used for exploratory work. fv3gfs-wrapper is an open-source Python-wrapped version of NOAA's FV3GFS global atmospheric model, which is coded in Fortran. The wrapper provides simple interfaces to progress the Fortran main loop and get or set state from the Fortran model. These interfaces enable a wide range of use cases such as modifying the behavior of the model, introducing online analysis code, or saving model state and reading forcings directly to and from cloud storage. Model performance is identical to the fully-compiled Fortran model, unless routines to copy state in and out of the model are used. This copy overhead is well within an acceptable range of performance, and could be avoided with modifications to the Fortran source code. The wrapping approach is outlined and can be applied similarly in other Fortran models to enable more productive scientific workflows.

scholarly journals Seasonal range test run with Global Eta Framework

2017 ◽  
Vol 14 ◽  
pp. 247-251 ◽  
Author(s):  
Dragan Latinović ◽  
Sin Chan Chou ◽  
Miodrag Rančić
Keyword(s):  
Model Performance ◽  
Seasonal Prediction ◽  
Atmospheric Model ◽  
Horizontal Resolution ◽  
Curvilinear Coordinates ◽  
Smooth Transition ◽  
Precipitation Pattern ◽  
Global Atmospheric Model ◽  
Coordinate Lines ◽  
Cubed Sphere

Abstract. Global Eta Framework (GEF) is a global atmospheric model developed in general curvilinear coordinates and capable of running on arbitrary rectangular quasi-uniform spherical grids, using stepwise (Eta) representation of the terrain. In this study, the model is run on a cubed-sphere grid topology, in a version with uniform Jacobians (UJ), which provides equal-area grid cells, and a smooth transition of coordinate lines across the edges of the cubed-sphere. Within a project at the Brazilian Center for Weather Forecasts and Climate Studies (CPTEC), a nonhydrostatic version of this model is under development and will be applied for seasonal prediction studies. This note describes preliminary tests with the GEF on the UJ cubed-sphere in which model performance is evaluated in seasonal simulations at a horizontal resolution of approximately 25 km, running in the hydrostatic mode. Comparison of these simulations with the ERA-Interim reanalyses shows that the 850 hPa temperature is underestimated, while precipitation pattern is mostly underestimated in tropical continental regions and overestimated in tropical oceanic regions. Nevertheless, the model is still able to well capture the main seasonal climate characteristics. These results will be used as a control run in further tests with the nonhydrostatic version of the model.

scholarly journals Seasonal Performance of a Nonhydrostatic Global Atmospheric Model on a Cubed‐Sphere Grid

2021 ◽  
Vol 8 (4) ◽  
Author(s):  
Jung‐Eun Esther Kim ◽  
Myung‐Seo Koo ◽  
Changhyun Yoo ◽  
Song‐You Hong
Keyword(s):  
Atmospheric Model ◽  
Global Atmospheric Model ◽  
Seasonal Performance ◽  
Cubed Sphere

Designing the Electricity Market with Energy Storage Devices

2020 ◽  
Vol 12 (12) ◽  
pp. 31-43
Author(s):  
Tatiana A. VASKOVSKAYA ◽  
◽  
Boris A. KLUS ◽  
Keyword(s):  
Energy Storage ◽  
Electricity Market ◽  
Power Flow ◽  
Optimal Power Flow ◽  
Storage Systems ◽  
Energy System ◽  
Energy Storage Systems ◽  
Storage Model ◽  
Optimal Power ◽  
Wide Range

The development of energy storage systems allows us to consider their usage for load profile leveling during operational planning on electricity markets. The paper proposes and analyses an application of an energy storage model to the electricity market in Russia with the focus on the day ahead market. We consider bidding, energy storage constraints for an optimal power flow problem, and locational marginal pricing. We show that the largest effect for the market and for the energy storage system would be gained by integration of the energy storage model into the market’s optimization models. The proposed theory has been tested on the optimal power flow model of the day ahead market in Russia of 10000-node Unified Energy System. It is shown that energy storage systems are in demand with a wide range of efficiencies and cycle costs.

scholarly journals Evaluating the accuracy and uncertainty of atmospheric and wave model hindcasts during severe events using model ensembles

2021 ◽  
Author(s):  
Ali Abdolali ◽  
Andre van der Westhuysen ◽  
Zaizhong Ma ◽  
Avichal Mehra ◽  
Aron Roland ◽  
...  
Keyword(s):  
Extreme Event ◽  
Numerical Models ◽  
Model Performance ◽  
Ground Truth ◽  
Wave Model ◽  
Atmospheric Model ◽  
Stationary Source ◽  
Source Point ◽  
Spectral Wave Model ◽  
Model Ensembles

AbstractVarious uncertainties exist in a hindcast due to the inabilities of numerical models to resolve all the complicated atmosphere-sea interactions, and the lack of certain ground truth observations. Here, a comprehensive analysis of an atmospheric model performance in hindcast mode (Hurricane Weather and Research Forecasting model—HWRF) and its 40 ensembles during severe events is conducted, evaluating the model accuracy and uncertainty for hurricane track parameters, and wind speed collected along satellite altimeter tracks and at stationary source point observations. Subsequently, the downstream spectral wave model WAVEWATCH III is forced by two sets of wind field data, each includes 40 members. The first ones are randomly extracted from original HWRF simulations and the second ones are based on spread of best track parameters. The atmospheric model spread and wave model error along satellite altimeters tracks and at stationary source point observations are estimated. The study on Hurricane Irma reveals that wind and wave observations during this extreme event are within ensemble spreads. While both Models have wide spreads over areas with landmass, maximum uncertainty in the atmospheric model is at hurricane eye in contrast to the wave model.

Thermal analysis method of electromagnetic linear actuator based on multiphysics coupling model

2021 ◽  
pp. 1-17
Author(s):  
Geng Wang ◽  
Renjing Gao ◽  
Qi Wang ◽  
Shutian Liu
Keyword(s):  
Thermal Analysis ◽  
Thermal Characteristics ◽  
Coupling Model ◽  
Analysis Method ◽  
Thermal Analysis Method ◽  
Performance Requirements ◽  
Wide Range ◽  
Multiphysics Coupling ◽  
Simulation And Experiment ◽  
Electromagnetic Linear Actuator

Electromagnetic linear actuators (ELAs) may be confronted with unsatisfactory performance when subjected to overheating. Therefore, it is significant to clarify its thermal characteristics and design the thermal performance requirements. A thermal analysis method based on multiphysics coupling model was presented, which uses the non-simplified loss distribution as the heat source to calculate the temperature field, adjusts the material properties by temperature, and considers the interaction between motion (including impact) and loss. More importantly, an improved universal equivalent winding to satisfy the condition of real compact concentrated winding was developed. Finally, the validity of this approach was verified through the experiment, and the regularity of temperature was summarized. The results show that the error of simulation and experiment is less than 6% and the permissible continuous operation frequency is no more than 30 Hz. The approach proposed in this paper can be employed not only to the ELA, but also to the design and analysis a wide range of electromagnetic machines.

SiC Semiconductor Applications - An Air Force Perspective

1996 ◽  
Vol 423 ◽  
Author(s):  
L. S. Rea
Keyword(s):  
Air Force ◽  
Device Performance ◽  
Full Potential ◽  
Materials Development ◽  
Device Development ◽  
Performance Requirements ◽  
Wide Range ◽  
The Status ◽  
Performance Results ◽  
High Temperature Electronic

AbstractThe Department of Defense (DoD) is investing in the development of Silicon Carbide (SiC) for a wide range of applications. Over the past year, SiC technology has demonstrated excellent device performance results for power devices, high temperature electronic devices and microwave devices. The materials growth and processing technology for SiC is now at a level of sufficient maturity to support substantial device development efforts. While there is still considerable materials and device research required for SiC to achieve it's full potential, the fundamental technology has been proven for several critical applications. A perspective on some Air Force device performance requirements will be presented. The status of SiC materials development, material limits to advances in device performance and issues relating to supporting technology will also be discussed.

scholarly journals Combined Vapor Permeation and Continuous Solid-State Distillation for Energy-Efficient Bioethanol Production

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2266
Author(s):  
Hongshen Li ◽  
Hongrui Liu ◽  
Yufang Li ◽  
Jilin Nan ◽  
Chen Shi ◽  
...  
Keyword(s):  
Solid State ◽  
Energy Efficient ◽  
Simulation Software ◽  
Separation Performance ◽  
Flow Sheet ◽  
Bioethanol Production ◽  
Permeate Flux ◽  
Rectification Column ◽  
Vapor Permeation ◽  
Wide Range

Extracting ethanol by steam directly from fermented solid-state bagasse is an emerging technology of energy-efficient bioethanol production. With continuous solid-state distillation (CSSD) approach, the vapor with more than 25 wt% ethanol flows out of the column. Conventionally, the vapor was concentrated to azeotrope by rectification column, which contributes most of the energy consumption in ethanol production. As an alternative, a process integrating CSSD and vapor permeation (VP) membrane separation was tested. In light of existing industrial application of NaA zeolite hydrophilic membrane for dehydration, the prospect of replacing rectification operation with hydrophobic membrane for ethanol enriching was mainly analyzed in this paper. The separation performance of a commercial PDMS/PVDF membrane in a wide range of ethanol–water-vapor binary mixture was evaluated in the experiment. The correlation of the separation factor and permeate flux at different transmembrane driving force was measured. The mass and energy flow sheet of proposed VP case and rectification case were estimated respectively with process simulation software based on experimental data. Techno-economic analysis on both cases was performed. The results demonstrated that the additional VP membrane cost was higher than the rectification column, but a lower utilities cost was required for VP. The discount payback period of supplementary cost for VP case was determined as 1.81 years compared with the membrane service lifetime of 3 years, indicating that the hybrid CSSD-VP process was more cost effective and energy efficient.

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