scholarly journals A new distributed algorithm for routing network generation in model coupling and its evaluation based on C-Coupler2

2020 ◽  
Author(s):  
Hao Yu ◽  
Li Liu ◽  
Chao Sun ◽  
Ruizhe Li ◽  
Xinzhu Yu ◽  
...  
Keyword(s):  
Distributed Algorithm ◽  
Data Transfer ◽  
System Modeling ◽  
Earth System ◽  
Major Step ◽  
Earth System Modeling ◽  
Network Generation ◽  
Collective Communications ◽  
Component Models ◽  
Processor Cores

Abstract. It is a fundamental functionality of a coupler for Earth system modeling to efficiently handle data transfer between component models. Routing network generation is a major step for initializing the data transfer functionality. Most existing couplers employ an inefficient and unscalable global implementation for routing network generation that relies on collective communications. That’s a main reason why the initialization cost of a coupler increases rapidly when using more processor cores. In this paper, we propose a new Distributed algorithm for Routing network generation (DaRong), which does not introduce any collective communication and achieves much lower complexities than the global implementation. DaRong is of course much more efficient and scalable than the global implementation, which has been further demonstrated via empirical evaluations. DaRong has already been implemented in C-Coupler2. We believe that existing and future couplers can also benefit from it.

scholarly journals DiRong1.0: a distributed implementation for improving routing network generation in model coupling

2020 ◽  
Vol 13 (12) ◽  
pp. 6253-6263
Author(s):  
Hao Yu ◽  
Li Liu ◽  
Chao Sun ◽  
Ruizhe Li ◽  
Xinzhu Yu ◽  
...  
Keyword(s):  
Data Transfer ◽  
System Model ◽  
Model Coupling ◽  
Earth System ◽  
Major Step ◽  
Network Generation ◽  
Broadcast Communication ◽  
Distributed Implementation ◽  
Component Models ◽  
Processor Cores

Abstract. A fundamental functionality of model coupling in an Earth system model is to efficiently handle data transfer between component models. An approach of M×N communication following a routing network has been used widely used for data transfer, and routing network generation becomes a major step required to initialize data transfer functionality. Some existing coupling software such as the Model Coupling Toolkit (MCT) and the existing versions of the Community Coupler (C-Coupler) employ a global implementation of routing network generation that relies on gather–broadcast communications, which can be very inefficient under a case of a large number of processes. This is an important reason why the initialization cost of a coupler increases with the number of processor cores. In this paper, we propose a “distributed implementation for routing network generation, version 1.0” (DiRong1.0), which does not introduce any gather–broadcast communication. Empirical evaluations show that DiRong1.0 is much more efficient than the global implementation. DiRong1.0 has already been implemented in C-Coupler2, and we believe that some other couplers can also benefit from it.

scholarly journals C-Coupler1: a Chinese community coupler for Earth system modeling

2014 ◽  
Vol 7 (5) ◽  
pp. 2281-2302 ◽  
Author(s):  
L. Liu ◽  
G. Yang ◽  
B. Wang ◽  
C. Zhang ◽  
R. Li ◽  
...  
Keyword(s):  
System Modeling ◽  
Software Tool ◽  
Earth System ◽  
Software Platform ◽  
Coupled Models ◽  
Earth System Modeling ◽  
Parallel Performance ◽  
Runtime Environment ◽  
High Level ◽  
Component Models

Abstract. A coupler is a fundamental software tool for Earth system modeling. Targeting the requirements of 3-D coupling, high-level sharing, common model software platform and better parallel performance, we started to design and develop a community coupler (C-Coupler) from 2010 in China, and finished the first version (C-Coupler1) recently. C-Coupler1 is a parallel 3-D coupler that achieves the same (bitwise-identical) results with any number of processes. Guided by the general design of C-Coupler, C-Coupler1 enables various component models and various coupled models to be integrated on the same common model software platform to achieve a higher-level sharing, where the component models and the coupler can keep the same code version in various model configurations for simulation. Moreover, it provides the C-Coupler platform, a uniform runtime environment for operating various kinds of model simulations in the same manner. C-Coupler1 is ready for Earth system modeling, and it is publicly available. In China, there are more and more modeling groups using C-Coupler1 for the development and application of models.

scholarly journals A European Network for Earth System Modeling

Eos ◽  
2007 ◽  
Vol 88 (12) ◽  
pp. 143 ◽  
Author(s):  
Sophie Valcke ◽  
Reinhard Budich ◽  
Mick Carter ◽  
Eric Guilyardi ◽  
Marie-Alice Foujols ◽  
...  
Keyword(s):  
System Modeling ◽  
Earth System ◽  
European Network ◽  
Earth System Modeling

scholarly journals Bitwise identical compiling setup: prospective for reproducibility and reliability of Earth system modeling

2016 ◽  
Vol 9 (2) ◽  
pp. 731-748 ◽  
Author(s):  
R. Li ◽  
L. Liu ◽  
G. Yang ◽  
C. Zhang ◽  
B. Wang
Keyword(s):  
System Modeling ◽  
Computer Software ◽  
Scientific Research ◽  
Test Cases ◽  
Earth System ◽  
Earth System Modeling ◽  
Software Bugs ◽  
Fast Development ◽  
Software And Hardware ◽  
Simulation Results

Abstract. Reproducibility and reliability are fundamental principles of scientific research. A compiling setup that includes a specific compiler version and compiler flags is an essential technical support for Earth system modeling. With the fast development of computer software and hardware, a compiling setup has to be updated frequently, which challenges the reproducibility and reliability of Earth system modeling. The existing results of a simulation using an original compiling setup may be irreproducible by a newer compiling setup because trivial round-off errors introduced by the change in compiling setup can potentially trigger significant changes in simulation results. Regarding the reliability, a compiler with millions of lines of code may have bugs that are easily overlooked due to the uncertainties or unknowns in Earth system modeling. To address these challenges, this study shows that different compiling setups can achieve exactly the same (bitwise identical) results in Earth system modeling, and a set of bitwise identical compiling setups of a model can be used across different compiler versions and different compiler flags. As a result, the original results can be more easily reproduced; for example, the original results with an older compiler version can be reproduced exactly with a newer compiler version. Moreover, this study shows that new test cases can be generated based on the differences of bitwise identical compiling setups between different models, which can help detect software bugs in the codes of models and compilers and finally improve the reliability of Earth system modeling.

scholarly journals Global land use for 2015–2100 at 0.05° resolution under diverse socioeconomic and climate scenarios

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Min Chen ◽  
Chris R. Vernon ◽  
Neal T. Graham ◽  
Mohamad Hejazi ◽  
Maoyi Huang ◽  
...  
Keyword(s):  
Land Use ◽  
Global Change ◽  
System Modeling ◽  
Earth System ◽  
Analysis Model ◽  
Change Analysis ◽  
Rcp Scenarios ◽  
Earth System Modeling ◽  
Modeling Studies ◽  
Important Input

Abstract Global future land use (LU) is an important input for Earth system models for projecting Earth system dynamics and is critical for many modeling studies on future global change. Here we generated a new global gridded LU dataset using the Global Change Analysis Model (GCAM) and a land use spatial downscaling model, named Demeter, under the five Shared Socioeconomic Pathways (SSPs) and four Representative Concentration Pathways (RCPs) scenarios. Compared to existing similar datasets, the presented dataset has a higher spatial resolution (0.05° × 0.05°) and spreads under a more comprehensive set of SSP-RCP scenarios (in total 15 scenarios), and considers uncertainties from the forcing climates. We compared our dataset with the Land Use Harmonization version 2 (LUH2) dataset and found our results are in general spatially consistent with LUH2. The presented dataset will be useful for global Earth system modeling studies, especially for the analysis of the impacts of land use and land cover change and socioeconomics, as well as the characterizing the uncertainties associated with these impacts.

Ocean Chlorophyll as a Precursor of ENSO: An Earth System Modeling Study

2018 ◽  
Vol 45 (4) ◽  
pp. 1939-1947 ◽  
Author(s):  
Jong-Yeon Park ◽  
John P. Dunne ◽  
Charles A. Stock
Keyword(s):  
System Modeling ◽  
Earth System ◽  
Earth System Modeling ◽  
Modeling Study
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