Posts by Collection

projects

Neural networks for accelerating numerics

Numerical methods are often limited by a CFL condition that limits the ability to take long timesteps. In collaboration with scientists at GFDL, we are investigating ways of using neural networks to predict ‘unroll’ a timeloop for a finite volume model and predict fluxes over multiple timesteps at once. In this way, we are mimicking a multi-dimensional, high CFL algorithm while still maintaining properties of conservation. The following image shows preliminary results using MOM6

Online, neural network inference for sub grid-scale physics

Neural networks trained on high-resolution data can ‘learn’ the relationships between the mean flow state variables and the turbulent terms. With scientists at NCAR and M2Lines, we have demonstrated the first implementations of using these neural networks online in climate-scale, ocean simulations. The image below is from a simulation performed on Frontier which we subseqently scaled to ~20,000 CPUs and ~5,000 AMD GPUs.

AI techniques applied to computational fluid dynamics

OpenFOAM, a widely-used, open-source CFD solver, has a wide user base. With the Data-driven Modeling Special Interest group, we explored a variety of cases where we could inject AI (and related) techniques to classic CFD problems. To give others in the community a starting point, we developed three cases: 1) training a CNN online and then using it to predict the motion of the mesh in the case of a moving airfoil (see the image below, red indicates that the neural network results in better mesh quality than the default algorithm) 2) implementing an online, distributed, PCA algorithm to calculate turbulent eigenmodes for a turbulent cylinder in a box 3) using Bayesian optimization to tune turbulence parameters for the Pitz and Daily combustion case.

publications

Mixed layer saturations of CFC-11, CFC-12, and SF6 in a global isopycnal model

Published in Journal of Geophysical Research: Oceans, 2013

Shao, Andrew E; Mecking, Sabine; Thompson, LuAnne; Sonnerup, Rolf E. "Mixed layer saturations of CFC-11, CFC-12, and SF6 in a global isopycnal model". Journal of Geophysical Research: Oceans, 2013.
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Properties of the Subantarctic Front and Polar Front from the skewness of sea level anomaly

Published in J. Geophys. Res. Oceans, 2015

Shao, Andrew E.; Gille, Sarah T.; Mecking, Sabine; Thompson, LuAnne. "Properties of the Subantarctic Front and Polar Front from the skewness of sea level anomaly". J. Geophys. Res. Oceans, 2015.
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Evaluating the use of 1‐D transit time distributions to infer the mean state and variability of oceanic ventilation

Published in JGR Oceans, 2016

Shao, Andrew E.; Mecking, Sabine; Thompson, LuAnne; Sonnerup, Rolf E.. "Evaluating the use of 1‐D transit time distributions to infer the mean state and variability of oceanic ventilation". JGR Oceans, 2016.
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The GFDL Global Ocean and Sea Ice Model OM4.0: Model Description and Simulation Features

Published in J Adv Model Earth Syst, 2019

Adcroft, Alistair; Anderson, Whit; Balaji, V.; Blanton, Chris; Bushuk, Mitchell; Dufour, Carolina O.; Dunne, John P.; Griffies, Stephen M.; Hallberg, Robert; Harrison, Matthew J.; Held, Isaac M.; Jansen, Malte F.; John, Jasmin G.; Krasting, John P.; Langenhorst, Amy R.; Legg, Sonya; Liang, Zhi; McHugh, Colleen; Radhakrishnan, Aparna; Reichl, Brandon G.; Rosati, Tony; Samuels, Bonita L.; Shao, Andrew; Stouffer, Ronald; Winton, Michael; Wittenberg, Andrew T.; Xiang, Baoqiang; Zadeh, Niki; Zhang, Rong. "The GFDL Global Ocean and Sea Ice Model OM4.0: Model Description and Simulation Features". J Adv Model Earth Syst, 2019.
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Modeled Impacts of Sea Ice Exchange Processes on Arctic Ocean Carbon Uptake and Acidification (1980–2015)

Published in JGR Oceans, 2020

Mortenson, Eric; Steiner, Nadja; Monahan, Adam H.; Hayashida, Hakase; Sou, Tessa; Shao, Andrew. "Modeled Impacts of Sea Ice Exchange Processes on Arctic Ocean Carbon Uptake and Acidification (1980–2015)". JGR Oceans, 2020.
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A General‐Coordinate, Nonlocal Neutral Diffusion Operator

Published in J Adv Model Earth Syst, 2020

Shao, Andrew E.; Adcroft, Alistair; Hallberg, Robert; Griffies, Stephen M.. "A General‐Coordinate, Nonlocal Neutral Diffusion Operator". J Adv Model Earth Syst, 2020.
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Ocean biogeochemistry in the Canadian Earth System Model version 5.0.3: CanESM5 and CanESM5-CanOE

Published in Geosci. Model Dev., 2021

Christian, James R.; Denman, Kenneth L.; Hayashida, Hakase; Holdsworth, Amber M.; Lee, Warren G.; Riche, Olivier G. J.; Shao, Andrew E.; Steiner, Nadja; Swart, Neil C.. "Ocean biogeochemistry in the Canadian Earth System Model version 5.0.3: CanESM5 and CanESM5-CanOE". Geosci. Model Dev., 2021.
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What causes the spread of model projections of ocean dynamic sea-level change in response to greenhouse gas forcing?

Published in Clim Dyn, 2021

Couldrey, Matthew P.; Gregory, Jonathan M.; Boeira Dias, Fabio; Dobrohotoff, Peter; Domingues, Catia M.; Garuba, Oluwayemi; Griffies, Stephen M.; Haak, Helmuth; Hu, Aixue; Ishii, Masayoshi; Jungclaus, Johann; Köhl, Armin; Marsland, Simon J.; Ojha, Sayantani; Saenko, Oleg A.; Savita, Abhishek; Shao, Andrew; Stammer, Detlef; Suzuki, Tatsuo; Todd, Alexander; Zanna, Laure. "What causes the spread of model projections of ocean dynamic sea-level change in response to greenhouse gas forcing?". Clim Dyn, 2021.
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Understanding AMOC stability: the North Atlantic Hosing Model Intercomparison Project

Published in Geosci. Model Dev., 2022

Jackson, Laura C.; Alastrué de Asenjo, Eduardo; Bellomo, Katinka; Danabasoglu, Gokhan; Haak, Helmuth; Hu, Aixue; Jungclaus, Johann; Lee, Warren; Meccia, Virna L.; Saenko, Oleg; Shao, Andrew; Swingedouw, Didier. "Understanding AMOC stability: the North Atlantic Hosing Model Intercomparison Project". Geosci. Model Dev., 2022.
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Anthropogenic Carbon Increase has Caused Critical Shifts in Aragonite Saturation Across a Sensitive Coastal System

Published in Global Biogeochemical Cycles, 2022

Jarníková, Tereza; Ianson, Debby; Allen, Susan E.; Shao, Andrew E.; Olson, Elise M.. "Anthropogenic Carbon Increase has Caused Critical Shifts in Aragonite Saturation Across a Sensitive Coastal System". Global Biogeochemical Cycles, 2022.
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Using Machine Learning at scale in numerical simulations with SmartSim: An application to ocean climate modeling

Published in Journal of Computational Science, 2022

Partee, Sam; Ellis, Matthew; Rigazzi, Alessandro; Shao, Andrew E.; Bachman, Scott; Marques, Gustavo; Robbins, Benjamin. "Using Machine Learning at scale in numerical simulations with SmartSim: An application to ocean climate modeling". Journal of Computational Science, 2022.
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The Role of Atlantic Basin Geometry in Meridional Overturning Circulation

Published in Journal of Physical Oceanography, 2022

Ragen, Sarah; Armour, Kyle C.; Thompson, LuAnne; Shao, Andrew; Darr, David. "The Role of Atlantic Basin Geometry in Meridional Overturning Circulation". Journal of Physical Oceanography, 2022.
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Representing Eddy Diffusion in the Surface Boundary Layer of Ocean Models With General Vertical Coordinates

Published in J Adv Model Earth Syst, 2023

Marques, Gustavo M.; Shao, Andrew E.; Bachman, Scott D.; Danabasoglu, Gokhan; Bryan, Frank O.. "Representing Eddy Diffusion in the Surface Boundary Layer of Ocean Models With General Vertical Coordinates". J Adv Model Earth Syst, 2023.
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Improvements in the Canadian Earth System Model (CanESM) through systematic model analysis: CanESM5.0 and CanESM5.1

Published in Geosci. Model Dev., 2023

Sigmond, Michael; Anstey, James; Arora, Vivek; Digby, Ruth; Gillett, Nathan; Kharin, Viatcheslav; Merryfield, William; Reader, Catherine; Scinocca, John; Swart, Neil; Virgin, John; Abraham, Carsten; Cole, Jason; Lambert, Nicolas; Lee, Woo-Sung; Liang, Yongxiao; Malinina, Elizaveta; Rieger, Landon; von Salzen, Knut; Seiler, Christian; Seinen, Clint; Shao, Andrew; Sospedra-Alfonso, Reinel; Wang, Libo; Yang, Duo. "Improvements in the Canadian Earth System Model (CanESM) through systematic model analysis: CanESM5.0 and CanESM5.1". Geosci. Model Dev., 2023.
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Clustering to characterize extreme marine conditions for the benthic region of the Northeastern Pacific continental margin

Published in Authorea Preprints, 2024

Holdsworth, Amber M; Shao, Andrew; Christian, James R. "Clustering to characterize extreme marine conditions for the benthic region of the Northeastern Pacific continental margin". Authorea Preprints, 2024.
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A Scale‐Dependent Analysis of the Barotropic Vorticity Budget in a Global Ocean Simulation

Published in J Adv Model Earth Syst, 2024

Khatri, Hemant; Griffies, Stephen M.; Storer, Benjamin A.; Buzzicotti, Michele; Aluie, Hussein; Sonnewald, Maike; Dussin, Raphael; Shao, Andrew. "A Scale‐Dependent Analysis of the Barotropic Vorticity Budget in a Global Ocean Simulation". J Adv Model Earth Syst, 2024.
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Combining machine learning with computational fluid dynamics using OpenFOAM and SmartSim

Published in Meccanica, 2024

Maric, Tomislav; Fadeli, Mohammed Elwardi; Rigazzi, Alessandro; Shao, Andrew; Weiner, Andre. "Combining machine learning with computational fluid dynamics using OpenFOAM and SmartSim". Meccanica, 2024.
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