Dr. Ronald M. Caplan

Computational Scientist
caplanr (at) predsci.com
Curriculum Vitae (pdf)

Predictive Science Inc.
9990 Mesa Rim Road, Suite 170
San Diego, CA 92121, United States

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Bio: Dr. Caplan is a computational scientist whose main interests are in developing and optimizing numerical methods for simulating physics-based models and their implementations in parallel high-performance-computing environments including GPU accelerators. His research currently focuses on the continued development and optimization of Predictive Science's magnetohydrodynamic codes used to study the solar corona and heliosphere, as well as providing computational solutions for additional projects.

Presentations

2025

Fortran Standard Parallelism on Grace-Hopper with Unified Memory
Ronald M. Caplan, Jeff Larkin, Miko M. Stulajter, and Jon A. Linker
Poster to be presented at the 2025
NVIDIA GPU Technology Conference.
March 17th-21st, 2025. San Jose, California, USA.

GPU Acceleration with the Fortran Standard Language
Ronald M. Caplan, Miko M. Stulajter, and Jon A. Linker
Poster presented at the
2025 SIAM Conference on Computational Science and Engineering.
March 3rd-7th, 2025. Forth Worth, Texas, USA.

CORHEL-CME , Open-source Flux Transport , Heliospheric Imaging
Ronald M. Caplan, et. al.
Talks presented at the 2025 COSPAR ISWAT Meeting.
February 10-14, 2025. Port Canaveral, Florida, USA.

2024

Portability of Fortran’s `do concurrent' on GPUs
Ronald M. Caplan, Miko M. Stuljater, and Jon A. Linker
Talk presented at the Open Accelerated Computing Summit 2024.
December 10th, 2024. Online.

Solar Corona Live! Predicting the 2024 Eclipse in Real Time
Ronald M. Caplan and Cooper Downs
Talk presented at the NASA exhibitor booth. at
Super Computing (SC) 24.
November 17th-22nd, 2024. Atlanta, Georgia, USA.
Click here to view details on the NASA SC24 page.

Portability of Fortran’s `do concurrent' on GPUs
Ronald M. Caplan, Miko M. Stuljater, Jon A. Linker, Jeff Larkin, Henry. A. Gabb,
Shiquan Su, Ivan Rodriguez, Zachary Tschirhart, and Nicholas Malaya
Talk presented at the 11th WACCPD workshop at
Super Computing (SC) 24.
November 18th, 2024. Atlanta, Georgia, USA.

Cosmic Breeze and Complexity Revealed
Ronald M. Caplan and Cooper Downs
Art exhibited at the Art of HPC at Super Computing (SC) 24.
November 19th-21st, 2024. Atlanta, Georgia, USA.
"Cosmic Breeze" can be also viewed on youtube here.

SWQU Workshop Day 2: Open-source Flux Transport (OFT)
SWQU Workshop Day 3: Solar Wind Generator (SWiG)
Ronald M. Caplan, Miko Stulajter, Jon Linker, Cooper Downs, James Turtle, Lisa Upton, Nick Arge,
Shaela I. Jones, Raphael Attié, Nick Arge, Carl Henney, and Bibhuti Jha
Talks presented at the 2024
SWQU Users meeting.
May 20th-23rd, 2024. Huntsville, Alabama, USA.
The workshop installation and assignment instructions can be viewed here.

Coronal Prediction for the 2024 Total Solar Eclipse: Boundary Conditions
Ronald M. Caplan, Cooper Downs, Jon A. Linker, James Turtle, Emily Mason, Lisa Upton,
Raphael Attié, Nick Arge, Carl Heney, Bibhuti Jha, and the Solar Orbiter PHI team.
Talk presented at the 2024
Triennial Earth-Sun Summit (TESS).
April 8th-12th, 2024. Dallas, Texas, USA.

Simulating Solar Storms on GPUs with Fortran Standard Parallelism
Ronald M. Caplan, Miko M. Stulajter, Jon A. Linker, Tibor Torok, Cooper Downs,
Andres Reyes, Viacheslav S. Titov, Roberto Lionello, and Pete Riley.
Talk presented at the 2024
NVIDIA GPU Technology Conference.
March 18th-21th, 2024. San Jose, California, USA.
The talk was recorded and is available on NVIDIA On-Demand.

2023

HipFT v1.0: An Open Source High-Performance Flux Transport Model
Ronald M. Caplan, Miko M. Stulajter, James A. Turtle, Jon A. Linker, Cooper Downs,
Lisa A. Upton, Charles Nicholos Arge, Raphael Attie, Carl J. Henney, and Nikoli Pogorelov
Poster presented at the
2023 Fall meeting of the American Geophysical Union (AGU).
December 11th-15th, 2021. San Francisco, California, USA.
The code can be downloaded from the Github repository here.

Early results using Fortran's `do concurrent` standard parallelism on
Intel GPUs with the IFX compiler
Ronald M. Caplan, Miko M. Stulajter, Cooper Downs, and Jon A. Linker
Talk presented at the
2023 Intel oneAPI DevSummit for AI and HPC
December 4th - 6th, 2023. Online.

Using Total Solar Eclipses as a Lens to Understand the Sun
Ronald M. Caplan, Cooper Downs, and Jon A. Linker
Talk presented at the NASA exhibitor booth. at
Super Computing (SC) 23.
November 12th-17th, 2023. Denver, Colorado, USA.
Click here to view details on the NASA SC23 page.

Recent Updates to the Solar Particle Event Threat Assessment Tool (STAT)
Ronald M. Caplan, Erika Palmerio, Jon A. Linker, Matthew A. Young, and Nathan A. Schwadron
Poster presented at the
54th Meeting of the SPD.
August 13th-18th, 2023.
Minneaplois, Minnesota, USA.

Accelerating a production Solar MHD code with Fortran standard parallelism
Ronald M. Caplan, Miko M. Stuljater, and Jon A. Linker
Talk presented for an OpenACC Webinar
July 11th, 2023. Online.

Evaluating a Practical Parabolic Time Step Limit for Unconditionally Stable Schemes
in a Thermodynamic MHD Model
Ronald M. Caplan, Craig D. Johnston, Lars K. S. Daldorff, and Jon A. Linker
Talk presented at the 15th ASTRONUM Conference.
June 25th-29th, 2023. Pasadena, California, USA.

Acceleration of a production Solar MHD code with Fortran standard parallelism:
From OpenACC to `do concurrent`
Ronald M. Caplan, Miko M. Stuljater, and Jon A. Linker
Talk presented at the 13th AsHES workshop held at the 37th IEEE IPDPS Symposium.
May 15th, 2023. St. Petersburg, Florida, USA.

ISC Student Cluster Competition HPC Application and Task Introduction: POT3D
Ronald M. Caplan.
Talk presented for the ISC Student Cluster Competition.
March 9th, 2023. Online.

2022

Make Your Own Solar Storms!
Ronald M. Caplan, Tibor Torok, Andres Reyes, and Cooper Downs
Talk presented at the NASA exhibitor booth at
Super Computing (SC) 22. November 13th-18th, 2022. Dallas, Texas, USA.
Click here to view details on the NASA SC22 page.

Numerical Modeling of Solar Storm Dynamics from the Sun to Earth
Ronald M. Caplan.
Talk presented at the CSRC Colloquium.
September 23rd, 2022. San Diego State University.

An Open Source Flux Transport Model
Ronald M. Caplan, James A. Turtle, Jon A. Linker, Lisa Upton, Nick Arge,
Raphael Attie, Cooper Downs, Carl J. Henney, and Nikolai Pogorelov
Poster presented at the 2022
TESS Meeting.
August 8th - August 11th, 2022. Bellevue, Washington, USA.

Interactive Tool for Modeling Multiple Solar Eruptions from Sun to Earth
Ronald M. Caplan, Tibor Torok, Cooper Downs, Andres Reyes,
Viacheslav Titov, Roberto Lionello, and Jon A. Linker
Poster presented at the 2022
SHINE Meeting.
June 26th - July 1st, 2022. Honolulu, Hawaii, USA.

Speeding up a banded-matrix solver by 3x using the updated cuSparse library
Ronald M. Caplan, Miko Stulajter, and Jon A. Linker.
Talk presented at the NVIDIA GPU Technology Conference.
March 21st-24th, 2022. Virtual.
The talk can be viewed here.

2021

Open-Source High-Performance Flux Transport
Ronald M. Caplan, Lisa Upton, Jon A. Linker, Charles Nick Arge, Raphael Attie,
Cooper Downs and Carl J. Henney
Poster presented at the 2021
Fall meeting of the American Geophysical Union (AGU).
December 13th-17th, 2021. New Orleans, Louisiana, USA.

Can Fortran's `do concurrent' Replace Directives for Accelerated Computing?
Ronald M. Caplan, Miko Stulajter, and Jon A. Linker.
Talk presented at
OpenACC Birds of a Feather at Supercomputing 2021.
November 16th, 2021. St. Louis, Missouri, USA.

Optimizing Stencil Operations in OpenACC
Ronald M. Caplan, Jon A. Linker, Cooper Downs, Roberto Lionello, Andres Reyes,
Pete Riley, Viacheslav Titov, and Tibor Torok.
Talk presented for
On-Demand NVIDIA Webinar.
January 14th, 2021. Virtual.

2020

Mitigation of Coronal Hole Obscuration for Open Flux Estimates
Ronald M. Caplan, Cooper Downs, and Jon A. Linker.
Poster presented at the 2020
Fall meeting of the American Geophysical Union (AGU).
December 1st-17th, 2020. Virtual.

Optimizing Stencil Operations in OpenACC
Ronald M. Caplan and Jon A. Linker.
Poster presented at the 2020
NVIDIA GPU Technology Conference.
March 23rd-26th, 2020. Virtual.

2019

Preparing photospheric magnetic field measurements
for use in coronal and heliospheric models
Ronald M. Caplan, Cooper Downs, and Jon A. Linker.
Poster presented at the 2019
Fall meeting of the American Geophysical Union (AGU).
December 9th-13th, 2019. San Francisco, California, USA.

Teaching Your Legacy Code New (GPU) Tricks
Ronald M. Caplan and Jon A. Linker
Poster and talk presented at the NASA exhibitor booth at
Super Computing (SC) 19. November 17th-21st, 2019. Denver, Colorado, USA.
Click here to view details on the NASA SC19 page.

Variations in Finite Difference Potential Fields
Download High-Resolution Q-Map:
[FULL 16000x8000 (121MB)] [HALF 8000x4000 (45MB)] [QUARTER 4000x2000 (14MB)] [SMALL 1600x800 (3MB)]
Ronald M. Caplan, Cooper Downs, and Jon A. Linker.
Poster presented at the 2019 SHINE Meeting.
August 5th-9th, 2019. Boulder, Colorado, USA.

Accelerating the Solar Wind with OpenACC
Ronald M. Caplan, Jon A. Linker, Zoran Mikic, Roberto Lionello, Pete Riley, and Cooper Downs.
Poster presented at the 2019
NVIDIA GPU Technology Conference.
March 18th-21st, 2019. San Jose, California, USA.

2018

Coronal Hole Obscuration and Open Flux
Ronald M. Caplan, Cooper Downs, Jon A. Linker, and Zoran Mikic.
Poster presented at the 2018
Fall meeting of the American Geophysical Union (AGU).
December 10th-14th, 2018. Washington DC, USA.

Shields Up! Towards Forecasting Solar Particle Threats Through Simulation
Ronald M. Caplan, Jon A. Linker, Cooper Downs, Zoran Mikić, Roberto Lionello, Tibor Török, Janvier Wijaya
Poster and talk presented at the NASA exhibitor booth at
Super Computing (SC) 18. November 11th-16th, 2018. Dallas, Texas, USA.
Click here to view details on the NASA SC18 page.

GPU-accelerating Established Science Applications with OpenACC:
Experiences, Results, and Development Tips
Ronald M. Caplan, Jon A. Linker, and Zoran Mikic.
Talk presented at the
OpenACC User Group Meeting @ SC18.
November 13th, 2018. Dallas, Texas, USA.

Linux Laptop + NVIDIA GPU: Running GPU Codes using Bumblebee
Ronald M. Caplan.
Talk presented at the
OpenACC User Group Meeting @ SC18.
November 13th, 2018. Dallas, Texas, USA.

Effect of Coronal Hole Obscuration on Open Flux Measurements
Ronald M. Caplan, Cooper Downs, Jon A. Linker, and Zoran Mikic.
Poster presented at the 2018
SHINE Meeting.
July 30th-August 3rd, 2018. Cocoa Beach, Florida, USA.

GPU-acceleration of an Established Solar MHD code using OpenACC
Ronald M. Caplan, Jon A. Linker, Zoran Mikic, Cooper Downs, and Tibor Torok.
Talk given at
ASTRONUM 2018.
June 25th-29th, 2018. Panama City Beach, Florida, USA.

Solar Storm Modeling using OpenACC:
From HPC cluster to “in-house”
Ronald M. Caplan, Jon A. Linker, Cooper Downs, Tibor Török, Zoran Mikić,
Roberto Lionello, Viacheslav Titov, Pete Riley, and Janvier Wijaya.
Talk given at the 2018
NVIDIA GPU Technology Conference.
March 26th-29th, 2018. San Jose, California, USA.
The talk was recorded and can be viewed here.

2017

Totality! Predicting the Corona of the 2017 Great American Solar Eclipse
Ronald M. Caplan, Zoran Mikić, Cooper Downs, Jon A. Linker, Pete Riley, Roberto Lionello, Tibor Török, Viacheslav Titov, Janvier Wijaya
Poster and talk presented at the NASA exhibitor booth at
Super Computing (SC) 17. November 12th-16th, 2017. Denver, Colorado, USA.
Click here to view details on the NASA SC17 page.
This work was awarded HPCwire's 2017 Readers Choice Award for "Top HPC-Enabled Scientific Achievement".

Using Coronal Hole Maps to Constrain MHD Models
Ronald M. Caplan, Cooper Downs, Zoran Mikic, and Jon A. Linker.
Poster presented at the
48th meeting of the Solar Physics Division of the American Astronomical Society.
August 21st-25th, 2017. Portland, Oregon, USA.

Potential Field Solutions of the Solar Corona:
Converting a PCG Solver from MPI to MPI+OpenACC
Ronald M. Caplan, Jon A. Linker, and Zoran Mikic.
Talk given at the 2017
NVIDIA GPU Technology Conference.
May 8th-11th, 2017. San Jose, California, USA.
The talk was recorded and can be viewed here.
Further details were presented at the user-feedback session of the July 24th, 2017 OpenACC Technical Committeee Meeting.
Those slides can be viewed here.

2016

A Free Database of Auto-detected Full-sun Coronal Hole Maps
Ronald M. Caplan, Cooper Downs, and Jon A. Linker.
Poster presented at the 2016
Fall meeting of the American Geophysical Union (AGU).
December 12th-16th, 2016. San Francisco, California, USA.

Advancing parabolic operators in thermodynamic MHD models:
Explicit super time-stepping vs. implicit methods with Krylov solvers
Ronald M. Caplan, Zoran Mikic, Jon A. Linker, and Roberto Lionello.
Poster presented at
Super Computing (SC) 16.
November 13th-18th, 2016. Salt Lake City, Utah, USA.
The extended two-page abstract can be viewed here

A freely available 4-yr database of synchronic full-sun EUV and coronal hole maps
Ronald M. Caplan, Cooper Downs, and Jon A. Linker.
Poster presented at the 2016
SHINE Meeting.
July 11th-15th, 2016. Santa Fe, New Mexico, USA.

Advancing parabolic operators in thermodynamic MHD models:
Explicit super time-stepping versus implicit schemes with Krylov solvers
Ronald M. Caplan, Zoran Mikic, Jon A. Linker, and Roberto Lionello.
Talk given at
ASTRONUM 2016.
June 6th-10th, 2016. Monterey, California, USA.
Click here to read the conference proceedings paper.

Non-uniform diffusion of the Solar surface magnetic field:
Code acceleration using OpenACC for both GPUs and x86
Ronald M. Caplan, Cooper Downs, and Zoran Mikic.
Poster presented at the 2016
NVIDIA GPU Technology Conference.
April 4th-7th, 2016. San Jose, California, USA.

2015

Full-sun synchronic EUV and coronal hole mapping using multi-instrument images:
Data and software made available
Ronald M. Caplan, Cooper Downs, and Jon A. Linker.
Talk given at the 2015
Fall meeting of the American Geophysical Union (AGU).
December 14th-18th, 2015. San Francisco, California, USA.

Unlocking the Secrets of Solar Storms
Ronald M. Caplan, Cooper Downs, Jon A. Linker, Roberto Lionello, Zoran Mikić, Pete Riley, Viacheslav Titov, Tibor Török
Poster and talk presented at the NASA exhibitor booth at
Super Computing (SC) 15
November 15th-20th, 2015. Austin, Texas, USA.
Click here to view details on the NASA SC15 page.

2014

Automatic Time-Dependent Coronal Hole Maps using Synchronized Multi-instrument EUV Data
Ronald M. Caplan, Cooper Downs, and Jon A. Linker.
Poster presented at the 2014
Fall meeting of the American Geophysical Union (AGU).
December 15th-19th, 2014. San Francisco, California, USA.

2013

Nonlinear Schrödinger Equation Multidimensional Matlab-based GPU-accelerated Integrators using Compact high-order schemes
Ronald M. Caplan and Ricardo Carretero.
Poster presented at the 2013
NVIDIA GPU Technology Conference.
March 24th-27th, 2013. San Jose, California, USA.