### SCIENCE SUB-PAGES

Select the sub-page you would like to go to below:

# PUBLICATIONS

### 2024

On the Origin of the sudden Heliospheric Open Magnetic Flux Enhancement

during the 2014 Pole Reversal

S.G. Heinemann, M. J. Owens, M. Temmer, J. A. Turtle, C. N. Arge, C. J. Henney,

J. Pomoell, E. Asvestari, J. A. Linker, C. Downs, R. M. Caplan, S. J. Hofmeister,

C. Scolini, R. F. Pinto, and M. S. Madjarska

*The Astrophysical Journal*.**Accepted**(2024). PDF (Coming Soon).Improved modelling of SEP event onset within the WSA–Enlil–SEPMOD framework

E. Palmerio, J.G. Luhmann, L. M. Mays, R. M. Caplan, D. Lario, I.G. Richardson, K. Whitman,

C.O. Lee, B. Sánchez-Cano, N. Wijsen, Y. Li, C. Cardoso, M. Pinto, D. Heyner, D. Schmid,

H. Auster, and D. Fischer

*Journal of Space Weather and Space Climate*.**14**,3 (2024). PDF.

### 2023

Global MHD Simulations of the Time-dependent Corona

R. Lionello, C. Downs, E. I. Mason, J. A. Linker, R. M. Caplan, V. S. Titov, and M. L. DeRosa

*The Astrophysical Journal*.**959**,77 (2023). PDF.Time-dependent Dynamics of the Corona

E. I. Mason, R. Lionello, C. Downs, J. A. Linker, R. M. Caplan, and M. L. DeRosa

*Astrophysical Journal Letters*.**959**,L4 (2023). PDF.Deflection of Coronal Mass Ejections in Unipolar Ambient Magnetic Fields

M. Ben-Nun, T. Torok, E. Palmerio, C. Downs, V. S. Titov, R. M. Caplan, and R. Lionello

*The Astrophysical Journal*.**957**,74 (2023). PDF.Improving Coronal Hole Detections and Open Flux Estimates

R. M. Caplan, E. I. Mason, C. Downs, and J. A. Linker

*The Astrophysical Journal*.**958**,43 (2023). PDF.Acceleration of a production Solar MHD code with Fortran standard parallelism:

From OpenACC to `do concurrent'

R. M. Caplan, M. M. Stulajter, and J. A. Linker

*13th AsHES Workshop.*2023 IEEE IPDPSW Proceedings., (2023) 582-590. PDF.Review of Solar Energetic Particle Prediction Models

K. Whitman, ..., R. M. Caplan, et. al.

*Advances in Space Research*.**72**(2023) 5161-5242. PDF.

### 2022

Can Fortran's `do concurrent' Replace Directives for Accelerated Computing?

M. M. Stulajter, R. M. Caplan, and J. A. Linker

*Accelerator Programming Using Directives. WACCPD 2021.*

Lecture Notes in Computer Science,**13194**, 3-21 (2022). Springer, Cham. PDF.Comparing and Contrasting the Properties of the Inner Heliosphere

for the Three Most Recent Solar Minima

P. Riley, R. M. Caplan, C. Downs, J. A. Linker, and R. Lionello.

*JGR: Space Physics*.**127**,8 (2022) e2022JA030261. PDF.

### 2021

Coronal Hole Detection and Open Magnetic Flux

J. A. Linker, S. G. Heinemann, M. Temmer, M. J. Owens, R. M. Caplan, C. N. Arge,

E. Asvestari, V. Delouille, C. Downs, and S. J. Hofmeister.

*The Astrophysical Journal*.**918**,1 (2021) 21. PDF.Variations in Finite Difference Potential Fields

R. M. Caplan, C. Downs, J. A. Linker, and Z. Mikic.

*The Astrophysical Journal*.**915**,1 (2021) 44. PDF.Using Parker Solar Probe observations during the first four perihelia to

constrain global magnetohydrodynamic models

P. Riley, R. Lionello, R. M. Caplan, C. Downs, J. A. Linker, S. Badman, and M. L. Stevens

*Astronomy & Astrophysics*.**650**(2021) A19. PDF.Energetic Proton Propagation and Acceleration Simulated for the

Bastille Day Event of July 14, 2000

M. A. Young, N. A. Schwadron, M. Gorby, J. Linker, R. M. Caplan, C. Downs,

T. Török, P. Riley, R. Lionello, V. Titov, R. A. Mewaldt, C. M. S. Cohen

*The Astrophysical Journal*.**909**,2 (2021) 160. PDF.

### 2020

Early Results from the Solar-minimum 2019 Total Solar Eclipse.

J. M. Pasachoff, C. A. Lockwood, J. L. Inoue, E. N. Meadors, A. Voulgaris, D. Sliski, A. Sliski, K. P. Reardon,

D. B. Seaton, R. M. Caplan, C. Downs, J. A. Linker, G. Schneider, P. Rojo, and A. C. Sterling.

*Proceedings of the International Astronomical Union*.**s354**,15 (2020) 3-14 PDF.

### 2019

Can an Unobserved Concentration of Magnetic Flux Above the Poles of the Sun

Resolve the Open Flux Problem?

P. Riley, J. A. Linker, Z. Mikic, R. M. Caplan, C. Downs and J. Thumm.

*The Astrophysical Journal*.**884**,1 (2019) 18. PDF.Predicting the Structure of the Solar Corona and Inner Heliosphere

during Parker Solar Probe's First Perihelion Pass.

P. Riley, C. Downs, J. A. Linker, Z. Mikic, R. Lionello, and R. M. Caplan.

*The Astrophysical Journal*.**874**,2 (2019) L15. PDF.GPU Acceleration of an Established Solar MHD Code using OpenACC.

R. M. Caplan, J. A. Linker, Z. Mikic, C. Downs, T. Torok, and V. S. Titov.

*Journal of Physics: Conference Series*. ASTRONUM 2018.**1225**,1 (2019) 012012 PDF.Coupled MHD-Focused Transport Simulations for Modeling Solar Particle Events.

J. A. Linker, R. M. Caplan, N. Schwadron, M. Gorby, C. Downs, T. Torok, R. Lionello, and J. Wijaya

*Journal of Physics: Conference Series*. ASTRONUM 2018.**1225**,1 (2019) 012007 PDF.

### 2018

Predicting the Corona for the 21 August 2017 Total Solar Eclipse.

Z. Mikic, C. Downs, J. A. Linker, R. M. Caplan, D. H. Mackay, L. A. Upton, P. Riley, R. Lionello,

T. Torok, V. S. Titov, J. Wijaya, M. Druckmuller, J. M. Pasachoff, and W. Carlos.

*Nature Astronomy*.**2**(2018) 913-921. ePDF.Sun-to-Earth MHD Simulation of the 14 July 2000 “Bastille Day” Eruption.

T. Torok, C. Downs, J. A. Linker, R. Lionello, V. S. Titov,

Z. Mikic, P. Riley, R. M. Caplan, and J. Wijaya

*The Astrophysical Journal*.**858**,1 (2018) 75. PDF.Regularized Biot-Savart Laws for Modeling Magnetic Flux Ropes.

V. S. Titov, C. Downs, Z. Mikic, T. Torok, J. A. Linker, and R. M. Caplan

*The Astrophysical Journal Letters*.**852**,2 (2018) L21. PDF.

### 2017

The Open Flux Problem.

J.A. Linker, R.M. Caplan, C. Downs, P. Riley, Z. Mikic, R. Lionello,

C. J. Henney, C. N. Arge, Y. Liu, M. L. Derosa, A. Yeates, and M. J. Owens.

*The Astrophysical Journal*.**848**,1 (2017) 70. PDF.

### 2016

Advancing parabolic operators in thermodynamic MHD models:

Explicit super time-stepping versus implicit schemes with Krylov solvers.

R. M. Caplan, Z. Mikic, J. A. Linker, and R. Lionello.

*Journal of Physics: Conference Series*. ASTRONUM 2016.**837**,1 (2017) 012016 PDF.Synchronic coronal hole mapping using multi-instrument EUV images:

Data preparation and detection method.

R.M. Caplan, C. Downs, and J.A. Linker.

*The Astrophysical Journal*.**823**,1 (2016) 53. PDF.Properties of the Fast Forward Shock Driven by the July 23 2012 Extreme Coronal Mass Ejection.

P. Riley, R.M. Caplan, J. Giacalone, D. Lario, and Y. Liu.

*The Astrophysical Journal*.**819**,1 (2016) 57. PDF.MHD Simulation of the Bastille Day Event.

J.A. Linker, T. Torok, C. Downs, R. Lionello, V. Titov, R.M. Caplan, Z. Mikic, and P. Riley.

*AIP Conference Proceedings*, Solar Wind 14.**1720**, (2016) 020002. PDF.An Empirically Driven Time-Dependent Model of the Solar Wind.

J. A. Linker, R.M. Caplan, C. Downs, R. Lionello, P. Riley, Z. Mikic, C.J. Henney, C.N. Arge, T. Kim, and N. Pogorelov.

*Journal of Physics: Conference Series*. ASTRONUM 2015.**719**,1 (2016) 012012 PDF.

### 2014

Scattering and Leapfrogging of Vortex Rings in a Superfluid.

R.M. Caplan, J. D. Talley, R. Carretero-González, and P.G. Kevrekidis.

*Physics of Fluids*.**26**(2014) 097101. PDF.A Modulus-Squared Dirichlet Boundary Condition for Time-Dependent

Complex Partial Differential Equations and its Application to the Nonlinear Schrödinger Equation.

R.M. Caplan and R. Carretero-González.

*SIAM Journal on Scientific Computing*.**36**,1 (2014) A1-A19 PDF.

### 2013

NLSEmagic: Nonlinear Schrödinger Equation Multidimensional Matlab-based

GPU-accelerated Integrators using Compact High-order Schemes.

R.M. Caplan.

*Computer Physics Communications*.**184**,4 (2013) 1250-1271. PDF.A Two-Step High-Order Compact Scheme for the Laplacian Operator and its

Implementation in an Explicit Method for Integrating the Nonlinear Schrödinger Equation.

R.M. Caplan and R. Carretero-González.

*Journal of Computational and Applied Mathematics*.**251**(2013) 33-46. PDF.Numerical Stability of Explicit Runge-Kutta Finite-Difference Schemes

for the Nonlinear Schrödinger Equation.

R.M. Caplan and R. Carretero-González.

*Applied Numerical Mathematics*.**71**(2013) 24-40. PDF.

Awarded the 6th most successful IMACS paper published in 2013 in Applied Numerical Mathematics.

### 2012

Existence, Stability, and Scattering of Bright Vortices in the

Cubic-Quintic Nonlinear Schrödinger Equation.

R.M. Caplan, R. Carretero-González, P.G. Kevrekidis, and B.A. Malomed.

*Mathematics and Computers in Simulation*.**82**,7 (2012) 1150-1171. PDF.

### 2010

Simulating the Nonlinear Schrödinger Equation using the Computational Capability of NVIDIA Graphics Cards

R.M. Caplan and R. Carretero-González.

*ACSESS Proceedings*.**ACSESS 2010**, (2010) AP10-04. PDF.

### 2009

Azimuthal Modulational Instability of Vortices in the

Nonlinear Schrödinger Equation.

R.M. Caplan, Q.E. Hoq, R. Carretero-González, and P.G. Kevrekidis.

*Optics Communications*.**282**,7 (2009) 1399-1405. PDF.Existence of Steady State Bright Vortex Solutions to the Cubic- Quintic Nonlinear Schrödinger Equation

R.M. Caplan and R. Carretero-González.

*ACSESS Proceedings*.**ACSESS 2009**, (2009) AP0903. PDF.

### Other Works

The Open Flux Problem: The Need for High Latitude Observations.

J.A. Linker, P. Riley, C. Downs, R.M. Caplan, C. DeForest, S.E. Gibson, D.M. Hassler,

J.T. Hoeksema, W.D. Pesnell, X. Sun, and N.M. Viall.

Heliophysics 2024 Decadal Whitepapers. Bulletin of the AAS 55(3) (2023). PDF.From MPI to MPI+OpenACC: Conversion of a legacy FORTRAN

PCG solver for the spherical Laplace equation.

R. M. Caplan, Z. Mikic, and J. A. Linker.

Presented at the 2017 NVIDIA GPU Technology Conference. arXiv:1709.01126 (2017) PDF.

### Ph.D. Dissertation

**Study of Vortex Ring Dynamics in the Nonlinear Schrödinger Equation utilizing**

GPU-Accelerated High-Order Compact Numerical Integrators

GPU-Accelerated High-Order Compact Numerical Integrators

Ph.D. Dissertation in Computational Science (2012).

Joint program with Claremont Graduate University and San Diego State University.

Committee Chair: Professor Ricardo Carretero.

Abstract▼. DOI: 10.5642/cguetd/52.

### Masters Thesis

**Azimuthal Modulational Instability of Vortex Solutions to the**

Two Dimensional Nonlinear Schrödinger Equation

Two Dimensional Nonlinear Schrödinger Equation

Masters Thesis in Computational Science (2008).

San Diego State University.

Thesis chair: Professor Ricardo Carretero.

Abstract▼ PDF.