Earth Sciences Division (ESD) Department of Energy (DOE) Lawrence Berkeley National Laboratory (LBNL)

Earth Sciences Division Staff: Jeffrey N. Johnson

Jeffrey Johnson

Jeffrey N. Johnson

Scientist

Climate Sciences Department

 

 

Phone: 510-486-4315

Fax: 510-486-5686

Email: JNJohnson@lbl.gov

Biographical Summary

I am a computational scientist in the Hydrogeology Department at Lawrence Berkeley National Laboratory. I received a Ph.D. in Applied Science from UC Davis in 2009 and worked as a postdoctoral fellow in the Computational Research Division before coming to the Earth Science Division in 2011. Before that, I spent several years as a scientist at Lawrence Livermore National Laboratory, working on parallel simulations relevant to problems in high energy density physics.

Currently, I am working on the "Multiscale" climate project, in which the CHOMBO framework is used to solve the equations of atmospheric dynamics, and the Community Atmosphere Model (a component of the Community Earth System Model) is used to provide sub-resolution physics representing various atmospheric processes.

As a developer on the ASCEM project's HPC Simulator effort, I am adding support for various geochemical packages using the Alquimia library. I am also providing computational support for the Sustainable Systems SFA 2.0 project, helping scientists use Amanzi to answer science questions involving carbon-producing and -consuming organisms at the watershed scale.

I am interested in improving the accuracy and robustness of parallel simulations, and developing tools that help scientists do reproducible work. Currently, I am working with J. Michael Owen and David Starinshak at the Lawrence Livermore National Laboratory on polytope, a C++ library for generating 2D and 3D Voronoi tessellations for unstructured meshes.

 

Education

  • University of California, Davis, CA
    Ph.D. in Applied Science (September 2009, GPA: 3.90)
    Advisor: Prof. Garry Rodrigue, Department of Applied Science
    M.S. in Applied Science (June 2004)
  • University of California, San Diego, CA
    B.S. in Physics (June, 1999)

Professional Experience

  • Research Scientist (3/2013 – present)
    Lawrence Berkeley National Laboratory (Berkeley, CA)
    • Providing computational support for various climate-related projects
    • Working on parallel simulation codes for subsurface flows and geomechanics
    • Conducting research in computational geometry in areas of automated grid generation, highorder boundary resolution
  • Software Engineer (3/2012 – 3/2013)
    Net Power and Light (San Francisco, CA)
    • Developed and debugged lowlevel networking components (RPC, congestion simulation and control) for a network protocol
    • Worked on the Together* family of iOS apps (application code and API)
  • Geological Project Scientist (11/2011 – 3/2012)
    Lawrence Berkeley National Laboratory (Berkeley, CA)
    • Worked on algorithms and software for parallel simulations for gas hydrates and other subsurface phenomena.
    • Designed and began implementation of a set of libraries for assets shared between related hydrogeology applications (TOUGH).
    • Provided computer science and software expertise for scientists in the Earth Science Division.
  • Postdoctoral Researcher (12/2009 – 11/2011)
    Lawrence Berkeley National Laboratory (Berkeley, CA)
    • Developed an algorithm and supporting models for simulating low temperature capillary discharges for the LOASIS Laboratory (http://loasis.lbl.gov). Implemented software in C++, driven by Python, to be used by physicists to study these discharges.
    • Worked on design and implementation of highorder algorithms for solving partial differential equations
    • Provided development support for Chombo, a parallel C++ AMR framework
  • Technical Scholar (9/2006 – 9/2009)
    Lawrence Livermore National Laboratory (Livermore, CA)
    • Extended and characterized a numerical algorithm to simulate the dynamics of strongly magnetized plasma with the equations of resistive magnetohydrodynamics.
    • Developed an open source multidimensional software package for studying algorithms in plasma physics and electrodynamics.
    • Collaborated with the Compact Toroid Injection Experiment at U.C. Davis (http://ctix.das.ucdavis.edu) to study magnetized plasmas.
  • Computer Scientist / Math Programmer (6/2000 – 2/2006)
    Lawrence Livermore National Laboratory (Livermore, CA)
    • Designed and implemented several major components for a parallel multiphysics inertial confinement fusion code (C++, Python)
    • Ran and debugged parallel simulations on thousands of processors.
    • Implemented and maintained a custom build system for the project.
    • Introduced software engineering techniques to improve code reliability.
    • Provided support and mentoring for other developers (25person staff) and for users
  • Engineer (7/1999 – 6/2000)
    ESSCOR, Inc. (Solana Beach, CA)
    • Helped design a user interface for simulations of 1D fluid/heat flows
    • Wrote software to allow a user interface to communicate remotely with a computational engine
    • Implemented logic to store initial conditions and simulation data in a database
  • Programmer / Technical Lead (9/1997 – 6/1999)
    EarthKAM project (University of California, San Diego)
    • Designed and implemented an objectoriented C++ framework to replace the project’s aging C software base.
    • Directed and mentored a group of 8 undergraduate programmers.
    • Wrote C++/Perl interfaces to a DB/2 database in collaboration with scientists at the Jet Propulsion Laboratory
    • See http://www.earthkam.ucsd.edu for more information on this project
  • Technical Advisor / Programmer (9/1996 – 9/1997)
    Visualizing Earth project (University of California, San Diego)
    • Provided software tools to assist teachers with the creation of more effective computeroriented science curricula.
    • Implemented a stereo image tool to project satellite photos onto digital elevation maps in collaboration with a group at the Jet Propulsion Laboratory.

Awards and Honors

  • Lawrence Scholar (20072009)
  • Lawrence Livermore Student Employee Graduate Research Fellowship (2006)
  • Phi Beta Kappa Honor Society (1999)
  • U.C. Regents Scholar (19951999)
  • National Merit Scholar (19951999)
  • California Space Grant Scholarship (19971998)
  • McNair Scholar (19961997)
  • Roger Revelle Scholarship (1995)