Modeling Nuclear Cloud Rise and Fallout in Complex Environments

Katherine Lundquist | 18-ERD-049

Project Overview

Understanding and predicting the transport of radioactive material from a nuclear accident or detonation is important to Lawrence Livermore National Laboratory's missions in consequence management and nuclear forensics. Most current nuclear detonation, cloud rise, and fallout models are empirical models derived from historical nuclear tests. These models fail to capture the complexities associated with realistic nuclear detonations, as they lack details such as complex terrain and feedbacks with atmospheric conditions. This project developed an integrated nuclear cloud rise model based on first principles, which will be useful in modeling detonations in complex environments. The modeling capability developed is a first-of-its-kind predictive computational tool based on the arbitrary Lagrangian-Eulerian multiphysics hydrocode (ALE3D) and the widely-used Weather Research and Forecasting (WRF) model, which together can more accurately simulate the cloud rise and fallout associated with nuclear detonations. This new capability will facilitate fundamental scientific research of the effects of nuclear detonations. A second goal within the project was to develop LLNL's capabilities in nuclear weapons effects to address a long-standing question regarding the possibility of long-term climate impacts from a nuclear exchange. A recent series of studies examined the global effects of a regional nuclear exchange in which one hundred 15 kt nuclear weapons are detonated [Robock et al., 2007, Toon et al., 2007, Mills et al., 2008, Stenke et al., 2013, Mills et al., 2014, Reisner et al., 2018]. We extended the work of the previous studies by performing large-eddy simulation of single fires that include considerations of meteorology and cloud microphysical processes, along with climate simulations that include the cumulative effects of the output from 100 fires. The Weather Research and Forecasting (WRF) model is used to simulate the fire plume and local-scale smoke transport. The Energy Exascale Earth System Model (E3SM), the new climate model at the Department of Energy, is used to simulate climate-scale atmospheric dynamics and chemistry. Findings are presented in Wagman et al. 2020.

Mission Impact

This research supports the NNSA's goals to manage the nuclear weapons stockpile and expand and apply our science and technology capabilities to deal with broader national security challenges. This project addresses the Laboratory's nuclear weapons stockpile stewardship mission area, as well as its nuclear threat reduction research and development challenge. It also enhances the Laboratory's core competencies in Earth and atmospheric science and high-performance computing, simulation, and data science.

Publications, Presentations, and Patents

Chow, F. K., C. S. Schär, N. Ban, K. A. Lundquist, L. Schlemmer, and X. Shi, 2019. "Crossing multiple gray zones in the transition from mesoscale to microscale simulation over complex terrain," Atmosphere, 10(5), 274. DOI: 10.3390/atmos10050274 LLNL-JRNL-764800.

Durling, R., 2020. "Hypothetical Scenarios for Black Carbon NARAC modeling." LLNL Technical Report. LLNL-TR-816078.

Glascoe, L., P. Goldstein, K. Lundquist, J. Osuna, G. Spriggs, Y. Kanarska, J. Morris, R. Arthur and S. Neuscamman, 2020. "Near and far field fallout analysis: SRP modelling approach and output,"Journal of Weapon Physics, 2020-01. JWP-2020-01-15, COPD-2020-0125.

Kanarska, Y., T. Dunn, L. Glascoe, K. Lundquist, and C. Noble, 2020. "Semi-implicit method to solve compressible multiphase fluid flows without acoustic time step restrictions," Computers & Fluids, 210, 104651. DOI: 10.1016/J.COMPFLUID.2020.104651 LLNL-JRNL-797139.

Wagman, B. M., K. A. Lundquist, Q. Tang, L. G. Glascoe, and D. C. Bader 2020. "Examining the Climate Effects of a Regional Nuclear Weapons Exchange Using a Multiscale Atmospheric Modeling Approach," Journal of Geophysical Research: Atmospheres, 125, e2020JD033056. DOI: 10.1029/2020JD033056 LLNL-JRNL-809541.

Wiersema, D. J., K. A. Lundquist, and F. K. Chow, 2020. "Mesoscale to microscale simulations over complex terrain with the immersed boundary method in the Weather Research and Forecasting model," Monthly Weather Review, 148, 577-595. DOI: 10.1175/MWR-D-19-0071.1 LLNL-JRNL-761310.

Arthur, R. S., K. A. Lundquist, D. J. Wiersema, J. D. Mirocha, Y. Kanarska, 2019. "Developing the Weather Research and Forecasting model for multiscale simulations of transport and dispersion." 23rd Annual George Mason University Conference on Atmospheric Transport and Dispersion. LLNL-PRES-777820.

Arthur, R.S., K. A. Lundquist, J. D. Mirocha, Y. Kanarska, S. Neuscamman, J. S. Nasstrom, 2020. "Simulating nuclear cloud rise within a realistic atmosphere using the Weather Research and Forecasting model." 24th Annual George Mason University Conference on Atmospheric Transport and Dispersion. LLNL-PRES-817093.

Kanarska, Y., T. Dunn, C. Noble, K. Lundquist, L. Glascoe, 2019. "A journey to derive semi-implicit compressible multiphase model without acoustic time step restrictions." 9th International Conference on Numerical Methods for Multi-Material Fluid Flow. (LLNL-PRES-787617)

Kanarsa, Y., R. Authur, B. Issac, K. Lundquist, J. Morris, G. Spriggs, 2020. The effects of the thermal layer on the particle entrainment and fallout in complex environments. 24th Annual George Mason University Conference on Atmospheric Transport and Dispersion Modeling. LLNL-PRES-816938.

Lundquist, K., L. Glascoe, J. Mirocha, R. Arthur, B. Wagman, Q. Tang, and D. Wiersema, 2019. "Modeling of Fires for National Security." Science to Understand Megafire Interactions with the Atmosphere. LLNL-PRES-781380.

Lundquist, K., R. Arthur, A. Gowardhan, Y. Kanarska, and D. Wiersema, 2020. "Multiscale and Large-Eddy Simulation Atmospheric Modeling." Air Force/Army Weather Research and Development Workshop. LLNL-PRES-814699.

Lundquist, K. A., Y. Kanarska, and R. S. Arthur, 2020. "Modeling Nuclear Cloud Rise and Fallout in Complex Environments." JOWOG 43. LLNL-PRES-814699.

Wagman, B. M., K. A. Lundquist, Q. Tang, L. G. Glascoe, and D. C. Bader, 2019. "How would a regional nuclear war affect the global climate?" Meteorology and Climate - Modeling for Air Quality Conference. LLNL-POST-789207.

Wagman, B. M., K. A. Lundquist, Q. Tang, L. G. Glascoe, and D. C. Bader, 2019. "Examining the climate perturbation caused by a regional nuclear exchange using unified micro- to global scale modeling." AGU Fall Meeting 2019, American Geophysical Union. LLNL-POST-798517.

Wagman, B. M., K. A. Lundquist, Q. Tang, L. G. Glascoe, and D. C. Bader, 2020. "Examining the Climate Effects of Fires from a Regional Nuclear Weapons Exchange." Meteorology for Nuclear Emergencies and Nonproliferation. LLNL-PRES-804676.

Wiersema, D. J., K. A. Lundquist, J. D. Mirocha, F. K. Chow, 2019. "Representation of Turbulence in Multiscale WRF-IBM Simulations Over Complex Urban Terrain." AGU Fall Meeting 2019, American Geophysical Union. LLNL-POST-799521.

Wiersema, D., K. Lundquist, J. Mirocha, F. Chow, 2020. "Evaluation of turbulence within a multiscale atmospheric model over complex urban terrain." 24th Annual George Mason University Conference on Atmospheric Transport and Dispersion Modeling. LLNL-PRES-817423.