A5001027593- Meteorological Phenomena and Simulations
- Climate variability and models
- Tropical and Extratropical Cyclones Research
- Atmospheric and Environmental Gas Dynamics
- Atmospheric chemistry and aerosols
- Atmospheric aerosols and clouds
- Computational Fluid Dynamics and Aerodynamics
- Oceanographic and Atmospheric Processes
- Atmospheric Ozone and Climate
- Fluid Dynamics and Turbulent Flows
- Wind and Air Flow Studies
- Cryospheric studies and observations
- Coastal and Marine Dynamics
- Precipitation Measurement and Analysis
- Ocean Waves and Remote Sensing
- Fire effects on ecosystems
- Methane Hydrates and Related Phenomena
- Geophysics and Gravity Measurements
- Lightning and Electromagnetic Phenomena
- Arctic and Antarctic ice dynamics
- Astro and Planetary Science
- Advanced Numerical Methods in Computational Mathematics
- Ionosphere and magnetosphere dynamics
- Air Quality Monitoring and Forecasting
- demographic modeling and climate adaptation
NSF National Center for Atmospheric Research
2016-2025
U.S. National Science Foundation
2024
Microscale (United States)
2001-2023
Yonsei University
2018-2019
National Central University
2019
Office National d'Études et de Recherches Aérospatiales
2000
NOAA National Severe Storms Laboratory
2000
Colorado State University
2000
University of North Dakota
2000
Georgia Institute of Technology
2000
Abstract : The development of the Weather Research and Forecasting (WRF) modeling system is a multiagency effort intended to provide next-generation mesoscale forecast model data assimilation that will advance both understanding prediction weather accelerate transfer research advances into operations. being developed as collaborative ort among NCAR Mesoscale Microscale Meteorology (MMM) Division, National Oceanic Atmospheric Administration's (NOAA) Centers for Environmental Prediction (NCEP)...
Abstract Since its initial release in 2000, the Weather Research and Forecasting (WRF) Model has become one of world’s most widely used numerical weather prediction models. Designed to serve both research operational needs, it grown offer a spectrum options capabilities for wide range applications. In addition, underlies number tailored systems that address Earth system modeling beyond weather. While WRF centralized support effort, truly community model, driven by developments contributions...
Kinetic energy spectra derived from observations in the free atmosphere possess a wavenumber dependence of k−3 for large scales, characteristic 2D turbulence, and transition to k−5/3 mesoscale. computed using mesoscale experimental near-cloud-scale NWP forecasts Weather Research Forecast (WRF) model are examined, it is found that model-derived match observational well, including transition. The decay at highest resolved wavenumbers compared with observations, indicating removal by model's...
Two time-splitting methods for integrating the elastic equations are presented. The based on a third-order Runge–Kutta time scheme and Crowley advection schemes. schemes combined with forward–backward high-frequency acoustic gravity modes to create stable split-explicit compressible Navier–Stokes equations. time-split facilitate use of both centered upwind-biased discretizations terms, allow larger steps, produce more accurate solutions than existing approaches. illustrates methodology...
The representation of convective processes within mesoscale models with horizontal grid sizes smaller than 20 km has become a major concern for the simulation weather systems. In this paper, authors investigate effects resolution on using nonhydrostatic cloud model to help clarify capabilities and limitations explicit physics resolve convection in models. By varying interval between 1 12 km, degradation response as is decreased documented that are not properly represented coarser resolutions...
Abstract The formulation of a fully compressible nonhydrostatic atmospheric model called the Model for Prediction Across Scales–Atmosphere (MPAS-A) is described. solver discretized using centroidal Voronoi meshes and C-grid staggering prognostic variables, it incorporates split-explicit time-integration technique used in many existing meso- cloud-scale models. MPAS can be applied to globe, over limited areas on Cartesian planes. are unstructured grids that permit variable horizontal...
Abstract Historically, time-split schemes for numerically integrating the nonhydrostatic compressible equations of motion have not formally conserved mass and other first-order flux quantities. In this paper, split-explicit integration techniques are developed that conserve these properties by prognostic quantities represented in form. These procedures presented both terrain-following height hydrostatic pressure (mass) vertical coordinates, two potentially attractive frameworks which...
The mathematical equivalence of the linearized two-dimensional (2D) shallow-water system and 2D acoustic-advection strongly suggests that time-split schemes designed for hydrostatic equations can be employed in nonhydrostatic models vice versa. Stability analyses are presented several numerical methods integrating two systems. primary interest is explicit where no multidimensional elliptic arise; thus, a detailed analysis Klemp Wilhelmson (KW) technique undertaken. It found interaction...
Abstract. We describe the large-scale meteorological conditions that affected atmospheric chemistry over Mexico during March 2006 when several field campaigns were conducted in region. In-situ and remote-sensing instrumentation was deployed to obtain measurements of wind, temperature, humidity profiles boundary layer free atmosphere at four primary sampling sites central Mexico. Several models run operationally campaign provide forecasts local, regional, synoptic meteorology as well...
Simulations of squall lines, using nonhydrostatic convection-resolving models, have been limited to two dimensions or three with the assumption along-line periodicity. The authors present 3D simulations, produced an adaptive grid model, where lines are finite in length and restriction periodicity is removed. base state for simulations characterized by weak, shallow shear high convective available potential energy (CAPE), environment which longlived midlatitude mesoscale systems (MCSs)...
Abstract Kinetic energy (KE) spectra derived from global high-resolution atmospheric simulations the Model for Prediction Across Scales (MPAS) are presented. The produced using quasi-uniform Voronoi horizontal meshes with 3-, 7.5-, and 15-km mean cell spacings. KE MPAS compare well observations other in literature possess canonical structure including a very-well-resolved shallow-sloped mesoscale region 3-km simulation. There is peak vertical velocity variance at model filter scale all...
Abstract In the Advanced Research Weather and Forecasting Model (ARW), versions 3.0 earlier, advection of scalars was performed using Runge–Kutta time-integration scheme with an option a positive-definite (PD) flux limiter. Large-eddy simulations aerosol–cloud interactions ARW model are to evaluate schemes. The basic alone produces spurious oscillations negative values in scalar mixing ratios because numerical dispersion errors. PD limiter assures positive definiteness but retains...
A forward-in-time splitting method for integrating the elastic equations is presented. second-order Runge–Kutta time integrator (RK2) large-time-step integration combined with forward–backward scheme in a manner similar to Klemp and Wilhelmson method. The new produces fully second-order-accurate integrations advection gravity wave propagation. RK2 uses upwind discretizations terms easily standard vertically semi-implicit techniques so as improve computational efficiency when grid aspect...
We attempt to clarify the factors that regulate propagation and structure of gravity currents through evaluation idealized theoretical models along with two-dimensional numerical model simulations. In particular, we seek reconcile research based on hydraulic theory for evolving from a known initial state analyses are assumed be at steady state, compare these approaches both simulations laboratory experiments. The time-dependent shallow-water solution current propagating in channel finite...
According to classical hydraulic theory, the energy losses within an external bore must occur expanding layer. However, application of this theory describe propagation internal bores leads contradiction with accepted gravity-current behaviour in limit as depth layer ahead becomes small. In seeking improved expression for bores, we have rederived steady front condition a two-layer Boussinesq fluid channel under assumption that loss occurs contracting The resulting is good agreement available...
Although atmospheric phenomena tend to be localized in both time and space, numerical models generally employ only uniform discretizations or fixed nested grids. An adaptive grid technique implemented 2D 3D nonhydrostatic elastic is described. The makes use of separate rectangular refinements increase resolution where truncation error estimates are large. Multiple, rotated, overlapping grids used along with an arbitrary number discrete grid-refinement levels. Refinements placed removed...
A nonhydrostatic numerical model is used to simulate two-dimensional frontogenesis forced by either horizontal deformation or shear. Both inviscid prior frontal collapse and with diffusion following are considered. The solutions generally agree well semigeostrophic (SG) theory, though differences can be substantial for intense fronts. Certain deviations from SG that have been previously discussed in the literature area, upon closer examination, associated spurious gravity waves produced...
Abstract A positive-definite transport scheme for moisture is tested in a nonhydrostatic forecast model using convection-permitting resolutions. Use of the found to significantly reduce large positive bias surface precipitation forecasts non-positive-definite forecasts, particular at high thresholds. The eliminates spurious sources water arising from clipping negative values formulation, leading reduction.