The Technical Note series provides an outlet for a variety of NCAR manuscripts that contribute in specialized ways to the body of scientific knowledge but which are not suitable for journal, monograph, or book publication. Reports in this series are issued by the NCAR Scientific Divisions ; copies may be obtained on request from the Publications Office of NCAR. Designation symbols for the series include: Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the authors and do not necessarily reflect the views of the National Science Foundation.

/pdf/a-description-of-the-advanced-research-wrf-version-3-o5qjsdx46x.pdf

A Description of the Advanced Research WRF Version 3

Abstract A two-dimensional version of the Pennsylvania State University mesoscale model has been applied to Winter Monsoon Experiment data in order to simulate the diurnally occurring convection observed over the South China Sea. The domain includes a representation of part of Borneo as well as the sea so that the model can simulate the initiation of convection. Also included in the model are parameterizations of mesoscale ice phase and moisture processes and longwave and shortwave radiation with a diurnal cycle. This allows use of the model to test the relative importance of various heating mechanisms to the stratiform cloud deck, which typically occupies several hundred kilometers of the domain. Frank and Cohen's cumulus parameterization scheme is employed to represent vital unresolved vertical transports in the convective area. The major conclusions are: Ice phase processes are important in determining the level of maximum large-scale heating and vertical motion because there is a strong anvil componen...

Numerical study of convection observed during the Winter Monsoon Experiment using a mesoscale two-dimensional model [presentation]

. The Model for Ozone and Related chemical Tracers, version 4 (MOZART-4) is an offline global chemical transport model particularly suited for studies of the troposphere. The updates of the model from its previous version MOZART-2 are described, including an expansion of the chemical mechanism to include more detailed hydrocarbon chemistry and bulk aerosols. Online calculations of a number of processes, such as dry deposition, emissions of isoprene and monoterpenes and photolysis frequencies, are now included. Results from an eight-year simulation (2000–2007) are presented and evaluated. The MOZART-4 source code and standard input files are available for download from the NCAR Community Data Portal ( http://cdp.ucar.edu ).

/pdf/description-and-evaluation-of-the-model-for-ozone-and-31ritydpb8.pdf

Description and evaluation of the Model for Ozone and Related chemical Tracers, version 4 (MOZART-4)

This paper describes the development and evaluation of a new Model for Simulating Aerosol Interactions and Chemistry (MOSAIC), with a special focus on addressing the long-standing issues associated with solving the dynamic partitioning of semi-volatile inorganic gases (HNO3, HCl, and NH3) to size-distributed atmospheric aerosol particles. The coupled ordinary differential equations (ODE) for dynamic gas-particle mass transfer are extremely stiff, and the available numerical techniques are either too expensive or produce oscillatory and/or inaccurate steady-state solutions. These limitations are overcome in MOSAIC, which couples an accurate and computationally efficient thermodynamic module [Zaveri et al., 2005a,b] with a new dynamic gas-particle partitioning module described here. The algorithm involves time-split integrations of non-volatile and semi-volatile species, and a new concept of “dynamic pH” and an adaptive time-stepping scheme hold the key to smooth, accurate, and efficient solutions over the entire relative humidity range. MOSAIC is found to be in excellent agreement with a benchmark version of the model that uses LSODES (a Gear solver) for rigorously integrating the stiff ODEs. The steady-state MOSAIC results for monodisperse aerosol test cases are also in excellent agreement with those obtained with the benchmark equilibrium model AIM. MOSAIC is also evaluated within a 3-D model, andmore » the average CPU speed is estimated to be over 100 times faster than the dynamic aerosol model MADM [Pilinis et al., 2000]. These results suggest that MOSAIC is highly attractive for use in 3-D aerosol and air quality models in which both accuracy and efficiency are critically important.« less

https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2007JD008782

Model for Simulating Aerosol Interactions and Chemistry (MOSAIC)

[1] A new fully coupled meteorology-chemistry-aerosol model is used to simulate the urban- to regional-scale variations in trace gases, particulates, and aerosol direct radiative forcing in the vicinity of Houston over a 5 day summer period. Model performance is evaluated using a wide range of meteorological, chemistry, and particulate measurements obtained during the 2000 Texas Air Quality Study. The predicted trace gas and particulate distributions were qualitatively similar to the surface and aircraft measurements with considerable spatial variations resulting from urban, power plant, and industrial sources of primary pollutants. Sulfate, organic carbon, and other inorganics were the largest constituents of the predicted particulates. The predicted shortwave radiation was 30 to 40 W m−2 closer to the observations when the aerosol optical properties were incorporated into the shortwave radiation scheme; however, the predicted hourly aerosol radiative forcing was still underestimated by 10 to 50 W m−2. The predicted aerosol radiative forcing was larger over Houston and the industrial ship channel than over the rural areas, consistent with surface measurements. The differences between the observed and simulated aerosol radiative forcing resulted from transport errors, relative humidity errors in the upper convective boundary layer that affect aerosol water content, secondary organic aerosols that were not yet included in the model, and uncertainties in the primary particulate emission rates. The current model was run in a predictive mode and demonstrates the challenges of accurately simulating all of the meteorological, chemical, and aerosol parameters over urban to regional scales that can affect aerosol radiative forcing.

Evolution of ozone, particulates, and aerosol direct radiative forcing in the vicinity of Houston using a fully coupled meteorology-chemistry-aerosol model

Rainer Schmitz

Papers

Fully coupled “online” chemistry within the WRF model

Modelling of air pollution dispersion in Santiago de Chile

WRF-Chem version 3.8.1 user's guide

Der Volkstumsdiskurs im Heimatschutz

Reichssportfeld/Olympiastadion