BER launches Environmental System Science Program. Visit our new website under construction!

U.S. Department of Energy Office of Biological and Environmental Research

BER Research Highlights

Simulating Convective Properties Using Physical Spectral-bin and Parameterized Bulk Microphysical Models
Published: April 29, 2015
Posted: December 11, 2015

Clouds play an important role in the climate system’s global energy and water cycles. Representation of clouds, especially cumulus clouds, remains a great modeling challenge due to their variability in time and space and the coarse grid spacing in regional and global climate models. Even at the cloud-resolving scale, models with bulk (computationally inexpensive) microphysical formulas have difficulties simulating the convective (updraft) properties of cumulus clouds. Using the Weather Research and Forecasting (WRF) model, researchers at the Department of Energy’s Pacific Northwest National Laboratory found that compared to observations, the spectral-bin (more physical, more computationally expensive) microphysics method provides better simulations of precipitation and vertical velocity of the cumulus convective cores than two methods that use double-moment (mass and number) bulk microphysics. The spectral-bin microphysics method reproduces the observed updraft intensity well, alleviating much of the overestimation of updraft speeds produced by the bulk method. This finding suggests that a cloud microphysical method can improve model simulation of convective cloud properties. The researchers then used the spectral-bin microphysics model output as benchmark simulations for their study of scale-dependence of convection transport (Part II of the study). They also discovered that mass flux (rate of mass flow), a quantity on which cumulus representations are based, is very sensitive to different microphysical methods for tropical convection, indicating strong microphysics modification to convection. But, the modeled mass fluxes of cloud systems in the mid latitudes are not sensitive to the choice of microphysics methods. Cloud microphysical measurements of rain, snow, and graupel in convective cores will be critically important to further understand and elucidate performances of cloud microphysics methods.

Reference: Fan, J., Y.-C. Liu, K.-M. Xu, K. North, S. Collis, X. Dong, G. J. Zhang, Q. Chen, P. Kollias, and S. J. Ghan. 2015. “Improving Representation of Convective Transport for Scale-Aware Parameterization: I. Convection and Cloud Properties Simulated with Spectral Bin and Bulk Microphysics,” Journal of Geophysical Research-Atmospheres 120(8), 3485–509. DOI: 10.1002/2014JD022142. (Reference link)

Contact: Dorothy Koch, SC-23.1, (301) 903-0105, Randall Laviolette, SC-21, (301) 903-5195
Topic Areas:

  • Research Area: Earth and Environmental Systems Modeling
  • Research Area: Atmospheric System Research

Division: SC-33.1 Earth and Environmental Sciences Division, BER


BER supports basic research and scientific user facilities to advance DOE missions in energy and environment. More about BER

Recent Highlights

Mar 23, 2021
Molecular Connections from Plants to Fungi to Ants
Lipids transfer energy and serve as an inter-kingdom communication tool in leaf-cutter ants&rsqu [more...]

Mar 19, 2021
Microbes Use Ancient Metabolism to Cycle Phosphorus
Microbial cycling of phosphorus through reduction-oxidation reactions is older and more widespre [more...]

Feb 22, 2021
Warming Soil Means Stronger Microbe Networks
Soil warming leads to more complex, larger, and more connected networks of microbes in those soi [more...]

Jan 27, 2021
Labeling the Thale Cress Metabolites
New data pipeline identifies metabolites following heavy isotope labeling.

Analysis [more...]

Aug 31, 2020
Novel Bacterial Clade Reveals Origin of Form I Rubisco

  • All plant biomass is sourced from the carbon-fixing enzyme Rub [more...]

List all highlights (possible long download time)