An Improved Convection Parameterization with Detailed Aerosol–Cloud Microphysics for a Global Model
- Department of Physical Geography and Ecosystem Science, Lund University, Lund, Sweden
- Department of Physical Geography and Ecosystem Science, Lund University, Lund, Sweden, Department of Troposphere, Institute of Meteorology and Climate Research, Karlsruhe Institute of Technology, Karlsruhe, Germany
- Department of Hydro and Renewable Energy, Indian Institute of Technology Roorkee, Roorkee, India
- Johannes Gutenberg University, Mainz, Germany
- Dynamical and Physical Meteorology Section, National Center for Atmospheric Research, Boulder, Colorado
- Global Modeling and Assimilation Office, NASA Goddard Space Flight Center, Greenbelt, Maryland
- Department of Geosciences, University of Oslo, Oslo, Norway
A new microphysical treatment that includes aerosol–cloud interactions and secondary ice production (SIP) mechanisms is implemented in the convection scheme of the Community Atmosphere Model, version 6 (CAM6). The approach is to embed a 1D Lagrangian parcel model in the bulk convective plume of the existing deep convection parameterization. Aerosol activation, growth processes including collision/coalescence, and three processes of SIP mechanisms, two of which are normally overlooked in atmospheric models, are represented in this embedded parcel model. These microphysical processes are treated with a hybrid bin/bulk scheme and a high spatial and temporal resolution for the integration of the embedded parcel in 1D, allowing vertical velocity to determine the microphysical evolution following the in-cloud motion during ascent. Simulations of an observed case (Midlatitude Continental Convective Clouds Experiment) of a mesoscale convective system in Oklahoma, United States, with a single-column model (SCAM) version of CAM, are compared with aircraft in situ and ground-based observations of microphysical properties from the convection and precipitation. Results from the validation show the new microphysical scheme has a good representation of the ice initiation in the bulk convective plume, including the known and empirically quantified pathways of primary and secondary initiation, with benefits for the accuracy of properties of its supercooled cloud liquid. The sensitivity simulations and use of tagging tracers for the validated simulation confirm that the newly included SIP mechanisms are of paramount importance for convective microphysics and can be successfully treated in the global model.
- Research Organization:
- Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States). Atmospheric Radiation Measurement (ARM) Data Center
- Sponsoring Organization:
- Swedish Agency for Innovation Systems (Vinnova); Swedish Research Council (FORMAS); USDOE; USDOE Office of Science (SC), Biological and Environmental Research (BER)
- Contributing Organization:
- Argonne National Laboratory (ANL); Brookhaven National Laboratory (BNL); Pacific Northwest National Laboratory (PNNL)
- Grant/Contract Number:
- SC0018932; SC0018967
- OSTI ID:
- 2504014
- Alternate ID(s):
- OSTI ID: 2513245
- Journal Information:
- Journal of the Atmospheric Sciences, Journal Name: Journal of the Atmospheric Sciences Journal Issue: 1 Vol. 82; ISSN 0022-4928
- Publisher:
- American Meteorological SocietyCopyright Statement
- Country of Publication:
- United States
- Language:
- English
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