Advanced two-moment bulk microphysics for global models. Part II: Global model solutions and aerosol-cloud interactions

Gettelman, A., Morrison, H., Santos, S., Bogenschutz, P. A., Caldwell, P.. (2015). Advanced two-moment bulk microphysics for global models. Part II: Global model solutions and aerosol-cloud interactions. Journal of Climate, doi:https://doi.org/10.1175/JCLI-D-14-00103.1

Title Advanced two-moment bulk microphysics for global models. Part II: Global model solutions and aerosol-cloud interactions
Genre Article
Author(s) Andrew Gettelman, Hugh Morrison, Sean Santos, Peter A. Bogenschutz, P. Caldwell
Abstract A modified microphysics scheme is implemented in the Community Atmosphere Model, version 5 (CAM5). The new scheme features prognostic precipitation. The coupling between the microphysics and the rest of the model is modified to make it more flexible. Single-column tests show the new microphysics can simulate a constrained drizzling stratocumulus case. Substepping the cloud condensation (macrophysics) within a time step improves single-column results. Simulations of mixed-phase cases are strongly sensitive to ice nucleation. The new microphysics alters process rates in both single-column and global simulations, even at low (200 km) horizontal resolution. Thus, prognostic precipitation can be important, even in low-resolution simulations where advection of precipitation is not important. Accretion dominates as liquid water path increases in agreement with cloud-resolving model simulations and estimates from observations. The new microphysics with prognostic precipitation increases the ratio of accretion over autoconversion. The change in process rates appears to significantly reduce aerosol-cloud interactions and indirect radiative effects of anthropogenic aerosols by up to 33% (depending on substepping) to below 1 W m⁻² of cooling between simulations with preindustrial (1850) and present-day (2000) aerosol emissions.
Publication Title Journal of Climate
Publication Date Feb 1, 2015
Publisher's Version of Record https://doi.org/10.1175/JCLI-D-14-00103.1
OpenSky Citable URL https://n2t.org/ark:/85065/d7bp03zx
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