Effects of Cloud Parameterization on Radiation and Precipitation: A Comparison Between Single-Moment Microphysics and Double-Moment Microphysics

  • Author(s): Seoung Soo Lee and Leo J. Donner
  • DOI: 10.3319/TAO.2011.03.03.01(A)
  • Keywords: Single-moment microphysics, Double-moment microphysics, Precipitation

 

Abstract

This study compares a single-moment microphysics scheme to a double-moment microphysics scheme using four observed cases of a mesoscale cloud system. Previous studies comparing a single-moment microphysics scheme to a double-moment microphysics scheme have focused on microphysical processes or overall dynamics, precipitation and morphology of cloud systems. However, they have not focused on how the different representation of microphysical processes between a single- and double-moment microphysics scheme affects precipitation. This study shifts its focus from that of previous studies to the effect of the different representation of microphysics on precipitation. In addition, this study examines the effect of the different representation of microphysical processes on different radiation budgets between single- and double-moment microphysics schemes.

The temporal evolution of precipitation simulated by a single-moment microphysics scheme is significantly different from that by a double-moment microphysics scheme in this study. This is mostly due to different physical representations of key processes (i.e., autoconversion, saturation, and nucleation). Also, a simulation by a single-moment microphysics scheme results in different radiation budgets compared to a double-moment microphysics scheme. More reflection of incident solar radiation in a simulation with a double-moment microphysics scheme than that with a single-moment microphysics scheme is simulated.

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