1. Geophysical Fluid Dynamics Laboratory Princeton, New Jersey Convective Vertical Velocities and Microphysics: Contrasts between 2D and 3D CSRMs Leo Donner (GFDL, Princeton University) Vaughan Phillips (Princeton University) GCSS WG4 Broomfield, CO October 2003

2. Geophysical Fluid Dynamics Laboratory Princeton, New Jersey Motivation CSRMs emerging as crucial component of multi-scale modeling framework for AGCMs, aka “superparameterization” 2D CSRMs have been employed in pioneering superparameterization studies Convective vertical velocities increasingly recognized as important for microphysics and radiation interactions

3. Geophysical Fluid Dynamics Laboratory Princeton, New Jersey

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13. Geophysical Fluid Dynamics Laboratory Princeton, New Jersey 2D

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21. Geophysical Fluid Dynamics Laboratory Princeton, New Jersey 2D > 3D SW Reflection: Microphysical Aspects Less cloud liquid,cloud ice, and snow in 3D More graupel in 3D Behavior holds for GATE, TOGA-COARE, and ARM A Precipitating stratiform fractional area less in 3D in all cases except ARM A 2D(y) Microphysics linked to convective vertical velocities, which differ sharply in 2 and 3D

22. Geophysical Fluid Dynamics Laboratory Princeton, New Jersey 2D > 3D SW Reflection: Dynamic Aspects Cumulus vertical velocities higher in 3D than 2D for GATE, TOGA-COARE, ARM Convective mass flux greater in 3D than 2D for GATE and TOGA-COARE, and, for vertical velocities > 5 m s -1, for ARM A Stratiform mass flux less in melting layer for GATE, ARM, and TOGA-COARE