Vertical Velocity Deduced from Ice Change in Deep Convection
Résumé
Vertical velocity inference is essential to advance our knowledge of deep convection. The Convective Core Observations through MicrOwave Derivatives in the trOpics (C2OMODO) mission aims to retrieve vertical velocity from ice-sensitive measurements in the microwaves taken at two successive short time intervals. The relation between vertical velocity and ice change is examined here for two large-eddy simulations run with the Meso-NH model, one over the sea, the other over land. A linear relationship is found between the vertical velocity and the ice change in convective cores. This relationship is valid in the upper part of the convective cores, above the altitude of vertical velocity maximum, and depends on the inverse of the vertical ice gradient. Knowing the altitude and value of the vertical velocity maximum, as well as the altitude of the top of the convective core, allows us to deduce the complete vertical velocity profile. Significant ice changes are also found in anvils. As they are mainly due to horizontal ice advection, they must be clearly differentiated from those due to vertical ice advection found in convective cores. The relationship between vertical velocity and ice change is highly sensitive to time delay so that the slope between w and the ice change increases by a factor of 3 between 1 and 5 min, and the magnitude in ice change decreases by a factor of 5. A delay less than 2 minutes between successive measurements of ice is therefore recommended to deduce vertical velocity in deep convection.
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Cite 10.5281/zenodo.15323443 Jeu de données Auguste, F., & Chaboureau, J.-P. (2025). Code and data for Vertical Velocity Deduced from Ice Change in Deep Convection [Data set]. Zenodo. https://doi.org/10.5281/ZENODO.15323443
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Cite 10.25326/789 Jeu de données Chaboureau, J.-P. (2025). Meso-NH database for C2OMODO [Data set]. Aeris. https://doi.org/10.25326/789