Estimating Vertical Velocity in Convective Updrafts from Temperature, Pressure, and Latent Heating

TL;DR

This paper introduces a new method to estimate vertical velocities in convective clouds using temperature, pressure, and latent heating data, validated against simulations across different environments.

Contribution

The paper develops an analytical model-based method for estimating convective vertical velocities from in-cloud profiles, enabling global long-term assessments.

Findings

Estimates are accurate within ~1 m/s in tropical clouds.

Method shows lower uncertainty in tropical regions compared to mid-latitudes.

Validation against simulations demonstrates the method's robustness across models and resolutions.

Abstract

The vertical velocity in convective clouds ($w_c$) mediates convective anvil development and global moisture transport, influencing Earth's energy budget, but has yet to be estimated globally over long periods due to the absence of spaceborne retrievals. Here, a method for estimating $w_c$ given vertical profiles of in-cloud temperature, pressure, and latent heating rate is presented and assessed. The method relies on analytical models for the approximately linear relationship between $w_c$ and condensation rate ($\dot{q}_{vc}$) in convective clouds, which we derive from steady-state and non-steady-state plume models. We include in our analysis a version of $\dot{q}_{vc}/w_c$ derived from the supersaturation rate in convective clouds, recently presented in Kukulies et al. (2024). We assess the accuracy of $w_c$ estimates against convective cloud simulations run with different model cores and spatial resolutions in both tropical and mid-latitude environments. The velocity estimates exhibit lower uncertainties and higher precision in the tropics than they do in the mid-latitudes. Vertical velocity is estimated to within $\approx1$ m/s for most samples in the tropics. Potential applications, validation against future satellite mission retrievals, and approaches for improving the estimation are discussed.