Revisiting the Entrainment Relationship in Convective Cloud Modeling: A CloudSat Perspective

Entrainment is an important process affecting convective transport and is a key parameter in convection modeling. For over half a century, an inverse relationship between entrainment rate (𝜆) and convective core size (R) has been used in modeling convective clouds. This short letter revisits the 𝜆 − 𝑅 relation using multiple years of CloudSat observations. Results show that the inverse relationship between 𝜆 and R is robust. However, they are not scaled by a simple constant. Global satellite observations provide some guidance for choosing the range of the scaling parameter. Further, our analysis shows that continental convective clouds tend to have smaller λ and larger 𝑅 compared to oceanic convective clouds, suggesting that vertical mass transport by continental convection is more efficient. The satellite-based study of the 𝜆 − 𝑅 relation has the potential to become a new diagnostic metric for assessing the representation of convection in weather and climate models.