Overestimation of Cloud Sensitivity in Orographic Clouds Over the Southern Tibetan Plateau Due To Neglected Dynamical Constraints

Abstract Accurately quantifying cloud sensitivity ( S aci ), the relative change in cloud droplet number with aerosol loading, is essential for reducing uncertainties in aerosol–cloud interactions. However, its dependence on cloud dynamics is often overlooked, causing biases in estimates of S aci and Twomey effect radiative forcing ( RF aci ). Using in situ observations of orographic clouds over the southern Tibetan Plateau (STP), we estimate cloud‐base updraft velocity ( w ) from the water vapor supersaturation budget and examine how S aci varies with w . Results reveal that S aci follows a sigmoid pattern with increasing w . Driven by Köhler activation theory and its mathematical definition, this pattern is theoretically expected to potentially hold across diverse cloud regimes. Ignoring this dependence yields a 14%–40% overestimate of S aci for STP shallow orographic clouds, which may consequently bias local estimates of RF aci . These findings provide new insights into quantifying cloud sensitivity, while their global applicability and implications require further observational validation.