<b>Impacts of cloud droplet identification criteria on aerosol-cloud interactions: A simulation study using the adiabatic cloud parcel model</b>

This study employes an adiabatic cloud parcel model to investigate the modulation of ACI quantification by different cloud droplet identification criteria. Two representative schemes are examined: a dynamically varying critical radius (<i>R</i>_<em>c</em>) derived from Köhler theory, and a fixed critical radius (<i>R</i>_<em>c</em>_<em>,</em>_<em>f</em>₎ of 1 μm that has been widely adopted in previous studies.

At the height of maximum supersaturation (<i>SS</i>_<em>max</em>) within cloud profile, the Köhler-based criterion producesa monotonic growth in cloud droplet number concentration (<i>N</i>_<em>c</em>) with rising aerosol number concentration (<i>N</i>_<em>a</em>) and updraft velocity (<i>w</i>), consistent with classical Twomey effect. By contrast, the fixed threshold generates pronounced artificial anomalies, including an anti-Twomey effect under high aerosol loading and reduced <i>N</i>_<em>c</em> under intensified<i> </i><i>w</i> for highly hygroscopic aerosols.