Technical note: Identification of two ice-nucleating regimes for dust-related cirrus clouds based on the relationship between number concentrations of ice-nucleating particles and ice crystals

Abstract. Large amounts of dust aerosols are lifted to the upper troposphere every year and play a major role in cirrus formation by acting as efficient ice nuclei. However, relative importance heterogeneous nucleation spontaneous homogenous dust-related clouds is still not well evaluated globally. Here, based on spaceborne observations, we propose method identify two ice-nucleating regimes clouds, i.e., (1) sole presence (2) competition between homogeneous nucleation, characterizing relationship particle concentrations (INPCs) calculated from Cloud-Aerosol LIdar with Orthogonal Polarization (CALIOP) using POlarization PHOtometer Networking (POLIPHON) in-cloud crystal number concentration (ICNC) DARDAR (lidar–radar) dataset. Two typical cases over central China shown demonstration. In first case, part (near cloud top) series successfully realized INPC–ICNC closure, meaning that solely takes place, while lower showed possible nucleation. second ICNCs dramatically exceeded INPCs vicinity more than an order magnitude, revealing besides dust-induced also participated produced additional crystals. The proposed identification anticipated apply evaluation influence upper-troposphere global investigation potential positive thinning offset climate warming.