A closed-cell marine stratocumulus case during the Aerosol and Cloud Experiments in the Eastern North Atlantic(ACE-ENA)aircraft field campaign is selected to examine the heterogeneities of cloud and drizzle microphysical properties and the aerosol-cloud-precipitation interactions.The spatial and vertical variabilities of cloud and drizzle microphysics are found in two different sets of flight legs:Leg-1 and Leg-2,which are parallel and perpendicular to the cloud propagation,respectively.The cloud along Leg-2 was close to adiabatic,where cloud-droplet effective radius and liquid water content linearly increase from cloud base to cloud top with less drizzle.The cloud along Leg-1 was sub-adiabatic with lower cloud-droplet number concentration and larger cloud-droplet effective,but higher drizzle droplet number concentration,larger drizzle droplet median diameter and drizzle liquid water content.The heavier drizzle frequency and intensity on Leg-1 were enhanced by the collision-coalescence processes within cloud due to strong turbulence.The sub-cloud precipitation rate on Leg-1 was significantly higher than that along Leg-2.As a result,the sub-cloud accumulation mode aerosols and CCN on Leg-1 were depleted,but the coarse model aerosols increased.This further leads to a counter-intuitive phenomenon that the CCN is less than cloud-droplet number concentration for Leg-1.The average CCN loss rates are-3.89 cm-3 h-1 and-0.77 cm-3 h-1 on Leg-1 and Leg-2,respectively.The cloud and drizzle heterogeneities inside the same stratocumulus can significantly alter the sub-cloud aerosols and CCN budget.Hence it should be treated with caution in the aircraft assessment of aerosol-cloud-precipitation interactions.

Xiaojian ZHENG;Xiquan DONG;Dale M.WARD;Baike XI;Peng WU;Yuan WANG

Department of Hydrology and Atmospheric Sciences,University of Arizona,Tucson 85721,AZ,USA;Pacific Northwest National Laboratory,Richland 99354,WA,USA;Division of Geological and Planetary Sciences,California Institute of Technology,Pasadena 91125,CA,USA

大气科学进展（英文版）

[1]Xiaojian ZHENG;Xiquan DONG;Dale M.WARD;Baike XI;Peng WU;Yuan WANG-.Aerosol-Cloud-Precipitation Interactions in a Closed-cell and Non-homogenous MBL Stratocumulus Cloud)[J].大气科学进展（英文版）,2022(12):2107-2123

Stratocumulus,stratocumulus,drizzle

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