Open AccessThe Vertical Profile of Liquid and Ice Water Content in Midlatitude Mixed-Phase Altocumulus Clouds
Author(s) -
Lawrence D. Carey,
Jianguo Niu,
Ping Yang,
J. Adam Kankiewicz,
Vincent E. Larson,
Thomas H. Vonder Haar
Publication year - 2008
Publication title -
journal of applied meteorology and climatology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.079
H-Index - 134
eISSN - 1558-8432
pISSN - 1558-8424
DOI - 10.1175/2008jamc1885.1
Subject(s) - liquid water content , middle latitudes , ice crystals , mixed phase , atmospheric sciences , environmental science , cloud top , cloud base , ice nucleus , ice cloud , cloud physics , liquid water path , particle (ecology) , meteorology , phase (matter) , radiative transfer , cloud computing , geology , satellite , physics , optics , aerosol , thermodynamics , oceanography , quantum mechanics , computer science , nucleation , operating system , astronomy
The microphysical properties of mixed-phase altocumulus clouds are investigated using in situ airborne measurements acquired during the ninth Cloud Layer Experiment (CLEX-9) over a midlatitude location. Approximately ⅔ of the sampled profiles are supercooled liquid–topped altocumulus clouds characterized by mixed-phase conditions. The coexistence of measurable liquid water droplets and ice crystals begins at or within tens of meters of cloud top and extends down to cloud base. Ice virga is found below cloud base. Peak liquid water contents occur at or near cloud top while peak ice water contents occur in the lower half of the cloud or in virga. The estimation of ice water content from particle size data requires that an assumption be made regarding the particle mass–dimensional relation, resulting in potential error on the order of tens of percent. The highest proportion of liquid is typically found in the coldest (top) part of the cloud profile. This feature of the microphysical structure for the midlatitude mixed-phase altocumulus clouds is similar to that reported for mixed-phase clouds over the Arctic region. The results obtained for limited cases of midlatitude mixed-phase clouds observed during CLEX-9 may have an implication for the study of mixed-phase cloud microphysics, satellite remote sensing applications, and the parameterization of mixed-phase cloud radiative properties in climate models.