DOI: 10.1029/2017JD027508
Scopus记录号: 2-s2.0-85048677731
论文题名: Cloud-Scale Droplet Number Sensitivity to Liquid Water Path in Marine Stratocumulus
作者: de Szoeke S.P. ; Verlinden K.L. ; Covert D.
刊名: Journal of Geophysical Research: Atmospheres
ISSN: 2169897X
出版年: 2018
卷: 123, 期: 10 起始页码: 5320
结束页码: 5334
语种: 英语
英文关键词: cloud droplet number concentration
; cloud lifetime indirect aerosol effect
; cloud optical depth
; liquid water path
; remote sensing
; stratocumulus clouds
英文摘要: Cloud droplet number concentration (Nc) is retrieved from remotely observed marine stratocumulus cloud liquid water path (LWP), cloud optical depth (τc), and cloud thickness, using an optical model that assumes liquid water content (LWC) increases linearly from cloud base. Assuming that LWC is vertically uniform would underestimate τc by 5% and Nc by 14%. Individual retrievals of Nc from 10-min averages vary by orders of magnitude from long-term averages. Surface cloud condensation nuclei (CCN) number concentration NCCN is weakly but significantly correlated with Nc (R = 0.3) for the day leading and 6 hr following Nc. Consistent with coalescence and drizzle scavenging cloud droplets, lag correlations show that Nc decreases for 1 hr after the peak area-average rain rate. Greater observed LWP for lower Nc [d(log Nc)/d(log LWP) = −2.3] is consistent with enhanced entrainment drying of clouds with greater Nc and consistent with removal of Nc by thicker clouds with more coalescence and drizzle. Stronger precipitation in clouds with greater Nc is the opposite sensitivity as expected were LWP to be controlled by the “cloud lifetime” indirect aerosol effect. The strong sensitivity of Nc to LWP suggests that cloud dynamic and thermodynamic forcings drive macrophysical variability that controls Nc in southeastern tropical Pacific stratocumulus clouds. Regressions are relatively insensitive to assumptions about the covariance of errors among the sensors. ©2018. American Geophysical Union. All Rights Reserved. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/113880
Appears in Collections: 气候减缓与适应
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作者单位: College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, Corvallis, OR, United States; Department of Atmospheric Sciences, University of Washington, Seattle, WA, United States
Recommended Citation:
de Szoeke S.P.,Verlinden K.L.,Covert D.. Cloud-Scale Droplet Number Sensitivity to Liquid Water Path in Marine Stratocumulus[J]. Journal of Geophysical Research: Atmospheres,2018-01-01,123(10)