TY - JOUR
T1 - Validation of satellite-retrieved CCN based on a cruise campaign over the polluted Northwestern Pacific ocean
AU - Wang, Yichuan
AU - Zhu, Yannian
AU - Wang, Minghuai
AU - Rosenfeld, Daniel
AU - Gao, Yang
AU - Yao, Xiaohong
AU - Sheng, Lifang
AU - Efraim, Avichay
AU - Wang, Juntao
N1 - Publisher Copyright:
© 2021 Elsevier B.V.
PY - 2021/10/1
Y1 - 2021/10/1
N2 - In this study, we present and validate a methodology for satellite retrievals of cloud condensation nuclei (CCN) in shallow marine boundary layer clouds. In our approach, supersaturation (S) is calculated by the retrieved cloud base drop concentration (Nd) and updrafts (Wb). Nd is the activated CCN concentration in clouds at a given S. We validate the accuracy of the satellite retrieval against surface-measured CCNs from a cruise campaign over the heavily polluted northwest Pacific Ocean. The satellite retrievals show a good agreement with surface measurements after performing corrections for temperature and adiabatic fraction when clouds are coupled with sea surface. This study broadens the applicability of the methodology from aerosol-limited to contaminated regions. The validation shows ±30% accuracy in retrieving CCN over both clean and polluted regions. The results further demonstrate the strong dependence of marine shallow cloud Nd on CCN number concentrations and updraft, which allows us to further apply this methodology to quantify CCN, cloud microphysical properties and the relationships between them. This is helpful in reducing the uncertainty of radiation forcing caused by the aerosol-cloud-interactions (ACI).
AB - In this study, we present and validate a methodology for satellite retrievals of cloud condensation nuclei (CCN) in shallow marine boundary layer clouds. In our approach, supersaturation (S) is calculated by the retrieved cloud base drop concentration (Nd) and updrafts (Wb). Nd is the activated CCN concentration in clouds at a given S. We validate the accuracy of the satellite retrieval against surface-measured CCNs from a cruise campaign over the heavily polluted northwest Pacific Ocean. The satellite retrievals show a good agreement with surface measurements after performing corrections for temperature and adiabatic fraction when clouds are coupled with sea surface. This study broadens the applicability of the methodology from aerosol-limited to contaminated regions. The validation shows ±30% accuracy in retrieving CCN over both clean and polluted regions. The results further demonstrate the strong dependence of marine shallow cloud Nd on CCN number concentrations and updraft, which allows us to further apply this methodology to quantify CCN, cloud microphysical properties and the relationships between them. This is helpful in reducing the uncertainty of radiation forcing caused by the aerosol-cloud-interactions (ACI).
KW - Aerosol cloud interaction
KW - Cloud base drop concentration
KW - Cloud condensation nuclei
KW - Satellite retrieval
KW - Shipboard measurements
UR - http://www.scopus.com/inward/record.url?scp=85107673084&partnerID=8YFLogxK
U2 - 10.1016/j.atmosres.2021.105722
DO - 10.1016/j.atmosres.2021.105722
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AN - SCOPUS:85107673084
SN - 0169-8095
VL - 260
JO - Atmospheric Research
JF - Atmospheric Research
M1 - 105722
ER -