TY - JOUR
T1 - Ice particle morphology andmicrophysical properties of cirrus clouds inferred from combined CALIOP-IIR measurements
AU - Saito, Masanori
AU - Iwabuchi, Hironobu
AU - Yang, Ping
AU - Tang, Guanglin
AU - King, Michael D.
AU - Sekiguchi, Miho
N1 - Funding Information:
The authors thank the Atmospheric Sciences Data Center for providing the CALIPSO products (https:// eosweb.larc.nasa.gov/project/ calipso/calipso_table), the NASA Earth Observing System Data and Information System for providing the MODIS data (https://earthdata. nasa.gov), and the Goddard Earth Sciences Data and Information Services Center for providing the MERRA data set (https://gmao. gsfc.nasa.gov/reanalysis/MERRA). The ice particle scattering calculations were conducted at the Texas A&M University Supercomputing Facility. The authors are grateful to Jiachen Ding for help in light scattering computations. This study was supported by Grant-in-Aid for Scientific Research (DC1 262947) and KAKENHI grant JP 25287117 from the Japan Society for the Promotion of Science (JSPS). The data provided by this paper are available from the first author upon request.
PY - 2017
Y1 - 2017
N2 - Ice particle morphology and microphysical properties of cirrus clouds are essential for assessing radiative forcing associated with these clouds. We develop an optimal estimation-based algorithm to infer cirrus cloud optical thickness (COT), cloud effective radius (CER), plate fraction including quasi-horizontally oriented plates (HOPs), and the degree of surface roughness from the Cloud Aerosol Lidar with Orthogonal Polarization (CALIOP) and the Infrared Imaging Radiometer (IIR) on the Cloud Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) platform. A simple but realistic ice particle model is used, and the relevant bulk optical properties are computed using state-of-the-art light-scattering computational capabilities. Rigorous estimation of uncertainties related to surface properties, atmospheric gases, and cloud heterogeneity is performed. The results based on the present method show that COTs are quite consistent with other satellite products and CERs essentially agree with the other counterparts. A 1 month global analysis for April 2007, in which CALIPSO off-nadir angle is 0.3°, shows that the HOP has significant temperature-dependence and is critical to the lidar ratio when cloud temperature is warmer than -40°C. The lidar ratio is calculated from the bulk optical properties based on the inferred parameters, showing robust temperature dependence. The median lidar ratio of cirrus clouds is 27-31 sr over the globe.
AB - Ice particle morphology and microphysical properties of cirrus clouds are essential for assessing radiative forcing associated with these clouds. We develop an optimal estimation-based algorithm to infer cirrus cloud optical thickness (COT), cloud effective radius (CER), plate fraction including quasi-horizontally oriented plates (HOPs), and the degree of surface roughness from the Cloud Aerosol Lidar with Orthogonal Polarization (CALIOP) and the Infrared Imaging Radiometer (IIR) on the Cloud Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) platform. A simple but realistic ice particle model is used, and the relevant bulk optical properties are computed using state-of-the-art light-scattering computational capabilities. Rigorous estimation of uncertainties related to surface properties, atmospheric gases, and cloud heterogeneity is performed. The results based on the present method show that COTs are quite consistent with other satellite products and CERs essentially agree with the other counterparts. A 1 month global analysis for April 2007, in which CALIPSO off-nadir angle is 0.3°, shows that the HOP has significant temperature-dependence and is critical to the lidar ratio when cloud temperature is warmer than -40°C. The lidar ratio is calculated from the bulk optical properties based on the inferred parameters, showing robust temperature dependence. The median lidar ratio of cirrus clouds is 27-31 sr over the globe.
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U2 - 10.1002/2016JD026080
DO - 10.1002/2016JD026080
M3 - Article
AN - SCOPUS:85018641031
VL - 122
SP - 4440
EP - 4462
JO - Journal of Geophysical Research
JF - Journal of Geophysical Research
SN - 0148-0227
IS - 8
ER -