TY - JOUR
T1 - Large-and-Sparse-particle Clouds (LSC)
T2 - Clouds which are subvisible for space-borne lidar and observable for space-borne cloud radar
AU - Iwasaki, Suginori
AU - Seguchi, Takafumi
AU - Okamoto, Hajime
AU - Sato, Kaori
AU - Katagiri, Shuichiro
AU - Fujiwara, Masatomo
AU - Shibata, Takashi
AU - Tsuboki, Kazuhisa
AU - Ono, Takashi
AU - Sugidachi, Takuji
N1 - Funding Information:
This work was supported by the Collaborative Research Program of Research Institute for Applied Mechanics, Kyushu University, and by the Joint Research Program of the Institute for Space-Earth Environmental Research, Nagoya University. TS and SI are supported by the JSPS Kakenhi Grant Number JP 16H02702. HO and KS are supported by JSPS Kakenhi Grant Number JP17H06139. SI and KS are also supported by JSPS Kakenhi Grant Numbers JP19K12314 and JP18K03745, respectively. Data from the CPR and CALIOP were obtained from the CloudSat Data Processing Center and the Atmospheric Sciences Data Center, respectively.
Funding Information:
This work was supported by the Collaborative Research Program of Research Institute for Applied Mechanics, Kyushu University , and by the Joint Research Program of the Institute for Space-Earth Environmental Research, Nagoya University . TS and SI are supported by the JSPS Kakenhi Grant Number JP 16H02702 . HO and KS are supported by JSPS Kakenhi Grant Number JP17H06139 . SI and KS are also supported by JSPS Kakenhi Grant Numbers JP19K12314 and JP18K03745 , respectively. Data from the CPR and CALIOP were obtained from the CloudSat Data Processing Center and the Atmospheric Sciences Data Center, respectively.
Publisher Copyright:
© 2019 Elsevier B.V. and NIPR
PY - 2019/9
Y1 - 2019/9
N2 - Large-and-Sparse-particle Clouds (LSC), characterized by large particle size (radius > 50 μm) and small number concentration (<104 m−3), were observed with the space-borne lidar, Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP), and with the space-borne 94-GHz cloud profiling radar (CPR). CALIOP was found to be less sensitive to the LSC as compared to CPR because of the particle size distribution of LSC; hence, the cloud type is different from usual ones because CALIOP is generally more sensitive to clouds as compared to CPR when there is no lidar attenuation. An empirical criterion was introduced to identify the LSC from CALIOP and CPR data. The data analysis showed that the LSC tend to appear at high latitudes. The lifetime of LSC would be in the order of hours, because the terminal velocity of LSC particles exceeded 1 km h−1. LSC would not be fallstreak because no cloud existed above. LSC appeared to destroy supercooled clouds (SC) because their cloud top heights were higher as compared to SC, and because LSC and SC did not tend to coexist. Because of their thin optical depth, LSC did not directly impact radiative forcing; however, LSC may indirectly influence radiative forcing through changes in the distribution of SC.
AB - Large-and-Sparse-particle Clouds (LSC), characterized by large particle size (radius > 50 μm) and small number concentration (<104 m−3), were observed with the space-borne lidar, Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP), and with the space-borne 94-GHz cloud profiling radar (CPR). CALIOP was found to be less sensitive to the LSC as compared to CPR because of the particle size distribution of LSC; hence, the cloud type is different from usual ones because CALIOP is generally more sensitive to clouds as compared to CPR when there is no lidar attenuation. An empirical criterion was introduced to identify the LSC from CALIOP and CPR data. The data analysis showed that the LSC tend to appear at high latitudes. The lifetime of LSC would be in the order of hours, because the terminal velocity of LSC particles exceeded 1 km h−1. LSC would not be fallstreak because no cloud existed above. LSC appeared to destroy supercooled clouds (SC) because their cloud top heights were higher as compared to SC, and because LSC and SC did not tend to coexist. Because of their thin optical depth, LSC did not directly impact radiative forcing; however, LSC may indirectly influence radiative forcing through changes in the distribution of SC.
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U2 - 10.1016/j.polar.2019.05.003
DO - 10.1016/j.polar.2019.05.003
M3 - Article
AN - SCOPUS:85065626420
SN - 1873-9652
VL - 21
SP - 117
EP - 123
JO - Polar Science
JF - Polar Science
ER -