Open AccessVertical cloud structure observed from shipborne radar and lidar: Midlatitude case study during the MR01/K02 cruise of the research vessel Mirai
Author(s) -
Okamoto Hajime,
Nishizawa Tomoaki,
Takemura Toshihiko,
Kumagai Hiroshi,
Kuroiwa Hiroshi,
Sugimoto Nobuo,
Matsui Ichiro,
Shimizu Atsushi,
Emori Seita,
Kamei Akihide,
Nakajima Teruyuki
Publication year - 2007
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2006jd007628
Subject(s) - lidar , drizzle , cirrus , radar , cloud fraction , cloud top , environmental science , meteorology , middle latitudes , remote sensing , atmospheric sciences , geology , cloud computing , cloud cover , physics , precipitation , telecommunications , computer science , operating system
We observed the vertical distribution of clouds over the Pacific Ocean near Japan in May 2001 using lidar and a 95‐GHz radar on the Research Vessel Mirai. Cloud analyses derived from synergy use of radar and lidar observations showed that there were two local maxima of cirrus cloud frequency of occurrence at 7 and 10.5 km and the drizzle frequency of occurrence was about the half compared with that of clouds below 4 km. The number of layers could be also measured using these schemes. Single, double, triple, and quadruple (or more) cloud layers had a 48, 23, 7, and 2% probability of occurrence, respectively. The average number of cloud layers when clouds existed was 1.54. The vertical structure of clouds observed with the radar/lidar system was compared to clouds in the aerosol transport model SPRINTARS, which is based on the CCSR‐NIES Atmospheric General Circulation Model. The cloud fraction, radar reflectivity factor, and lidar backscattering coefficient were simulated by the model and compared to those by the observations using height‐time cross‐sections where the radar sensitivity was taken into account. The overall pattern of cloud fraction was well reproduced, although the model underestimated (overestimated) mean cloud fraction below 8 km (above 8 km). Cloud microphysics in the model could also be validated through comparison of derived model radar and lidar signals in grid mean with observations. The model overestimated ice particle size above 10 km, and simulated particle sizes in water clouds of 10 μ m were larger than observed.