Geoscience Reference
In-Depth Information
BOUNDARY LAYER PHENOMENA OBSERVED BY
CONTINUOUSLY OPERATED, TEMPORARY
HIGH-RESOLUTION LIDAR
NOBUO TAKEUCHI, GERRY BAGTASA,
NOFEL LAGROSAS and HIROAKI KUZE
CEReS, Chiba University, 1-33 Yayoi-cho, Inage-ku,
Chiba-shi, 263-8522, Japan
SUEKAZU NAITO
Chiba Prefecture Environmental Research Center,
1-8-8 Iwasakinishi, Ichikawa-shi, 290-0046, Japan
MAKOTO WADA
National Institute of Polar Research, 1-9-10, Kaga,
Itabashi-ku, Tokyo 173-8515, Japan
AKIHIRO SONE and HIROFUMI KAN
Hamamatsu Photonics, Inc., 5000 Hirakuchi, Hamakita-ku,
Hamamatu-shi, Shizuoka-ken, 434-8601, Japan
TATSUO SHIINA
Faculty of Engineering, Chiba University, 1-33 Yayoi-cho,
Inage-ku, Chiba-shi, 263-8522, Japan
Continuous lidar observation of the atmosphere is important for monitoring
various phenomena such as air pollution, local meteorology, and plume
diffusion. Center for Environmental Remote Sensing (CEReS), Chiba
University, developed a portable automatic lidar (PAL) with the cooperation of
Hamamatsu Photonics Inc. After installing the automatic alignment capability,
the PAL system has provided continuous observation data in every 20 s except
for some maintenance periods. The lidar operates at 532 nm (second harmonic
of Nd:YAG laser), with 1.4 kHz pulse-repetition frequency, 50 ns pulse width,
and 15
µ
J pulse energy. The signal is received by a 20-cm diameter telescope
pointed northward with an elevation angle of 38
◦
, and processed by a photon
counter. The range resolution is 24 m (height resolution is 15 m). During the
operation period of 3 years, we have observed atmospheric oscillations of
Brunt-Vaisala type with oscillation periods of several to several 10 minutes,
raindrops yielding information on falling speeds and corresponding droplet
sizes, upward/downward motion of air in the boundary layer, and statistics
on the cloud bottom height. In this chapter, we describe various features of
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