PEM10-P01

会場:コンベンションホール

時間:5 月 27 日 18:15-19:30

Retrieval of Raindrop Size Distribution Parameters by Combining Rainfall Rate and Electromagnetic Wave Attenuation Data
Retrieval of Raindrop Size Distribution Parameters by Combining Rainfall Rate and Electromagnetic Wave Attenuation Data
MARZUKI, Marzuki1∗ ; INDRAYANI, Wira1 ; VONNISA, Mutya1 ; HASHIGUCHI, Hiroyuki2 ; L. RANDEU, Walter3 ;SHIMOMAI, Toyoshi4 ; KOZU, Toshiaki4 ; MAEKAWA, Yasuyuki5 ; SHIBAGAKI, Yoshiaki5
MARZUKI, Marzuki1∗ ; INDRAYANI, Wira1 ; VONNISA, Mutya1 ; HASHIGUCHI, Hiroyuki2 ; L. RANDEU, Walter3 ;SHIMOMAI, Toyoshi4 ; KOZU, Toshiaki4 ; MAEKAWA, Yasuyuki5 ; SHIBAGAKI, Yoshiaki5
1

Department of Physics Andalas University, Padang, Indonesia, 2 RISH, Kyoto University, Japan, 3 Graz University of Technology, Austria, 4 Shimane University, Japan, 5 Osaka Electro-Communication University, Neyagawa, Japan1
Department of Physics Andalas University, Padang, Indonesia, 2 RISH, Kyoto University, Japan, 3 Graz University of Technology, Austria, 4 Shimane University, Japan, 5 Osaka Electro-Communication University, Neyagawa, Japan
Rain attenuation of down-link radio wave signals of satellite Superbird C (144oE in orbit) and surface rainfall data are used toestimate the parameter of exponential raindrop size distribution (DSD) at Koto Tabang (KT), west Sumatera, Indonesia. Rainfall
rate and temperature during rain event are measured by an optical rain gauge (ORG). The effect of rain type on path length
estimation is first examined using Simple Attenuation Model (SAM) and the ITU-R. Mie extinction efficiency is calculated byassuming raindrop shape being a spherical. Result shows that taking 5 km as a constant equivalent path length for stratiform rain
at KT is generally acceptable in which the model-generated attenuation has been found to closely follow the measured attenuation. For deep and shallow convective rains, the equivalent path length varies, i.e., 5-4 km and 3-2 km, respectively. Combinationof specific rain attenuation and rainfall rate successfully estimated the DSD parameters of stratiform rain with steady intensity,
indicated by small difference between the parameter derived from rain attenuation and that from 2D-Video Disdrometer (2DVD).
For deep convective rain with a short duration, the result also showed a good agreement with the 2DVD. Low performance ofthe method was observed for stratiform with strong rain intensity fluctuation and for shallow convective rain, indicated by highdiscrepancy with the 2DVD data. This phenomenon was probably due to the bias in estimating the specific rain attenuation. The
bias can be caused by a constant path length assumption throughout the rain.
キーワード: Raindrop size distribution, Rainfall rate, Rain attenuation
Keywords: Raindrop size distribution, Rainfall rate, Rain attenuation

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PEM10-P02

会場:コンベンションホール

時間:5 月 27 日 18:15-19:30

E-F REGION FIELD ALIGNED IRREGULARITIES OBSERVED WITH EQUATORIAL ATMOSPHERIC RADAR AND IONOSONDEE-F REGION FIELD ALIGNED IRREGULARITIES OBSERVED WITH EQUATORIAL ATMOSPHERIC RADAR AND IONOSONDEMARTININGRUM, Dyah rahayu1∗ ; YAMAMOTO, Mamoru1 ; YOKOYAMA, Tatsuhiro2 ; HUSIN, Asnawi3 ;YATINI, Clara yono3
MARTININGRUM, Dyah rahayu1∗ ; YAMAMOTO, Mamoru1 ; YOKOYAMA, Tatsuhiro2 ; HUSIN, Asnawi3 ;YATINI, Clara yono311RISH, Kyoto University-Japan, 2 NICT, Tokyo-Japan, 3 Center of Space Science, LAPAN-Indonesia
RISH, Kyoto University-Japan, 2 NICT, Tokyo-Japan, 3 Center of Space Science, LAPAN-Indonesia

The irregular plasma density and velocity fluctuations often occur in the Earth’s ionosphere regions. When radio signals propagate through that region, they cause a fade in received signal power known as scintillation. The generation of these plasma
irregularities is one of the important manifestations of space weather. Recently, research of the mechanism and the morphologyof plasma irregularities has progressed. In this study, we analyzed E and F region field aligned irregularities (FAI) observed by aVHF backscatter radar with operating frequency 47 MHz have been operated at Kototabang (0.20o S, 100.32o E; dip lat 10.36o S),
Indonesia. Seasonal variation of E and F region field aligned irregularities observation compared with sporadic E (Es ) and equatorial spread F (ESF) occurrences observed by ionosonde. The ionosonde provide various E and F region parameters such as
the critical frequency of F2 layer (fo F2 ), the critical frequency of sporadic E layer (fo Es ), and the maximum height of F2 layer(hmF2). We analyzed for equinox (March, April, September, and October), June solstice (May-August), and December solstice(November-Februry) of data observations during 2011-2012. We also discussed correlation between sporadic E (Es ) and equatorial spread F (ESF) occurrences to understand morphological of coupling between E and F region of the Earth’s ionosphere.

キーワード: plasma irregularities, ionosphere, E-F region, coupling
Keywords: plasma irregularities, ionosphere, E-F region, coupling

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会場:コンベンションホール

時間:5 月 27 日 18:15-19:30

MU レーダー実時間アダプティブクラッター抑圧システムの開発
Development of MU radar real-time processing system with adaptive clutter rejection
万城 孝弘 1∗ ; 橋口 浩之 1 ; 山本 衛 1
MANJOU, Takahiro1∗ ; HASHIGUCHI, Hiroyuki1 ; YAMAMOTO, Mamoru1
1
1

京都大学生存圏研究所
Research Institute for Sustainable Humanosphere, Kyoto University

Strong clutter echoes from a hard target such as a mountain or building sometimes cause problems of observations with atmospheric radars. In order to reject or suppress clutter echoes, it is effective to use DCMP-CN (Directionally Constrained Minimum
Power-Constrained Norm) method, which makes null toward the direction of the clutter, if we can receive signals independently
from plural antennas. It has been demonstrated that the DCMP-CN method is effective to real observation data with the MU(Middle and Upper atmosphere) radar, but it was processed in off-line. The objective of this study is to implement the clutter
rejection by DCMP-CN method into the on-line processing system of the MU radar. Namely, we can adaptively suppress clutter
echoes in real time without changing any MU radar hardware.
The MU radar which located in Shigaraki, Shiga Prefecture, Japan is one of the most powerful VHF-band atmospheric radars,
which can observe atmospheric motion and circulation between the troposphere and the upper atmosphere and which has contributed to a wide variety of research areas. Its operational frequency, occupied frequency bandwidth, and peak output power
are 46.5 MHz, 3.5 MHz and 1 MW, respectively. The MU radar has an active phased array system. Its antenna consists of 475
elements of crossed Yagi antennas and is divided into 25 groups. Each group has 19 antenna elements. After installing the ultra
multi-channel digital receiving system in 2004, we can receive signals from each 25 group, independently.
We cannot apply simple DCMP method for the MU radar signals. Because DCMP method suppresses clutter echoes too muchto break main robe of antenna pattern in high SNR case. In order to solve this problem, Nishimura et al. supposed DCMP-CN
method, which can maintain the shape of main robe with suppressing clutter echoes to add pseudonoise and demonstrated its
effectiveness for atmospheric radar observations. So far we sum up independent signals without weighting from 25 channels(groups). Applying DCMP-CN method before summing enables on-line processing. Now, we are implementing DCMP-CN
method into observation system and expect to show test results in our presentation. In order to apply DCMP-CN method appropriately, we have to change constraints which depend on desired SNR. Through the real observation data, we will optimize
constraints. In this presentation, we have taken account of clutter echoes from only fixed targets such as mountain, but we aregoing to deal with airplane and meteor echoes. Furthermore, we can apply the achievement of this study to the Equatorial MU
radar (EMU), which is proposed to be constructed at West Sumatera, Indonesia. The EMU system is the similar as the MU radar,but its antenna consists of 1045 Yagi antennas with 55 groups.
キーワード: 大気レーダー, クラッター抑圧, ウエイトノルム拘束付 DCMP 法, MU レーダー
Keywords: Atmospheric radar, Clutter rejection, DCMP-CN method, MU radar

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PEM10-P04

会場:コンベンションホール

時間:5 月 27 日 18:15-19:30

赤道 MU レーダー・RASS による温度プロファイル測定に関する基礎研究
Measurement of Temperature Profiles Using Equatorial Middle and Upper Atmosphere(EMU) Radar with Radio Acoust
田畑 啓 1∗ ; 津田 敏隆 2TABATA, Hiraku1∗ ; TSUDA, Toshitaka2
11

京都大学工学部電気電子工学科, 2 京都大学生存圏研究所
KUEE, 2 RISH, Kyoto Univ.

Because of intense solar radiation, the equatorial atmosphere involves various atmospheric disturbances with a wide range oftemporal and spatial scales. The tropopause located at 15-17 km altitude separates the troposphere (0-15 km) and the stratosphere(15-60 km). There are a number of interesting phenomena in the upper troposphere ? lower stratosphere (UTLS) region, includingtransport and exchange of energy and atmospheric minor constituents. Thus it is important to observe structure and variations ofwind velocity and temperature in the UTLS region.
We have been promoting to construct the Equatorial Middle and Upper Atmosphere (EMU) Radar in Koto Tabang (-0.204 deg,100.320 deg), Indonesia. The EMU radar is a high power Doppler radar similar to the MU radar in Shigaraki, Japan, and it canmeasure three components of wind velocity up to about 25 km altitude. In addition, we plan to apply the radio acoustic soundingsystem (RASS) to the EMU radar. RASS is an advanced radar observation method, by combining an acoustic transmitter anda radar, to measure a temperature profile. Adding RASS in the EMU radar makes it possible to observe the height profiles oftemperature in the entire troposphere and lower stratosphere with good accuracy and high time resolution.
In order to estimate a possible height range of RASS measurements in the equatorial region, we analyzed the sound propagation
characteristics using ray-tracing method, assuming realistic profiles for horizontal winds and temperature. Equatorial region isknown that wind velocity is relatively weak. However, the zonal winds sometimes become strong at around 5 km and 15 km
altitude, and a sharp bent in the temperature gradient near the tropopause affect the RASS observation. The quasi-biennial
oscillation (QBO) of the zonal winds in the stratosphere also affects the observation height range of RASS.
We summarized the effects of zonal wind and temperature on RASS measurements. We further investigated that steering ofradar antenna beam and relative position between an acoustic speaker and the radar enable us to observe temperature from theground up to height 25 km throughout a year, where the speakers should be moved along the wind direction by 200 to 500 m.

キーワード: 赤道 MU レーダー, RASS, 気温プロファイル, 赤道大気, 対流圏, 成層圏
Keywords: EMU, RASS, Temperature profile, Equatrial atmosphere, Troposphere, Stratosphere

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PEM10-P05

会場:コンベンションホール

時間:5 月 27 日 18:15-19:30

赤道大気上下結合研究のためのオゾンライダー観測
Lidar observations of ozone profile in the tropopause region for study of coupling processes over the equatorial region
阿保 真 1∗ ; 長澤 親生 1 ; 柴田 泰邦 1
ABO, Makoto1∗ ; NAGASAWA, Chikao1 ; SHIBATA, Yasukuni1
11

首都大学東京Tokyo Metropolitan University

Tropospheric ozone in the tropics zone is significant in terms of the oxidizing efficiency and greenhouse effect. However, in theupper troposphere, the ozone budget in the tropics has not been fully understood yet because of the sparsity of the range-resolved
observations of vertical ozone concentration profiles.
We have constructed the lidar facility for survey of atmospheric structure over troposphere, stratosphere, mesosphere andlow thermosphere over Kototabang (100.3E, 0.2S), Indonesia in the equatorial region. The lidar system consists of the Mieand Raman lidars for tropospheric aerosol, water vapor and cirrus cloud measurements, the Rayleigh lidar for stratospheric andmesospheric temperature measurements and the Resonance lidar for metallic species such as Na, Fe, Ca ion measurements andtemperature measurements in the mesopause region. The lidar observations started from 2004, and routine observations of clouds
and aerosol in the troposphere and stratosphere are continued now.
We have installed DIAL (differential absorption lidar) system for high-resolution measurements of vertical ozone profiles inthe equatorial tropopause region over Kototabang. There were many ozone DIAL systems in the world, but their systems arealmost optimized for stratospheric ozone layer measurement or tropospheric ozone measurement. Because of deep ozone absorption in the UV region, the wavelength selection is important. Over the equatorial region, the tropopause height is almost 17km.
So we use 314nm for on-line and 355nm for off-line using second harmonics of dye laser and third harmonics of Nd:YAG laser.
We have observed large ozone enhancement in the upper troposphere, altitude of 13-17km in June 2014, concurring with azonal wind oscillation associated with the equatorial Kelvin wave around the tropopause[1] at equatorial region.
REFERENCES
1. Fujiwara, M. et al., JGR, 103, D15, 19,173-19,182, 1998.

キーワード: 大気上下結合, 赤道対流圏界面領域, ライダー
Keywords: coupling process, tropical tropopause region, lidar

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