• Title, Summary, Keyword: Sonde

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The Effects of Data Assimilation on Simulated Wind Fields Using Upper-Air Observations (고층기상관측자료를 이용한 바람장 개선 효과 연구)

  • Jeong, Ju-Hee;Kwun, Ji-Hye;Kim, Yoo-Keun
    • Journal of Environmental Science International
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    • v.16 no.10
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    • pp.1127-1137
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    • 2007
  • We focused on effects on data assimilation of simulated wind fields by using upper-air observations (wind profiler and sonde data). Local Analysis Prediction System (LAPS), a type of data assimilation system, was used for wind field modeling. Five cases of simulation experiments for sensitivity analysis were performed: which are EXP0) non data assimilation, EXP1) surface data, EXP2) surface data and sonde data, EXP3) surface data and wind profiler data, EXP4) surface data, sonde data and wind profiler data. These were compared with observation data. The result showed that the effects of data assimilation with wind profiler data were found to be greater than sonde data. The delicate wind fields in complex coastal area were simulated well in EXP3. EXP3 and EXP4 using wind profiler data with vertically high resolution represented well sophisticated differences of wind speed compared with EXP1 and EXP2, this is because the effects of wind profiler data assimilation were sensitively adjusted to first guess field than those of sonde observations.

Bias Correction for Aircraft Temperature Observation Part I: Analysis of Temperature Bias Characteristics by Comparison with Sonde Observation (항공기 온도 관측 자료의 편향 보정 Part I: 존데와 비교를 통한 온도 편향 특성 분석)

  • Kwon, Hui-nae;Kang, Jeon-ho;Kwon, In-Hyuk
    • Atmosphere
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    • v.28 no.4
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    • pp.357-367
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    • 2018
  • In this study, the temperature bias of aircraft observation was estimated through comparison with sonde observation prior to developing the temperature bias correction method at the Korea Institute of Atmospheric Prediction Systems (KIAPS). First, we tried to compare aircraft temperature with collocated sonde observations at 0000 UTC on June 22, 2012. However, it was difficult to estimate the temperature bias due to the lack of samples and the uncertainty of the sonde position at high altitudes. Second, we attempted a background innovation comparison for sonde and aircraft using KIAPS Package for Observation Processing (KPOP). The one month averaged background innovation shows the aircraft temperature have a warm bias against sonde for all levels. In particular, there is a globally distinct warm bias about 0.4 K between 200 hPa and 300 hPa corresponding to flight level. Spatially, most of the areas showed the warm bias except for below 300 hPa in some part of China at 0000 and 1200 UTC and below 850 hPa in Australia at 0000 UTC. In general, the temperature bias was larger at 1200 UTC than 0000 UTC. Based on the estimated temperature bias, we have applied the static bias correction method to the aircraft temperature observation. As a result, the warm bias of the aircraft temperature has decreased at most levels, but a slight cold bias has occurred in some areas.

Intercomparisons of ADEOS/IMG Measurements with the Sonde Observations over Korea (한반도 상공의 ADEOS/IMG 관측 자료와 존데 자료의 비교 분석)

  • 조하만;김주공;오성남
    • Korean Journal of Remote Sensing
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    • v.15 no.3
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    • pp.253-266
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    • 1999
  • ADEOS(Advanced Earth Observing Satellite)/IMG(Interferometric Monitor for Greenhouse Gases) measurements - temperature, water vapor($H_2O$), ozone($O_3$) have been compared with the radio sonde and ozone sonde observations at Osan and Pohang stations for the 4 cases on 10 Jan.(a), 28 Jan.(b), 2 Apr.(c), and 19 Jun.(d) 1997 to detect the error ranges of the IMG data. It showed that the IMG data of the cases (b), (d) when the ADEOS passed over the central part of Korea were quite stable with the good agreement with the sonde observations, however, that of (a),(c) when the ADEOS passed over south- east coastal area were unstable with the larger differences from the sonde-observations. The RMSE and bias analyses of temperature for the stable cases (b),(d) showed that the differences between the IMG data and the sonde observations were about 1~4 K at the 700~300 hPa level and about 4~5 K or more at the higher level, and the IMG measurements tended to be larger than the sonde observations at the higher level above 200 hPa, while no typical bias was seen at the lower level. The RMSE and bias analysis for the version of level 2 5_6_4_4 of ozone showed that the RMSE of ozone were quite small, in general, except at the higher level above 50~60 hPa in the all 4 cases, however the bias was generally big with the positive value in the troposphere and the negative in the stratosphere. An example of vertical profile of trace gases such as $CO_2, N_2O, CH_4, HNO_3$, CO measured by IMG was also presented and it showed that the IMG data had large differences between the 5 different observation points.

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The Properties of Wind Analyzed by Observation of Tethered Sonde and Sodar in Gwangyang Coastal Area (Tethered Sonde와 Sodar 관측으로 분석한 광양만 지역의 풍환경 특성)

  • Lee, Hwa-Woon;Park, Soon-Young;Lim, Heon-Ho;Kim, Dong-Hyuk;Kim, Min-Jung
    • 한국신재생에너지학회:학술대회논문집
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    • pp.324-326
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    • 2008
  • When we urgently need to develop and supply an alternative energy, wind power is growing with much interest because it has relative low cost of power and area of tower. To estimate the wind power resource, it is necessary to make an wind resource map first. On the study of wind resource map in the Korean peninsula, Southern coast was needed to investigate the possibility of developing wind power complex because of good wind resources. In this study, we made a vertical observation to analyze the properties of wind in coastal area. From tethered sonde observation, we knew that synoptic effect had an influence higher in second day than first day. This means local wind circulation is generated on first day but not second day. The local wind made vertical wind shear strong in first day. Also, there was large difference of wind speed between layers at night time by analysis of SODAR observation.

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Features on the Vertical Size Distribution of Aerosols using Ballon-borne Optical Particle Counter at Anmyeon (광학입자계수기를 이용한 안면도 연직 에어러솔 수농도 크기 분포 특성)

  • Choi, B.C.;Iwasaka, Y.;Lim, J.C.;Jeong, S.B.;Kim, Y.S.;Dmitri, T.;Nagatani, T.;Yamada, M.;Kim, S.B.;Hong, G.M.;Lee, Y.G.;Yoo, H.J.
    • Atmosphere
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    • v.15 no.3
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    • pp.149-153
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    • 2005
  • A balloon-borne Optical Particle Counter (hereafter "OPC Sonde"), which was developed by the atmospheric research group of Nagoya University, is used for getting the information of vertical profile of particle size and concentration in Anmyeon ($36^{\circ}32^{\prime}N$ $126^{\circ}19^{\prime}E$) on 18 March 2005. A range of five different particle sizes is shown in the vertical profile of aerosol number density estimated from the OPC Sonde. It was found that small size particles have vertically larger aerosol number density than relatively big ones. For all size ranges the vertical aerosol number density shows a decreased pattern as the altitude becomes higher. The aerosol number density of $0.3{\sim}0.5{\mu}m$, $0.5{\sim}0.8{\mu}m$, $0.8{\sim}1.2{\mu}m$ size ranges at the 10km height, which is the tropopause approximately, are $1,000,000ea/m^3$, $100,000ea/m^3$, $10,000ea/m^3$ respectively. The data of OPC Sonde are also compared with the data of PM10 $\beta$-ray) and Micro Pulse Lidar which are operating at Korea Global Atmosphere Watch Observatory in Anmyeon.

Construction of calibration models and calibrating experiment for efficient Held application of density log (밀도검층의 효과적인 현장 적용을 위한 모형 보정공 건설과 밀도 보정 기초연구)

  • Kim Ji-hoon;Kong Nam-young;Zhao Weijun;Kim Yeong-hwa
    • 한국지구물리탐사학회:학술대회논문집
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    • pp.73-82
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    • 2005
  • We constructed a series of calibration models in the campus of Kangwon National University. A series of experiment for calibrating sonde response as well as casing effect in field measurement. Here we explained the process of construction of calibrating facility which consists of three model holes of different density and three model holes of different diameter. It was discussed the calibration equations obtained from its sonde response calibration test. A density correction chart for different separation of detector from hole wall was suggested, and verified the possibility of determining true density from measurements in cased hole.

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Neutron Induced Capture Gamma Spectroscopy Sonde Design and Response Analysis Based on Monte Carlo Simulation (Monte Carlo 시물레이션에 기초한 포획모드 중성자-감마 스펙트럼 존데 설계 및 반응 분석)

  • Won, Byeongho;Hwang, Seho;Shin, Jehyun;Kim, Jongman;Kim, Ki-Seog;Park, Chang Je
    • Geophysics and Geophysical Exploration
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    • v.18 no.3
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    • pp.154-161
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    • 2015
  • For efficiently designing neutron induced gamma spectroscopy sonde, Monte Carlo simulation is employed to understand a dominant location of thermal neutron and classify the formation elements from the energy peak of capture gamma spectrum. A pulsed neutron generator emitting 14 MeV neutron particles was used as a source, and flux of thermal neutron was calculated from the twelve detectors arranged at each 10 cm intervals from the source. Design for reducing borehole effects using shielding materials was also applied to numerical sonde model. Moreover, principal elements and quantities of numerical earth models were verified through the energy spectrum analysis of capture gamma detected from a gamma detector. These results can help to enhance the signal-to-noise ratio, and determine an optimal placement of capture gamma detectors of neutron induced gamma spectroscopy sonde.

An Experimental Study on Density Tool Calibration (밀도검층 검출기 보정에 관한 기초 연구)

  • Kim, Yeonghwa;Kim, Kiju;Lim, Heontae;Kim, Jihoon;Kong, Nam-Young
    • Journal of the Korean Geophysical Society
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    • v.7 no.4
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    • pp.237-245
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    • 2004
  • Series of basic experiments for current density calibration by user process and for density calibration using geophysical model borehole were made. We tried to find the sonde response characteristics for current calibration using water and aluminium field jig, and using the equation of half life of 137Cs source. The result of calibration test made in a geophysical model borehole built first in Korea shows a perfect linear calibration equation. By adopting this calibration equation we could estimate the limitation as well as possibility of current density calibration by user process.

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