National Institute Of Meteorological Research Research Articles

낙동강 구미 보의 증기 안개에 관한 연구

We analyzed the characteristics of fog formation in the Gumi Reservoir of Nakdong river with the field observation data for recent 2 years (1 April 2013~31 March 2015) collected by the national institute of meteorological research, KMA. In early morning, we frequently observe the steam rising from the water surface. The fog occurs from adding water vapor into the air. We call the fog as steam fog. Steam fogs occur when cold, dry air mixes with warm, moist air above a water surface. The steam fog appears mainly in autumn under the following conditions; (1) sensible heat is positive values (), (2) latent heat is more positive values () than sensible heat, (3) cloudless nights with light winds (about 1.5 m/s), (4) under condition(3), mountainous winds easily blows into the reservoir.

계절별 AERI 기준 스펙트럼 적용을 통한 구름에 영향을 받은 스펙트럼 자료 제거방법 개선

Abstract : The Atmospheric Emitted Radiance Interferometer (AERI) which is the Fourier TransformInfraRed (FTIR) spectrometer has been operated by the National Institute of Meteorological Research(NIMR) in Anmyeon island, South Korea since June 2010. The ground-based AERI with similar hyper-spectral infrared sensor to satellite could be an alternative way to validate satellite-based remote sensing.In this regard, the NIMR has focused on the improvement of Cloud data Filtering Method (CFM) whichemployed only one reference spectrum of clear sky in winter season. This study suggests Seasonal-Clouddata Filtering Method (S-CFM) which applied seasonal AERI reference spectra. For the comparison ofapplied S-CFM and CFM, the methane retrievals (surface volume mixing ratio) from AERI spectra areused. The quality of AERI methane retrieval applied S-CFM was significantly more improved than thatof CFM. The positive result of S-CFM is similar pattern with the seasonal variation of methane fromground-based in-situ measurement, even if the summer season’s methane is retrieved over-estimation. Inaddition, the comparison of vertical total column of methane from AERI and GOSAT shows good resultexcept for the summer season.Key Words : AERI, Cloud Filtering, FTIR, Infrared, Remote sensing, Satellite, GOSAT, Methaneretrieval요약 :

Analysis of wind power potentials at abandoned mine promotion districts in Korea

This study assessed the wind power potentials at seven abandoned mine promotion districts in Korea. The wind power system with a capacity of 2 MW was considered at each district. The meteorological data measured by National Institute of Meteorological Research in Korea were used to determine the representative values of wind data at each district. The estimated electric power productions and economic effects of wind power systems were analyzed using RETScreen software developed by Natural Resources Canada. The results showed that the Taebaek district has the highest wind power potential where the estimated electric power production is about 3642 MWh/year, the net present value is 8984 million KRW, and the payback period is about 5.3 years.

AERI 스펙트럼 분석을 통한 구름에 영향을 받은 스펙트럼 자료 제거 방법 개선

Abstract : The National Institute of Meteorological Research (NIMR) has operated the FourierTransform InfraRed (FTIR) spectrometer which is the Atmospheric Emitted Radiance Interferometer(AERI) in Anmyeon island, Korea since June 2010. The ground-based AERI with similar hyper-spectralinfrared sensor to satellite could be an alternative way to validate satellite-based remote sensing. In thisregard, the NIMR has focused on the improvement of retrieval quality from the AERI, particularly cloud-data filtering method. The AERI spectrum which is measured on a typical clear day is selected referencespectrum and we used region of atmospheric window. We performed test of threshold in order to selectvalid threshold. We retrieved methane using new method which is used reference spectrum, and the othermethod which is used KLAPS cloud cover information, each retrieved methane was compared with thatof ground-based in-situ measurements. The quality of AERI methane retrievals of new method wassignificantly more improved than method of used KLAPS. In addition, the comparison of vertical totalcolumn of methane from AERI and GOSAT shows good result.Key Words : AERI, Cloud Filtering, FTIR, Infrared, Remote sensing, Satellite.요약 :

Ka-밴드 구름레이더 자료품질 및 구름통계 기초연구

The Ka-band cloud radar (KCR) has been operated by the National Institute of Meteorological Research (NIMR) of Korea Meteorological Administration (KMA) at Boseong National Center for Intensive Observation of severe weather since 2013. Evaluation of data quality is an essential process to further analyze cloud information. In this study, we estimate the measurement error and the sampling uncertainty to evaluate data quality. By using vertically pointing data, the statistical uncertainty is obtained by calculating the standard deviation of each radar parameter. The statistical uncertainties decrease as functions of sampling number. The statistical uncertainties of horizontal and vertical reflectivities are identical (0.28 dB). On the other hand, the statistical uncertainties of Doppler velocity (spectrum width) are 2.2 times (1.6 times) larger at the vertical channel. The reflectivity calibration of KCR is also performed using X-band vertically pointing radar (VertiX) and 2-dimensional video disdrometer (2DVD). Since the monitoring of calibration values is useful to evaluate radar condition, the variation of calibration is monitored for five rain events. The average of calibration bias is 10.77 dBZ and standard deviation is 3.69 dB. Finally, the statistical characteristics of cloud properties have been investigated during two months in autumn using calibrated reflectivity. The percentage of clouds is about 26% and 16% on September to October. However, further analyses are required to derive general characteristics of autumn cloud in Korea.

RCP8.5 기후변화 시나리오에 따른 애멸구 월동 개체군의 성충 발생시기 및 연간 세대수 변화 예측

최근 WMO는 온실가스 배출량 시나리오(SRES)를 대신하여 대표농도경로(RCP)를 바탕으로 새로운 기후변화 시나리오를 생산하였으며 기상연구소는 RCP 시나리오를 바탕으로 한반도의 새로운 기후변화 시나리오를 생산하였다. 본 연구에서는 과거 관측값을 바탕으로 평년(1981-2010)의 애멸구의 우화시기와 세대수를 추정하였으며, RCP 8.5 시나리오를 바탕으로 2020년대(2015-2024), 2050년대(2045-2054)와 2090년대(2085-2094) 애멸구의 우화시기와 세대수를 예측하였다. 평년 애멸구 월동 1세대수의 우화일인 <TEX>$176.0{\pm}0.97$</TEX>일과 비교하여 2050년대에서는 <TEX>$13.2{\pm}0.18$</TEX>일(<TEX>$162.8{\pm}0.91$</TEX>일), 2090년대에는 <TEX>$32.1{\pm}0.61$</TEX>일(<TEX>$143.9{\pm}1.08$</TEX>일) 앞당겨질 것을 예측되었다. 그리고 애멸구의 연간 세대수는 2050년대에서는 현재보다 <TEX>$2.0{\pm}0.02$</TEX>세대, 2090년대에는 <TEX>$5.2{\pm}0.06$</TEX>세대 증가할 것으로 예측되었다. Recently, climate change scenarios were substituted by the Special Report on Emission Scenarios (SRES) for Representative Concentration Pathway (RCP). Using the RCP scenario, the World Meteorological Organization (WMO) produced new climate change scenarios. Further, the National Institute of Meteorological Research (NIMR) of Korea produced new climate change scenarios for the Korean Peninsula. In this study, emergence time of small brown planthopper (SBPH), Laodelphax striatellus and the number of generations a year were estimated during climatic normal year (1981-2010) with previous studies and they were predicted during 2050s (2045-2054) and 2090s (2085-2094) by means of RCP8.5 climate change scenario. In comparison with <TEX>$176.0{\pm}0.97$</TEX> Julian data in the climatic normal year, the emergence time of overwintering SBPH was predicted to be <TEX>$13.2{\pm}0.18$</TEX> days (<TEX>$162.8{\pm}0.91$</TEX> Julian date) earlier in 2050s and <TEX>$32.1{\pm}0.61$</TEX> days (<TEX>$143.9{\pm}1.08$</TEX> Julian date) earlier in 2090s. The SBPH was expected to produce an additional <TEX>$2.0{\pm}0.02$</TEX> generations in 2050s and <TEX>$5.2{\pm}0.06$</TEX> generations in 2090s.

한국의 관학 대기과학 연구 발전을 위한 미국 협동연구 사례 분석 - 콜로라도대학 환경과학협동연구소를 중심으로

A public-academia cooperative research system is suggested to improve the level of national research on atmospheric science and to enable the National Institute of Meteorological Research (NIMR) to meet its overloaded demand for research and results. As a practical example of cooperative research the CIRES case was reviewed. CIRES, the Cooperative Institute for Research in Environmental Sciences, located at the University of Colorado Boulder, is one of NOAA's 18 cooperative research centers located at universities across the U.S. NOAA, the National Oceanic and Atmospheric Administration, as a part of government, gives clear guideline for research topics and supplies research funds to research centers and audits their research processes and accomplishments. NOAA Boulder Laboratories, as a large, well-established government research center managed by government scientists, supplies depth of experiences and major research infra-structure to CIRES. CIRES pursues innovative and challenging research with their younger and brand-new researchers who are university employees. This cooperative work between government research organizations and the university produces high level research efficiently. Not only does Boulder have a beautiful natural setting where researchers live and work but also the city is a home to many scientific agencies and research facilities. This robust scientific network provides rich opportunities for CIRES researchers to collaborate with others in their scientific fields.

The relationship of pollen count and occurrence of asthma

Background: Asthma is typical allergic disease and incidence rate is increasing. Some cause of increase may be due to pollen change related with climate change. However, in South Korea, a few studies have been performed to explain the correlation of climates changes, pollen count, and allergic diseases using national data such as National Health Insurance Corporation. Objective: The aim of this ecological study was to characterize the correlation of pollen count and asthma which is typical allergic disease in South Korea. Method: All asthma cases of South Korea (2006~2010) composed of J45.0 and J45.9 from ICD-10 code were counted in the Reports of National Health Insurance Corporation. Meteorological data (average temperature and precipitation), and three area (Seongdong-gu, Guri, &amp; Jeju) pollen counts (weekly added value of Birch, Alder, Oak, Ragweed, Wormwood, Japanese hop, Grass, Hazel) were provided by National Institute of Meteorological Research, and air pollution data (CO, NO2, O3, PM10, SO2) by National Institute of Environmental Research. We used General Additive Model to see relative risk of occurrence of asthma, when weekly pollen count is more than 10 compared to less than 10. Other meteorological and air pollution data were adjusted. Results: Number of asthma case is increasing every year from 2006 (6,939,178) to 2010 (15,633,105). Total count of asthma for five years is 65,602,525. Occurence of asthma was increased with pollen counts of Oak, Birch in Seongdong-gu, Grass, Hazel, Oak in Guri, and Alder, Oak, Hazel, Birch. But some pollen count increase was shown to reduce occurrence of asthma. Conclusion: Occurrence of asthma in South Korea is increasing every year and may be associated with some pollen counts. Some pollen decreased asthma occurrence. Maybe pollen in addition to a variety of causes affect occurencece of asthma. Difference of the pollen effects by area would be due to the latitude of the region.

Soil moisture retrieved from microwave satellite data and its relationship with the Asian dust (Hwangsa) frequency in East Asia during the period from 2003 to 2010

A soil moisture retrieval algorithm using AMSR-E microwave satellite data has been developed by the National Institute of Meteorological Research (NIMR). This algorithm is based on a simple inversion method that does not require a prior soil texture data. In this study, the relationship between soil moisture retrieved from the NIMR algorithm and the occurrence of Asian dust (Hwangsa) is statistically analyzed. The frequency of occurrence of Asian dust events was recorded at 410 sites in China from 2003–2010 in three regions; the Gobi desert, Inner Mongolia and Northeast China. Results showed low soil moisture values of around 0.1 g cm−3 in the Gobi desert and Inner Mongolia-lowest in summer and a little higher in winter. Soil moisture values in Northeast China were marginally higher than in other regions, but lowest in winter and higher in summer. About 55% of Asian dust in the Gobi desert occurred when the monthly mean soil moisture was less than the monthly mean soil moisture for eight years. Approximately 75% of Asian dust in Northeast China occurred when soil moisture was the same as the monthly mean soil moisture for eight years. While soil moisture in the Gobi desert and Inner Mongolia declined in spring, it increased in Northeast of China.

2012년 겨울철 특별관측자료를 이용한 강수현상 시 대기 연직구조와 민감도 실험

This study analyzed the synoptic distribution and vertical structure about four cases of precipitation occurrences using NCEP/NCAR reanalysis data and upper level data of winter intensive observation to be performed by National Institute of Meteorological Research at Bukgangneung, Incheon, Boseong during 63days from 4 JAN to 6 MAR in 2012, and Observing System Experiment (OSE) using 3DVAR-WRF system was conducted to examine the precipitation predictability of upper level data at western and southern coastal regions. The synoptic characteristics of selected precipitation occurrences were investigated as causes for 1) rainfall events with effect of moisture convergence owing to low pressure passing through south sea on 19 JAN, 2) snowfall events due to moisture inflowing from yellow sea with propagation of Siberian high pressure after low pressure passage over middle northern region on 31 JAN, 3) rainfall event with effect of weak pressure trough in west low and east high pressure system on 25 FEB, 4) rainfall event due to moisture inflow according to low pressures over Bohai bay and south eastern sea on 5 MAR. However, it is identified that vertical structure of atmosphere had different characteristics with heavy rainfall system in summer. Firstly, depth of convection was narrow due to absence of moisture convergence and strong ascending air current in middle layer. Secondly, warm air advection by veering wind with height only existed in low layer. Thirdly, unstable layer was limited in the narrow depth due to low surface temperature although it formed, and also values of instability indices were not high. Fourthly, total water vapor amounts containing into atmosphere was small due to low temperature distribution so that precipitable water vapor could be little amounts. As result of OSE conducting with upper level data of Incheon and Boseong station, 12 hours accumulated precipitation distributions of control experiment and experiments with additional upper level data were similar with ones of observation data at 610 stations. Although Equitable Threat Scores (ETS) were different according to cases and thresholds, it was verified positive influence of upper level data for precipitation predictability as resulting with high improvement rates of 33.3% in experiment with upper level data of Incheon (INC_EXP), 85.7% in experiment with upper level data of Boseong (BOS_EXP), and 142.9% in experiment with upper level data of both Incheon and Boseong (INC_BOS_EXP) about accumulated precipitation more than 5 mm / 12 hours on 31 January 2012.

Development of Coastal Inundation Forecasting System (CIFOS) and Its Application to the Future Climate Change

ABSTRACT Eom, H.-M., Kang, K., Ryoo. S.B., Lee, Y.H., 2013. Development of Coastal Inundation FOrecasting System (CIFOS) and Its Application to the Future Climate Change The low-lying area is frequently damaged by the typhoon, monsoon and high tide resulting inundation. Especially, the southern coastal area in Korea was seriously damaged by the typhoon-induced heavy flood in 2003, which took tremendous toll on human lives and properties. The National Institute of Meteorological Research (NIMR) has been developing and improving the Coastal Inundation Forecasting System (CIFOS) for the provision of flooding information and the effects of the climate change on coastal areas. The system was applied to typhoon Maemi (0314) case to simulate flooding process and inundation area in the south coast of Korea. We also tried to estimate the change of coastal environment by the future climate conditions: three cases of sea level rise 0.4, 0.8, and 1.0 m. The model results during typhoon Maemi(0314) period showed good ...

정지기상위성자료를 이용한 중규모 바람장 산출 알고리즘 최적화

The Atmospheric motion vectors (AMVs) derived using infrared (IR) channel imagery of geostationary satellites have been utilized widely for real-time weather analysis and data assimilation into global numerical prediction model. As the horizontal resolution of sensors on-board satellites gets higher, it becomes possible to identify atmospheric motions induced by convective clouds (meso-β meso-γ scales). The National Institute of Meteorological Research (NIMR) developed the high resolution visible (HRV) AMV algorithm to detect mesoscale atmospheric motions including ageostrophic flows. To retrieve atmospheric motions smaller than meso-β scale effectively, the target size is reduced and the visible channel imagery of geostationary satellite with 1 km resolution is used. For the accurate AMVs, optimal conditions are decided by investigating sensitivity of algorithm to target selection and correction method of height assignment. The results show that the optimal conditions are target size of 32km x 32 km, the grid interval as same as target size, and the optimal target selection method. The HRV AMVs derived with these conditions depict more effectively tropical cyclone OMAIIS than IR AMVs and the mean speed of HRV AMVs in OMAIS is slightly faster than that of IR AMVs. Optimized mesoscale AMVs are derived for 6 months (Feb. 2010-Jun. 2010) and validated with radiosonde observations, which indicated NIMRs HRV AMV algorithm can retrieve successfully mesoscale atmospheric motions.

HadGEM2-AO를 강제자료로 사용한 SNURCM과 WRF의 동아시아 지역기후 모의

본 연구에서는 신뢰성 있는 국가표준 지역기후변화 시나리오 생산을 위해 현재기후에 대한 SNURCM과 WRF의 재현성을 검증하였다. 국립기상연구소에서 생산된 HadGEM2-AO 전구자료를 지역기후모형의 경계조건으로 사용하여 CORDEX 규준 하에 28년(1978-2005)간의 장기적분을 수행하였다. 두 모형은 연평균 지표 온도 분포를 관측과의 공간상관계수가 0.98 이상으로 매우 높은 일치성을 나타내었지만, 모형 영역의 북쪽 경계를 중심으로 한랭 편차를 공통적으로 보였다. 강수의 경우 또한 육지 지역을 대상으로 한 관측과의 공간 상관 계수는 SNURCM이 0.85, WRF가 0.79로 나타나 우수한 모의 결과를 보였다. 두 모형에서 모의된 강수 분포는 적도와 중위도 지역 간에 상반되는 특성을 보였다. SNURCM은 WRF에 비교하여 중위도 동아시아 몬순 강수대의 분포를 적도 지역의 강수대보다 상대적으로 잘 모의하였으나, WRF는 그 반대의 결과를 나타내었다. 여름철(JJA) 보다 봄철(MAM)에 과다 모의되었지만 모의된 강수 분포의 일치성은 봄철에 높게 나타났다. 세부영역 별 분석에서 두 모형은 7월 강수 최대 시점과 양을 비교적 정확히 모의하였고, 특히 내륙 지역 강수량의 모의 정확도가 해양에 영향 받는 지역보다 높았다. 모의결과는 한반도 상의 높은 일평균 지표온도일수와 강한 강수일수를 표현하는데 한계를 보였다. In this study, the reproducibility of the simulated current climate by using two regional climate models, such as Seoul National University Regional Climate Model (SNURCM) and Weather Resuearch and Forecasting (WRF), is evaluated in advance to produce the standard regional climate scenario of future climate. Within the evaluation framework of a COordinated Regional climate Downscaling EXperiment (CORDEX), 28-year-long (1978-2005) regional climate simulation was conducted by using the Hadley Centre Global Environmental Model (HadGEM2-AO) global simulation data of the National Institute of Meteorological Research (NIMR) as a lateral boundary forcing. The simulated annual surface temperatures were in good agreement with the observation; the spatial correlation coefficients between each model and observation were over 0.98. The cold bias, however, were shown over the northern boundary in the both simulated results. In evaluation of the simulated precipitation, the skill was reasonable and good. The spatial correlation coefficients for the precipitation over the land area were 0.85 and 0.79 in SNURCM and WRF, respectively. It is noted that two regional climate models (RCMs) have different characteristics for the distribution of precipitation over equatorial and midlatitude areas. SNURCM shows better distribution of the simulated precipitation associated with the East Asia summer monsoon in the mid-latitude areas, but WRF shows better in the equatorial areas in comparison to each other. The simulated precipitation is overestimated in summer season (JJA) rather than in spring season (MAM), whereas the spatial distribution of the precipitation in spring season corresponds to the observation better than in summer season. Also the RCMs were capable of reproducing the annual variability of the maximum amount and its timing in July, in which the skills over the inland area were in better agreement with the observation than over the maritime area. The simulated regional climates, however, have the limitation to represent the number of days for extremely hot temperature and heavy rainfall over South Korea.

남한전역 1Km×1Km 격자지점에 대한 수치기상모의풍속의 정확도 향상을 위한 통계적 보정법

This paper suggests a for a numerically simulated wind speed data, provided by NIMR(National Institute of Meteorological Research) and generated from a numerical meteorological model to improve a wind resource map with a resolution. To this end, tuning factor method is developed that consists of two procedures. First, estimate monthly wind fields based on a suitably designed statistical wind field model that covers 345,682 regions obtained by lattice sites in South Korea. The second procedure computes the factor and then tunes the generated wind speeds of each month as well as each lattice site. The second procedure is based on the wind fields estimated by the first procedure. The performance of the suggested is demonstrated by using two wind data(both TMY and numerically simulated wind speed data) of 75 weather station areas.

Observing System Experiments Using KLAPS and 3DVAR for the Upper-Air Observations over the South and West sea during ProbeX-2009

Numerical prediction capability has been improved over the decades, but progress of prediction for high-impact weather (HIW) was unsatisfactory. One reason of low predictability for HIW is lack of observation data. The National Institute of Meteorological Research (NIMR) has been performed observation program for improvement of predictability, and reduction in social and economical cost for HIW. As part of this observation program, summer intensive observation program (ProbeX-2009) was performed at the observation-gap areas from 25 August to 6 September 2009. Sounding observations using radiosonde were conducted in the Gisang2000 research vessel (R/V) from the Korea Meteorological Administration (KMA) over the West Sea and the Eardo R/V from the Korea Ocean Research and Development Institute (KORDI) over the South Sea. Observation System Experiment (OSE) is carried out to examine the effect of ProbeX-2009 data. OSEs using Korea Local Analysis and Prediction System (KLAPS) and Weather Research and Forecasting (WRF) Model are conducted to investigate the predictability for a short time forecast. And, OSEs using WRF/3DVAR system and WRF forecast model are conducted to study the predictability for an extended time. Control experiment (K_CTL and CNTL) used only GTS observation and experiment (K_EXP and SWEXP) used ProbeX-2009 data from two system are performed. ETS for 3hr accumulated rainfall simulated by KLAPS-WRF shows that K_EXP is higher than K_CTL. Also, ETS for 12hr accumulated rainfall of SWEXP from 3DVAR-WRF is higher than CNTL. The results indicate that observation over the ocean has positive impact on HIW prediction.

통계적 바람장모형에의한 고해상도(1Km×1Km)풍력에너지지도 작성에 관한 연구

This paper details a method for establishing a wind energy map having() resolution. The map is essential for measurement and efficiency-testing of wind energy resources and wind site analysis. To this end, a statistical wind field model is estimated that covers 345,682 regions obtained by lattices made over South Korea. The paper derives various characteristics of a regional wind energy resource under the statistical wind field model and estimates them to construct the wind energy map. Kolmogorov-Smirnov test, based on TMY(typical meteorological year) wind data of 76 weather station areas, shows that a Log-normal model is adequate for the statistical wind field model. The model is estimated by using the wind speed data of 345,682 regions provided by the National Institute of Meteorological Research(NIMR). Various wind energy statistics are studied under the Log-normal wind field model. As an application, the wind energy density(W) map of South Korea is constructed with a resolution of and its utility for the wind site analysis is discussed.

계산유체역학모형 CFD_NIMR_SNU를 이용한 국지적으로 가열된 산악지역의 상세 바람 흐름 모사 - 화왕산 산불 사례 -

The unexpected wind over the Mt. Hwawang on 9 February 2009 was deadly when many spectators were watching a traditional event to burn dried grasses and the fire went out of control due to the wind. We analyzed the fatal wind based on wind flow simulations over a digitized complex terrain of the mountain with a localized heating area using a three dimensional computational fluid dynamics model, CFD_NIMR_SNU (Computational Fluid Dynamics_National Institute of Meteorological Research_Seoul National University). Three levels of fire intensity were simulated: no fire, and of surface temperature at the site on fire. The surface heat accelerated vertical wind speed by as much as (for ) and (for ) at the center of the fire. Turbulent kinetic energy was increased by the heat itself and by the increased mechanical force, which in turn was generated by the thermal convection. The heating together with the complex terrain and strong boundary wind induced the unexpected high wind conditions with turbulence at the mountain. The CFD_NIMR_SNU model provided valuable analysis data to understand the consequences of the fatal mountain fire. It is suggested that the place of fire was calm at the time of the fire setting due to the elevated terrain of the windward side. The suppression of wind was easily reversed when there was fire, which caused updraft of hot air by the fire and the strong boundary wind. The strong boundary wind in conjunction with the fire event caused the strong turbulence, resulting in many fire casualties. The model can be utilized in turbulence forecasting over a small area due to surface fire in conjunction with a mesoscale weather model to help fire prevention at the field.