• 제목/요약/키워드: NCEP

검색결과 221건 처리시간 0.021초

CMAQ 모델링을 통한 초기 기상장에 대한 미세먼지 농도 예측 민감도 연구 (Sensitivity Study of the Initial Meteorological Fields on the PM10 Concentration Predictions Using CMAQ Modeling)

  • 조유진;이효정;장임석;김철희
    • 한국대기환경학회지
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    • 제33권6호
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    • pp.554-569
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    • 2017
  • Sensitivity analysis on $PM_{10}$ forecasting simulations was carried out by using two different initial and boundary conditions of meteorological fields: NCEP/FNL (National Centers for Environmental Prediction/Final Analysis) reanlaysis data and NCEP/GFS (National Centers for Environmental Prediction/Global Forecast System) forecasting data, and the comparisons were made between two different simulations. The two results both yielded lower $PM_{10}$ concentrations than observations, with relatively lower biased results by NCEP/FNL than NCEP/GFS. We explored the detailed individual meteorological variables to associate with $PM_{10}$ prediction performance. With the results of NCEP/FNL outperforming GFS, our conclusion is that no particular significant bias was found in temperature fields between NCEP/FNL and NCEP/GFS data, while the overestimated wind speed by NCEP/GFS data influenced on the lower $PM_{10}$ concentrations simulation than NCEP/FNL, by decreasing the duration time of high-$PM_{10}$ loaded air mass over both coastal and metropolitan areas. These comparative characteristics of FNL against GFS data such as maximum 3~4 m/s weaker wind speed, $PM_{10}$ concentration control with the highest possible factor of 1.3~1.6, and one or two hour difference of peak time for each case in this study, were also reflected into the results of statistical analysis. It is implying that improving the surface wind speed fluctuation is an important controlling factor for the better prediction of $PM_{10}$ over Korean Peninsula.

북반구 겨울철 에디들에 의한 운동량, 열 그리고 수분 수송: 세 가지 재분석 자료 비교 (Eddy Momentum, Heat, and Moisture Transports During the Boreal Winter: Three Reanalysis Data Comparison)

  • 문혜진;하경자
    • 대기
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    • 제26권4호
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    • pp.649-663
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    • 2016
  • This study investigates eddy transports in terms of space and time for momentum, heat, and moisture, emphasizing comparison of the results in three reanalysis data sets including ERA-Interim from the European Center for Medium-range Weather Forecasts (ECMWF), NCEP2 from the National Center for Environmental Prediction and the Department of Energy (NCEP-DOE), and JRA-55 from the Japan Meteorological Agency (JMA) during boreal winter. The magnitudes for eddy transports of momentum in ERA-Interim are represented as the strongest value in comparison of three data sets, which may be mainly come from that both zonal averaged meridional and zonal wind tend to follow the hierarchy of ERA-Interim, NCEP2, and JRA-55. Whereas in relation to heat and moisture eddy transports, those of NCEP2 are the strongest, implying that zonal averaged air temperature (specific humidity) tend to follow the raking of NCEP2, ERA-Interim, and JRA-55 (NCEP2, JRA-55, and ERA-Interim), except that transient eddy transports for heat in ERA-Interim are the strongest involving both meridional wind and air temperature. The stationary and transient eddy transports in the context of space and time correlation, and intensity of standard deviation demonstrate that the correlation (intensity of standard deviation) influence the structure (magnitude) of eddy transports. The similarity between ERA-Interim and NCEP2 (ERA-Interim and JRA-55) of space correlation (time correlation) closely resembles among three data sets. A resemblance among reanalysis data sets of space correlation is larger than that of time correlation.

NCEP 계절예측시스템과 정준상관분석을 이용한 북동아시아 여름철 강수의 예측 (A Prediction of Northeast Asian Summer Precipitation Using the NCEP Climate Forecast System and Canonical Correlation Analysis)

  • 권민호;이강진
    • 한국지구과학회지
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    • 제35권1호
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    • pp.88-94
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    • 2014
  • 현재 최고 수준의 대순환 모형에서 북동아시아 여름몬순 강도의 계절예측 능력은 낮으나 북서태평양 아열대 고기압 강도의 예측률은 상대적으로 높다. 북서태평양 아열대 고기압은 북서태평양 지역 및 동아시아 지역에서 가장 주된 기후 변동성이다. 본 연구에서 NCEP 계절예측시스템에서 예측된 북서태평양 아열대 고기압의 예측성에 대해 논의될 것이다. 한편, 북동아시아 여름몬순의 경년변동성은 북서태평양 아열대 고기압과 높은 상관성을 가지고 있다. 본 연구에서는 이 관계에 근거하여, NCEP 계절예측시스템과 정준상관분석을 이용한 계절예측 모형을 제안하고 그 예측률을 평가하였다. 이 방법은 북동아시아 지역 여름철 강수량 편차에 대한 계절예측에 있어 통계적으로 유의한 예측성능을 제공한다.

NCEP 재분석 자료를 이용한 전지구 지표층의 2000-2009년 풍속 분포 (Global Distribution of Surface Layer Wind Speed for the years 2000-2009 Based on the NCEP Reanalysis)

  • 변재영;최영진;이재원
    • 대기
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    • 제21권4호
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    • pp.439-446
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    • 2011
  • NCEP reanalysis data were analyzed in order to provide distribution of global wind resource and wind speed in the surface layer for the years 2000-2009. Wind speed at 10 m above ground level (AGL) was converted to wind speed at 80 m above the ground level using the power law. The global average 80 m wind speed shows a maximum value of $13ms^{-1}$ at the storm track region. High wind speed over the land exists in Tibet, Mongolia, Central North America, South Africa, Australia, and Argentina. Wind speed over the ocean increased with a large value in the South China Sea, Southeast Asia, East Sea of the Korea. Sea surface wind in Western Europe and Scandinavia are suitable for wind farm with a value of $7-8ms^{-1}$. Areas with great potential for wind farm are also found in Eastern and Western coastal region of North America. Sea surface wind in Southern Hemisphere shows larger values in the high latitude of South America, South Africa and Australia. The distribution of low-resolution reanalysis data represents general potential areas for wind power and can be used to provide information for high-resolution wind resource mapping.

NCEP-ATP III에 근거한 체질별 심혈관질환 위험도에 대한 임상적 고찰 (A Study of Relationship between Coronary Heart Disease Risk and Sasang Constitution Based on NCEP-ATP III)

  • 한경수;이한얼;이주용;안택원
    • 사상체질의학회지
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    • 제20권3호
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    • pp.94-106
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    • 2008
  • 1. Objective The purpose of this study was to prove the correlation between risk factor of cardiovascular disease and sasang constitution. 2. Methods We analyzed the data of 200 patients who visited Cheonan oriental medical hospital from Apr 1, 2007 until September 31, 2007, for medical examination, which includes sasang constitution examination, blood chemistry test and physical examination. And we classified their results into 3 groups based on with NCEP-ATP III diagnostic criterions. 3. Results and Conclusion The results were as follows : 1. The frequency of dyslipoproteinemia(Hypertriglycemia) was significantly higher in Teaumin group than other constitutions. 2. The frequency of Metabolic syndrome was significantly higher in Taeumin group than other constitutions. 3. The risk of coronary heart disease was higher in Teaumin than other constitutions.

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태풍 기상장의 신뢰도 분석: 태풍 산바(1216) (Analysis of Reliability of Weather Fields for Typhoon Sanba (1216))

  • 권갑근;조명환;류경호;윤성범
    • 한국해안·해양공학회논문집
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    • 제32권6호
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    • pp.465-480
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    • 2020
  • 2012년 남해안에 내습한 태풍 산바에 의해 발생한 폭풍해일과 파랑을 JMA-MSM 예보기상자료, NCEP-CFSR 재분석 기상자료, ECMWF-ERA5 재분석 기상자료, JTWC의 최적경로를 이용한 기상자료를 이용하여 수치모의하고, 계산된 해일고를 전국 해안의 항만에서 관측된 폭풍해일 시계열 자료와 비교하였으며, 파랑에 대해서는 계산된 유의파고를 해상 부이 및 수압식 파고 관측 자료와 비교하였다. 이 비교를 통해 태풍 산바에 대한 각종 기상장의 신뢰도를 평가하였다. 그 결과 JMA-MSM 기상자료와 NCEP-CFSR 기상자료가 가장 신뢰도가 높았고, ECMWF-ERA5 기상자료는 전반적으로 해일고나 파고의 크기가 작게 나타났으나, 태풍 전면부의 수렴대는 가장 잘 재현하는 것으로 나타났다. JTWC의 최적경로를 이용한 기상자료는 신뢰도가 가장 낮게 나타났다.

Effects of a newborn care education program using ubiquitous learning on exclusive breastfeeding and maternal role confidence of first-time mothers in Vietnam: a quasi-experimental study

  • Nguyet, Tran Thi;Huy, Nguyen Vu Quoc;Kim, Yunmi
    • 여성건강간호학회지
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    • 제27권4호
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    • pp.278-285
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    • 2021
  • Purpose: This study aimed to examine the effect of a newborn care education program using ubiquitous learning (UL-NCEP) on exclusive breastfeeding and maternal role confidence of first-time mothers in Vietnam. Methods: This quasi-experimental study with a nonequivalent control group design was conducted at a university hospital in Hue city, Vietnam, between June and July 2018. Eligible first-time mothers were conveniently allocated to the experimental (n=27) and the control group (n=25). Mothers in the control group received only routine care, whereas mothers in the experimental group received UL-NCEP through tablet personal computers in addition to routine care in the hospital. Then, the educational content was provided to mothers by their smartphone for reviewing at home. UL-NCEP was developed based on the World Health Organization's "Essential Newborn Care Course" guidelines. The exclusive breastfeeding rate and maternal role confidence level after birth and at 4 weeks postpartum were assessed in both groups to assess the effect of UL-NCEP. Results: At 4 weeks postpartum, the experimental group showed a significantly higher level than the control, for exclusive breastfeeding rate (p<.05) as well as mean maternal role confidence (p<.05). Conclusion: UL-NCEP was a feasible and effective intervention in increasing first-time Vietnamese mothers' exclusive breastfeeding rate and maternal role confidence level. This program may be integrated into routine care for postpartum mothers to promote mother and infant health among first-time mothers in Vietnam.

초기 입력 자료에 따른 WRF 기상장 모의 결과 차이 - ERA-Interim과 FNL자료의 비교 (Impact of Meteorological Initial Input Data on WRF Simulation - Comparison of ERA-Interim and FNL Data)

  • 문정혁;이화운;전원배;이순환
    • 한국환경과학회지
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    • 제26권12호
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    • pp.1307-1319
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    • 2017
  • In this study, we investigated the impact of different initial data on atmospheric modeling results using the Weather Research and Forecast (WRF) model. Four WRF simulations were conducted with different initialization in March 2015, which showed the highest monthly mean $PM_{10}$ concentration in the recent ten years (2006-2015). The results of WRF simulations using NCEP-FNL and ERA-Interim were compared with observed surface temperature and wind speed data, and the difference of grid nudging effect on WRF simulation between the two data were also analyzed. The FNL simulation showed better accuracy in the simulated temperature and wind speed than the Interim simulation, and the difference was clear in the coastal area. The grid nudging effect on the Interim simulation was larger than that of the FNL simulation. Despite of the higher spatial resolution of ERA-Interim data compared to NCEP-FNL data, the Interim simulation showed slightly worse accuracy than those of the FNL simulation. It was due to uncertainties associated with the Sea Surface Temperature (SST) field in the ERA-Interim data. The results from the Interim simulation with different SST data showed significantly improved accuracy than the standard Interim simulation. It means that the SST field in the ERA-Interim data need to be optimized for the better WRF simulation. In conclusion, although the WRF simulation with ERA-Interim data does not show reasonable accuracy compared to those with NCEP-FNL data, it would be able to be Improved by optimizing the SST variable.

종관 관측 자료 변화에 따른 예보 성능 분석 (Analysis of Forecast Performance by Altered Conventional Observation Set)

  • 한현준;권인혁;강전호;전형욱;이시혜;임수정;김태훈
    • 대기
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    • 제29권1호
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    • pp.21-39
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    • 2019
  • The conventional observations of the Korea Meteorological Administration (KMA) and National Centers for Environmental Prediction (NCEP) are compared in the numerical weather forecast system at the Korea Institute of Atmospheric Prediction Systems (KIAPS). The weather forecasting system used in this study is consists of Korea Integrated Model (KIM) as a global numerical weather prediction model, three-dimensional variational method as a data assimilation system, and KIAPS Package for Observation Processing (KPOP) as an observation pre-processing system. As a result, the forecast performance of NCEP observation was better while the number of observation is similar to the KMA observation. In addition, the sensitivity of forecast performance was investigated for each SONDE, SURFACE and AIRCRAFT observations. The differences in AIRCRAFT observation were not sensitive to forecast, but the use of NCEP SONDE and SURFACE observations have shown better forecast performance. It is found that the NCEP observations have more wind observations of the SONDE in the upper atmosphere and more surface pressure observations of the SURFACE in the ocean. The results suggest that evenly distributed observations can lead to improved forecast performance.