• Title/Summary/Keyword: NCEP2

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

  • Moon, Hyejin;Ha, Kyung-Ja
    • Atmosphere
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    • v.26 no.4
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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.

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

  • Han, Kyung-Su;Lee, Han-Eol;Lee, Joo-Yong;Ahn, Taek-Won
    • Journal of Sasang Constitutional Medicine
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    • v.20 no.3
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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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Accuracy Evaluation of Daily-gridded ASCAT Satellite Data Around the Korean Peninsula (한반도 주변 해역에서의 ASCAT 해상풍 격자 자료의 정확성 평가)

  • Park, Jinku;Kim, Dae-Won;Jo, Young-Heon;Kim, Deoksu
    • Korean Journal of Remote Sensing
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    • v.34 no.2_1
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    • pp.213-225
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    • 2018
  • In order to access the accuracy of the gridded daily Advanced Scatterometer (hereafter DASCAT) ocean surface wind data in the surrounding of Korea, the DASCAT was compared with the wind data from buoys. In addition, the reanalysis data for wind at 10 m provided by European Centre for Medium-Range Weather Forecasts (ECMWF, hereafter ECMWF), National Centers for Environmental Prediction and National Center for Atmospheric Research (NCEP/NCAR, hereafter NCEP), Modern Era Retrospective-analysis for Research and Applications-2 (MERRA-2, hereafter MERRA) were compared and analyzed. As a result, the RMSE of DASCAT for the actual wind speed is about 3 m/s. The zonal components of wind of buoys and the DASCAT have strong correlation more than 0.8 and the meridional components of wind them have lower correlation than that of zonal wind and are the lowest in the Yellow Sea (r=0.7). When the actual wind speed is below 10 m/s, the EMCWF has the highest accuracy, followed by DASCAT, MERRA, and NCEP. However, under the wind speed more than 10 m/s, DASCAT shows the highest accuracy. In the nature of error according to the wind direction, when the zonal wind is strong, all dataset has the error of more than $70^{\circ}$ on the average. On the other hand, the RMSE of wind direction was recorded $50^{\circ}$ under the strong meridional winds. ECMWF shows the highest accuracy in these results. The RMSE of the wind speed according to the wind direction varied depending on the actual wind direction. Especially, MERRA has the highest RMSE under the westerly and southerly wind condition, while the NCEP has the highest RMSE under the easterly and northerly wind condition.

Validation Study of Gridded Product of Surface Wind/Wind-stress derived by Satellite Scatterometer Data in the Western North Pacific using Kuroshio Extension Observatory Buoy

  • Kutsuwada, Kunio;Morimoto, Naoki;Koyama, Makoto
    • Proceedings of the KSRS Conference
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    • v.1
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    • pp.394-397
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    • 2006
  • Gridded products of surface wind/wind-stress over the world ocean have been constructed by using satellite scatterometer as the Japanese Ocean Flux data sets with Use of Remote-sensing Observation (J-OFURO) data. Our previous validation study in the tropical Pacific using TAO/Triton and NDBC buoys revealed high reliability of our products. In this study, the Kuroshio Extension Observatory (KEO) buoy data are used for validation of other gridded wind-stress products including the NCEP-1 and 2 in the western North Pacific region where there have been few in-situ data. Results reveal that our J-OFURO product has almost zero mean difference and smallest root-mean-square (RMS) difference, while the NCEP-1 and 2 ones significantly positive biases and relatively high RMS difference. Intercomparison between the J-OFURO and NCEP products in a wide region of the North Pacific covered by the westerly winds exhibits that the NCEPs have larger magnitudes in the wind stress than the J-OFURO's, suggesting overestimation of the NCEPs.

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Verification of the Wind-driven Transport in the North Pacific Subtropical Gyre using Gridded Wind-Stress Products Constructed by Scatterometer Data

  • Aoki, Kunihiro;Kutsuwada, Kunio
    • Proceedings of the KSRS Conference
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    • 2007.10a
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    • pp.418-421
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    • 2007
  • Using gridded wind-stress products constructed by satellite scatterometers (ERS-1, 2 and QSCAT) data and those by numerical weather prediction(NWP) model(NCEP-reanalysis), we estimate wind-driven transports of the North Pacific subtropical gyre, and compare them in the central portion of the gyre (around 300 N) with geostrophic transports calculated from historical hydrographic data (World Ocean Database 2005). Even if there are some discrepancies between the wind-driven transports by the QSCAT and NCEP products, they are both in good agreement with the geostrophic transports within reasonable errors, except for the regional difference in the eastern part of the zone. The difference in the eastern part is characterized by an anticyclonic deviation of the geostrophic transport resulting from an anti-cyclonic anomalous flow in the surface layer, suggesting that it is related to the Eastern Gyral produced by the thermohaline process associated with the formation of the Eastern Subtropical Mode Water. We also examine the consistency of the Sverdrup transports estimated from these products by comparing them with the transports of the western boundary current, namely the Kuroshio regions, in previous studies. The net southward transport, based on the sum of the Sverdrup transports by QSCAT and NCEP products and the thermohaline transport, agrees well with the net northward transport of the western boundary current, namely the Kuroshio transport. From these results, it is concluded that the Sverdrup balance can hold in the North Pacific subtropical gyre.

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Meteorological Field Generation Method for CALPUFF Model

  • Park, Ji-Hoon;Park, Geun-Yeong
    • Journal of Integrative Natural Science
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    • v.11 no.1
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    • pp.30-38
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    • 2018
  • CALPUFF is one of the recommended air pollution models by EPA with AERMOD. It has been used to simulate the ambient concentration of critical air pollutants as well as non-critical pollutants such as persistent organic matters and the organic materials causing odor. In this model, the air pollutants go through dispersion, transportation, chemical reaction, and deposition process. These mechanisms are significantly influenced by meteorological condition. This study produces the meteorological field in three different methods for the simulation of $SO_2$ using CALPUFF: 1) CALMET model by using both ground-level and aerological observation, 2) CALMET model by using MM5 results with NCEP/NCAR reanalyzed data, 3) CALMET model by using MM5 results in which FDDA is applied with NCEP/NCAR reanalyzed data as well as the meteorological data of Korea Meteorological Administration. As a result of CALPUFF model, the resolved concentration of $SO_2$ showed different behaviors in three cases. For the first case, the fluctuation of SO2 concentration was frequently observed while the fluctuation is reduced in the second and third cases. In addition, the maximum concentration of $SO_2$ in the first case was about 2~3 times higher than the second case, and about 4~6 times higher than the third case. These results can be caused by the accuracy of the resolved meteorological field. It is inferred that the meteorological field of the first case could be less accurate than other two cases. These results show that the use of correct meteorological data can improve the result of dispersion model. Moreover, the contribution of various sources such as point, line, and area sources on the ambient concentration of air pollutant can be roughly estimated from the sensitivity analysis.

Mean Meridional Circulation-Eddy Interaction in Three Reanalysis Data Sets during the Boreal Winter (세 가지 재분석 자료에서의 겨울철 북반구 평균 자오면 순환-에디 상호작용)

  • Moon, Hyejin;Ha, Kyung-Ja
    • Atmosphere
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    • v.25 no.3
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    • pp.543-557
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    • 2015
  • The present study examines an interaction between the eddy and mean meridional circulation (MMC) comparing the results in three reanalysis data sets including ERA-Interim, NCEP2, and JRA-55 during the boreal winter in the Northern Hemisphere. It is noteworthy that the JRA-55 tends to produce stronger MMC compared to those of others, which is mainly due to the weak eddy flux. ERA-Interim represents the ensemble averages of MMC. The MMC-eddy interaction equation was adopted to investigate the scale interaction of the eddy momentum flux (EMF), eddy heat flux (EHF), and diabatic heating (DHT) with MMC. The EMF (EHF) shows a significant correlation coefficient with streamfunction under (above) 200 hPa-level. The perturbation (time mean) part of each eddy is dominant compared to another part in the EMF (EHF). The DHT is strongly interacted with streamfunction in the region between the equator and extra-tropical latitude over whole vertical column. Thus, the dominant term in each significant region modulates interannual variability of MMC. The inverse (proportional) relationship between MMC and pressure (meridional) derivative of the momentum (heat) divergence contributions is well represented in the three reanalysis data sets. The region modulated interannual variability of MMC by both EMF and DHT (EHF) is similar in ERA-Interim and JRA-55 (ERA-Interim and NCEP2). JRA-55 shows a lack of significant region of EHF due to the high resolution, compared to other data sets.

An Analysis of Aerosol-Cloud Relationship Using MODIS and NCEP/NCAR Reanalysis Data around Korea (한반도 주변에서 MODIS와 NCEP/NCAR 재분석 자료를 이용한 에어로졸과 구름의 연관성 분석)

  • Kim, Yoo-Jun;Lee, Jin-Hwa;Kim, Byung-Gon
    • Journal of Korean Society for Atmospheric Environment
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    • v.27 no.2
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    • pp.152-167
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    • 2011
  • MODIS/Terra level 3 and NCEP/NCAR Reanalysis data from 2001 to 2008 have been analyzed to understand long-term aerosol and cloud optical properties, and their relationships around Korea. Interestingly, cloud fraction(CF) has the similar annual variation to aerosol optical depth (${\tau}_a$) without any temporal significant trend. Horizontal distributions of ${\tau}_a$ showed the substantial horizontal gradient from China to Korea, especially with the strong difference over the Yellow Sea, which could represent the evidence of the anthropogenic influence from China in the perspective of long-term average. Specifically the negative correlations between ${\tau}_a$ and liquid-phase cloud effective radius ($r_e$) were shown on the monthly-average basis, only in summer with significant associations over the Yellow Sea, but not in the other seasons and/or specific regions. Relationship between ${\tau}_a$ and CF for the low-level liquid-phase clouds exhibited the overall positive correlation, being consistent with cloud lifetime effect. Meanwhile static stability showed no deterministic relationships with ${\tau}_a$ as well as CF. The dependence of aerosol-cloud relationship on the meteorological conditions should be examined more in detail with the satellite remote sensing and reanalysis data.

Construction of Gridded Wind-stress Products over the World Ocean by Tandem Scatterometer Mission

  • Kutsuwada Kunio;Kasahara Minoru;Morimoto Naoki
    • Proceedings of the KSRS Conference
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    • 2004.10a
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    • pp.192-195
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    • 2004
  • Products of gridded surface wind and windstress vectors over the world ocean have been constructed by satellite scatterometer data with highly temporal and spatial resolutions. Even if the ADEOS-II/SeaWinds has supplied surface wind data only for short duration in Apr. to Oct. 2003 to us, it permits us to construct a product with higher resolution together with the Qscat/SeaWinds. In addition to our basic product with its resolution of $1^{\circ}\times1^{\circ}$ in space and daily in time, we try to construct products with $1/2^{\circ}\times1/2^{\circ}$ and semi- and quarter-daily resolution. These products are validated by inter-comparison with in-situ data (TAO and NDBC buoys), and also compared with numerical weather prediction(NWP) ones (NCEP reanalysis). Result reveals that our product has higher reliability in the study area than the NCEP's. For the open ocean regions in the middle and high latitudes where there are no in-situ data, we find that there are clear differences between them. Especially in the southern westerly region of 400-600S, the' wind-stress magnitudes by the NCEP are significantly larger than the others, suggesting that they are overestimated. We also calculate wind-stress curl field that is an important factor for ocean dynamics and focus its spatial character in the northwestern Pacific around Japan. Positive curl areas are found to cover from southwest to northeast in our focus region and almost correspond to the Kuroshio path. It is suggested that the vorticity field in the lower atmosphere is related to the upper oceanic one, and thus an aspect of air-sea interaction process.

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Differences in Prevalence and Risk Factors of the Metabolic Syndrome by Gender in Type 2 Diabetic Patients (제 2형 당뇨병환자 성별 대사증후군 유병률과 위험요인 차이)

  • Kim, Hee-Seung;Jung, Sun-Ha
    • Korean Journal of Adult Nursing
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    • v.18 no.1
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    • pp.3-9
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    • 2006
  • Purpose: The purpose of this study was to assess the difference between prevalence and risk factors of the metabolic syndrome(MS) by gender in type2 diabetic patients. Method: 108 participants(males 69, females 39) were recruited from the endocrinology outpatient department of a tertiary care hospital in an urban city. MS was defined by a third report of the national cholesterol education program (NCEP) expert panel on detection, evaluation, and treatment of high blood cholesterol in adults(Adult Treatment Panel III)(ATP III), and abdominal obesity was determined by Asia-Pacific criteria in waist circumference. Results: The prevalence of MS by definition of NCEP-ATP III and the Asia-Pacific criteria in waist circumference was 39.3% in males and 66.7% in females type2 diabetic patients. The abdominal obesity prevalence was seen in 44.9% of males and in 79.5% of females patients. The prevalence of low HDL-cholesterolemia in serum was 26.2% in male, 52.8% in female type2 diabetic patients. Conclusion: These results show that nurses should focus on female diabetic patients for preventing MS.

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