단파 영역에서의 복사전달모델 결과들의 상호 비교

유정문,손병주,이규태,이광목,김재환,김준,허창회,안명환,정명재,정주용,신인철,최용상,김영미,윤미영,유혜림,이주은,이윤곤,이재화,윤종민,전형욱,이현진,하종성 한국기상학회 2006 한국기상학회 학술대회 논문집 Vol.2006 No.-

가시광선 및 적외선 위성관측을 이용한 안개탐지

유정문,윤미영,정명재 한국기상학회 2006 한국기상학회 학술대회 논문집 Vol.2006 No.-

인천 국제공항 부근의 안개 발생시에 MODIS 위성관측 자료의 특성

유정문,정은주,박유민,김영미,유주영 한국기상학회 2004 한국기상학회 학술대회 논문집 Vol.2004 No.-

위성관측과 수치실험에서 조사된 안개 탐지에서의 상층운 효과

유정문,윤미영 한국기상학회 2005 한국기상학회 학술대회 논문집 Vol.2005 No.-

Temperature Trends in the Skin/Surface, Mid-troposphere and Low Stratosphere Near Korea from Satellite and Ground Measurements

유정문,원영인,조영준,정명재,신동빈,이석조,이유리,오수민,반수진 한국기상학회 2011 Asia-Pacific Journal of Atmospheric Sciences Vol.47 No.5

Various types of satellite (AIRS/AMSU, MODIS) and ground measurements are used to analyze temperature trends in the four vertical layers (skin/surface, mid-troposphere, and low stratosphere) around the Korean Peninsula (123-132°E, 33-44°N) during the period from September 2002 to August 2010. The ground-based observations include 72 Surface Meteorological Stations (SMSs), 6 radiosonde stations (RAOBs), 457 Automatic Weather Stations (AWSs) over the land, and 5 buoy stations over the ocean. A strong warming (0.052 K y^(r−1)) at the surface, and a weak warming (0.004~0.010 K yr^(−1)) in the mid-troposphere and low stratosphere have been found from satellite data, leading to an unstable atmospheric layer. The AIRS/AMSU warming trend over the ocean surface around the Korean Peninsula is about 2.5 times greater than that over the land surface. The ground measurements from both SMS and AWS over the land surface of South Korea also show a warming of 0.043~0.082 K yr−1, consistent with the satellite observations. The correlation average (r = 0.80) between MODIS skin temperature and ground measurement is significant. The correlations between AMSU and RAOB are very high (0.91~0.95) in the anomaly time series, calculated from the spatial averages of monthly mean temperature values. However, the warming found in the AMSU data is stronger than that from the RAOB at the surface. The opposite feature is present above the mid-troposphere, indicating that there is a systematic difference. Warming phenomena (0.012~0.078 K yr^(−1)) are observed from all three data sets (SMS, AWS, MODIS), which have been corroborated by the coincident measurements at five ground stations. However, it should also be noted that the observed trends are subject to large uncertainty as the corresponding 95% confidence intervals tend to be larger than the observed signals due to large thermal variability and the relatively short periods of the satellitebased temperature records. The EOF analysis of monthly mean temperature anomalies indicates that the tropospheric temperature variability near Korea is primarily linked to the Arctic Oscillation (AO), and secondarily to ENSO (El Niño and Southern Oscillation). However, the low stratospheric temperature variability is mainly associated with Southern Oscillation and then additionally with Quasi-Biennial Oscillation (QBO). Uncertainties from the different spatial resolutions between satellite data are discussed in the trends.

안개 원격 탐지와 관련된 수치실험

유정문,정명재,윤미영 한국기상학회 2005 한국기상학회 학술대회 논문집 Vol.2005 No.-

에어러솔 대기에서 단파 영역에서의 복사전달모델들의 상호비교

유정문,정명재,이규태,김준,이주은,허영민,김보미,이윤곤,이재화,윤종민,이원학 한국지구과학회 2008 한국지구과학회지 Vol.29 No.2

Intercomparison among the three radiative transfer models (RTMs) which have been used in the studies for COMS, was carried out on the condition of aerosol-laden atmospheres. Also the role of aerosols in the atmospheric radiation budget was analyzed. The results(hereafter referred to as H15) from Halthore et al.’s study (2005) were used as a benchmark to examine the models. Aerosol Radiative Forcing(ARF) values from the three RTMs, calculated under two conditions of Aerosol Optical Thickness(AOT=0.08, 0.24), were systematically underestimated in comparison to H15 in the following shortwave components; 1) direct and diffuse irradiance at the surface, 2) diffuse upward fluxes at the surface and the top of the atmosphere, and 3) atmospheric absorbance. The ARF values for the direct and diffuse fluxes at the surface was -10~-40 Wm-2. The diffuse upward values became larger with increasing both AOT and Solar Zenith Angle(SZA). Diffuse upward/downward fluxes at the surface were more sensitive to the SZA than to the atmospheric type. The diffuse downward values increased with increasing AOT and decreasing SZA. The larger AOT led to surface cooling by exceeding the reduction of direct irradiance over the enhancement of diffuse one at the surface. The extinction of direct solar irradiance was due mainly to water vapor in tropical atmospheres, and to both ozone and water vapor in subarctic atmospheres. The effect of water vapor in the tropics was 3∼4 times larger than that of the ozone. The absorbance values from the three RTMs agree with those from H15 within ±10%. 본 연구에서는 에어러솔 대기 상태에서 국내 COMS 연구자들이 사용하는 세 개의 단파 복사전달모델에서 산출된 복사속 성분을 비교분석하였으며, 대기 복사 수지에서 에어러솔 역할도 분석하였다. 국내 모델들의 평가를 위하여, 15개 모델값을 평균한 Halthore et al. (2005) 결과를 기준값으로 사용하였다. 두 종류 에어러솔 농도(AOT=0.08, 0.24)에서 조사된 열대 또는 한대 대기의 에어러솔 강제력은 지표에서의 하향 일사 및 상향 산란, 대기 상부의 상향 산란, 그리고 대기 흡수도의 복사 성분들에 있어서 국외 연구에 비하여 국내 결과들에서 체계적으로 약하게 나타났다. 에어러솔 강제력은 지표에서의 하향 일사에 대하여 -10~-40 Wm-2 이었으며, 지표 및 대기 상부의 상향 산란의 경우에 상대적으로 큰 태양천정각과 고농도 에어러솔 상태에서 컸다. 두 종류 에어러솔 조건에서 지표에서의 하향 및 상향 산란값들은 대기 종류보다는 태양천정각에 더 민감하였다. 하향 산란은 상대적으로 작은 태양천정각과 고농도 에어러솔 조건에서 컸다. 에어러솔 농도 증가는 하향 산란 증가에도 불구하고 하향 직달 일사의 감소가 이를 초과함으로써 지표 냉각을 유도하는 것으로 조사되었다. 동일한 에어러솔 농도 및 태양천정각 조건에서 직달일사 소산은 열대 대기에서는 주로 수증기, 그리고 한대 대기에서는 수증기 뿐만 아니라 오존에도 기인하는 것으로 조사되었다. 특히 열대 대기에서는 수증기의 역할이 오존에 비하여 3~4배 컸다. 저농도 및 고농도 에어러솔 대기에서 대기 흡수도는 국내외 연구 간에 ±10% 내에서 일치하였다.

레일리 대기에서 단파 영역에서의 복사전달모델 결과들의 상호 비교

유정문,정명재,이규태,김준,허창회,안명환,허영민,이주은,유혜림,정주용,신인철,최용상,김영미,이윤곤,이재화,윤종민,이원학 한국지구과학회 2007 한국지구과학회지 Vol.28 No.3

Intercomparison between eight radiative transfer codes used for the studies of COMS (Communications, Ocean,fluxes: 1) direct solar irradiance at the surface, 2) diffuse irradiance at the surface, 3) diffuse upward flux at the surface,and 4) difuse upward flux at the top of the atmosphere. The result (hereafter called the H15) from Halthore et al.’s study(2005) which intercompared and averaged 15 codes was used as a benchmark to examine the COMS models. Uncertaintyof the seven COMS models except STREAMER was ±4% with respect to the H15, comparable with ±3% of Halthore etal.’s (2005). The uncertainty increased under a large SZA = 75o. The SBDART model generally agreed with the H15better than the 6S model, but both models in the shortwave infrared region were equally good. The direct solar irradiance(12.1 Wm2). This reason was partially due to diferently installing the wavelength resolution in the flux integration. Thisstudy may be useful for selecting the optimum model in the shortwave region.......... intercomparison, radiative transfer model, Rayleigh atmosphere, SBDART, 6S(. . ) 본 연구에서는 레일리 ( 순수 기체 ) 대기 조건 하에서 국내 COMS 연구자들이 사용하는 여덟 개 단파 복사전달 모델에서 산출된 네 종류 복사속 (flux) 성분을 상호비교함으로써 상대 오차를 조사하였다 . 이들 복사속 성분은 지표에서 의 직달 일사 , 하향 산란 , 상향 산란 , 그리고 대기 상부에서의 상향 산란이다 . 또한 국내 모델의 평가를 위하여 , 15 개 모델을 평균한 Halthore et al.(2005) 결과 ( 예 , H15) 를 기준값으로 사용하였다 . 동일한 태양천정각에서 모델 간의 불일치 는 열대 대기에서 수증기에 기인하였고 , 한대 대기에서는 오존에 기인하였다 . STREAMER 를 제외한 국내 7 개 모델의 지상에서의 하향 직달일사값은 H15 에 대하여 ±4% 내에서 일치하였다 . 이러한 상대 오차는 태양천정각이 커질 때 증가 하였으며 , Halthore et al.(2005) 에서의 ±3% 와 근접하였다 . 네 종류 복사속 분석에서 SBDART 모델이 6S 모델에 비하 여 전반적으로 우수하였으나 , 근적외 파장역에서는 서로 비교할만하였다 . 네개 기관의 연구자들이 같은 SBDART 모델 에서 산출한 지표에서의 하향 직달일사값 간에도 12.1 Wm − 2 (1.4%) 의 불일치가 존재하였다 . 불일치의 원인은 부분적으 로 복사속 적분에 있어서 서로 다르게 설정된 파장 분해능에도 있었다 . 본 연구는 단파 영역에서 최적 모델을 선정하 는 데 도움을 줄 수 있다 .

전지구에 대한 TOMS 오존전량과 반사율의 경년 변화

유정문,전원선,Yoo, Jung-Moon,Jeon, Won-Sun 한국지구과학회 2000 한국지구과학회지 Vol.21 No.6

In order to investigate interannual variation of total ozone and reflectivity over the globe, Nimbus-7/TOMS data were used on the monthly mean and its anomaly for the period of 1979-92. This study also examined MSU channel 4(Ch4; lower-stratosphere) brightness temperature data and two model reanalyses of NCEP and GEOS to compare the ozone variation with atmospheric thermal condition. In addition, the MSU channel 1(Ch1 ; lower-troposphere) brightness temperature was used to compare with the reflectivity. The ozone showed strong annual cycle with downward trend(-6.3${\pm}$0.6 DU/decade) over the globe, and more distinct response to volcanic eruption than El Ni${\tilde{n}$o. The relationship between total ozone and MSU Ch4 observation, and between the ozone and model reanalyses of lower stratosphere temperature showed positive correlation(0.2-0.7) during the period of 1980-92. Reflectivity increased interannually by 0.2${\pm}$0.06%/decade over the globe during the above period and reflected El Ni${\tilde{n}$o(1982-83, 1991-92) well. Its variability in annual cycle was remarkably smaller in tropics than in higher latitudes. This is inferred due to cloud suppression and tropical upwelling regions. Reflectivity correlated negatively(-0.9) to the Ch1 temperature over the globe, but positively(0.2) over tropical ocean. The positive value over the ocean results from the effect of microwave emissivity which increases the Ch1 temperature with enhanced hydrometeor activity. Significant correlations between total ozone and the Ch4 temperature, and between reflectivity and the Ch1 Suggest that the TOMS data may use valuably to better understand the feedback mechanism of climate change.

MSU와 ECMWF에서 유도된 중간 및 하부 대류권 온도의 시 ${\cdot}$ 공간 변동

유정문,이은주,Yoo, Jung-Moon,Lee, Eun-Joo 한국지구과학회 2000 한국지구과학회지 Vol.21 No.5

Intercomparisons between four kinds of data have been done to estimate the accuracy of satellite observations and model reanalysis for middle and lower tropospheric thermal state over regional oceans. The data include the Microwave Sounding Units (MSU) Channel 2 (Ch2) brightness temperatures of NOAA satellites and the vertically weighted corresponding temperature of ECMWF GCM (1980-93). The satellite data for midtropospheric temperatures are MSU2 (1980-98) in nadir direction and SC2 (1980-97) in multiple scans, and for lower tropospheric temperature SC2R (1980-97). MSU2 was derived in this study while SC2 and SC2R were described in Spencer and Christy (1992a, 1992b). Temporal correlations between the above data were high (r${\ge}$0.90) in the middle and high latitudes, but low(r${\sim}$0.65) over the low latitude and more convective regions. Their values with SC2R which included the noises due to hydrometeors and surface emission were conspicuously low. The reanalysis shows higher correlation with SC2 than with MSU2 partially because of the hydrometeors screening. SC2R in monthly climatological anomalies was more sensitive to surface thermal condition in northern hemisphere than MSU2 or SC2. The first EOF mode for the monthly mean data of MSU and ECMWF shows annual cycle over most regions except the tropics. The mode in MSU2 over the Pacific suggests the east-west dipole due to the Walker circulation, but this tendency is not clear in other data. In the first and second modes for the Ch2 anomalies over most regions, the MSU and ECMWF data commonly indicate interannual variability due to El Ni${\tilde{n}$o and La Ni${\tilde{n}$a. The substantial disagreement between observations and model reanalysis occurs over the equatorial upwelling region of the western Pacific, suggesting uncertainties in the model parameterization of atmosphere-ocean interaction.