• 제목/요약/키워드: Earth Sciences

검색결과 4,334건 처리시간 0.039초

Comparison of multi-planetary systems including hot-Super Earth with and without exo-Jupiter

  • Choi, Beom Kyu;Yoon, Tae Seog
    • 천문학회보
    • /
    • 제40권1호
    • /
    • pp.90.1-90.1
    • /
    • 2015
  • Almost hot-Super Earths ($R_p$~1 to $4R_{earth}$ orbital period < 100 days) are around Sun-like stars. But our solar system does not have hot-Super Earth. Andre et al. 2015 has explained this phenomenon by that Jupiter blocks migration of super earth. We have found a multi-planetary system KOI-94 with exo-Jupiter and hot-Super Earth from NASA exoplanet archive data (http://exoplanetarchive.ipac.caltech.edu). In this study, within multi-planetary systems including hot-Super Earth, we compared those with and without exo-Jupiter using their host star and exoplanet parameters, such as metallicity [Fe/H], $T_{eff}$ and $R_*/R_p$.

  • PDF

New records of genus Tripos (Dinophyceae) around Jeju Island, Korea

  • Lee, Joon-Baek;An, So-Jeong;Chung, Han-Sik;Shah, Md. Mahfuzur Rahman
    • Journal of Ecology and Environment
    • /
    • 제37권4호
    • /
    • pp.271-284
    • /
    • 2014
  • The morphology of 26 species of the genus Tripos was studied among a total of 51 species of this genus, which were taken using $20{\mu}m$ net samples from June 2006 to January 2011 at 14 stations around Jeju Island. Of these, 23 species were first described as new records in Korean waters and 3 species were redescribed. Short descriptions and synonyms are given for each species in the present study. The dinoflagellates of family Ceratiaceae include marine and freshwater species, belonged to originally the genus Ceratium. Recently, this genus were divided into a new combination with the genus Tripos, which contains the marine species, and the original genus Ceratium, including the freshwater species. We used the Tripos genus for the marine species in this study as a valid name.

동북아시아 초미세먼지의 희토류 원소 특성 비교: 북경과 광주 (Rare Earth Elements of Atmospheric Particulates (PM2.5) in Northeast Asia: Beijing and Gwangju)

  • 정석;이지영;박상희;양민준;장혜정;류종식
    • 대한원격탐사학회지
    • /
    • 제38권5_3호
    • /
    • pp.863-872
    • /
    • 2022
  • 희토류 원소(rare earth elements, REEs)는 유사한 물리적·화학적 성질을 가지고 있어 지질학적 환경변화를 해석하는 유용한 도구로 사용되고 있다. 이번 연구에서는 2018년 1월 한 달간 북경 및 광주광역시에서 포집된 초미세먼지 내 희토류 원소의 특성을 비교하였다. 북경 및 광주 초미세먼지 내 총 희토류 원소 농도는 북경이 광주보다 약 16배 높았으며 두 지역 모두 경희토류가 중희토류에 비해 8-10배 이상 부화되었다. Post Archean Australian Shale (PAAS) 표준화 분포 패턴을 통해 북경과 광주 초미세먼지는 Eu, Tb, Er이 다른 원소보다 부화된 양상을 보였고, 두 지역 모두 양(+)의 Eu 이상치와 음(-)의 Ce 이상치가 나타났다. 희토류 원소 간 상관관계를 통해 북경과 광주의 초미세먼지는 중국 사막 및 황토 고원과 북경 주변 도시(Zhangbei, Fengning, Miyun)의 영향을 받는 것으로 나타났다. 이번 연구를 통해 초미세먼지 내 희토류 원소는 국가 간 미세먼지의 차이를 밝힐 수 있는 중요한 지시자로 활용될 수 있으며, 국내 미세먼지 기원 및 이동에 대한 보다 명확한 정보를 제공하는 유용한 도구로 활용될 것으로 판단된다.

다목적실용위성 3호의 지상관측확률에 관한 연구 (Surface Observation Probability System of KOMPSAT-3)

  • 박명숙;허창회;김영미;김응현;김규선
    • 대기
    • /
    • 제16권4호
    • /
    • pp.371-378
    • /
    • 2006
  • The surface observation probability system (SOPS) of the Korea Multi-Purpose Satellite (KOMPSAT) has been developed based on the climatological distribution of cloud coverage and the expected passage of satellite orbit. While the optical camera loaded on KOMPSAT series has been operated with the purpose of observing earth's surface, it cannot see the surface when an obstacle (i.e., cloud) exists between them. In the present study, cloud information of International Satellite Cloud Climatology Project incorporates into high resolution grid of the KOMPSAT-3 orbit. The characteristics of the KOMPSAT SOPS are discussed.

Evaluation of ALOS PALSAR Interferometry in the West Coast of Korea;Preliminary Results

  • Choi, Jung-Hyun;Lee, Chang-Wook;Won, Joong-Sun
    • 대한원격탐사학회:학술대회논문집
    • /
    • 대한원격탐사학회 2007년도 Proceedings of ISRS 2007
    • /
    • pp.25-28
    • /
    • 2007
  • Precise digital elevation model (DEM) is an important issue in coastal area where DEMs in a time series are especially required. Although LIDAR system is useful in coastal regions, it is not yet popular in Korea mainly because of its high surveying cost and national security reasons. Recently, precise coastal DEM have been made using radar interferometry, waterline method. One of these methods, Spaceborne imaging radar interferometry has been widely used to measure the topography and deformation of the Earth. We acquired ALOS PALSAR FBD mode (Fine Beam Dual) data for evaluating the quality of interferograms and their coherency. The purpose of this study is construction of DEM using the ALOS PALSAR data using radar interferometry and analysis of surface characteristics by coherence and magnitude map over the Ganghwado and Siwha tidal flats and near coastal lands.

  • PDF

REE variation of Ultramafic rocks related to the Serpentinization, the Gyeonggi Massifs in the western Korea

  • Seo, Ji-Eun;Park, Seon-Gyu;Oh, Chang-Whan;Song, Suck-Hwan
    • 대한자원환경지질학회:학술대회논문집
    • /
    • 대한자원환경지질학회 2003년도 춘계 학술발표회 논문집
    • /
    • pp.194-195
    • /
    • 2003
  • High-pressure amphibolite-facies rocks with serpentinized ultramafic rocks occur in the Gyeonggi Massif. Ultramafic rocks occur as lenses within Precambrian granite gneiss, which showing dominantly tectonic lines of NNE directions as well as east extensional area of the chinese collision belt between south and north China block(\ulcorner). This study regionally makes a comparative study of ultramafic rocks in the western part of the Gyeonggi Massif in Korea. (omitted)

  • PDF

Extraction of Ground Control Point (GCP) from SAR Image

  • Hong, S.H.;Lee, S.K.;Won, J.S.;Jung, H.S.
    • 대한원격탐사학회:학술대회논문집
    • /
    • 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
    • /
    • pp.1058-1060
    • /
    • 2003
  • A ground control point (GCP) is a point on the surface of Earth where image coord inates and map coordinates can be identified. The GCP is useful for the geometric correction of systematic and unsystematic errors usually contained in a remotely sensed data. Especially in case of synthetic aperture radar (SAR) data, it has serious geometric distortions caused by inherent side looking geometry. In addition, SAR images are usually severely corrupted by speckle noises so that it is difficult to identify ground control points. We developed a ground point extraction algorithm that has an improved capability. An application of radargrammetry to Daejon area in Korea was studied to acquire the geometric information. For the ground control point extraction algorithm, an ERS SAR data with precise Delft orbit information and rough digital elevation model (DEM) were used. We analyze the accuracy of the results from our algorithm by using digital map and GPS survey data.

  • PDF

한반도-일본열도 사이의 광역지진관측 및 해석 ; 포항 STS지진관측소에서의 광대역, 고감도의 지진관측 (Trans Korean Peninsula-Japanese Island Seismic Observation and Analysis; Seismic Observation of Broad Band and Wide Dynamic Range at Pohang STS Observatory, Korea)

  • 김성균;정승환;전명순;경재복;전정수;류용규;가주오 오이케;요시오 후까오;이사오 야마다;게이꼬 이시하라;야수시 이시하라
    • 자원환경지질
    • /
    • 제26권1호
    • /
    • pp.97-106
    • /
    • 1993
  • In order to provide informations for the earth's deep interior and the earthquake mechanism, we have been operating the three components of Streckeisen Seismometers at Pohang Observatory, Korea, as a part of a long period seismic network (POSEIDON) in the northwestern Pacific now under construction. The recording system is specially designed to be able to obtain outputs of broad band and wide dynamic range; BRB (Broad Band), LP (Long Period), and VLP (Very Long Period) output. The triggered BRB and LP signals are digitized with the sampling intervals of 0.1 and 0.4 second, respectively. The lowpass filtered VLP output is digitized and recorded contineously with the sampling interval of 10 seconds. About 120 regional and teleseismic events have been successfully recorded for one and half year since late March, 1991. As a preliminary study, eight events of them are analyzed to determine Rayleigh wave dispersion curves in the period range of 20 to 300 seconds for the continental and oceanic paths. The curves are compared with the typical continental and oceanic ones to discuss the earth's deep interior.

  • PDF

친환경 자동차 도입에 따른 지역별 오존 농도 변화 특성 분석 (Characterizing Regional Ozone Concentration Changes Due to the Adoption of Eco-Friendly Vehicles in South Korea)

  • 양채영;전원배;김동진;박재형;최현식;문정혁
    • 한국환경과학회지
    • /
    • 제32권9호
    • /
    • pp.613-626
    • /
    • 2023
  • This study investigates the impact of increased adoption of eco-friendly vehicles on ozone (O3) concentrations in South Korea, utilizing the community multiscale air quality (CMAQ) model. In the summer of 2017 (June-August), we conducted two experiments: a BASE experiment, representing baseline emissions, and an R_30 experiment, involving a 30% emission reduction due to eco-friendly vehicles. The contrast between these experiments reveals that, while most air pollutants decreased with reduced vehicle emissions, O3 concentrations surprisingly increased (up to 2.1 parts per billion) across South Korea. A further examination of O3 concentration changes was conducted by analyzing daytime and nighttime variations as well as wind direction. During the daytime, O3 concentrations notably rose near metropolitan areas due to reduced O3 titration (O3 + NO → O2 + NO2) resulting from emission reductions. At nighttime, O3 concentrations exhibited a greater increase, attributed to the transport of daytime-generated O3 to rural regions. Notably, the impact of reduced emissions in metropolitan areas on O3 concentrations in downwind areas varied depending on the prevailing wind direction. These findings highlight that the promotion of eco-friendly vehicles, though effective in lowering certain air pollutants, might not directly influence O3 concentrations. This study underscores the need to comprehensively understand the complicated chemistry of O3 to develop effective strategies for air quality management.

동아시아 여름철 대기의 강 단기 예측성 검증 (Evaluation of Short-Term Prediction Skill of East Asian Summer Atmospheric Rivers)

  • 김혜인;권예은;백승윤;황재영;손석우;박향숙;차은정
    • 대기
    • /
    • 제34권2호
    • /
    • pp.83-95
    • /
    • 2024
  • Atmospheric rivers (ARs) are closely related to local precipitation which can be both beneficial and destructive. Although several studies have evaluated their predictability, there is a lack of studies on East Asian ARs. This study evaluates the prediction skill of East Asian ARs in the Korean Integrated Model (KIM) for 2020~2022 summer. The spatial distribution of AR frequency in KIM is qualitatively similar to the observation but overestimated. In particular, the model errors greatly increase along the boundary of the western North Pacific subtropical high as the forecast lead time increases. When the prediction skills are quantitatively verified by computing the Anomaly Correlation Coefficient and Mean Square Skill Score, the useful prediction skill of daily AR around the Korean Peninsula is found up to 5 days. Such prediction limit is primarily set by the wind field errors with a minor contribution of moisture distribution errors. This result suggests that the improved prediction of atmospheric circulation field can improve the prediction of East Asian summer ARs and the associated precipitation.