海洋层积云中的云滴谱宽度及其影响因子     

朱磊  陆春松  高思楠  YUM Seong Soo 《大气科学》2020,44(3):575-590

云滴谱宽度对模式中云的光学厚度的参数化、气溶胶间接效应的评估以及降水形成过程的研究至关重要。本文利用美国POST（Physics of Stratocumulus Top）项目2008年7月19日的飞机观测资料，分析了微物理量和云滴谱的垂直分布及微物理过程。结果表明，该云系云滴谱宽度在云底附近较大，这是由低层核化过程导致的；中层凝结增长过程使得云滴谱宽度随高度增加逐渐减小；云顶附近夹卷混合过程导致云滴谱宽度增大。绝热云中垂直速度的增大会促进云凝结核的活化使云滴数浓度增大，促进凝结增长使云滴尺度增大、云滴谱宽度减小，云滴谱宽度与云滴数浓度、云滴尺度呈现负相关关系；云洞中受夹卷混合过程影响，垂直速度减小，云滴蒸发，云滴数浓度和云滴尺度减小、云滴谱宽度增大，且该效应随绝热程度减小而增强。建议云滴谱宽度的参数化将垂直速度、云滴数浓度、云滴尺度和绝热程度等考虑在内。  相似文献   

Deposition of coarse-grained sediments in the Korea Strait during late Pleistocene low sea level     

Soo C. Park  Dong G. Yoo 《Geo-Marine Letters》1992,12(1):19-23

The wide area of the Korea Strait shelf is covered by a thin veneer of gravelly sands, sands, or muddy sands. Most gravels are sub- to well-rounded and their content reaches up to 25%. These sediments were derived from the Korean Peninsula through the paleochannel of the Nakdong River, which extended onto the mid-shelf during late Pleistocene low sea level. The gravel distribution pattern suggests reworking and transport of the sediments by strong currents during times of low sea level.  相似文献   

A numerical experiment of the M2 tide in the Yellow sea   总被引：1，自引：0，他引：1  

Hui Soo An 《Journal of Oceanography》1977,33(2):103-110

Semi-diurnal tides in the Yellow Sea are calculated by integrating the shallow water wave equations with frictional and inertial terms.It is found that the results depend on the bottom friction. In the frictionless case the tidal range is unstably amplified because of the occurrence of resonance of the semi-diurnal tidal component in Inchon Bay. When the bottom friction is in the form of the square of velocity, the results agree fairly well with the observations.The following results are obtained. First, the tidal range is larger at the coast of the Korean Peninsula than at the China Coast. Second, resonance of the semi-diurnal tide occurs in Inchon Bay. Third, bottom friction is very important in the shallow ocean,i.e., when the bottom friction become large, the phase lag is retarded and the tidal range decreases.The amplitude and the phase lag calculated in this study agree well with the observations in the case of _b =_b ² V¦V¦, _b ²=0.0026, especially in the coast of the Korean Peninsula.  相似文献   

Evaluating the transport and removal of chromate using pyrite and biotite columns     

Chul‐Min Chon  Jae Gon Kim  Hi‐Soo Moon 《水文研究》2007,21(14):1957-1967

To remove chromate from a wastewater, a porous permeable reactive barrier system (PRBS), using pyrite and biotite, was adapted. This study included bench‐scale column experiments to evaluate the efficiency of the PRBS and investigate the reaction process. The total chromium concentration of the effluent from the biotite and pyrite columns reached the influent concentration of 0·10 mM after passing through more than 150 pore volumes (PVs) and 27 PVs respectively, and remained constant thereafter. The Cr^VI concentration in the effluent from the biotite column became constant at about 0·08 mM , accounting for approximately 80% of the influent concentration, after passing through 200 PVs. Moreover, in the pyrite column, the Cr^VI concentration remained at about 0·01 mM , 10% of the input level, after passing through 116 PVs. This shows that both columns maintained their levels of chromate reduction once the Cr^VI breakthrough curves (BTCs) had reached the steady state, though the steady‐state output concentration of total chromium had reached the influent level. The variances of the iron concentration closely followed those of the chromium. The observed data for both columns were fitted to the predicted BTCs calculated by CXTFIT, a program for estimating the solute transport parameters from experimental data. The degradation coefficient µ of the total chromium BTCs for both columns was zero, suggesting the mechanisms for the removal of chromate limit the µ of the Cr^VI BTCs. The Cr^VI degradation of the pyrite column (6·60) was much greater than that of the biotite column (0·27). In addition, the Cr^VI retardation coefficient R of the pyrite column (253) was also larger than that of the biotite column (125). The R values for the total chromium BTCs from both columns were smaller than those of the Cr^VI BTC. Whereas the total chromium BTC for the pyrite column showed little retardation (1·5), the biotite column showed considerable retardation (80). The results for the 900 °C heat‐treated biotite column were analogous to those of the control column (quartz sand). This suggests that the heat‐treated biotite played no role in the retardation and removal of hexavalent chromium. The parameters of the heat‐treated biotite were calculated to an R of 1·2 and µ of 0·01, and these values confirmed quantitatively that the heated biotite had little effect on the transport of Cr^VI. These solute transport parameters, calculated by CXTFIT from the data obtained from the column tests, can provide quantitative information for the evaluation of bench‐ or field‐scale columns as a removal technology for Cr^VI in wastewater or contaminated groundwater. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   

First report of the small bird track Koreanaornis from the Cretaceous of North America: implications for avian ichnotaxonomy and paleoecology     

Owen A. Anfinson  Martin G. Lockley  Sam Hyang Kim  Kyung Soo Kim  Jeong Yul Kim 《Cretaceous Research》2009,30(4):885-894

Although body fossils of shorebirds and shorebird-like species are extremely rare from the Cretaceous, rapid increase in the discovery of bird footprint sites provides valuable alternate evidence to help fill gaps in the story of the early evolution of shorebird-like species. Newly discovered bird tracks from the Albian-Cenomanian Dakota Formation in northeastern Utah represent the first report of the ichnogenus Koreanaornis from North America and only the second report of bird tracks from this formation. These tracks are not attributable to Aquatilavipes as previously claimed. Three well-preserved trackways are described and provisionally referred to Koreanaornis cf. hamanensis (Kim). However, a review of the ichnotaxonomy of shorebird ichnites reveals that this ichnotaxon also closely resembles the Miocene ichnospecies Avipeda sirin (Vyalov). This latter comparison points to the need for a thorough evaluation of the similarity between Mesozoic and Cenozoic avian ichnotaxa, which may be over-split in some cases and under-differentiated in others.The new material helps distinguish ichnogenus Koreanaornis from the larger bird track Aquatilavipes, which is more abundant and widespread in North America. In some cases Aquatilavipes has been incorrectly used as a catch-all ichnogenus both in North America and Asia. The Dakota Formation stratigraphy at the tracksite indicates that the track makers lived in a marginal marine paleoenvironment. However, despite the widespread distribution of such facies, often replete with dinosaur tracks, the bird track record of the Dakota Formation, and the Cretaceous of the western USA remains relatively sparse in comparison with other areas such as east Asia.  相似文献   

Sandstone diagenesis of the Lower Cretaceous Sindong Group, Gyeongsang Basin, southeastern Korea: Implications for compositional and paleoenvironmental controls     

Yong Il  Lee  Dong Hyun  Lim 《Island Arc》2008,17(1):152-171

Abstract The Gyeongsang Basin is a non‐marine sedimentary basin formed by extensional tectonism during the Early Cretaceous in the southeastern Korean Peninsula. The sediment fill starts with the Sindong Group distributed along the western margin of the basin. It consists of three lithostratigraphic units: the Nakdong (alluvial fan), Hasandong (fluvial) and Jinju (lacustrine) formations with decreasing age. Sindong Group sandstones are classified into four petrofacies (PF) based on their detrital composition: PF‐A consists of the lower Nakdong Formation with average Q₇₃F₁₂R₁₅; PF‐B the upper Nakdong and lower Hasandong formations with Q₆₆F₁₅R₁₈; PF‐C the middle Hasandong to middle Jinju formations with Q₄₉F₂₉R₂₂; and PF‐D the upper Jinju Formation with Q₂₆F₃₄R₄₁. The variations of detrital composition influenced the diagenetic mineral assemblage in the Sindong Group sandstones. Illite and dolomite/ankerite are important diagenetic minerals in PF‐A and PF‐B, whereas calcite and chlorite are dominant diagenetic minerals in PF‐C and PF‐D. Most of the diagenetic minerals can be divided into early and late diagenetic stages of formation. Early diagenetic calcites occur mostly in PF‐C, probably controlled by arid to semiarid climatic conditions during the sandstone deposition, no early calcite being found in PF‐A and PF‐B. Late‐stage calcites are present in all Sindong Group sandstones. The calcium ions may have been derived from shale diagenesis and dissolution of early stage calcites in the Hasandong and Jinju sandstones. Illite, the only diagenetic clay mineral in PF‐A and lower PF‐B, is inferred to be a product of kaolinite transformation during deep burial, and the former presence of kaolinite is inferred from the humid paleoclimatic conditions during the deposition of the Nakdong Formation. Chlorites in PF‐C and PF‐D are interpreted to be the products of transformation of smectitic clay or of precipitation from alkaline pore water under arid to semiarid climatic conditions. The occurrence of late‐stage diagenetic minerals largely depended on the distribution of early diagenetic minerals, which was controlled initially by the sediment composition and paleoclimate.  相似文献   

Genesis and Mineralogy of Serpentinite Deposits,West of South Korea     

Song Suckhwan  Choi Seon Gyu  Lee Hyun Koo 《中国地质大学学报(英文版)》2000,11(2)

The serpentinite deposits derived from ultramafic rockswithin the South Korea mainly occur in the west ofChungcheongnam - Do,the south of South Korea,Ulsan andAndong area,and in the middle of South Korea,Gapyeongarea. The present study is on the genesis and m ineral compo-sitions of the serpentinite deposits consisting of abouteighteenmasses in the west of Chungcheongnam- Do. The ultramaficrocks mainly occur as discontinuously isolated lenticular or el-liptical bodies and extend to NNE d…  相似文献   

Crown fuel characteristics and carbon emission from Japanese red pine stands burned by crown fire in Mt. Palgong, South Korea     

Byungdoo LEE  Myoung Soo WON  Yohan LEE  Myung Bo LEE 《山地科学学报》2012,9(5):656-664

Carbon emissions from forest fires are considered an important factor of ecosystem carbon balance and global climate change. Carbon emissions from Japanese red pine stands (Pinus densiflora S. et Z.) burned by crown fire were estimated at Mt. Palgong in Daegu Metropolitan City, and crown fuel characteristics, including crown bulk density, crown base height, and fuel moisture content of Japanese red pine, were analyzed. Total biomass combusted was calculated by subtracting the biomass of burned stands from that of unburned stands exhibiting similar stand structures and site environments. Ten trees in the unburned area and five trees in the burned area were cut by using direct harvesting techniques to estimate crown layer biomass. All biomass sampled was oven-dried and weighed. The dry weight ratios of stems, branches, and needles were 70%, 21%, and 9%, respectively. The available fuel load susceptible to combustion during the crown fire spread was equivalent to 55% of the crown layer biomass. The crown bulk density was 0.24 kg/ m 3 on average. The estimated amount of CO 2 was 23,454 kg CO 2 /ha for the crown layer. These results will be useful for calculating the amount of CO 2 emitted from forest fires and for developing a forest carbon model in P. densiflora forests.  相似文献   

Evaluation of seismic behaviour of Cheomseongdae using dynamic centrifuge model test          下载免费PDF全文

Heon‐Joon Park  Dong‐Soo Kim 《地震工程与结构动力学》2015,44(5):695-711

Cheomseongdae is known to be the oldest astronomical observatory in Asia. According to historical records, the Gyeongju area, where Cheomseongdae is located, suffered from numerous medium‐scale earthquakes. Cheomseongdae has a masonry structure, which is apparently vulnerable to horizontal dynamic loads such as earthquakes. However, despite its appearance, features such as the filler of the lower half, inner irregular‐shaped stones which can induce high frictional resistance, eight long horizontal tie stones inside the artefact, and a grid of interlocking headstones increase its resistance to horizontal dynamic loads. Dynamic centrifuge model tests were performed on Cheomseongdae in order to evaluate the seismic response characteristics of this architectural heritage structure. Model tests were executed on two 1/15‐scale models: one which was an exact duplicate of the original Cheomseongdae and the other without the long horizontal tie stones and grid of interlocking headstones. On the basis of the amplification patterns in the time and frequency domains, the differences in seismic behaviour between the two Cheomseongdae models, and a broken stone at the 19th layer during tests, the long horizontal tie stones and headstones were found to increase the seismic resistance within Cheomseongdae and provide a glimpse of the ‘seismic design’ of our ancestors. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   

Proteomic Analysis of Microbial Community Inhabiting Asian Dust Source Region          下载免费PDF全文

Simranjeet Singh Sekhon  Mina Kim  Hyun‐Ju Um  Fumihisa Kobayashi  Yasunobu Iwasaka  Guangyu Shi  Bin Chen  Sung‐Jin Cho  Yang‐Hoon Kim 《洁净——土壤、空气、水》2016,44(1):25-28

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