Inter-comparison of the infrared channels of the meteorological imager onboard COMS and hyperspectral IASI data

The successful launch and commissioning of the first geostationary meteorological satellite of Korea has the potential to enhance earth observation capability over the Asia Pacific region. Although the specifications of the payload, the meteorological imager(MI), have been verified during both ground and in-orbit tests, there is the possibility of variation and/or degradation of data quality due to many different reasons, such as the accumulation of contaminants, the aging of instrument components, and unexpected external disturbance. Thus, for better utilization of MI data, it is imperative to continuously monitor and maintain the data quality. As a part of such activity, this study presents an inter-calibration, based on the Global Space-based Inter-Calibration System(GSICS), between the MI data and the high quality hyperspectral data from the Infrared Atmospheric Sounding Interferometer(IASI) of the Metop-A satellite. Both sets of data, acquired for three years from April 2011 to March 2014, are processed to prepare the matchup dataset, which is spatially collocated, temporally concurrent,angularly coincident, and spectrally comparable. The results show that the MI data are stable within the specifications and show no significant degradation during the study period. However, the water vapor channel shows a rather large bias value of-0.77 K, with a root-mean-square difference(RMSD) of around 1.1 K, which is thought to be due to the shift in the spectral response function. The shortwave channel shows a maximum RMSD of around 1.39 K, mainly due to the coarse digitization at the lower temperature. The inter-comparison results are re-checked through a sensitivity analysis with different sets of threshold values used for the matchup dataset. Based on this, we confirm that the overall quality of the MI data meets the user requirements and maintains the expected performance, although the water vapor channel requires further investigation.     

First report on the occurrence of the comb pen shell,Atrina pectinata (Linnaeus, 1767) (Bivalvia: Pinnidae) in Ulleungdo Island in the East Sea: Ecology and molecular identification of the species using COI gene sequence

Pen shell is one of the largest marine bivalves inhabiting shallow subtidal soft bottoms in the west Pacific and Indian Oceans. In Korea, the comb pen shell Atrina pectinata fisheries has been established on the south and west coasts. Recently, a pen shell population has been discovered from a subtidal sand flat (25–30 m depth) in Ulleungdo Island located in the East Sea of Korea, suggesting a potential shellfish resource in this area. In the present study, we first surveyed the population density and size of the unique pen shell using SCUBA, and identified the pen shell to species level using mitochondrial cytochrome oxidase I gene (COI) sequence. An underwater survey carried out from July to September 2013 revealed that populations of pen shell patched on subtidal sand flat at a depth of 20–25 m. Grain size analysis indicated that sand particles accounted for 99% of the 600 × 700 m sand flat. The underwater survey also indicated that density of the pen shell ranged between 6–19 ind/m², with a mean of 11 ind/m². Shell height (i.e. longest axis of the shell) of the pen shell on the sand flat varied between 17.2 cm to 28.8 cm, with a mean of 25.1 cm, and the age was estimated to range between 1.5–7.5 yrs, with a mean of 5 yr. COI DNA sequence obtained from the pen shell in this study showed 98.9–99.2% similarity to Atrina pectinata (Linnaeus 1767) reported from Japan. In the cluster analysis, the COI DNA sequence of the pen shells from Ulleungdo Island was grouped with A. pectinata reported from Japan and China, indicating that the pen shell discovered in this study was A. pectinata, commonly distributed on the west and south coasts of Korea.     

雅布赖盆地构造演化与油气聚集

雅布赖含油气盆地位于中国西部河西走廊地区北部,处于华北克拉通阿尔善地块中南部过渡带,属北祁连构造带,中生代为走滑拉分盆地,新生代为挤压冲断坳陷盆地。燕山早期,形成东西向雅布赖拉张断陷,主控断裂为北大山正断层,沉积中心位于盆地南部;燕山中期,碰撞造山作用致使盆地北部急剧抬升,北部中-下侏罗统地层遭受强烈剥蚀;燕山晚期,阿拉善地块及其北部地区处于伸展构造环境,雅布赖山前产生东西向正断层,急剧活动,快速沉降,形成了北东向展布的新的拉张断陷盆地。喜马拉雅期,在挤压走滑作用下,雅布赖盆地南部形成北西向南倾逆冲的推覆构造,致使北大山正断层发生错断瓦解,最终形成"东隆西坳,南断北超"的挤压坳陷构造格局。雅布赖盆地主体沉积凹陷具有较强分割性,沉降凹陷分布于南部,最大沉积岩厚度为5 400 m;凹陷内侏罗系最为发育,中侏罗统新河组、青土井组暗色泥岩、煤岩为烃源岩,砂岩为储集层,新河组泥岩互层作盖层,构成盆地内最主要的含油气组合。由于雅布赖盆地特定的早期深埋,晚期抬升破坏构造格局,造就侏罗系砂岩储层早期强烈压实致密,侏罗系煤系烃源岩成熟较晚,构造发育期与烃源岩排烃期不匹配,生成油气主要表现为近源成藏与层内滞留,形成源内自生自储,致密油应是主要勘探对象。     

Geochemical evidence of paleogeography and paleoclimate during deposition of the 2nd Member of Kongdian Formation in Kongnan area

The 2nd Member of Kongdian Formation has been made up of a large number of oil shale and mudstone in the Kongnan aera of Huanghua depression around the Bohai Bay.In the Kongnan area,the lake basins were very large and deep during the deposition of the 2nd Member of Kongdian Formation.During that period,the lakes were sealed,uncommunicated with the sea water and the paleoclimate was very warm and wet in Kongnan area.Analyzing the content of the trace element and the rare earth element,carbon and oxygen isotope in the disquisition,The authors prove the two views correct.     

Temporal variations of physical and hydrochemical properties of springs in the Mid‐Levels area,Hong Kong: results of a 1‐year comprehensive monitoring programme

Springs and seeps occur in the spaces around Po Hing Fong Street in the Mid‐Levels area, Hong Kong. Most of the springs occur through the drainage weepholes on retaining walls at the street. This paper first examines the geology and history of the springs. The paper then reports the findings from a 1‐year comprehensive spring monitoring programme. The temporal variations of flow rate, physiochemical parameters and hydrochemistry of the springs are discussed. The average temperatures of the springs were close to the mean air temperature, although there was a systematic lag time of 40 to 50 days between the peak air temperature and highest water temperatures. Spring waters from two rows of weepholes in the retaining wall showed significantly different physical and hydrochemical responses to the changes in rainfall and temperature, though their vertical distance is only about 1 m. The results suggest that water from the upper row of weepholes may represent a recharge source that is shallow or close to the spring outlets, whereas that from the lower row of weepholes may represent a recharge source that is much deeper or further up the hill. Although the spring flows increased rapidly after rainstorms, analysis of the total dissolved solids showed a delayed response to rainstorm events. The concentration of individual ions in the spring water varied in a unique way in response to rainstorm events. It is clear that the presence of underground man‐made drainage systems and the leakage from water mains in the study area may add complexity to the solute responses and transport mechanisms. Further studies are required to constrain the impacts of these man‐made structures on the hydrogeology of the springs. Copyright © 2007 John Wiley & Sons, Ltd.     

Groutability of cement‐based grout with consideration of viscosity and filtration phenomenon

The groutability depends on the properties of the grout, its injection processes, and on the mechanical properties of the soil formation. During the process of pouring cement‐based grouting into a porous medium, a variation with time occurs in the viscosity of grout suspension. In addition, the particle filtration phenomenon will limit the expansion of the grouted zone because cement particles are progressively stagnant within the soil matrix. In this paper, a closed‐form solution was derived by implementing the mass balance equations and the generalized phenomenological filtration law, which can be used to evaluate the deposition of cement‐based grout in the soil matrix. The closed‐form solution relevant to a particular spherical flow was modified by a step‐wise numerical calculation, considering the variable viscosity caused by a chemical reaction, and the decrease in porosity resulting from grout particle deposition in the soil pores. A series of pilot‐scale chamber injection tests was performed to verify that the developed step‐wise numerical calculation is able to evaluate the injectable volume of grout and the deposition of grout particles. The results of the chamber injection tests concurred well with that of the step‐wise numerical calculation. Based on the filtration phenomenon, a viable approach for estimating the groutability of cement‐based grout in a porous medium was also suggested, which might facilitate a new insight in the design of the grouting process. Copyright © 2009 John Wiley & Sons, Ltd.     

PCVSAT单收站系统的应用

对PCVSAT单收站系统的配置、业务流程、软件应用、维护及故障检测作较全面的介绍,为各级气象台站使用PCVSAT系统的业务人员提供一份技术参考手册.