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51.
Comparison of the Bright Band Characteristics Measured by Micro Rain Radar (MRR) at a Mountain and a Coastal Site in South Korea 总被引:1,自引:0,他引:1
Data from a long term measurement of Micro Rain Radar (MRR) at a mountain site (Daegwallyeong,DG, one year period of 2005) and a coastal site (Haenam, HN, three years 2004–2006) in South Korea were analyzed to compare the MRR measured bright band characteristics of stratiform precipitation at the two sites. On average, the bright band was somewhat thicker and the sharpness (average gradient of reflectivity above and below the reflectivity peak) was slightly weaker at DG, compared to those values at HN. The ... 相似文献
52.
53.
Kangseok Hwang Eun-A Yoon Sukyung Kang Hyungkee Cha Kyounghoon Lee 《Ocean Science Journal》2017,52(4):563-571
The present study focuses on the influence of target strength (TS) changes in the swimming angle of the hairtail (Trichiurus lepturus). We measured in-situ TS at 38 and 120 kHz with luring lamps at a fishing ground for jigging boats near the coastal waters of Jeju-do in Korea. Swimming angle and size of hairtails were measured using an acoustic camera. Results showed that mean preanal length was estimated to be 13.5 cm (SD = 2.7 cm) and mean swimming tilt angle was estimated to be 43.9° (SD = 17.6°). The mean TS values were ?35.7 and ?41.2 dB at 38 and 120 kHz, respectively. The results will assist in understanding the influence of swimming angle on the TS of hairtails and, thus, improve the accuracy of biomass estimates. 相似文献
54.
Satellite observations of sea level anomalies(SLA) from January 1993 to December 2012 are used to investigate the interannual to decadal changes of the boreal spring high SLA in the western South China Sea(SCS) using the Empirical Orthogonal Function(EOF) method. We find that the SLA variability has two dominant modes. The Sea Level Changing Mode(SLCM) occurs mainly during La Ni?a years, with high SLA extension from west of Luzon to the eastern coast of Vietnam along the central basin of the SCS, and is likely induced by the increment of the ocean heat content. The Anticyclonic Eddy Mode(AEM) occurs mainly during El Ni?o years and appears to be triggered by the negative wind curl anomalies within the central SCS. In addition, the spring high SLA in the western SCS experienced a quasi-decadal change during 1993–2012; in other words, the AEM predominated during 1993–1998 and 2002–2005, while the La Ni?a-related SLCM prevailed during 1999–2001 and 2006–2012. Moreover, we suggest that the accelerated sea level rise in the SCS during 2005–2012 makes the SLCM the leading mode over the past two decades. 相似文献
55.
We observed the spectrum of 44i Boo in 1981 March and in 1983 March. We found that the equivalent widths of the CaII K and CaI 4227 A lines showed periodic variations with different phases, and that the profile of the Hα line also varied in step. A preliminary analysis is made based on our observations and the recent IUE data and a simple model atmosphere with stellar activity of 44i Boo (B) is proposed. 相似文献
56.
M. Chaâbane M. Masmoudi K. Medhioub F. Elleuch 《Meteorology and Atmospheric Physics》2006,92(1-2):103-114
Summary Spectral aerosol optical thickness have been measured at Thala site (central West of Tunisia) from March to October 2001.
The measurement site is located in a continental and non industrialized region, approximately 150 km from the North coast
of the Mediterranean Sea and nearby the Algerian border. Thala site could be then influenced by the dust content of the continental
air masses carried by western and southern winds. A second pollution source is constituted by industrial and/or maritime particles
carried by northern and eastern winds. AOT measurements acquired through the ground-based AERONET are analyzed. The diurnal
cycle over Thala and two other areas within the network showed various trends and a prevailing pattern of the optical thickness
increase by 10–40% during the day. Daily AOT and monthly averaged aerosol optical thickness, ?ngstr?m coefficient and precipitable
water vapor are computed and compared with those of other sites. Measured meteorological parameters represent a valuable supplement
to the data sets with the sunphotometer measurements. The analysis of the results shows that there is a high correlation between
aerosol optical properties (AOT and ?ngstr?m coefficient) and the local weather conditions, essentially wind speed and direction
and air specific humidity. 相似文献
57.
Sung-Soo Cha Jin-Yong Lee Dae-Hyuck Lee Eric Amantini Kang-Kun Lee 《Engineering Geology》2006,84(3-4):229-243
Feasibility of storing LNG in a lined rock cavern was evaluated using a pilot cryogenic rock cavern constructed in Daejeon, Korea. The pilot program included hydrogeological and engineering characterization of the rock mass around the cavern, design and construction of a drainage system, and pilot operation of the cryogenic cavern. An appropriate drainage system is most important to protect the containment system of LNG from thermal shocks due to ice lenses and hydrostatic pressure of groundwater. As a part of the pilot program, this study focused on the evaluation of hydraulic and engineering properties of the rock mass around the cavern. For this purpose, engineering logging of the rock cores, single and cross-hole hydraulic tests, and recharge/drainage tests were performed using seven drilled holes with different trends and plunges. Three main joint sets were found from the logging of the rock cores, acoustic borehole televiewer, and window mapping. The orientations of the three major joint sets were 60/209, 40/171, and 29/331, which can provide the main groundwater flow paths. Mean RQD values ranged from 56 to 88, which were classified as fair and good, although varying with depth along single boreholes. Hydraulic conductivity from the single and cross-hole hydraulic tests estimated in the order of 10−6 or 10−7 m/s and corresponding transmissivity ranged between 10−5 and 10−6 m2/s. Permeable intervals identified from the hydraulic tests were mostly located above the cavern roof. Below the roof, the permeable zone was difficult to observe. According to the hydraulic communication tests performed for some designated intervals, hydraulic connection between boreholes was highly varied with depth or location, which indicated a very different distribution of water conducting joint sets along the boreholes. When water was injected at R1 with constant or varying flow rates, monotonous and stable seepage was observed at observation boreholes. From this, some stable drainage was expected even in relatively heavy rainfalls. When designing the drainage system of the cavern, the drainage holes should be orientated to maximize frequency of encountering the major joint sets and the permeable intervals identified from this study. 相似文献
58.
Liu Xue-fu Peng Song-chuan Cha Guang-wei LI Xiao-yu 《Chinese Astronomy and Astrophysics》1985,9(4):296-299
We give results of photoelectric photometry and spectral observations of Aur during its 1982–1984 ingress and total eclipse. Narrow-band light curves and variations in radial velocity within a night resulting from autoregression analysis all indicate short time scale variations in the F supergiant primary on the order of hours or fractions thereof. Fluctuations with an amplitude of ±25 Km/s and a period of 400 d appear to be present in the measured radial velocity of the primary during ingress and totality. Obvious changes in the H profile were also observed: around the second contact of the total eclipse, there was emission in the blue wing; while around the third contact of the atmosphere eclipse, there was emission in the red wing. 相似文献
59.
Hyun-Ju Cha Man Sik Choi Chang-Bok Lee Dong-Hyeok Shin 《Journal of Asian Earth Sciences》2007,29(5-6):685-697
We analyzed 77 surface sediment samples collected in the southwestern East/Japan Sea from the Korea Strait through the Ulleung Basin and the Korea Plateau for grain size, calcium carbonate, organic carbon, and major (Na, Mg, Al, Fe, K, Ca, and Ti) and trace elements (P, Mn, Sr, Li, Sc, V, Cr, Co, Ni, Zn, Cu, and Pb).The chemical composition of the surface sediments was found to be highly variable spatially. Cluster analysis of surface sediment chemical compositions indicated five major geochemical sedimentary environments: basin, lower slope, coast and upper slope, inner shelf, and outer shelf. Continental-shelf sediments were rich in shell fragments and had relict and coarse-grained characteristics. Recent fine-grained sediments were only distributed in coastal, slope, and basin areas. Concentrations of Al, K, Ca, Ti, Cr, and Sc were highest in the coastal and upper slope areas and decreased with water depth. Elemental ratios using major and trace elements indicated that coastal and upper slope detrital sediments were mixtures of sediments derived from the Changjiang (Yangtze) and Nakdong Rivers. Although the concentrations of organic carbon, P, Mn, V, Co, Ni, Cu, and Pb increased with water depth, their distribution patterns indicated authigenic (V, Cu, and Pb) and diagenetic (Fe, P, Mn, Co, and Ni) origins. The distribution pattern with water depth suggested that the chemical composition of surface sediment was determined by sedimentologic and geochemical processes, such as the supply of detrital and biogenic materials, and authigenic and post-depositional diagenetic processes in sediments. 相似文献
60.