A Wind-tunnel Study of Atmospheric Boundary-Layer Flow over Vegetated Surfaces to Suppress PM10 Emission on Owens (dry) Lake     

Dae Seong Kim  Greg H. Cho  Bruce R. White 《Boundary-Layer Meteorology》2000,97(2):309-329

Dust storms on Owens (dry) Lake located 200 milesnortheast of Los Angeles, California, U.S.A., havecaused serious PM₁₀ emission problems. Alaboratory-based experimental study was conducted toinvestigate the efficiency of 'vegetation cover' onthe playa to suppress dust emission rates as part ofa mitigation plan.Erodible lakebed material and field vegetation (saltgrass) taken from Owens (dry) Lake were placed in awind tunnel to simulate near-surface wind flow in theatmospheric boundary layer. Vertical wind-speedprofiles and vertical PM₁₀-concentration profileswere measured over six different levels of surfacevegetation cover. In order to understand the mechanismof aeolian particle transport and dust injection intothe atmosphere, the roughness parameter, z₀, thefriction velocity, u_*, and the surface dragcoefficient, C_D, were carefully determined.An empirical equation was developed to predictPM₁₀ emission rates as a function of wind speedand level of vegetation coverage for Owens (dry) Lake.Although the current results apply only to theeffectiveness of vegetation cover to suppressPM₁₀ emissions at Owens playa, the procedure canbe employed for any arid area or region that mightutilize added vegetation as a mitigation measure.  相似文献   

Effect of model error representation in the Yellow and East China Sea modeling system based on the ensemble Kalman filter   总被引：1，自引：1，他引：0  

Kyung Man Kwon  Byoung-Ju Choi  Sang-Ho Lee  Young Ho Kim  Gwang-Ho Seo  Yang-Ki Cho 《Ocean Dynamics》2016,66(2):263-283

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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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Effects of spilled oil on microbial communities in a tidal flat     

Katayama Y  Oura T  Iizuka M  Orita I  Cho KJ  Chung IY  Okada M 《Marine pollution bulletin》2003,47(1-6):85-90

Effects of spilled oil on microbial communities in tidal flats were examined by use of a simulator for a tidal flat ecosystem. The simulator is composed of a wave generator, a tide control device, and a tidal flat. Sediment for the tidal flat was obtained at a natural tidal flat in Hiroshima Bay, Japan. After stabilizing the benthic organisms, fuel oil C was added to the surface of the flat at 1 lm(-2). Although the total number of micro-organisms remained at 1.5-3.5 x 10(9) cells g(-1) dry sediment irrespective of the addition of oil, bacterial communities which were analyzed based on the 16S rDNA showed clear changes after the addition of fuel oil C and after a subsequent recovery period. Bacterial colonies were randomly isolated from the oil-supplemented sediment during the experiments, and the isolates were examined for susceptibility to hydrocarbons in order to screen the oil-susceptible bacteria. The proportion of oil-susceptible bacteria in the isolates decreased with the addition of the oil. Oil-susceptible bacteria showed an inability to assimilate petroleum compounds as well as an inhibition of growth. The possibility of using oil-susceptible bacteria as an indicator of bioremediation in tidal flats was discussed.  相似文献   

Seasonal and spatial distribution of nonylphenol and IBP in Saemangeum Bay, Korea     

Li D  Dong M  Shim WJ  Hong SH  Oh JR  Yim UH  Jeung JH  Kanan N  Kim ES  Cho SR 《Marine pollution bulletin》2005,51(8-12):966-974

In order to investigate spatial and temporal distribution of organic pollutants in the Saemangeum Bay, organophosphorus pesticides (10), alkylphenols (8), chlorophenols (2), bisphenol A were analyzed from the surface seawater taken in 2002–2003. Most of the analytes were not detected in all stations except nonylphenol and S-benzyl-O,O-di-isopropyl phosphorothioate (IBP). Concentrations of nonylphenol and IBP ranged from ND to 298 ng/l and from ND to 1840 ng/l, respectively. The high levels of nonylphenol and IBP were found in the estuary areas of Mangyeong and Dongjin River. The levels of nonylphenol and IBP in surface seawater varied through seasons and the high levels of nonylphenol and IBP were in summer season (August). Based on real time monitoring of IBP and on correlation between concentrations of target compounds and contents of salinity in seawater, physical mixing and diffusion of seawater were found to be the major factors that affect the spatial distribution of IBP and nonylphenol in the Saemangeum Bay environment.  相似文献   

Response of submersed aquatic vegetation (SAV) in Lake Pontchartrain, Louisiana to the 1997–2001 El Niño Southern Oscillation shifts     

Hyun Jung Cho  Michael A. Poirrier 《Estuaries and Coasts》2005,28(2):215-225

Lake Pontchartrain is a large, shallow, low salinity estuary north of New Orleans, Louisiana. It is a water quality impaired system with restoration efforts in progress. One restoration goal is the reestablishment of historic submersed aquatic vegetation (SAV;Vallisneria americana Michx. andRuppia maritima L.), which has been in a state of decline since first studied in 1953. Annual SAV surveys and monthly water quality monitoring were conducted at four to five sites from 1996 through 2003 to evaluate trends and determine the causes of SAV change. We found a rapid increase in the distribution and abundance ofR. maritima in 1999 that persisted through 2002. An El Niño Southern Oscillation shift occurred between 1997 and 2001, which produced a drought in southern Louisiana as an ancillary effect of La Niña. This study was conducted to investigate causal links between the El Niño to La Niña climate phase shift and SAV change. We found that salinity and water clarity increased during La Niña. Increased water clarity produced a rapid increase in the euryhaline speciesR. maritima in deeper water and at historic sites where SAV had not been found since 1953. As salinity increased, the freshwater speciesV. americana andMyriophyllum spicatum L. declined, andNajas guadalupensis (Spreng.) Magnus andPotamogeton perfoliatus L. disappeared. In 2003, after the La Niña phase, salinity and water clarity decreased,R. maritima decreased, and the freshwater species increased, butP. perfoliatus was still absent. We found that salinity controlled SAV species composition, and water clarity controlled SAV colonization depth (Z_col=2.3/K_d). Our study demonstrated that climatic shifts cause cyclic changes in Lake Pontchartrain SAV and that restoration could be accomplished by improving water clarity. Due to the sensitivity of SAV to environmental change, similar responses to short-term and long-term climate changes should occur in other estuarine systems.  相似文献   

Holocene climate and environmental changes inferred from sediment characteristics and diatom assemblages in a core from Hwajinpo Lagoon,Korea     

Ara Cho  Daekyo Cheong  Jin Cheul Kim  Dong-Yoon Yang  Jin-Young Lee  Kaoru Kashima  Kota Katsuki 《Journal of Paleolimnology》2018,60(4):553-570

Hwajinpo is the largest lagoon in Korea and is located along the east coast of the country. It possesses Holocene sediments that provide an important record of past climate change. We studied the evolution of Hwajinpo Lagoon using grain size data and diatom assemblages in an 11.0-m core (HJ02), which was obtained at the mouth of a small river that drains into the lagoon. Core chronology was established with accelerator mass spectrometry ¹⁴C dates and optically stimulated luminescence dates. Diatom assemblages and grain size analysis revealed that estuarine conditions in the inner lagoon area transitioned to an open embayment ca. 8 ka as a result of sea-level rise. Around 7.8 ka, the open bay became a semi-closed bay as a consequence of development of a sand barrier. After the bay was semi-closed, marine water inflow was increasingly restricted as the sand barrier developed, and the semi-closed bay became a completely enclosed, low-salinity, brackish lagoon around 6 ka. There was an erosional hiatus between 5.5 and 1.7 ka (7.0 m depth), likely caused by river flooding and a switch in the location of drainage along the delta. The lagoon became oligohaline around 1.6 ka, likely because of increasing precipitation associated with an intensified Asian summer monsoon. This increase in precipitation resulted in expansion of the sand bar by sediment inflow, driven by agricultural development in the area. About 1000 years ago, the diatom assemblage was similar to the modern assemblage, suggesting the lagoon’s current geomorphic conditions had been established.  相似文献   

Evaluating Hyperspectral Imager for the Coastal Ocean (HICO) data for seagrass mapping in Indian River Lagoon,FL     

Hyun Jung Cho  Igor Ogashawara  Deepak Mishra  Joseph White  Andrew Kamerosky  Lori Morris 《地理信息系统科学与遥感》2014,51(2):120-138

Differentiation between benthic habitats, particularly seagrass and macroalgae, using satellite data is complicated because of water column effects plus the presence of chlorophyll-a in both seagrass and algae that result in similar spectral patterns. Hyperspectral imager for the coastal ocean data over the Indian River Lagoon, Florida, USA, was used to develop two benthic classification models, Slope_RED and Slope_NIR. Their performance was compared with iterative self-organizing data analysis technique and spectral angle mapping classification methods. The slope models provided greater overall accuracies (63–64%) and were able to distinguish between seagrass and macroalgae substrates more accurately compared to the results obtained using the other classifications methods.  相似文献   

Marine environmental impact assessment of abalone,Haliotis discus hannai,cage farm in Wan-do,Republic of Korea     

Hyun-Taik Oh  Rae-Hong Jung  Yoon-Sik Cho  Dong-Woon Hwang  Yong-Min Yi 《Ocean Science Journal》2015,50(4):657-667

To assess the marine environmental impacts of abalone, Haliotis discus hannai, cage farms in Wan-do, we monitored the benthic environment on top of the sediment underneath cage farm stations and reference stations. We applied two methods for this assessment. One was the A- and B-investigation of the MOM system (Modeling–On fish farm–Monitoring) developed in Norway. The other was a general environmental monitoring method which is widely used. In this study, we found benthic animals in all samples that belonged to condition 1 which were based on group 1(presence of macrofauna) of the B-investigation method. The values of redox potential (group 2–pH, redox potential) in all samples were above +65 mV belonging to condition 1. Based on sensory results (group 3–gas, color, odor, thickness of deposits), five out of seven experiment samples showed condition 1 while stations 2 and 7 showed condition 2, which have been cultured for 10 years in semi-closed waters. As group 2 takes precedence over group 3, the level of the conditions for B-investigation results consequently showed condition 1 in all stations. We found that pollutants and trace metals in the sediment underneath cage farms were lower than the pollution standard. This led us to conclude that the environmental impacts of the cage farms in this study were not significant.  相似文献   

Long-term comparison of satellite and in-situ sea surface temperatures around the Korean Peninsula     

Kwak  Myeong-Taek  Seo  Gwang-Ho  Cho  Yang-Ki  Kim  Bong-Guk  You  Sung Hyup  Seo  Jang-Won 《Ocean Science Journal》2015,50(1):109-117

Ocean Science Journal - Satellite remotely sensed sea surface temperature (SST) was compared with in-situ SST in the seas around the Korean Peninsula from 1984 to 2013. A matchup dataset between...  相似文献