• Title/Summary/Keyword: Mountain wind

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On Surface Ozone Observed in the Seoul Metropolitan Area during 1989 and 1990 (서울 수도권 지역의 광화학오존에 관한 연구)

  • 정용승;정재섭
    • Journal of Korean Society for Atmospheric Environment
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    • v.7 no.3
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    • pp.169-179
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    • 1991
  • Atmospheric $O_3$ in the biosphere is formed under the favourable meteorological condition, when the primary pollutants, such as $NO_2, HC, CO, CH_4$, etc., react with over constituents. Observed annual average concentrations for 1989 and 1990 were 11.8 and 10.4 ppb, respectively. THe number of days measured ozone over 80 ppb in Seoul were 36 in 1989 and 39 in 1990. In general, monthly maximum values occurred in May and August. In comparison with 1 $\sim$ 2 maxima of $O_3$ distribution in large cities in other countries, it was found that there were 3 $\sim$ 4 maxima in Seoul and its suburbs. Topographic effects, resulted by wind channelling in the Han River valley and by the blocking of air pollutants in the mountain, appeared to produce multiple centres of $O_3$ maxima in Seoul. Surface $O_3$ values were low with decreasing solar radiation, when the cloudiness increased and precipitation occurred. According to 12 cases examined, 2 cases shown here, $O_3$ values exceeding 80 ppb were occurred when the Korean peninsular was under the influence of the backside airflows with high intensity of solar radiation. Occasionally, sea breezes were observed to occur in warm seasons, and the chanelling effect of the Han River valley appeared to increase the general wind (speed) to the east side of Seoul. In this meso-scale situation $O_3$ in downwind is highly correlated with precursors. The sea breeze of 2 $\sim$ 4 m $s^{-1}$ will take 3 $\sim$ 5 hours to transport photochemical precursors for 20 $\sim$ 50 km. In turn the areas of maximum $O_3$ occurrence in Seoul are in the range of meso-scale transport of air pollutants.

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The Features Associated with the Yellow Sand Phenomenon Observed in Korea in Wintertime (겨울철 황상 현상의 특징)

  • 전영신;김지영;부경온;김남욱
    • Journal of Korean Society for Atmospheric Environment
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    • v.16 no.5
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    • pp.487-497
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    • 2000
  • Spring time is a favorable season to be easily observed the Yellow Sand phenomenon in East Asia. In particular most of the phenomenon tend to occur in April. However, Yellow Sand phenomenon was observed from almost the whole country of Korea in winter of 1966, 1977 and 1999. The features of the synoptic weather pattern in the source regions, air stream flow between the source region and Korea, the measurement of TSP concentration, aerosol size distribution, and chemical composition of snow samples associated with Yellow Sand phenomenon were investigated. The result showed the characteristic evolutionary feature of the synoptic system associated with Yellow Sand phenomena, that is, a strong low level wind mobilized the dust within 2 or 3 days before Yellow Sand phenomenon being observed in Seoul. The wind was remarkably intensified in the source region on January 24, 1999 under the strong pressure gradient, A trajectory analysis showed that the Yellow Sand particle could be reached to Korea within 2 days from the source region, Gobi desert, through Loess plateau and Loess deposition region. The TSP concentration at the top of Kwanak mountain during the Yellow Sand phenomenon is abruptly increasing than the monthly mean concentration. The size resolved number concentration of aerosols ranging from 0.3 to 25${\mu}{\textrm}{m}$ was analyzed during Yellow Sand episode. It was evident that aerosols were distinguished by particles in the range of 2-3 ${\mu}{\textrm}{m}$ to result in the abrupt increase in January 1999, After Yellow Sand phenomenon, there was heavy snow in Seoul. By the analysis of snow collected during that time, it was observed that both the Ca(sup)2+ concentration and pH were increased abnormally compared to those in the other winter season.

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Development of Optimal Modeling System for Analyzing Mountain Micrometeorology (산림 미기상 해석을 위한 최적모델 개발)

  • Lee, SukJun;choi, YongHan;Jung, JeaHee;Won, MyoungSoo;Lim, Gyu-Ho
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.17 no.2
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    • pp.165-172
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    • 2015
  • The extreme weather conditions become frequent and severe with global warming. To prevent and cope forest disaster like a forest fire, we need an accurate micrometeorological prediction system for mountainous regions. This study addressed the forest fires occurred at Bonghwa and Gangneung in March, 2013. We constructed and optimized the prediction system that were required to interpret and simulate the forest micrometeorology. At first, we examined WRF physical sensitivity. Subsequently, KMA AWS observation data were assimilated using three-dimensional variation data assimilation method. The effectiveness of the assimilation was examined by using AWS observations enhanced with the Forest Research Institute observations. Finally, The 100 meters spatial resolution wind data were obtained by using the MUKLIMO for the given wind vector from WRF.

WEATHER CHARACTERISTICS AT OBSERVATORY CANDIDATE SITES IN WEST TIBET

  • SASAKI, TOSHIYUKI;NAOE, HIROAKI;UTSUMI, YOSUKE;WANG, HONGSHUAI;YAO, YONGQIANG;YOSHIDA, MICHITOSHI;OHSHIMA, NORIO;MIKAMI, YOSHITAKA;OKADA, NORIO;KOYANO, HISASHI;SEKIGUCHI, KAZUHIRO;ANDO, HIROYASU;LIU, LIYONG;LIU, CAI-PIN;KAIFU, NORIO
    • Publications of The Korean Astronomical Society
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    • v.30 no.2
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    • pp.699-701
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    • 2015
  • The high plateaus in west China may provide suitable sites for astronomical observations with the institute's middle-range telescopes and possibly with larger telescopes. Under China-Japan collaborations for site survey in west China, we have been conducting searches for good sites and monitoring their characteristics over several years. As recent results of our site survey show, sites in west Tibet are revealed with a high possibility of good astronomical observations. Weather characteristics at Gar in Ali, Tibet, show its high clear-sky ratios, especially in winter, comparable to Mauna Kea, Hawaii. But it has some wind problem in winter, where stronger wind speeds, over 20m/sec, occur frequently even though the sky is clear. To find calmer sites, we have conducted numerical simulations for the Ali area using the Japan Meteorological Agency NonHydrostatic Model. We have found another site, named ZoZo Hill, near Gar. We will continue to monitor the Gar site to clarify weather characteristics over the whole year and hopefully start to negotiate for site monitoring at ZoZo Hill this year.

The Analytic and Numerical Solutions of the 1$\frac{1}{2}$-layer and 2$\frac{1}{2}$-layer Models to the Strong Offshore Winds.

  • Lee, Hyong-Sun
    • Journal of the korean society of oceanography
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    • v.31 no.2
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    • pp.75-88
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    • 1996
  • The analytic and numerical solution of the 1$\frac{1}{2}$-layer and 2$\frac{1}{2}$-layer models are derived. The large coastal-sea level drop and the fast westward speed of the anticyclonic gyre due to strong offshore winds using two ocean models are investigated. The models are forced by wind stress fields similar in structure to the intense mountain-pass jets(${\sim}$20 dyne/$cm^{2}$) that appear in the Gulfs of Tehuantepec and Papagayo in the Central America for periods of 3${\sim}$7 days. Analytic and numerical solutions compare favorably with observations, the large sea-level drop (${\sim}$30 cm) at the coast and the fast westward propagation speeds (${\sim}$13 km/day) of the gyres. The coastal sea-level drop is enhanced by several factors: horizontal mixing, enhanced forcing, coastal geometry, and the existence of a second active layer in the 2$\frac{1}{2}$-layer model. Horizontal mixing enhances the sea-level drop because the coastal boundary layer is actually narrower with mixing. The forcing ${\tau}$/h is enhanced near the coast where h is thin. Especially, in analytic solutions to the 2$\frac{1}{2}$-layer model the presence of two baroclinic modes increases the sea-level drop to some degree. Of theses factors the strengthened forcing ${\tau}$/h has the largest effect on the magnitude of the drop, and when all of them are included the resulting maximum drop is -30.0 cm, close to observed values. To investigate the processes that influence the propagation speeds of anticyclonic gyre, several test wind-forced calculations were carried out. Solutions to dynamically simpler versions of the 1$\frac{1}{2}$-layer model show that the speed is increased both by ${\beta}$-induced self-advection and by larger h at the center ofthe gyres. Solutions to the 2$\frac{1}{2}$-layer model indicate that the lower-layer flow field advects the gyre westward and southward, significantly increasing their propagation speed. The Papagayo gyre propagates westward at a speed of 12.8 km/day, close to observed speeds.

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An Analysis of Preference for Forest Therapy Programs Depending on the Emotional Characteristics of Subfertile Women

  • Bu, Seo-Yun;Shin, Chang-Seob
    • Journal of People, Plants, and Environment
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    • v.22 no.5
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    • pp.489-503
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    • 2019
  • This study aimed to analyze the preference of subfertile women for forest therapy programs depending on their emotional characteristics, and to provide basic data for the development of forest therapy programs in order to promote the mental health of subfertile women. Among the surveyed emotional characteristics of subfertile women, the level of emotions including pressure to become pregnant, impatience and frustration were high, while that of emotions including anxiety and fear; depression, hopelessness, helplessness, loneliness and sadness tended to be medium. The level of emotions including shame and guilt tended to be low. The top six forest therapy programs preferred by subfertile women include a deep breath of air /phytoncide, forest bathing/wind bathing/sun bathing, self-esteem recovery program, eating organic foods, low body bathing/foot bathing/hot spring bathing, and breathing/breathing exercises. Subfertile women highly pressured to become pregnant showed significant differences in the preference of the self-esteem recovery program, Domar 's relaxation therapy, NLP therapy, and sleeping in the woods, while women with anxiety and fear showed significant differences in the preference of walking barefoot in forests, mountain walking in silence, listening to water sounds/ hand and foot soak, self-esteem recovery program, NLP therapy, cognitive behavior therapy, aroma therapy, integrated art therapy in forests, forest bathing/wind bathing/sunbathing, a deep breath of air/phytoncide, and observing stars. Women with depression, hopelessness, helplessness, loneliness, and sadness showed significant differences in eating organic foods, self-esteem recovery program, counseling/coaching, and cognitive behavior therapy. The significance of this study was to analyze the preference of subfertile women, as subjects, for forest therapy program. The results of this study are expected to be used as basis data for developing forest therapy programs for subfertile women.

Studies on the Winter Damage of Tree Species by the Cold-dry Wind (임목(林木)의 동기(冬期) 한건풍(寒乾風) 피해(被害)에 관(關)한 연구(硏究))

  • Ma, Sang Kyu
    • Journal of Korean Society of Forest Science
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    • v.40 no.1
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    • pp.25-34
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    • 1978
  • Trial and demonslative reforestations were planted by Korea German Management Project at Ulju district in 1976. The follow results that were investigated at spring time in 1977 showed the different situation of winter damage according to site condition and species. 1. Picea abies was completely dried out in this district and its reason was to be thought as a winter damage by cold-dry wind. 2. Cryptomeria japonica was seriously damaged in comparing with Chamaecyparis obtusa and very seriously damaged on the wind-exposured site. So these species are also unsuitable species like Picea abies in this district. 3. The resistance ranking to winter dry wind damage were Picea, Cryptomeria, Chamaecyparis, ${\times}$ Pinus rigitaeda. Pinus rigida, Larix leptolepis and Alnus hirsuta. The falling leave species like larch in this district during winter were thought in necessary to select as the planting species for almost very little winter damage. 4. ${\times}$ Pinus rigitaeda to be showed as a suitable species in this district were also seriously damaged on exposured site and, Pinus rigida and Larix were also attacked with small damage. The potassium-phosphorus fertilizer dressing plots had a trend to reduce this winter damage until some level. 5. The winter climate can be devided into 10 zone in order to evaluate the right or wrong of suitable on the exotic species. The Yongnam region in eastern side of Sobaik mountain are far drier than the Honam region in western side of Sobaik mountain during winter time. Picea abies, Cryptomeria and Chamaecyparis originated in the high humidity winter climate are to be thought to be more suitable in the Honam region than the Yongnam region. Specially the suitable site of Picea abies should be only found in the region with high humidity and much precipitation except the Yongnam region.

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Responses of an herbaceous community to wild boar (Sus scrofa coreanus Heude) disturbance in a Quercus mongolica forest at Mt. Jeombong, Korea

  • Lyang, Doo-Yong;Lee, Kyu-Song
    • Journal of Ecology and Environment
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    • v.33 no.3
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    • pp.205-216
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    • 2010
  • This research identified a disturbance regime caused by wild boar in a mature Quercus mongolica forest and analyzed the impact of this disturbance on the structure and distribution of herbaceous plants in Mt. Jeombong, Korea. We demonstrate that disturbance by wild boar was most frequent from winter to early spring, but also occurred year round. Areas which were frequently disturbed by wild boar included the mountain ridge, the mild slope on the north face, and sites with high concentration of Erythronium japonicum. The disturbance cycle by the wild boar in this region was estimated at approximately 2.8 years. The wild boar's reduced the community's species diversity and herbaceous coverage, and increased its evenness. This disturbance reduced the coverage of spring ephemeral; Veratrum nigrum var. ussuriense, Symplocarpus niponnicus, Anemone koraiensis and Corydalis turtschaninovii were particularly sensitive. In addition, summer green herbaceous plants such as Astilbe chinensis, Ainsliaea acerifolia, Meehania urticifolia, and Pimpinella brachycarpa were sensitive to the wild boar's. It was found that wild boar ate E. japonicum most selectively of all plants in this investigation area. In conclusion, together with micro-topography, wind, formation of gaps of a forest and rearrangement of litter layer, wild boar's disturbance is an important factor influencing the dynamic changes of an herbaceous community in a mature temperate hardwood forest.

Investigation on Cloud Properties for Fog Modification at Daegwallyeong Mountains (대관령 산악지역 안개조절을 위한 구름특성 조사)

  • Yang, Ha-Young;Oh, Sung-Nam
    • Journal of the Korean Society of Hazard Mitigation
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    • v.5 no.2 s.17
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    • pp.45-56
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    • 2005
  • Cloud meteorological properties over Daegwallyeong mountain area were analyzed for experimental cloud seeding which related to a feasibility study of fog modification. The cloud seeding for fog modification has been refocused to using hygroscopic chemical to dissipate warm fog. In this study, the statistics of fog observations were analyzed and discussed. Fog properties mostly showed the Summer warm fog, the early morning occurrences before to 6 o'clock AM, and 7 to 9 o'clock dissipation in the statistics. In the Spring and Winter season an easterly wind produced cold fog which is good applied with AgI seeding agents. Extrapolation of these results suggests that the suitable seeding method and material for fog modification will be introduced from the actual seeding experiments in the cold and warm fog.

Pungsu Research of Location and Space Layout of King Cheoljong's Mother's Parents' Traditional House

  • Han, Jong-Koo
    • KIEAE Journal
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    • v.16 no.6
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    • pp.21-27
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    • 2016
  • Purpose: The research is focused on the 25th King Cheoljong's mother's parents' traditional House in Ganghwa-do, for finding out how the surrounding natural environment was considered with Pungsu, a traditional ecological architectural science in case of site selection and architectural planning by the relative of royal family of Joseon period. Method: The study is processed as follows. Human Environment of the region where the house is located, is analyzed in chapter 2. Feature of mountain expressed as dragon and four important hills of the house are analyzed in chapter 3, Highly regarded factors for site selection by the scholar of the Realist School of Confucianism such as wind environment, the front and back of the Hyunmubong and building orientation are analyzed in chapter 4. Finally Pungsu applied in architectural space is analyzed in chapter 5. Result: The house considered Pungsu to some extent, but it shows the appearance contrary to the Pungsu in a certain part in order to show authority and proud as the house of the relatives of the King. It can be seen that the degree of application of Pungsu may be different depending on the will of the building owner.