• Title/Summary/Keyword: Tropical Distribution

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Extreme wind speeds from multiple wind hazards excluding tropical cyclones

  • Lombardo, Franklin T.
    • Wind and Structures
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    • v.19 no.5
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    • pp.467-480
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    • 2014
  • The estimation of wind speed values used in codes and standards is an integral part of the wind load evaluation process. In a number of codes and standards, wind speeds outside of tropical cyclone prone regions are estimated using a single probability distribution developed from observed wind speed data, with no distinction made between the types of causal wind hazard (e.g., thunderstorm). Non-tropical cyclone wind hazards (i.e., thunderstorm, non-thunderstorm) have been shown to possess different probability distributions and estimation of non-tropical cyclone wind speeds based on a single probability distribution has been shown to underestimate wind speeds. Current treatment of non-tropical cyclone wind hazards in worldwide codes and standards is touched upon in this work. Meteorological data is available at a considerable number of United States (U.S.) stations that have information on wind speed as well as the type of causal wind hazard. In this paper, probability distributions are fit to distinct storm types (i.e., thunderstorm and non-thunderstorm) and the results of these distributions are compared to fitting a single probability distribution to all data regardless of storm type (i.e., co-mingled). Distributions fitted to data separated by storm type and co-mingled data will also be compared to a derived (i.e., "mixed") probability distribution considering multiple storm types independently. This paper will analyze two extreme value distributions (e.g., Gumbel, generalized Pareto). It is shown that mixed probability distribution, on average, is a more conservative measure for extreme wind speed estimation. Using a mixed distribution is especially conservative in situations where a given wind speed value for either storm type has a similar probability of occurrence, and/or when a less frequent storm type produces the highest overall wind speeds. U.S. areas prone to multiple non-tropical cyclone wind hazards are identified.

Analysis of Tropical Tropospheric Ozone Derivation from Residual-Type Method

  • Na Sun-Mi;Kim Jae-Hwan
    • Korean Journal of Remote Sensing
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    • v.22 no.1
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    • pp.1-10
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    • 2006
  • During the northern burning season, biomass burning is found north of the equator, while satellite estimates from the residual-type method such as the CCD method show higher ozone south of the equator. This discrepancy is called the tropical Atlantic paradox (Thompson et ai., 2000). We use satellite and ground-based measurements to investigate the paradox. When the background tropospheric ozone over the Pacific Ocean from TOMS measurements is subtracted from the latitudinal total ozone distribution (e.g. TOMS-Pacific method), the results show remarkable agreement with the latitudinal stratospheric ozone distribution using the CCD method. The latitudinal tropospheric ozone distribution using the CCD method, with a persistent maximum over the southern tropical Atlantic, is also seen in the latitudinal tropospheric ozone distribution using the TOMS-Pacific method. It suggests that the complicated CCD method can be replaced by the simple TOMS-Pacific method. However, the tropical Atlantic paradox exists in the results of both the CCD and TOMS-Pacific methods during the northern buming season. In order to investigate this paradox, we compare the latitudinal ozone distributions using the CCD and TOMS-Pacific methods by using the SAGE measurements (e.g. TOMS-SAGE method) and the SHADOZ ozonesoundings (e.g. TOMS-Sonde method) assuming zonally invariant stratospheric ozone, which is the same assumption as of the CCD method. During the northern burning season, the latitudinal distributions in the tropospheric ozone derived from the TOMS-SAGE and TOMS-Sonde methods show higher tropospheric ozone over the northern tropical Atlantic than the southern Atlantic due to a stronger gradient in stratospheric ozone relative to that from the CCD and TOMS-Pacific methods. This indicates that the latitudinal tropospheric ozone distribution can be changed depending on the data that is used to determine the latitudinal stratospheric ozone distribution. Therefore, there is a possibility that the north-south gradient in stratospheric ozone over the Atlantic can be a solution of the paradox.

Studies on the Infection Rate and Distribution Pattern of Metacercaria of Clonorchis sinensis in Pseudorasbora Parva (참붕어내 간흡충 피낭유충의 감염률 및 분포양상에 관한 연구)

  • Kim, Ki-Hong;Yie, Jae-Hyun;Joo, Kyoung-Hwan;Lee, Joon-Sang;Rim, Han-Jong
    • Journal of agricultural medicine and community health
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    • v.14 no.1
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    • pp.44-53
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    • 1989
  • The distribution pattern of Clonorchis sinensis metacercaria in Pseudorasvora parva population and correlation between P. parva and metacercaria of C. sinensis were studied. The surveved areas were Chomanpo and Bulamdong, Kim-Hae Gun which were endemic area of clonorchiasis, and wansa, Sa-Chon Gun, Souh Kyong-Sang Do. The results are as follows: 1) The areas of Chornanpo and Wansa showed high infectivity in 99-100% of infection rate and 282-308 of average infection number per-fish. But the area of Bulamdong showed relatively. low infectivity in 95.8% of infection rate and 44 of average infection number. 2) The distribution patterns of C. sinensis metacercaria in P. parva population which were collected in Chomanpo and Wansa were shown Poisson distribution and the distribution pattern in Bulamdong showed mid-pattern of shifting over from Poisson distribution to Negative binomial distribution. 3) The correlation between P. parva length and average number of C. sinensis metacercaria in the present studied areas represented as direct proportion relationship.

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Interpretation of tropical tropospheric ozone derivation from TOMS

  • Na Suomi;Kim Jae-Hwan
    • Proceedings of the KSRS Conference
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    • 2005.10a
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    • pp.366-369
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    • 2005
  • A persistent maximum over the southern tropical Atlantic in the latitudinal tropospheric ozone distribution from the CCD method is seen in the latitudinal tropospheric ozone distribution from the TOMS-Pacific method. The tropical Atlantic paradox exists in the results of both the CCD and TOMS-Pacific methods. During the northern burning season, the latitudinal distributions in the tropospheric ozone derived from the TOMS-SAGE and TOMS-Sonde methods show higher tropospheric ozone over the northern tropical Atlantic than the southern Atlantic due to a stronger gradient in stratospheric ozone relative to that from the CCD and TOMS-Pacific methods.

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Mapping Distribution of Dipterocarpus in East Kalimantan, Indonesia

  • Aoyagi, Kota;Tsuyuki, Satoshi;Phua, Mui-How;Teo, Stephen
    • Journal of Forest and Environmental Science
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    • v.28 no.3
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    • pp.179-184
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    • 2012
  • Dipterocarps (Dipterocarpaceae) is a dominant tree family of tropical rainforest in Southeast Asia. Dipterocarps have been exploited for its timber and disappearing fast in East Kalimantan. In this study, we predicted the distribution of dipterocarpus, one of the main dipterocarps genera, by evaluating its habitat suitability using logistic regression analysis with specimen collection points and environmental factors from GIS data. Current distribution of dipterocarpus was generated by combining the habitat suitability classes with an updated forest cover map. Rainfall, soil type, followed by elevation was the main factors that influence the distribution of dipterocarpus in East Kalimantan. Dipterocarpus can be found in a quarter of the current forest cover, which is highly suitable as habitat of Dipterocarpus.

A Study on the Thermal Characteristics of Midsummer in Daegu Metropolitan Area

  • Park, Myung-Hee;Lee, Joon-Soo;Ahn, Won-Shik;Kim, Hae-Dong;Oh, Sung-Nam
    • Journal of Environmental Science International
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    • v.22 no.6
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    • pp.667-677
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    • 2013
  • This study aims to examine the actual status of the urban heat island in Daegu by analyzing the data of 17 automatic weather stations installed in the Daegu area. And the results can be summarized as follows: First, regarding the temperature distribution in Daegu by summer time zones, for the 31 days(August 1st till 31st), 18 days showed daily maximum temperature over $30^{\circ}C$, and 11 days indicated daily minimum temperature over $25^{\circ}C$. The day that showed the highest daily maximum temperature was August 5th, which indicated $36^{\circ}C$. Second, about the spatial distribution of time ratio exceeding $30^{\circ}C$ and $25^{\circ}C$, the area with the highest time ratio exceeding $30^{\circ}C$ is mostly the downtown(central area), eastern area, and northern area. Meanwhile, regarding the time ratio exceeding $25^{\circ}C$, the downtown area centering around the central area were high as over 70%, and the outskirts were low as under 65%. Third, considering the temporal distribution of daily maximum temperature and daily minimum temperature, daily maximum temperature was shown around 14:00 to 15:00 while the daily minimum temperature was indicated around 17:00 to 18:00. Daily maximum and minimum temperature were appeared at northeast and downtown, respectively. Fourth, regarding the spatial distribution of tropical days and tropical night days, tropical days showed 77% and tropical night days indicated 42% before and after the 24th and also the 13th each. Tropical days were occurred up to 24 days at northeastern area. And the southwestern area of Daegu showed under 22 days. The downtown showed the 14 days of the tropical night. However, the outskirts indicated relatively few days as under 10 days. Fifth, about the spatial distribution of the average daily temperature range (the difference between the highest temperature and lowest temperature), the central area, the central part of the city, showed the smallest as $7.2^{\circ}C$, and as it was closer to the northern area, it became larger, so in the eastern and northern area, it was over $8.8^{\circ}C$ or so.

Geographical Distribution and Epidemiologic Factors of Chigger Mites on Apodemus agrarius during Autumn in Korea

  • Lee, In Yong;Lim, Jae-Won;Seo, Jang Hoon;Kim, Heung Chul;Lee, Ku Jae;Yong, Tai-Soon;Lee, Won-Ja;Yu, Jae-Ran;Sim, Seobo
    • Parasites, Hosts and Diseases
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    • v.59 no.5
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    • pp.473-479
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    • 2021
  • A nationwide survey of chigger mites causing scrub typhus and an investigation of epidemiologic factors for chigger mites was conducted at 16 localities in 8 provinces in Korea during autumn 2009, 2012, and 2013. A total of 233 Apodemus agrarius were captured, and all were infested with chigger mites. The chigger index was highest in Chungcheongbuk-do in 2009 (358.3) and 2012 (290.1) and Chungcheongnam-do in 2013 (294.4). The predominant chigger mite species was Leptotrombidium pallidum in the northern and central parts and L. scutellare in the southern and western parts, Korea. L. pallidum was not found in Jellanam-do and Gyeongsangnam-do and the distribution of L. scutellare had been expanded in the northern parts of Korea. The chigger index of L. pallidum was positively correlated with temperature and negatively correlated with humidity. The incidence of scrub typhus is dependent on L. scutellare index. These findings could be helpful to monitor the distribution of chigger mites and to develop a preventive measures for scrub typhus in Korea.

On Extratropical Transition of Tropical Cyclone MINDULLE (태풍 민들레의 온대저기압화 과정에 대하여)

  • Kwon, H. Joe;Kim, Ji-Young
    • Atmosphere
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    • v.15 no.1
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    • pp.17-25
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    • 2005
  • A significant number of tropical cyclones move into the midlatitudes and go through transformation procedure into extratropical cyclones. This process is generally referred to as extratropical transition of the tropical cyclone. In this study, MIDULLE(0407) case is selected. A thorough analysis is made using the GDAPS analysis data and MTM (Moving-nest Typhoon Model) model output. It is found that during the extratropical transition an important dynamics in the environmetal flow field occurs in which colder, drier (warm, moist) air penetrates in the western (eastern) quadrant of MINDULLE's outer circulation, which in turn initiates an asymmetry in the distribution of wind and temperature of the tropical cyclone. Simulated MTM result also reveals similar properties as in GDAPS analysis data. MTM result shows the gradual transition to the asymmetric distribution of wind and thickness as the extratropical transition proceeds. It is also found that the warm core disappears during the extratropical transition stage. Also, vortex tube is shown tilting towards the west during the transition. And the precipitation expands poleward of the center and the maximum precipitation appears to the left of MINDULLE which is consistent to the observations.

Subtype Distribution of Blastocystis in Thai-Myanmar Border, Thailand

  • Popruk, Supaluk;Udonsom, Ruenruetai;Koompapong, Khuanchai;Mahittikorn, Aongart;Kusolsuk, Teera;Ruangsittichai, Jiraporn;Palasuwan, Attakorn
    • Parasites, Hosts and Diseases
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    • v.53 no.1
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    • pp.13-19
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    • 2015
  • Blastocystis sp. is a common zoonotic intestinal protozoa which has been classified into 17 subtypes (STs). A cross-sectional study was conducted to determine the prevalence and subtype distribution of Blastocystis in villagers living on the Thai-Myanmar border, where the risk of parasitic infection is high. A total of 207 stool samples were collected and DNA was extracted. PCR and sequencing using primers targeting small-subunit ribosomal RNA (SSU rRNA) gene were performed. The prevalence of Blastocystis infection was 37.2% (77/207). ST3 (19.8%; 41/207) was the predominant subtype, followed by ST1 (11.6%; 24/207), ST2 (5.3%; 11/207), and ST4 (0.5%; 1/207). A phylogenetic tree was reconstructed using the maximum likelihood (ML) method based on the Hasegawa-Kishino-Yano + G + I model. The percentage of bootstrapped trees in which the associated taxa clustered together was relatively high. Some sequences of Blastocystis positive samples (TK18, 39, 46, 71, and 90) were closely related to animals (pig and cattle) indicating zoonotic risks. Therefore, proper health education in parasitic prevention for the villagers should be promoted to improve their personal hygiene. Further longitudinal studies are required to monitor the prevalence of parasitic infections after providing health education and to investigate Blastocystis ST in animals living in these villages.