• Title/Summary/Keyword: thermal growing season length

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Change of Climatic Growing Season in Korea (한반도의 기후학적 식물생육기간의 변화)

  • Jung, Myung-Pyo;Shim, Kyo-Moon;Kim, Yongseok;Choi, In-Tae
    • Korean Journal of Environmental Agriculture
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    • v.34 no.3
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    • pp.192-195
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    • 2015
  • BACKGROUND: The growing season (GS) has been understood as a useful indicator for climate change due to high relationship with increasing temperature. Hear this study was conducted to examine changes in the thermal GS over South Korea from 1970 to 2013 based on daily mean air temperature for assessing the temporal and spatial variability in GS. METHODS AND RESULTS: Three GS parameters (starting date, ending date, and length) were determined at 19 stations throughout South Korea. The results show that the GS has been extended by 4.2 days/decade between 1970 and 2013 on average. The growing season start (GSS) has been advanced by 2.7 days/decade and the growing season end (GSE) has been delayed by 1.4 day/decade. Spatial variation in the GS parameters in Korea are shown. The GS parameters, especially GSS, of southeastern part of Korea have been changed more than that of northwestern part of Korea. The extension of GS may be more influenced on earlier onset in spring rather than later GSE. CONCLUSION: Under climate change scenarios, the GS will be more extended due to delayed GSE as well as advanced GSS. And These are more notable in the northeastern part of Korea.

Misgurnus Anguillicaudatus Growing in Winter Season by Solar Thermal Heating (태양에너지를 이용한 겨울철 미꾸라지 성장에 관한 연구)

  • Jung, Hyun-Chai;Sun, Kyung-Ho;Jo, Jae-Sun;Nam, Sang-Yul
    • Solar Energy
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    • v.11 no.3
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    • pp.31-36
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    • 1991
  • We have maintained the optimum water temperature for misgumus in winter season by solar thermal heating energy. The optimum temperatures for the misgumus anguillicaudatus were experimentally estimated, i.e. for the total length $4{\sim}5cm$ and body weight $1{\sim}2g$, the optimum temperature was $18{\sim}20^{\circ}C$. For the total length $5{\sim}7cm$, body weight $2{\sim}3g$ was $20{\sim}22^{\circ}C$ and for the total length $7{\sim}9cm$, body weight $4{\sim}6g$ was $22{\sim}24^{\circ}C$. The smaller misgumas($1{\sim}3g$) grows relatively slow but the bigger one($4{\sim}8g$) grows relatively fast and total average body weight increment was about $30{\sim}50g$ per month.

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Trends on Temperature and Precipitation Extreme Events in Korea (한국의 극한 기온 및 강수 사상의 변화 경향에 관한 연구)

  • Choi, Young-Eun
    • Journal of the Korean Geographical Society
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    • v.39 no.5 s.104
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    • pp.711-721
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    • 2004
  • The aim of this study is to clarify whether frequency and/or severity of extreme climate events have changed significantly in Korea during recent years. Using the best available daily data, spatial and temporal aspects of ten climate change indicators are investigated on an annual and seasonal basis for the periods of 1954-1999. A systematic increase in the $90^{th}$ percentile of daily minimum temperatures at most of the analyzed areas has been observed. This increase is accompanied by a similar reduction in the number of frost days and a significant lengthening of the thermal growing season. Although the intra-annual extreme temperature range is based on only two observations, it provides a very robust and significant measure of declining extreme temperature variability. The five precipitation-related indicators show no distinct changing patterns for spatial and temporal distribution except for the regional series of maximum consecutive dry days. Interestingly, the regional series of consecutive dry days have increased significantly while the daily rainfall intensity index and the fraction of annual total precipitation due to events exceeding the $95^{th}$ percentile for 1901-1990 normals have insignificantly increased.

Effects of Mulching Practices on Soil Temperature and Soil Physical Properties (Mulching방법별(方法別) 토양온도(土壤溫度)와 토양물리성(土壤物理性) 변화(變化))

  • Jung, Pil-Kyun;Lee, Kwang-Seek;Ko, Mun-Hwan;Um, Ki-Tae;Ha, Ho-Seong
    • Korean Journal of Soil Science and Fertilizer
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    • v.18 no.4
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    • pp.366-372
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    • 1985
  • Soil temperatures and soil physical properties were investigated in order to better understand the effects of mulchings in the red pepper field. The red pepper was planted in the lysimeter installed at the Yesan sandy loam with 20% slope and 10cm slope length. The results were summarized as follows: 1. Average soil temperatures at 10cm and 20cm depth in vinyl mulching plots were $1.6^{\circ}C$ and $1.1^{\circ}C$ higher than those of control, respectively. However, the average soil temperatures in rice straw mulching plots were relatively lower than those of control during the growing season. 2. The greatest diurnal fluctuation of soil temperature was found at the vinyl mulching plots and it was decreased with increasing soil depth. 3. The calculated thermal diffusivities were 0.011, 0.009 and $0.007cm^2/sec$ for the vinyl mulching, control and straw mulching, respectively. 4. Soil losses were 103kg/10a for the vinyl mulching and 36kg/10a for the straw mulching which were nearly negligible as compared to the control. 5. Soil physical properties such as bulk density, hardness and water content were significantly improved by the vinyl and straw mulchings.

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