• Fisheries and Aquatic Sciences
• /
• v.26 no.11
• /
• pp.639-648
• /
• 2023

The sea surface temperature (SST) and ocean heat content in the Korea Waters are gradually increased. Especially the increasing trend of annual mean SST in the Korea Water is higher about 2.6 times than the global mean during past 55 years (1968-2022). Before 2010s, the increasing trend of SST was led by winter season in the Korea Waters. However, this pattern was clearly changed after 2010s. The increasing trend of SST during summer is higher about 3.9 times than during winter after 2010s. We examine the long-term variations of several ocean and climate factors to understand the reasons for the long-term pattern changes of SST between summer and winter in recent. Tsushima warm current was significantly strengthened in summer compare to winter during past 33 years (1986-2018). The long-term patterns of Siberian High and East Asian Winter Monsoon were definitely changed before and after early- or mid-2000s. The intensities of those two climate factors was changed to the increasing trend or weakened decreasing trend from the distinctive decreasing trend. In addition, the extreme weather condition like the heatwave days and cold spell days in the Korea significantly increased since mid- or late-2000s. From these results, we can consider that the occurrences of frequent and intensified marine heatwaves during summer and marine cold spells during winter in the Korea Waters might be related with the long-term pattern change of SST, which should be caused by the long-term change of climate factors and advection heat, in a few decade.

• International Journal of Industrial Entomology and Biomaterials
• /
• v.20 no.2
• /
• pp.45-59
• /
• 2010

It is well established fact that under tropical condition, unlike polyvoltines, bivoltines are more vulnerable to various stresses i.e. hot climatic conditions of tropics, poor leaf quality and improper management during summer which are not conducive for bivoltine rearing. Therefore, attempt has been made in this study to develop promising bivoltine breeds tolerant to high temperature and high humidity conditions of the tropics. In the present study, by utilizing temperature tolerant breeds six breeding lines were made and at every generation the 5th instar larvae were exposed to high temperature and high humidity and the survived ones were back crossed with the breeds moderately tolerant to diseases were made to improve the quantitative traits. From F6 generations, alternate rearing in normal temperature and high temperature were conducted. At the end of F12 generation, it was possible to isolate three dumbbell breeds viz., HH8, HH10 and HH12 with improvement in quantitative traits. The methodologies followed for the development are discussed.

• Korean journal of food and cookery science
• /
• v.1 no.1
• /
• pp.45-52
• /
• 1985

For the knowledge of characteristics of the cooking condition of different varieties of patato, 4 kinds of spring cultivated (Namjak, Sumi, Daiji, and Dowon) and 4 kinds of summer cultivated (Namjak, Sumi, Bintze, Radosa) were selected. The quality of potato starch, the viscosity, and the palatability of each potato soup were measured respectively. The amylograph characteristics of potato starch showed great difference not only between the spring and the summer cultivated, but also among the various kinds of potatoes. The amylograph of the spring cultivated didn't show the breakdown and the set back largely but showed the gradual increase of the viscosity and the high gelatinization temperature. Bintze and Namjak among the summer cultivated were gelatinized easily and in low temperature, and showed the beakdown. The low gelati-nization temperature of the summer cultivated infers that the starch granules of the summer cultivated are less compact then those of the spring ones. Sumi, Daiji and Dowon of the spring products showed the soup was falling down, but the viscosity of Namjak and 4 summer cultivated increased only slightly. The taste of soup is different according to the consistency of soup, and so the taste of soup of Daiji, Dowon, and Sumi of the spring cultivated products was good at the consistency 19.8％ and 23.5％. All the summer cultivated products and Namjak of the spring cultivated were good at 27％.

• Journal of Environmental Science International
• /
• v.25 no.2
• /
• pp.259-265
• /
• 2016

We analyzed diurnal variations in the surface air temperature using the high density urban climate observation network of Daegu in summer, 2013. We compared the time elements, which are characterized by the diurnal variation of surface air temperature. The warming and cooling rates in rural areas are faster than in urban areas. It is mainly due to the difference of surface heat capacity. In addition, local wind circulation also affects the discrepancy of thermal spatiotemporal distribution in Daegu. Namely, the valley and mountain breezes affect diurnal variation of horizontal distribution of air temperature. During daytimes, the air(valley breeze) flows up from urban located at lowlands to higher altitudes of rural areas. The temperature of valley breeze rises gradually as it flows from lowland to upland. Hence the difference of air temperature decreases between urban and rural areas. At nighttime, the mountains cool more rapidly than do low-lying areas, so the air(mountain breeze) becomes denser and sinks toward the valleys(lowlands). As the result, the air temperature becomes lower in rural areas than in urban areas.

• Journal of Microbiology and Biotechnology
• /
• v.30 no.7
• /
• pp.1072-1081
• /
• 2020

Screening suitable strains with high temperature adaptability is of great importance for reducing the cost of temperature control in microalgae cultivation, especially in summer. To obtain high temperature-tolerant diatoms, water samples were collected in summer from 7 different regions of China across the Northeast, North and East. A total of 731 water samples was collected and from them 131 diatom strains were isolated and identified based on the 18S rRNA sequences. Forty-nine strains out of the 131 diatoms could survive at 30℃, and 6 strains with relatively high biomass and lipid content at high temperature were selected and were found to be able to grow at 35℃. Cyclotella sp. HB162 had the highest dry biomass of 0.46 g/l and relatively high triacylglycerol (TAG) content of 237.4 mg/g dry biomass. The highest TAG content of 246.4 mg/g dry biomass was obtained in Fistulifera sp. HB236, while Nitzschia palea HB170 had high dry biomass (0.33 g/l) but relatively low TAG content (105.9 mg/g dry biomass). N. palea HB170 and Fistulifera sp. HB236 presented relatively stable growth rates and lipid yields under fluctuating temperatures ranging from 28 to 35℃, while Cyclotella HB162 maintained high lipid yield at temperatures below 25℃. The percentage of saturated fatty acids and monounsaturated fatty acids in all the 6 strains was 84-91% in total lipids and 90-94% in TAGs, which makes them the ideal feedstock for biodiesel.

• Journal of Bio-Environment Control
• /
• v.15 no.4
• /
• pp.340-345
• /
• 2006

A potato (Solanum tuberosum L. cv. Superior) cultivar was grown in aeroponic cultivation system to investigate the effect of root zone cooling in summer. Based on their nutrient uptake, growth responses, and tuberization, the possibilities for potato seed production were determined. Although shoot growth and early tuberization increased in the conventional non-cooling root zone system (root zone temperature of $25\pm2^{\circ}C$), stolen growth, photosynthesis, transpiration rate and number of tubers produced were higher in the cooling root zone system ($20\pm2^{\circ}C$) than in the non-cooling system. Increasing root zone temperature above $25^{\circ}C$ stimulated absorption of K more than T-N, P, Ca, Fe and Mn. On the other hand, root zone temperatures in the range of $20^{\circ}C$ to $25^{\circ}C$ did not affect Mg contents. The lower uptake and supply to leaves of T-N, Fe and Mn at the high root zone temperature promoted early tuberization and advanced haulm senescence. The results stress the importance of keeping root zone temperature to as low as below 20, particularly in summer under temperate Bone.

• Journal of the Korean Solar Energy Society
• /
• v.38 no.5
• /
• pp.1-9
• /
• 2018

The purpose of this study is to analyze the urban heat island ultimately by analyzing long-wave radiation which is the dominant factor of night minimum temperature formation. We observed during two months with four elements which is long and short wave radiation, temperature, relative humidity. And we analyzed the correlation between the four factors of long-wave radiation, temperature, cloud form, and cloud amount during the summer two months on the night time. Observations were carried out at two sites in Daegu and nearby. The results are as follows. (1) Long-wave radiation change per $1^{\circ}C$ in summer was larger than winter. (2) Long-wave radiation amount is affected by temperature change when the amount of cloud is small. (3) Low cloud was analyzed to have more influence on long-wave radiation than high cloud.

• Journal of the Korean Society for Marine Environment & Energy
• /
• v.19 no.4
• /
• pp.274-285
• /
• 2016

In order to elucidate the spatiotemporal variations of marine environmental parameters, we collected seawater samples in the middle east coast of Korea in 2013-2014. A high temperature and low salinity were distinctively observed in the summer and a low temperature and high salinity pattern in the winter. The temperature of the bottom water was in the range of $2^{\circ}C$ to $7^{\circ}C$, with the temperature being relatively high in the winter, while the salinity was measured to be around 34, with no large differences across the seasons. The dissolved oxygen concentrations were in the range of $7mg\;L^{-1}$ to $12mg\;L^{-1}$, and it was relatively high in May compared to other seasons. The seawater temperature and dissolved oxygen concentration at the surface layer showed a significant negative correlation in the autumn and winter seasons, based on which it is seemed that water temperature is the main factor controlling the amount of dissolved oxygen in the autumn and winter seasons. The dissolved inorganic nitrogen (DIN) and silicate (DSi) increased 11- and 7-fold, respectively, in the winter compared to the summer. The DIN to DIP (dissolved inorganic phosphorus) ratio for the surface seawater was approximately 16, but it was relatively low in the spring season. On the other hand, the DIN to DIP ratio was relatively high in the summer. Based on this, it is seemed that nitrogen and phosphorus were the growth-limiting nutrients for phytoplankton in the spring and summer, respectively. Water quality was I (excellent) ~III (medium) level at the most stations except for some stations (level IV) during the autumn season, having low dissolved oxygen saturations.

• Asian-Australasian Journal of Animal Sciences
• /
• v.9 no.6
• /
• pp.705-709
• /
• 1996

A simplified dilutor for cock spermatozoa at ambient temperature was achieved by adjusting the 5% concentration of fructose in isotonic saline. Motility of cock spermatozoa was arrested completely for maximum 6 hrs without affection the survivability of spermatozoa by employing this sugar. To study the effect of high concentration of fructose on fertility, sperm were inseminated with or without fructose at different hrs. Fructose from semen samples was removed by centrifugation. High fertility obtained in the hens inseminated with fructose free sperm (washed). In addition, washed sperm maintained the 85.00% fertility for 6 hrs in winter season ($17-21^{\circ}C$) and 82.67% fertility for 3 hrs in summer season ($31-35^{\circ}C$). Whereas control groups showed 47.33 and 25.33% fertility in winter and summer season respectively. No significant difference was found in percent motility and live counts between the control and washed experimental groups during winter season. However, these measures differed significantly in summer. Washing of cock spermatozoa more than once, high speed centrifugation and more duration for centrifugation proved harmful to fertility. It may be concluded that fructose (5%) can be used as a motility or metabolic inhibitor of spermatozoa for short-term storage of cock semen at ambient temperatures.

• Asian-Australasian Journal of Animal Sciences
• /
• v.28 no.3
• /
• pp.442-450
• /
• 2015

Climate temperature affects animal production. This study was conducted to evaluate whether climatic conditions affect beef carcass characteristics of Korean cattle steers. The monthly carcass characteristics of Korean cattle steers (n = 2,182,415) for 8 yr (2006 through 2013) were collected from the Korean Institute for Animal Products Quality Evaluation. Daily climate temperature (CT) and relative humidity (RH) data were collected from the Korean Meteorological Administration. Weather conditions in South Korea during summer were hot and humid, with a maximum temperature of $28.4^{\circ}C$ and a maximum RH of 91.4%. The temperature-humidity index (THI), calculated based on CT and RH, ranges from 73 to 80 during summer. Winter in South Korea was cold, with a minimum temperature of $-4.0^{\circ}C$ and a wind-chill temperature of $-6.2^{\circ}C$. Both marbling score (MS) and quality grade (QG) of Korean cattle steer carcasses were generally best (p<0.05) in autumn and worst in spring. A correlation analysis showed that MS and QG frequencies were not associated (p>0.05) with CT. Yield grade (YG) of Korean cattle steer carcasses was lowest (p<0.05) in winter (November to January) and highest in spring and summer (May to September). A correlation analysis revealed that YG frequency was strongly correlated ($r{\geq}0.71$; p<0.01) with CT and THI values. The rib eye area, a positive YG parameter, was not associated with CT. Backfat thickness (BT), a negative YG factor, was highest in winter (November and December). The BT was strongly negatively correlated ($r{\leq}-0.74$; p<0.01) with CTs. Therefore, the poor YG during winter is likely due in part to the high BT. In conclusion, YG in Korean cattle steer carcasses was worst in winter. QGs were not associated with winter or summer climatic conditions.