• Journal of Bio-Environment Control
• /
• v.27 no.1
• /
• pp.80-85
• /
• 2018

This study was carried out to clarify the effect of CHO-CO and PO film on air temperature in greenhouse and Korean melon fruit characteristics and yield. On January 8 in 2017, the maximum, minimum and average air temperature in greenhouse covered with CHO-CO film were $38.9^{\circ}C$, $13.4^{\circ}C$ and $20.1^{\circ}C$, respectively. At the same date, the maximum, minimum and average air temperature in greenhouse covered with PO film were $40.0^{\circ}C$, $14.9^{\circ}C$ and $20.3^{\circ}C$, respectively. On August 7 in 2017, the maximum, minimum and average air temperature in greenhouse covered with CHO-CO film were $47.2^{\circ}C$, $23.1^{\circ}C$ and $32.4^{\circ}C$, respectively, and the maximum, minimum and average air temperature in greenhouse covered with PO film were $50.3^{\circ}C$, $23.6^{\circ}C$ and $34.0^{\circ}C$, respectively. The results of investigation of qualities and yields of Korean melons from May 26 to August 15 in 2017 were as follows. The fruit weight of Korean melon harvested in CHO-CO film's greenhouse was 371.6g which was 22.2g less than that of PO film greenhouse. The sugar contents of Korean melon harvested in CHO-CO film greenhouse was $14.5^{\circ}brix$ which was $1.4^{\circ}brix$ greater than that of the fruits harvested in PO film greenhouse. The chromaticity (a-value) of fruit skin of Korean melon harvested in CHO-CO film greenhouse was 12.3 which was 1.5 greater than that of the fruits harvested in PO film greenhouse. The marketable yield rate of Korean melon harvested in CHO-CO film's greenhouse was 89.4% which was 8.0% higher than the fruits harvested in PO film greenhouse. The yield of Korean melon harvested in CHO-CO film's greenhouse was 2694kg per 10 a which was 26% more than that harvested in PO film greenhouse. In conclusion, the CHO-CO film could be effective to produce Korean melon in high temperature season.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.31 no.1
• /
• pp.84-90
• /
• 1986

An experiment was conducted to know the effects of planting dates (March 5, 15, and 25 and April 4) and transparent polyethylene (P.E.) film treatments(tunnel, tunnel slit, and mulch) on air and soil temperatures and growth and yield of a sweet corn variety, Great Bell. Maximum air and soil temperatures and minimum air and soil temperatures were greater at tunnel>tunnel slit>mulch in that order. Differences in maximum air and soil temperatures among the P.E. film treatments were much greater than those in minimum air and soil temperatures. However, when film was opened due to high air temperature over 40$^{\circ}C$ in the tunnel, air temperature was similar but soil temperature was lower com-pared to mulch. High temperature stress could be avoided in tunnel slit without opening film by increase in the number of slits. Cold damage of corn seedlings was avoided by tunnel and reduced by tunnel slit, and frost-damaged seedlings under the mulch were recovered in few days. The number of days from planting to silking was reduced as planting date delayed. At early plantings, tunnel enhanced early growth and silking, but it delayed at late plantings because tunnel was opened during the most of day time due to high temperature. Black streaked dwarf virus(BSDV) disease was more severe at early plantings and it was reduced in tunnel slit at late plantings because plants were grown under the film at the time of infection. The number of marketable ears was similar among all treatments except mulch at March 5 planting where BSDV was severely infected. Gross income was high in tunnel and tunnel slit at March 25 planting which had more larger marketbale ears and tunnel and tunnel slit at March 5 planting which had higher market price.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.39 no.5
• /
• pp.444-452
• /
• 1994

Early critical seeding date based on the appearance characteristic analysis was examined to obtain the fundamental data for the safty of dry-seeded rice under the local climatic conditions. The effective standard temperature at the early critical seeding date was applied for determination of the appearance date at the daily mean air temperature (DMAT) 13$^{\circ}C$. The first appearance date at DMAT 13$^{\circ}C$ for 20 years('73~'92) was found to be 30~40 days (standard deviation:8 days) in year fluctuation. Mean appearance date of it, also, was 10 days earlier than that of its 80% chance. The first appearance date at DMAT 13$^{\circ}C$ was April 26 for Suwon, April 14 for Kwangju, April 13 for Taegu and April 21 for Kangnung, and found to be 13 days in regional change between Suwon and Taegu. Thus agroclimatic characteristics based on the latitude and altitude would be analyzed systematically.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.43 no.5
• /
• pp.55-64
• /
• 2015

In this study, negative air ions, which can increase comfort and positively influence human health, was set as an evaluative factor for school forests. The characteristics, location and microclimate of school forests were examined to determine an effective school forest model for maximum negative air ion generation. It also aimed to provide basic data for the development of urban green fields. The negative air ion concentrations were different according to the green types. The order from the highest to the lowest was: single-layer structure($934ea/cm^3$) > multi-layer structure($794ea/cm^3$) > grass($553ea/cm^3$) > bare ground($529ea/cm^3$). As for the correlation with microclimate, negative air ion concentration was negatively correlated with temperature. The negative air ion concentration was significantly different according to planting type. The negative air ion concentration was higher at single-layer structure sites than at multi-layer structure sites, which appears to indicate that the temperature is higher when the vegetation structure was single-layer compared to multi-layer. Wind speed was higher at the single-layer planted site than at the multi-layer planted site. The vegetation wind shielding effect was lower at single-layer planted sites than at multi-layer planted sites. The single-layer planted site provided more favorable conditions for the generation and dispersion of negative air ions.

• Journal of Bio-Environment Control
• /
• v.12 no.4
• /
• pp.195-199
• /
• 2003

In polyethylene film house treated with surfactants(SF316+FB0800), waterdrops attached on film surface were absorbed to filter paper of 9 cm in diameter and measured 1.21 mL in control, 0.15 mL in 1% and 0.07 mL in 2% on December 10 at 10:00, 2002. However, there was no clear difference between surfactant concentrations 1% and 2%, And the most waterdrop was measured at 10:00 in daytime. As the air temperature was higher in greenhouse, waterdrop was sweled. So, the least waterdrop was measured at 14:00. In greenhouse covered with surfactants concentrated 1% and 2%, transmittances of solar radiation were 9.3% and 12.9% higher than control, respectively. In air temperature and relative humidity, there were no significant difference in all greenhouse. in forenoon, the air temperature and relative surfactant treated film greenhouse tended 1~2$^{\circ}C$ warmer than that of control. However, sil temperatures of surfactant treated film greenhouse tended 3~4$^{\circ}C$ warmer than that of control. During winter, the lettuce growth in surfactant treated film greenhouse was faster than that of control. However, there was no difference between surfactant concentrations of 1% and 2%.

• Korean Journal of Remote Sensing
• /
• v.30 no.5
• /
• pp.571-586
• /
• 2014

Moderate Resolution Imaging Spectroradiometer (MODIS) provides air temperature (Tair) and dew point temperature (Tdew) profiles at a spatial resolution of 5 km. New Collection 6 (C006) MODIS07_L2 atmospheric profile product has been produced since 2012. The Collection 6 algorithm has several modifications from the previous Collection 5 (C005) algorithm. This study evaluated reliabilities of two alternative datasets of surface-level Tair and Tdew derived from C005 and C006 Aqua MODIS07_L2 (MYD07_L2) products using ground measured temperatures from 77 National Weather Stations (NWS). Saturated and actual vapor pressures were calculated using MYD07_L2 Tair and Tdew. The C006 Tair showed lower mean error (ME, -0.76 K) and root mean square error (RMSE, 3.34 K) than the C005 Tair (ME = -1.89 K, RMSE = 4.06 K). In contrasts, ME and RMSE of C006 Tdew were higher than those (ME = -0.39 K, RMSE = 5.65 K) of C005 product. Application of ambient lapse rate for Tair showed appreciable improvements of estimation accuracy for both of C005 and C006, though this modification slightly increased errors in C006 Tdew. The C006 products provided better estimation of vapor pressure datasets than the C005-derived vapor pressure. Our results indicate that, except for Tdew, C006 MYD07_L2 product showed better reliability for the region of South Korea than the C005 products.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.18 no.3
• /
• pp.135-142
• /
• 2016

The aim of this study was to confirm the improvement of efficiency for temperature estimation at 0600 and 1500 LST by using a simple method for estimating temperature lapse rate modulated by the amount of clouds in comparison with the case adopting the existing single temperature lapse rate ($-6.5^{\circ}C/km$ or $-9^{\circ}C/km$). A catchment of the 'Hadong Watermark2,' which includes Hadong, Gurye, and Gwangyang was selected as the area for evaluating the practicality of the temperature lapse rate estimation method. The weather data of 0600 and 1500 LST at 12 weather observation sites within the catchment were collected during the entire year of 2015. Also, the 'sky condition' of digital forecast products of KMA in 2015 ($5{\times}5km$ lattice resolution) were overlapped with the catchment of the 'Hadong Watermark2,' to calculate the spatial average value within the catchment, which were used to simulate the 0600 and 1500 LST temperature lapse rate of the catchment. The estimation errors of the temperatures at 0600 LST were ME $-0.39^{\circ}C$ and RMSE $1.45^{\circ}C$ in 2015, when applying the existing temperature lapse rate. Using the estimated temperature lapse rate, they were improved to ME $-0.19^{\circ}C$ and RMSE $1.32^{\circ}C$. At 1500 LST, the effect of the improvements found from the comparison between the existing temperature lapse rate and the estimated temperature lapse rate were minute, because the estimated lapse rate of clear days is not very different from the existing lapse rate. However, the estimation errors of the temperatures at 1500 LST during cloudy days were improved from ME $-0.69^{\circ}C$, RMSE $1.54^{\circ}C$ to ME $-0.51^{\circ}C$, RMSE $1.19^{\circ}C$.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.40 no.1
• /
• pp.12-22
• /
• 2012

In Seoul, skyscrapers are built in commercial zones known as residential-commercial complexes, which cause such environmental problems as urban heat islands(UHI) and air pollution. To investigate air temperature differences in areas near skyscrapers at Gangnam-gu, Seoul, South Korea, fixed air temperature observation and traverse observations were performed from March 16, 2008 to March 15, 2009. The annual mean air temperature at Tower Palace(TPL) was higher than that at Sookmyung Girls' High School(SMG) by $0.7^{\circ}C$, although the distance between the two observation positions is only 200m. The number of tropical nights at TPL was 13, while that at SMG was 5. The higher air temperature at TPL was due to a significantly lower sky view factor(SVF), which prevented long-wave radiation from emitting into the sky. The highest air temperature increases near TPL occurred on summer nights because of the high-electricity consumption value of $70.22Wh/m^2$ for the TPL block in August due to air conditioning for cooling. It is concluded that the warm air pocket centered on TPL.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.22 no.2
• /
• pp.65-70
• /
• 1977

The effects of regional climatic factors on wheat quality were discussed. The most important climatic factor on wheat quality during the ripening period of wheat was air temperature during the ripening period of wheat. The protein content and sedimentation value were higher in northern parts of Korea compared to southern parts in Korea. The varietal effects of ripening temperature on protein content and sedimentation value of wheat were varied in nine tested varieties.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.68 no.4
• /
• pp.402-412
• /
• 2023

To cope with climate change, we compared the quality of naked oats (Avena sativa L.) cultivated in different regions. Naked oats were collected from domestic farms in different cultivation regions grouped as G1 and G2 for 3 years (2020-2022). The appearance, quality, and nutritional and functional compounds in the samples were assessed. In terms of appearance quality, the brightness and yellowness of the samples from the G1 region were significantly lower than those of the samples from the G2 region in 2020; however, no differences were observed between cultivation regions in the other 2 years. The results of testing the vitality of naked oats seeds showed that the electrical conductivity value was significantly lower in the samples from the G1 region than in those from the G2 region only in 2022. Among the nutritional components, moisture content was higher in the G2 region than in the G1 region over all 3 years, and the crude protein content was significantly higher in the G2 region than in the G1 region over all years. Carbohydrate content was significantly higher in the G1 region than in the G2 region in all 3 years and was inversely proportional to the crude protein content. The crude fat content tended to be significantly higher in the G1 region than in the G2 region, except in 2022. The levels of beta-glucan, a functional compound rich in naked oats, ranged between 3.4% and 4.2%, and except in 2020, there was no significant difference between cultivation regions. In addition, the content of avenanthramides, representative functional compounds that exist only in oats, was assessed. Over 2 years, in 2021 and 2022, the avenanthramide content was in the range of 2.4-20.7 ㎍/g and tended to be significantly higher in the G2 region than in the G1 region in both years. According to a survey of the average and minimum temperatures during the growing season of naked oats from 2020 to 2022, the average and minimum temperatures in January in the G2 region, which is the cultivation-limit area, were similar to those in Haenam in the G1 region. In conclusion, differences in nutritional and functional compounds were observed in naked oats grown in different cultivation areas. Therefore, considering the cultivation area of naked oats is expanding because of climate change, changes in the compounds that affect quality should be investigated.