• Atmosphere
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• v.33 no.5
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• pp.477-492
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• 2023

Based on the new climate normals (1991~2020), annual mean, maximum and minimum temperature is 12.5℃, 18.2℃, and 7.7℃, respectively while annual precipitation is 1,331.7 mm, the annual mean wind speed is 2.0 m s^-1, and the relative humidity is 67.8% in the Republic of Korea. Compared to 1981~2010 normal, annual mean temperature increased by 0.2℃, maximum and minimum temperatures increased by 0.3℃, while the amount of precipitation (0.7%) and relative humidity (1.1%) decreased. There was no distinct change in annual mean wind speed. The spatial range of the annual mean temperature in the new normals is large from 7.1 to 16.9℃. Annual precipitation showed a high regional variability, ranging from 787.3 to 2,030.0 mm. The annual mean relative humidity decreased at most weather stations due to the rise in temperature, and the annual mean wind speed did not show any distinct difference between the new and old normals. With the addition of a warmer decade (2011~2020), temperatures all increased consistently and in particular, the increase in the maximum temperature, which had not significantly changed in previous decades, was evident. The increasing trend of annual and summer precipitation by the 2010s has disappeared in the new normals. Among extreme climate indices, MxT30 (Daily maximum temperature ≥ 33℃ days), MnT25 (Daily minimum temperature ≥ 25℃ days), and PH30 (1 hour maximum precipitation ≥ 30 mm days) increased while MnT-10 (Daily minimum temperature < -10℃ days) and W13.9 (Daily maximum wind speed ≥ 13.9 m/s days) decreased at a statistically significant level. It is thought that a detailed study on the different trends of climate elements and extreme climate indices by region should be conducted in the future.

• Atmosphere
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• v.22 no.3
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• pp.299-307
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• 2012

This study is aimed to validate errors for detected suspicious temperature data using various quality control procedures for 61 weather stations in the Republic of Korea. The quality control algorithms for temperature data consist of four main procedures (high-low extreme check, internal consistency check, temporal outlier check, and spatial outlier check). Errors of detected suspicious temperature data are judged by examining temperature data of nearby stations, surface weather charts, hourly temperature data, daily precipitation, and daily maximum wind direction. The number of detected errors in internal consistency check and spatial outlier check showed 4 days (3 stations) and 7 days (5 stations), respectively. Effective and objective methods for validation errors through this study will help to reduce manpower and time for conduct of quality management for temperature data.

• Journal of the Korean earth science society
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• v.27 no.2
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• pp.188-197
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• 2006

The characteristics of variability of temperature and precipitation in Jeju were investigated using data observed in Jeju station for from 1924 to 2004. Annual mean temperature change for the last 81 years is $0.02^{\circ}C$ increase per year. After 1980, the increase is $0.05^{\circ}C$ per year, larger than the former. The increase of the minimum temperature is larger than that of the maximum temperature in Jeju and has resulted in the increase of mean temperature. The frequency of climate extreme occurrence of temperature and rainfall was also investigated. The temporal variation of frequency of the extremely higher temperature has increased in the 1980's with global warming. The appearance of the extremely lower minimum temperature has decreased during the summers and winters. The facts that the frequencies of rainy days has decreased and heavy rainfall days of more than 80 mm per day in precipitation has increased indicate the increase of rainfall intensity.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.1B
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• pp.41-53
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• 2008

Unprecedented weather phenomena are occurring because of climate change: extreme heavy rains, heat waves, and severe rain storms after the rainy season. Recently, the frequency of these abnormal phenomena has increased. However, regular pattern or cycles cannot be found. Analysis of annual data or annual average data, which has been established a research method of climate change, should be applied to find frequency and tendencies of extreme climate events. In this paper, extreme indicators of precipitation and temperature marked by objectivity and consistency were established to analyze data collected by 66 observatories throughout Korea operated by the Meteorological Administration. To assess the statistical significance of the data, linear regression and Kendall-Tau method were applied for statistical diagnosis. The indicators were analyzed to find tendencies. The analysis revealed that an increase of precipitation along with a decrease of the number of rainy days. A seasonal trend was also found: precipitation rate and the heavy rainfall threshold increased to a greater extent in the summer(June-August) than in the winter (September-November). In the meanwhile, a tendency of temperature increase was more prominent in the winter (December-February) than in the summer (June-August). In general, this phenomenon was more widespread in inland areas than in coastal areas. Furthermore, the number of winter frost days diminished throughout Korea. As was mentioned in the literature, the progression of climate change has influenced the increase of temperature in the winter.

• Journal of Korean Society on Water Environment
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• v.33 no.3
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• pp.282-290
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• 2017

A long-term resuspension of small particles, called persistent turbidity, is one of the most important water quality concerns in the dam reservoirs system located in North Han River. Persistent turbidity may incur aesthetic nuisance and harmful effect on the ecosystem health, in addition to elevated water treatment costs for the drinking water supply to the Seoul metropolitan area. These sufferings have been more intensified as the strength and frequency of rainfall events increase by climate change in the basin. This study was to analyze the effect of an extreme turbidity flow event that occurred in 2006 on the serial reservoirs system (Soyang-Uiam-Cheongpyung-Paldang) in North Han River. The CE-QUAL-W2 model was set up and calibrated for the river and reservoirs system using the field data obtained in 2006 and 2007. The results showed that Soyang Reservoir released turbid water, which was classified as the TSS concentration is greater than 25 mg/L, for 334 days with peak TSS of 264.1 mg/L after the extreme flood event (592.7 mm) occurred between July 10 and 18 of 2006. The turbid water departed from Soyang Reservoir reached at the most downstream Paldang Reservoir after about 20 days and sustained for 41 days, which was validated with water treatment plant data. Since the released water from Soyang Reservoir had low water temperature and high TSS, an underflow formed in the downstream reservoirs and vertically mixed at Paldang Reservoir due to dilution by the sufficient inflow from South Han River.

• Atmosphere
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• v.29 no.5
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• pp.585-597
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• 2019

This study evaluates the performance of Weather Research and Forecasting (WRF) model in simulating temperature over the COordinated Regional climate Downscaling EXperiment-East Asia (CORDEX-EA) Phase 2 domain for the reference period (1981~2005), and assesses the changes in temperature and its extremes in the mid-21st century (2026~2050) under global warming based on Representative Concentration Pathway (RCP) scenarios. MPI-ESM-LR forced by two RCP scenarios (RCP2.6 and RCP8.5) is used as initial and lateral boundary conditions. Overall, WRF can capture the observed features of temperature distribution reflecting local topographic characteristic, despite some disagreement between the observed and simulated patterns. Basically, WRF shows a systematic cold bias in daily mean, minimum and maximum temperature over the entire domain. According to the future projections, summer and winter mean temperatures over East Asia will significantly increase in the mid-21st century. The mean temperature rise is expected to be greater in winter than in summer. In accordance with these results, summer (winter) is projected to begin earlier (later) in the future compared to the historical period. Furthermore, a rise in extreme temperatures shows a tendency to be greater in the future. The averages of daily minimum and maximum temperatures above 90 percentiles are likely to be intensified in the high-latitude, while hot days and hot nights tend to be more frequent in the low-latitude in the mid-21st century. Especially, East Asia would be suffered from strong increases in nocturnal temperature under future global warming.

• Asian Journal of Atmospheric Environment
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• v.11 no.3
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• pp.184-193
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• 2017

People spend the majority of their time in indoor environments. Maintaining adequate indoor temperature and humidity is necessary to support health and improve quality of life. However, people with low incomes can be vulnerable because they may not be able to use effective cooling and heating systems in their homes. In this study, the indoor temperature and humidity in low-income residences over a year in Seoul, Korea was characterized. Indoor temperature and humidity were measured in three types of homes (12 rooftop residences, 16 basement residences, and 18 public rental apartments) occupied by low-income residents. Both differed significantly among the three types of residence, particularly during the summer and winter seasons. A regression model between indoor and outdoor temperature detected a heating threshold at $3.9^{\circ}C$ for rooftop residences, $9.9^{\circ}C$ for basement residences, and $17.1^{\circ}C$ for public rental apartments. During tropical nights and cold-wave advisory days, rooftop residences showed the most extreme indoor temperatures. This study demonstrates that people living in rooftop residences could be at risk from extreme hot and cold conditions.

• International Journal of Industrial Entomology and Biomaterials
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• v.24 no.2
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• pp.69-74
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• 2012

Tropical tasar silkworm Antheraea mylitta Drury experiences extreme temperature stress conditions during its life cycle particularly during diapauses and first crop. The present study witnessed the impact of high temperature on some biochemical profiles and egg production (fecundity) of semi-domesticated Daba and Shorea robusta (Sal) based wild ecorace Laria during seed cocoon (pupa) preservation. Cocoons of Daba and Laria were treated with high temperature at $40^{\circ}C$ for 10 days in a BOD incubator. The protein profile and carbohydrate content in the hemolymph and fat body and total haemocyte count (THC) in the hemolymph of pupa were investigated. Further, the fecundity and fertility of egg was assessed. Significant increase in the protein concentration was observed in the hemolymph with reduction in the fat body (p<0.05). The difference in protein concentration was highly significant between the semidomesticated Daba and wild ecorace Laria (p<0.05). High pupal mortality (20%) and reduced fecundity (10-15%) in Daba was noticed compared to wild Laria. Also an increased THC (>28000) was recorded in Laria. The study infers the potentials of wild ecoraces in sustaining the extreme temperature conditions and need of adopting suitable package of practices for the preservation of diapause seed cocoons during extreme summer conditions. There is possibility to introgression thermal stress resistant traits in the semi-domesticated races of tasar silkworm by resorting to conventional breeding plans with wild races and keeping the thermal stress induced response as markers.

• Atmosphere
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• v.24 no.4
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• pp.541-554
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• 2014

Historical, RCP4.5 and RCP8.5 scenarios from HadGEM2-AO are dynamically downscaled over the northeast East Asia with WRFV3.4. The horizontal resolution of the produced data is 12.5 km and the periods of integration are 1979~2010 for historical and 2019~2100 for both RCP4.5 and RCP8.5. We analyze the time series, climatology, EOF and extreme climate in terms of 2 m-temperature and precipitation during 30-year for the Historical (1981~2010) and RCP4.5 and RCP8.5 (2071~2100) scenarios. According to the result, the temperature of the northeast Asia centered at the Korean Peninsula increase 2.9 and $4.6^{\circ}C$ in the RCP4.5 and RCP8.5 scenarios, respectively, by the end of the 21st century. The temperature increases with latitude and the increase is larger in winter rather than in summer. The annual mean precipitation is expected to increase by about $0.3mm\;day^{-1}$ in RCP4.5 scenario and $0.5mm\;day^{-1}$ in RCP8.5 scenario. The EOF analysis is also performed for both temperature and precipitation. For temperature, the EOF $1^{st}$ modes of all scenarios in summer and winter show that temperature increase with latitude. The $2^{nd}$ mode of EOF of each scenario shows the natural variability, exclusive of the global warming. The summer precipitation over the Korean Peninsula projected increases in EOF $1^{st}$ modes of all scenarios. For extreme climate, the increment of the number of days with daily maximum temperature above $30^{\circ}C$ per year ($DAY_{TX30}$) is 25.3 and 49.7 days in RCP4.5 and RCP8.5 respectively over the Korean Peninsula. The number of days with daily precipitation above $20mm\;day^{-1}$ per year ($DAY_{PR20}$) also increases 3.1 and 3.5 days in RCP4.5 and RCP8.5 respectively.

• Journal of the Korean association of regional geographers
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• v.19 no.4
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• pp.600-614
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• 2013

This study aims to examine spatially-detailed changes and projection of subtropical climate zones based on the modified K$\ddot{o}$ppen-Trewartha's climate classification and extreme temperature indices using $1km{\times}1km$ high resolution RCP 4.5 and RCP 8.5 climate change scenarios based on PRIDE model over the Republic of Korea. Subtropical climate zones currently located along the southern coastal region. Future subtropical climate zones would be pushed northwards expanding to the western and the eastern coastal regions as well as some metropolitan areas. For both scenarios, the frequency of cold-related extreme temperatures projects to be reduced while the frequency of hot-related ones projects to be increased. Especially, hot days with $33^{\circ}C$ or higher temperature projects to occur more than 30 days over the most of regions except for some mountain areas with high altitudes during the period of 2070~2100. This study might provide essential information to make climate change adaptation processes be enhanced.