간행물

기후연구 KCI 등재 Journal of Climate Research

권호리스트/논문검색
이 간행물 논문 검색

권호

제16권 제2호 (2021년 6월) 5

1.
2021.06 서비스 종료(열람 제한)
The present study aims to analyze climate change and trend of extreme temperature events occurred over the Republic of Korea. The observation data used are daily average, maximum, and minimum temperature from 6 weather stations for the period of 1912-2020. Seven extreme indices regarding frequency and extreme value of temperature are calculated in seasonal and annual time range. In addition, hot extremes and their changes by four physical terms that include information on the annual mean temperature, the amplitude of the annual cycle, the diurnal temperature range and the local temperature anomaly on the day of the extreme are analyzed. The climatology for the analysis is updated to the new normal year of 1991-2020. Consistent with the previous findings, statistically significant change was detected in the indices of annual lowest daily minimum temperature, annual extreme temperature range, frequency of daily minimum temperature below -12℃ and 10%ile(TN10p) during winter. Due to the gradual decrease of the occurrence days regarding the extreme minimum temperature during winter, the frequency calculated by the relative threshold in extreme high temperature during summer prevail since 1990s. Indices related with extreme high temperature had larger low-frequency variability than significant climate change during the analysis period. However, the assessment of hot extremes according to the terms describing mean, variability and tails during the new normal year of 1991-2020, significant increasing trend was detected not only in the annual mean and the amplitude of the seasonal cycle, but also in the daily hot extreme anomaly.
2.
2021.06 서비스 종료(열람 제한)
Tropical cyclones (TCs) over the western North Pacific (WNP) mainly occur during June-October, and result in significant casualties and damages to property in East Asian countries (e.g., Korea, Japan, Taiwan, and China, etc.). Although the total number of TCs that occurred over WNP was similar to normal years, the numer of TCs that affected Korea in August and September 2019 was 3 times higher than with the same number of TCs in July. Therefore, this study examined why more TCs migrated into Korea in 2019 through analyzing four environmental conditions: steering flow, geopotential height at 500 hPa, vertical wind shear (VWS), and sea surface temperature (SST). Results showed that the tracks of TCs were significantly associated with steering flows from July to September. Furthermore, weaker VWS and warmer SST were distributed near the tracks of TCs during August and September, whereas strong VWS and lower SST were dominant in July. The environmental conditions in August and September were favorable for maintaining and developing TCs, explaining why more typhoons have affected Korea during August and September in 2019.
3.
2021.06 서비스 종료(열람 제한)
This study analyzed how the impacts of major teleconnection patterns on December mean temperature in Korea have been changed during the period before and after the regime shift of 1986 for the last 61 years from 1958 to 2018. During the period before the regime shift, the teleconnection patterns originating from the North Atlantic mainly affected the temperature variability in Korea, but its influence almost disappeared after the regime shift. On the other hand, the Arctic Oscillation (AO) and warm Arctic and cold Eurasia (WACE) patterns played a more important role in the temperature variability in Korea after the regime shift. Regression analysis showed that the AO could explain about 12% of the total temperature variability before the regime shift, but about 22% after the regime shift. WACE pattern also explained about 4% before the regime shift, but after the regime shift, the importance increased by about 4.5 times to 18%. On the other hand, East Atlantic pattern (EA) and North Atlantic Oscillation (NAO), which are east-west teleconnection patterns, explained 27% and 11%, respectively, before the regime shift, but had little influence within 3% after the regime shift. This means that the influence of east-west teleconnection patterns disappeared after the regime shift, and teleconnection patterns by the Arctic Circle became more important.
4.
2021.06 서비스 종료(열람 제한)
Heatwaves can affect human health and vegetation growth and bring about energy problems and socioeconomic damages, so the analysis and prediction of the heatwave is a crucial issue under a warming climate. This paper examines the production of STCI (Standard Temperature Condition Index) using ASOS (Automated Synoptic Observing System) in-situ observation data for the period of 1979-2020, and an STCI predictability assessment with an RF (Random Forest) model using ERA5 (ECMWF Reanalysis 5) meteorological variables. The accuracy was quite high with the MAE (Mean Absolute Error) of 0.365 and the CC (Correlation Coefficient) of 0.873, which corresponded to 7% to 10% difference for the range of STCI<1.5, and to 1% to 3% difference for the range of STCI>1.5, in terms of the probability density function. Also, we produced gridded maps for the summer STCI from 1979 to 2020 by utilizing the ERA5 raster data for the RF prediction model, which enables the spatial expansion of the ASOS point-based STCI to a continuous grid nationwide. The proposed method can be applied to forecasting of STCI by adopting future meteorological or climatic datasets.
5.
2021.06 서비스 종료(열람 제한)
In this study, an analysis were conducted to utilize the thermal infrared image using drone to present the temperature correction method of thermal infrared image and the thermal environment by the type of land cladding. The analysis was applied to the temperature correction of the thermal infrared image and total eight thermal infrared images were produced based on the land surface temperature. The thermal infrared image compared accuracy through RMSE calculation. Based on the result of RMSE, the thermal infrared image corrected by the land surface temperature was relatively accurate and contained at 2.26 to 3.58. According to the results, it is expected that the aggregation and waters will perform the functions of the green park sufficiently to improve the thermal comfort and improve the microclimate stability using the thermal infrared image and the reclassified land cover map. The results of this study obtained by Drone and the usability of the drone thermal infrared image in the detection of the thermal environment. Finally, it is expected to contribute to the improvement and management of the thermal environment in the city by being used as a basic data for the improvement and management policy of the thermal environment. Moreover, the macro view is expected to contribute to the mitigation of urban temperature reduction and heat island.