Spatiotemporal changes in air temperature and humidity associated with the restoration of an innercity stream in Seoul, Korea, are investigated based on long-term monitoring data. The Cheonggye stream, covered under a...Spatiotemporal changes in air temperature and humidity associated with the restoration of an innercity stream in Seoul, Korea, are investigated based on long-term monitoring data. The Cheonggye stream, covered under a concrete structure for 46 years, was restored in 2005 and runs 5.8 km eastward through a central region of Seoul. Long-term monitoring of the air temperature and relative humidity was made along the stream throughout the restoration and across the stream after the restoration. The area along the stream had a higher air temperature than the entire metropolitan area. The temperature anomaly between the monitoring area and the surrounding metropolitan area was 0.13℃ lower on average at the center of the stream after the restoration. The stream＇s effect on the air temperature was also evident in the temperature distribution along a street traversing the stream. The relative and specific humidities were increased due to the restoration. The restored stream modified the nearby urban climate in the opposite direction compared to urbanization. The results could be used as a model case in mitigating urban climate by a stream in future urban planning practices.展开更多
Cluster analysis has been performed on the tracks of 51 Tropical Cyclones （TCs） that made landfall on the Korean Peninsula （KP） for the period of 1951-2004. The classification technique of the landfalling tracks u...Cluster analysis has been performed on the tracks of 51 Tropical Cyclones （TCs） that made landfall on the Korean Peninsula （KP） for the period of 1951-2004. The classification technique of the landfalling tracks used in this study was the fuzzy clustering method （FCM） and the resultant silhouette coefficient suggested four clusters as an optimal cluster number. Most TCs of Cluster 2 and Cluster 3 （C-23） tended to pass through China's Mainland before landfall, but those of Cluster 1 and Cluster 4 （C-14） tended to mostly land after moving northward from the East China Sea （ECS） without passing over China's Mainland. The TC landfalling frequency of C-14 has begun to clearly increase since the late 1980s, particularly the maximum landfalling frequency in the early 2000s set a record for the 54-year analysis period. The ridge axis of the western North Pacific high （WNPH） of C-23 bends more equatorward than that of C-14, so that the monsoon trough of C-23 is located more equatorward than that of C-14. As a consequence, most TCs of C-23 tend to recurve inland of China, but over the ECS for C-14.展开更多
基金supported by the project "Diagnosis of Characteristics of Local Meteorology and Development of Techniques for the Meteorological Environment Impact Assessment" of the NationalInstitute of Meteorological Research/Korea Meteorological Adminstration.
文摘Spatiotemporal changes in air temperature and humidity associated with the restoration of an innercity stream in Seoul, Korea, are investigated based on long-term monitoring data. The Cheonggye stream, covered under a concrete structure for 46 years, was restored in 2005 and runs 5.8 km eastward through a central region of Seoul. Long-term monitoring of the air temperature and relative humidity was made along the stream throughout the restoration and across the stream after the restoration. The area along the stream had a higher air temperature than the entire metropolitan area. The temperature anomaly between the monitoring area and the surrounding metropolitan area was 0.13℃ lower on average at the center of the stream after the restoration. The stream＇s effect on the air temperature was also evident in the temperature distribution along a street traversing the stream. The relative and specific humidities were increased due to the restoration. The restored stream modified the nearby urban climate in the opposite direction compared to urbanization. The results could be used as a model case in mitigating urban climate by a stream in future urban planning practices.
基金supported by the National Instituteof Meteorological Research (NIMR) in the Korea Meteoro-logical Administration.
文摘Cluster analysis has been performed on the tracks of 51 Tropical Cyclones （TCs） that made landfall on the Korean Peninsula （KP） for the period of 1951-2004. The classification technique of the landfalling tracks used in this study was the fuzzy clustering method （FCM） and the resultant silhouette coefficient suggested four clusters as an optimal cluster number. Most TCs of Cluster 2 and Cluster 3 （C-23） tended to pass through China's Mainland before landfall, but those of Cluster 1 and Cluster 4 （C-14） tended to mostly land after moving northward from the East China Sea （ECS） without passing over China's Mainland. The TC landfalling frequency of C-14 has begun to clearly increase since the late 1980s, particularly the maximum landfalling frequency in the early 2000s set a record for the 54-year analysis period. The ridge axis of the western North Pacific high （WNPH） of C-23 bends more equatorward than that of C-14, so that the monsoon trough of C-23 is located more equatorward than that of C-14. As a consequence, most TCs of C-23 tend to recurve inland of China, but over the ECS for C-14.
