Mobile Observation of Air Temperature and Humidity Distributions under Summer Sea Breezes in the Central Area of Osaka City
Thermal environment of urban areas in the summertime has become harmful to human health due to global warming and the urban heat island (UHI) effect. Mobile observations enable us to obtain the distribution of air temperature at microscale, such as urban blocks, which cannot be captured by the coars...
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| Format: | Article |
| Language: | English |
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MDPI AG
2020-11-01
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| Series: | Atmosphere |
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| Online Access: | https://www.mdpi.com/2073-4433/11/11/1234 |
| _version_ | 1797547716902912000 |
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| author | Atsumasa Yoshida Ryusuke Yasuda Shinichi Kinoshita |
| author_facet | Atsumasa Yoshida Ryusuke Yasuda Shinichi Kinoshita |
| author_sort | Atsumasa Yoshida |
| collection | DOAJ |
| description | Thermal environment of urban areas in the summertime has become harmful to human health due to global warming and the urban heat island (UHI) effect. Mobile observations enable us to obtain the distribution of air temperature at microscale, such as urban blocks, which cannot be captured by the coarse network of meteorological sites. A series of mobile measurements was executed in the central area of Osaka City in Japan, around the Nakanoshima district which lies between two rivers, to investigate the air temperature and humidity distributions in a built-up area under sea breeze conditions. Upper wind and surface temperature of the rivers were also observed using pilot balloons and infrared thermography camera, respectively. The mean air temperature in Nakanoshima was generally lower than that of the surrounding area. Urban geometries such as building density and building height seem to affect the mean air temperature by changing the ventilation efficiency. Humidity was inversely correlated with air temperature distribution but was higher at the confluence of rivers and green parks. The depth of the sea breeze layer was found to be about 1 km. Sea breezes close to the ground surface penetrated the city along the rivers, sandwiching the Nakanoshima district. During the daytime, the surface temperatures of the rivers were lower than the air temperature observed at the nearest stationary observation point, and the difference reached approximately 2 °C. |
| first_indexed | 2024-03-10T14:49:09Z |
| format | Article |
| id | doaj.art-c0e6de2bad59404c96ffca0e6766ba9a |
| institution | Directory Open Access Journal |
| issn | 2073-4433 |
| language | English |
| last_indexed | 2024-03-10T14:49:09Z |
| publishDate | 2020-11-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Atmosphere |
| spelling | doaj.art-c0e6de2bad59404c96ffca0e6766ba9a2023-11-20T21:10:48ZengMDPI AGAtmosphere2073-44332020-11-011111123410.3390/atmos11111234Mobile Observation of Air Temperature and Humidity Distributions under Summer Sea Breezes in the Central Area of Osaka CityAtsumasa Yoshida0Ryusuke Yasuda1Shinichi Kinoshita2Department of Mechanical Engineering, Osaka Prefecture University, Sakai 599-8531, JapanDepartment of Mechanical Engineering, Osaka Prefecture University, Sakai 599-8531, JapanDepartment of Mechanical Engineering, Osaka Prefecture University, Sakai 599-8531, JapanThermal environment of urban areas in the summertime has become harmful to human health due to global warming and the urban heat island (UHI) effect. Mobile observations enable us to obtain the distribution of air temperature at microscale, such as urban blocks, which cannot be captured by the coarse network of meteorological sites. A series of mobile measurements was executed in the central area of Osaka City in Japan, around the Nakanoshima district which lies between two rivers, to investigate the air temperature and humidity distributions in a built-up area under sea breeze conditions. Upper wind and surface temperature of the rivers were also observed using pilot balloons and infrared thermography camera, respectively. The mean air temperature in Nakanoshima was generally lower than that of the surrounding area. Urban geometries such as building density and building height seem to affect the mean air temperature by changing the ventilation efficiency. Humidity was inversely correlated with air temperature distribution but was higher at the confluence of rivers and green parks. The depth of the sea breeze layer was found to be about 1 km. Sea breezes close to the ground surface penetrated the city along the rivers, sandwiching the Nakanoshima district. During the daytime, the surface temperatures of the rivers were lower than the air temperature observed at the nearest stationary observation point, and the difference reached approximately 2 °C.https://www.mdpi.com/2073-4433/11/11/1234building densitymobile observationsea breezeurban heat islandurban ventilationriver island |
| spellingShingle | Atsumasa Yoshida Ryusuke Yasuda Shinichi Kinoshita Mobile Observation of Air Temperature and Humidity Distributions under Summer Sea Breezes in the Central Area of Osaka City Atmosphere building density mobile observation sea breeze urban heat island urban ventilation river island |
| title | Mobile Observation of Air Temperature and Humidity Distributions under Summer Sea Breezes in the Central Area of Osaka City |
| title_full | Mobile Observation of Air Temperature and Humidity Distributions under Summer Sea Breezes in the Central Area of Osaka City |
| title_fullStr | Mobile Observation of Air Temperature and Humidity Distributions under Summer Sea Breezes in the Central Area of Osaka City |
| title_full_unstemmed | Mobile Observation of Air Temperature and Humidity Distributions under Summer Sea Breezes in the Central Area of Osaka City |
| title_short | Mobile Observation of Air Temperature and Humidity Distributions under Summer Sea Breezes in the Central Area of Osaka City |
| title_sort | mobile observation of air temperature and humidity distributions under summer sea breezes in the central area of osaka city |
| topic | building density mobile observation sea breeze urban heat island urban ventilation river island |
| url | https://www.mdpi.com/2073-4433/11/11/1234 |
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