Sea land breeze (SLB) is one of the important mesoscale circulation systems over coastal areas, which is caused by the temperature difference between sea and land. The variations in the intensity and duration of SLB affect the atmospheric environment and climate features of the coastal critical zone. The coastal area of Tianjin is undergoing urbanization while the sea surface temperature in the Bohai sea is rising. However, the long-term trend of SLB and how the factors affect SLB trend are still poorly understood due to the lack of long-term observational and modeling studies.
Recently, the research teams from School of Earth System Science at Tianjin University and Tianjin Institute of Meteorological Science work together to establish a localized criterion for identifying the SLB coastal area of Tianjin. The hourly meteorological data from 2005 to 2019 were measured in three National Meteorological Observatory Stations (urban, coastal, and marine) in Tianjin to evaluate the long-term trend of SLB. They found that in the past 15 years, Tianjin experienced a decrease in the number of SLB days, reduction of the intensity of SLB resulting in the decrease in the horizontal and vertical influencing distance and variation in the occurrence time of SLB. Above mentioned changes in SLB are very likely to have an impact on the dispersion of atmospheric pollutants and climate in Tianjin. Their research improved the description of land use caused by urbanization and diurnal variation of sea surface temperature used in the numerical simulation model. Researchers also improved the simulation accuracy of the characteristics of SLB changes in Tianjin over the past 15 years. The simulation experiment elucidated the mechanisms of urbanization and ocean warming on the long-term weakening of SLB in different seasons.
This study illustrated that urbanization and global warming can lead the climate change of coastal cities. As a result, control of global warming and reasonable planning of urban morphology will help to slow down the weakening trend of SLB. Therefore, the ventilation capacity of coastal cities can be enhanced, further improving the air quality and climate comfort of coastal cities. This study, entitled "Weakened Sea-Land Breeze in a Coastal Megacity Driven by Urbanization and Ocean Warming", have been published in Earth's Future (Volume11, Issue8). Yunting Xiao, the PhD candidate from the School of Earth System Science at Tianjin University, is the first author of the paper. Prof. Jialei Zhu from the School of Earth System Science at Tianjin University and Dr. Jianbo Yang from the Tianjin Institute of Meteorological Science are the co-corresponding authors of the paper.
Figure 1. The mechanism of sea land breeze weakening in a coastal megacity
This study was supported by the National Natural Science Foundation of China (Grant 42221001, 42177082, and 42205092) and the applied fundamental research project of Tianjin (22JCQNJC00370).
How to cite:
Yunting Xiao, Jianbo Yang*, Lehui Cui, Junjun Deng, Pingqing Fu, Jialei Zhu* (2023). Weakened sea-land breeze in a coastal megacity driven by urbanization and ocean warming. Earth's Future, 11, e2022EF003341. https://doi.org/10.1029/2022EF003341
