Amplified Increases of Compound Hot Extremes Over Urban Land in China. Issue 6 (17th March 2021)

• Record Type: Journal Article
• Authors: Liao, Weilin; Li, Dan; Malyshev, Sergey; Shevliakova, Elena; Zhang, Honghui; Liu, Xiaoping
• Is Part Of: Geophysical research letters. Volume 48:Issue 6(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-03-17
• Subjects: Geophysics -- Periodicals; Planets -- Periodicals; Lunar geology -- Periodicals; 550
• DOI: 10.1029/2020GL091252
• Languages: English
• ISSNs: 0094-8276

Abstract

Abstract: Consecutive hot periods without nighttime heat relief significantly increase mortality and morbidity rates. Using the Geophysical Fluid Dynamics Laboratory land model coupled with a newly developed and validated urban canopy model, changes in three types of summertime hot extremes, that is, independent hot days, independent hot nights, and compound hot events (CHEs), in the 21st century are quantified in China. Results indicate that all three types of hot extremes become more frequent, and CHEs are projected to be the dominant type at the end of this century under the representative concentration pathway 8.5 scenario. Furthermore, compared to the rural land, the urban land experiences even stronger increases in CHEs in terms of frequency, duration, and intensity. These faster increases of CHEs in urban areas highlight the urgency of developing and implementing mitigation and adaptation strategies to combat the adverse health effects of global warming and urban heat islands. Plain Language Summary: As the urban population continues to rise, it is important to quantify the increase of hot extremes over urban areas, which have profound impacts on human health. According to climate simulations and meteorological observations, both urban and rural summertime hot extremes become more frequent, more intense, and longer lasting in China. As the climate warms, hot extremes transition from daytime‐/nighttime‐only events to compound events, and this transition is accelerated over urban land than rural land. As consecutive hot days without nighttime relief will significantly increase mortality and morbidity rates, increases in compound hot events over urban areas have extremely important implications for human health. Key Points: Both urban and rural summertime hot extremes become more frequent, more intense, and longer lasting in China Simulations indicate faster increases of compound hot extremes over urban land than rural land Urbanization accelerates the transition of hot extremes from daytime‐/nighttime‐only events toward compound events