Evaluating the contributions of urban surface expansion to regional warming in Shanghai using different methods to calculate the daily mean temperature. Issue 6 (2nd November 2018)

• Record Type: Journal Article
• Authors: ZHAO, De-Ming; WU, Jian
• Is Part Of: Atmospheric and oceanic science letters. Volume 11:Issue 6(2018)
• Page Start: 518
• Page End: 525
• Publication Date: 2018-11-02
• Subjects: Urban surface expansion -- urban-related warming -- surface air temperature -- maximum -- minimum; 城市下垫面扩张 -- 城市化增温 -- 气温 -- 最高气温 -- 最低气温; Atmospheric physics -- Periodicals; Oceanography -- Periodicals; Ocean-atmosphere interaction -- Periodicals; Climatology -- Periodicals; Periodicals; 551.5
• DOI: 10.1080/16742834.2018.1530563
• Languages: English
• ISSNs: 1674-2834

Abstract

ABSTRACT: The contributions of urban surface expansion to regional warming over subregions of Shanghai and Shanghai as a whole using different methods to calculate the daily mean surface temperature (SAT), including the averages of four daily time-records (0000, 0600, 1200, and 1800 UTC; T 4 ), eight daily time-records (0000, 0300, 0600, 0900, 1200, 1500, 1800, and 2100 UTC; T 8 ), and the averages of the SAT maximum ( T max ) and minimum ( T min ), T xn, were compared based on simulated results using nested numerical intergrations with the Weather Research and Forecasting regional climate model, where only the satellite-retrieved urban surface distributions differed between two numerical experiments. The contributions from urban-related warming expressed similar intensities when using T 8 and T xn, while the smallest values occurred when using T 4 over different subregions of Shanghai (with the exception of areas that were defined as urban for both time periods (U2U)) and Shanghai as a whole. Similar values for the changing trends could be detected over different subregions when no urban surface expansion (EX1) was detected for both T 4 and T xn . The corresponding values increased under urban surface expansion (EX2) and varied over different subregions, revealing much stronger intensities over urban-surface expansion areas; the weakest intensities occurred over U2U areas. The increasing trends for EX2 and relative contributions when using T 4 were smaller than those when using T xn, with the exception of those over U2U areas, which could be explained by the changing trends in T max and T min due to urban surface expansion, especially during intense urban expansion periods. Graphical Abstract: