Assessment of urban effect on observed warming trends during 1955-2012 over China: a case of 45 cities

• This study aims at qualifying the contribution of the urban effect to the total warming recorded by 45 urban or suburban stations in China where rapid and extensive urbanization over the last few decades occurred. Partly due to differences in urbanization and stations' geographic location, the total warming trends for 1955-2012 vary from of -0.10 to 0.49 A degrees C and -0.03 to 0.64 A degrees C per decade for the annual averaged daily mean and daily minimum temperature, respectively. A principal component analysis of seven factors on the siting and geographical coordinates of the meteorological stations shows three dominant factors (urban size, relative position of meteorological station to city center and geographic location of station) accounting for 87.1 % of the total explained variance. An index quantifying the impact of the first two dominating factors of the urban effect is proposed considering also the dominating wind direction. The positive correlation between the temperature trends and the index is significant (P < 0.05), indicating that urbanization has significantly influenced the warming trends at these stations. The average contribution of the urbanization for all the stations to the total mean temperature trend is estimated to be 19 %.

Subject headings

NATURVETENSKAP  -- Geovetenskap och miljövetenskap -- Meteorologi och atmosfärforskning (hsv//swe)

NATURAL SCIENCES  -- Earth and Related Environmental Sciences -- Meteorology and Atmospheric Sciences (hsv//eng)

NATURVETENSKAP  -- Biologi -- Ekologi (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences -- Ecology (hsv//eng)

Keyword

surface-temperature change

land-use data

heat-island

air-temperature

united-states

mean temperature

urbanization

climate

impact

variability

Environmental Sciences & Ecology

Meteorology & Atmospheric Sciences

Publication and Content Type

ref (subject category)

art (subject category)