Effects of pollution on temperature trends over mountains and cities in China

Abstract:

In this paper the global hourly surface observational climate data (NCDC) from 1980 to 2012 are used to investigate the effects of visibility on the different temperature trends in four mountain stations and their nearby city and plain stations. No doubt, the mountains, cities, and plains all show the significant warming trend during 1980-2012. However, except for Chengdu, the trends in all cities and plains are low than their nearby mountains. The climatological visibilities of cities are much lower than mountains and the negative trends of visibility in cities are larger than those in mountains. The hazy days (visibility < 10 km) in cities also show the larger positive trends than those in mountains. There are larger aerosol concentrates in low visibility situations and the cooling radiation effects of aerosol induce the lower temperature trends in cities than in mountains. The stronger warming in Chengdu is due to its larger hot island effects.