Urban impacts on mean and trend of surface incident solar radiation

Anthropogenic aerosols over urban areas may have important effects on surface incident solar radiation ( R s ). Studies have claimed that R s decreased significantly more in urban areas than in rural areas from 1964 to 1989. However, these estimates have substantial biases because they ignored the spatial inhomogeneity of R s measurements. To address this issue, we selected urban‐rural station pairs collocated within 2° × 2° and found 105 such pairs based on the Global Energy Balance Archive (GEBA). On average, the impact of urban aerosols on mean and trend of R s is 0.2(0.7, median) ± 11.2 W m −2 and 0.1(−0.7, median) ± 6.6 W m −2 per decade from 1961 to 1990, respectively. Hence, the averaged urban impacts on the mean and trend of R s over Europe, China and Japan from 1961 to 1990 are small although they may be significant at specific sites.