How did the Sun affect the air pollution on the
Earth? There are few papers about this question. This work
investigates the relationship between the air pollution and
solar activity by using the geophysical and environmental
data during the period of 2000–2016. It is quite certain that
the solar activity may impact on the air pollution, but the
relationship is very weak and indirect. The Pearson corre-
lation, Spearman rank correlation, Kendall’s rank correla-
tion, and conditional probability were adopted to analyze the
air pollution index (API), air quality index (AQI), sunspot
number (SSN), radio flux at wavelength of 10.7 cm (F10.7),
and total solar irradiance (TSI). The analysis implies that
the correlation coefficient between API and SSN is weak
(−0.17 < r < 0.32) with complex variation. The main re-
sults are: (1) For cities with higher air pollution, the prob-
ability of high API will be increased along with SSN, then
reach to a maximum, and then decreased; (2) For cities with
lower air pollution, the API has lower correlation with SSN;
(3) The relationship between API and F10.7, or API and TSI
are also similar as API and SSN. The solar activities take di-
rect effect on TSI and the energetic particle flux, and indirect
and long-term effect on lower atmosphere and weather near
the Earth. All of these factors contribute to the air pollution
on the Earth.

EB00000004054K

Available

• Investigation of the relationship between the air pollution and solar activity