According to the aerosol optical properties

the aerosol chemical composition can be simplified as a mixture of five components. They are three absorbing components like Black Carbon （ BC）

Brown Carbon （ BrC）

and dust （ DU） ; one scattering （ non-absorbing） component of ammonium sulfate （ AS） as well as aerosol water （ AW）

which is responsible for aerosol hygroscopic characteristics. In this study

we estimate the contents of the five chemical components of haze aerosols during January 2013 over Beijing from the ground-based remote sensing measurements. We find that BC

BrC

DU

AS and AW occupy 2%

9%

30%

33%

and 26% in volume

respectively on average for the selected haze days

while they are 3%

3%

15%

71%

and 8% on a verage for the selected clear days. As for the column mass concentration

BC

BrC

DU

AS and AW in the haze aerosol are 7

35

166

131

and 73 mg/m2 on average

while during the clear days they are 4

4

29

78 and 6 mg/m2 on average. The comparisons of these remote sensing results with in situ BC and PM 2. 5 measurements are also presented in the paper. Results show that the retrievals agree well with the measurements

with coefficient R2 0.45 for BC and 0. 85 for PM2.5 .