Black carbon (BC), primary brown carbon (BrC_pri), and secondary brown carbon (BrC_sec) are important light‐absorbing aerosol. BC and BrC from the surrounding area can reach the Tibetan Plateau (TP) and influence climate change and glacial melting. Here, we presented a study of the light absorption, radiative forcing, and potential source areas of BC and BrC over the northeastern, central, and southwestern TP. The higher light absorption was observed in the northeastern and southwestern sites compared to the central TP site. The major carbonaceous light‐absorbing was attributed to BC with the percentages of 65%, 56%, and 82% in Ngari, Qinghai Lake, and Beiluhe, respectively. The heighten contribution of BrC_sec to total light absorption indicated the importance of BrC_sec in the TP, especially in the northeastern and southwestern areas. The BrC_sec radiative forcings relative to BC were much higher than those of BrC_pri. The potential BC and BrC_pri source distributions were obtained.

The samples of atmospheric total suspended particle (TSP) were obtained at the remote Tibetan site (named Lulang) from November 2015 to November 2016. The seasonal characteristics of n‐alkanes, polycyclic aromatic hydrocarbons (PAHs) variations, and their correlations to brown carbon (BrC) light absorption in TSP were investigated. Elevated TSP n‐alkanes and PAHs levels were observed in winter (2.8 and 10 times higher than in monsoon, respectively), largely due to the seasonal contributions of wintertime home heating and long‐range transport. The total‐PAHs was found to correlate strongly with the methanol‐soluble BrC (MeS‐BrC) light absorption coefficient (b_abs) (R = 0.80) compared to water‐soluble BrC (WS‐BrC) (R = 0.70) at 365 nm. The BrC solar absorptions percentages to those of element carbon (EC) in the range of ultraviolet (300–400 nm) were high in both winter and premonsoon seasons, which can affect the vulnerable environmental radiative balance and atmospheric photochemistry.