Carbonaceous aerosols and their potential role in atmospheric chemistry

This paper considers the nature of carbonaceous surfaces, the means by whic h they are activated, the nature of some functional groups that they suppor t, and some reaction mechanisms that may be involved. Because of the strong affinity of carbonaceous surfaces for organic species and because of the e ase with which compounds in a high oxidation state can oxidize the carbonac eous surface, it is highly likely that carbonaceous aerosols are interactin g chemically with a range of organic species in ways that have, as yet, not been fully characterized but may significantly affect the oxidizing capaci ty of our atmosphere. If HONO is formed on the surface of carbonaceous aero sols then this could be a significant source of HOx, as HONO is readily pho tolyzed to give OH, and it could explain the large values of HONO often obs erved in the troposphere. In general, the reduction of NOy on carbonaceous aerosols is an important consideration, and it is addressed here.