Introduction

The research of carbonaceous aerosol has recently become one of the most favorite topics in the field of atmospheric sciences. The main reason for its popularity is that carbonaceous aerosol represents an extreme diversity within atmospheric aerosol. No matter from which standpoint researchers look at atmospheric aerosol they likely run into some type of carbonaceous aerosol. For those who are concerned with the health effects of air pollution, there are thousands of potentially harmful organic compounds associated with the respirable fraction of atmospheric aerosol. Those, on the other hand, who are primarily interested in inadvertent climate modification, will find by far the largest uncertainties accompanying the effects of carbonaceous aerosol. It is now understood that important atmospheric reactions take place on or are affected by the surface of carbonaceous aerosol particles. Even in cloud formation, which had long been thought not to be affected by aerosol components other than sulfate or sea salt, carbonaceous aerosol now seems to play an important role.