Atmospheric Information Systems is a small consulting firm that provides highly-specialized research and applications services in the atmospheric, physical, and environmental sciences. Atmospheric Information Systems is a sole proprietorship that singly or in collaboration with other small environmental consulting firms provides expert consulting services to government and industry. The firm offers research and applications services in the following areas: (1) photochemical and mesoscale meteorological modeling, (2) urban and regional SIP/FIP air quality planning, (3) analysis and expert evaluation of prior photochemical modeling applications, (4) design and management of large aerometric field programs (in support of modeling activities), (5) aerometric data analysis, and (6) training programs in the use of photochemical and meteorological modeling tools for regulatory applications. In addition, Atmospheric Information Systems offers considerable expertise in the regulatory perspective of air quality modeling, computer simulation procedures, data base management, and statistical and interpretive analysis.