Over the past 10-15 years atmospheric chemistry has evolved from a young research discipline devoted primarily to local problems of urban pollution and air quality to a mature science concerned with the hemispheric to global scale cycling of a wide variety of chemical species. To a large extent this change has resulted from an increasing realization that human activities can cause chemical disturbances to the natural troposphere on scales far beyond local concerns. Well-known examples include changes in the regional-to-global concentrations of certain nitrogen compounds, lead and other heavy metals, artificial radionuclides, a number of synthetic organic substances, certain acid-forming species, carbon dioxide and methane. These chemical changes in the atmosphere can often extend to the earth's soils, oceans, and biota far from the original source region. They can result in alterations in the earth's climate, changes in vital nutrient cycles, and impact significantly on the public health and quality of life on earth. The Atmosphere/Ocean Chemistry Experiment (AEROCE) will be a coordinated multi-institutional atmospheric and marine chemistry research project centered in the North Atlantic region. The ultimate goal of the AEROCE project will be the development of a predictive capability for the continentally derived species observed in the marine troposphere over the North Atlantic. The selection of sites and the measurement protocol in AEROCE has been developed jointly by modelers and field experimentalists. This project provides installation and operational support for AEROCE. A network of four aerosol, gas and precipitation sampling stations will be established in the North Atlantic Ocean at the following locations: Barbados, West Indies; Bermuda on the west end; Mace Head, Ireland, on the west coast; Tenerife, Canary Islands, at the obervatory at Izania at 2600 meters. Each station will have a three-pump aerosol filter sampling system and a triplet rain collector. The network will be completely operational by early 1988. During the first year all stations will collect aerosol and precipitation samples on a weekly basis, thereafter, on a daily basis. When the four station network is in full operation, it will yield about 6000 discrete filter and precipitation samples each year. The Secondary Network Operations Group will construct all equipment, install the stations on site, manage operations at the site through a local cooperative, and support and maintain the network stations. This group will also receive the samples and data from secondary network stations and redistribute the materials as required by AEROCE investigators.