ence global ecosystems. Carbon dioxide and other greenhouse gases, halocarbons that affect stratospheric ozone, and sulfur gases that create sulfate aerosol all have important source and/or sink terms in the oceans. More accurate determination of air-sea fluxes of these gases, of both natural and anthropogenic origin, are critical to assess processes affected by these gases.

7. Relationships among photosynthesis, internal cycling, and material export from the upper water column. Most production and remineralization of organic matter occurs in the shallow euphotic zone. Our understanding of processes such as CO₂ and N₂ sequestration from the atmosphere and pelagic-benthic coupling are thus critically dependent on improving our understanding of euphotic zone recycling.

8. Controls on the accumulation of sedimentary phases and their chemical and isotopic compositions. Further development of paleoenvironmental indicators will enable better understanding of past climatic and carbon cycle variations. Earth historical records provide an invaluable guide to natural variability of the chemistry/climate system, including natural "experiments" in which the whole system has responded to a perturbation.

Synthesizing these eight topics, three major areas appear especially fertile for future discovery. The first is boundary interactions between major reservoirs, including gas exchange between air and sea and advective flows through ridge systems and coastal aquifers, which promise resolution of important mass balances for the surface of the Earth. The second area where we are on the verge of making sizable discoveries is the ocean's ability to support life, its effect on the cycling of elements in the upper ocean, and the forms of organic matter that fuel various life forms. Last, and perhaps most important are the links between environmental changes (e.g., anthropogenically induced impacts) and the chemistry of the ocean—links that have both local and global significance.

Future advances in ocean chemistry will require new approaches to infrastructure to support the science. Emerging technologies, and access to them, will be critical for the next advances. These include methods to sample, analyze, and visualize chemical distributions in the oceans at vastly wider ranges of time and space scales than heretofore possible. As we focus more strongly on variability in the ocean, higher data densities over longer time scales will be required. Sensor technology that can be used at sea is particularly well-poised to enable new insights into the functioning of the oceans. There is need for some tuning in the funding approaches to certain kinds of research, such as new opportunities for mid-size research groups or long-time series.

Shifts in approach to recruitment, training, and career guidance are needed to provide the human resources for growth of this field. Because ocean chemistry is among the most interdisciplinary of marine sciences, greater linkage is recommended to other oceanographic and materials science disciplines. For example, shifts in training from chemical to oceanographic programs must not lead to atrophy of our connections to the chemical sciences. Examples of such connections include more active recruiting of chemistry undergraduates and involvement of ocean chemists in their environmental science program areas.

The picture that emerges from this self-assessment is one of a field with a record of impressive recent gains and a prospect of imminent further advance. These advances should benefit not only the field of ocean chemistry narrowly defined, but will be central to a variety of other fields of Earth science.