OCEAN BIOGEOCHEMICAL FLUXES - NEW PRODUCTION AND EXPORT OF ORGANIC-MATTER FROM THE UPPER OCEAN

Studies of ocean biogeochemical fluxes have been energized in this decade, by the urgency of our need to understand and predict the effects of continued CO2 accumulation in the atmosphere, by the global perspectives offered by satellite views of ocean color and related physical fields (McClain et al. 1991; Yoder et al. 1992; Mitchell 1994), and by the successful implementation of the Joint Global Ocean Flux Study (JGOFS; Bowles and Livingston, 1993). In this review, I focus on oceanic new production, originally defined as the fraction of primary production supported by inputs of ‘new’ nitrogen from outside the euphotic zone. With a growing appreciation of the role of this fundamental biogeochemical flux in the global carbon cycle, it has become more common to refer interchangeably to new production so defined, and to the export of organic matter from the upper ocean (e.g.. Sarmiento and Siegenthaler 1992). New production, the driving process of the ocean carbon cycle, is responsible for maintaining over half the vertical gradient in total inorganic carbon. In this review I refer to nitrate‐based new production in the open sea, and not to new production supported by other N compounds as observed in the coastal zone. Eppley (1992) gives a personal view of the modern formulation of the concept of equivalence between new production and upper ocean export. This review is dedicated to the memory of John Martin, a friend, colleague, leader and teacher who contributed mightily to our field. Copyright 1995 by the American Geophysical Union.