An Inexpensive Moored Water Sampler for Investigating Chemical Variability

Abstract

Recent developments in moored oceanographic sampling devices and in satellite techniques have led to a realization of the inadequacies of past descriptions of the sea which, due to limitations in technology, placed a heavy reliance on coarse-scale measurements and the assumption of a steady-state ocean. The increasing interest in Gulf Stream Rings and long period coastal trapped wave phenomena with several-day periods (e.g. Smith, 1978) are just two illustrations of the increased recognition of the need for better definitions of the ocean’s temporal and spatial variability. Over the last 15 years or so, chemical and biological oceanographers have attempted to redress the problem of inadequate sampling densities by continuous mapping of temperature, salinity, nutrients and chlorophyll a at the sea-surface (e.g. Packard, in press; Schink et al. in press), by using vertically lowered shipboard pumping systems to better resolve high vertical gradients in chemical and biochemical properties (e.g. Anderson, 1982) and by a heavier reliance on satellite information and other optical techniques (Yentsch and Yentsch, 1984). Attempts to develop moored devices for sampling chemical and biological variables have, however, tended to lag behind development of modern high resolution instruments for measuring physical variables.