Nutrients, Chlorophyll, Primary Production and Related Biogeochemical Properties in the Ocean Mixed Layer. A Compilation of Data Collected at Nine JFOFS Sites.

摘要

Global carbon cycle models are becoming more prevalent and sophisticated as the scientific community seeks to understand how various earth systems will respond to increasing Co2 in the atmosphere. The role of the biosphere, particularly in the marine environment, is gaining more attention as physical and biological modelers alike realize that the ocean's role in the carbon cycle may be largely influenced by biogeochemical reactions in the upper ocean. The fixing of inorganic carbon by phytoplankton in the euphotic zone (production), largely depends on physical processes to deliver limiting macronutrients from deeper oceanic zones. The ultimate fate of that production is in turn controlled by physics (advection, mixing), and by biological processes such as how various food webs package the carbon into sinking particles or dissolved organic matter (DOM), how much is recycled in the euphotic zones, and how much is exported as sinking material or DOM. Net community export production is a measure of how much fixed carbon is removed from the surface ocean. These values are difficult to obtain on a global or even regional basis, and vary widely from studies based on satellite data (e.g. Field et al. 1998), empirical and theoretical temperature relationships (e.g. Laws et al. 2000) and ecosystem models (e.g. Moore et al. in press (a), in press (b)). Bringing these various approaches toward a more complete understanding of upper ocean carbon cycle science has been a standing goal of the U.S. JGOFS Synthesis and Modeling Project (U.S. JGOFS 1997). This technical report is an effort to provide investigators with physical, biological, and chemical data in a common format for various sites around the globe (Fig. 1). This technical report provides summary data for nine distinct US JGOFS and international JGOFS sites. Four of these are point-locations where long-term time-series data have been collected: the Bermuda Atlantic Time-series Study (BATS); the Hawaiian Ocean Time-series (HOT); KERFIX, the French JOGOFS site; and Station P, the Canadian JGOFS time-series station. The remaining sites are U.S. JGOFS Process Study sites: Arabian Sea; Equatorial Pacific (EqPac); North Atlantic Bloom Experiment (NABE); and the Antarctic Environment and Southern Ocean Survey (AESOPS) (which includes two distinct regions: the Ross Sea and Antarctic Polar Front Zone). To provide an easy to use, practical presentation of data from each of these sites, both depth-profile data and the mixed layer average for each variable are determined on a cast-by-cast basis.