Oceans equatorial

High nutrient low chlorophyll regions Include the Southern Ocean, equatorial and subarctic North Pacific, and some strong upwelling areas such as off Peru and California. 

Defined as a region with a primary prodnctivity greater than 35 g C m" yr (Berger and Wefer 1991). Phosphoms accumulation rate is a mean of various moderate to high productivity pelagic regions (e.g., Southern Ocean, equatorial Atlantic, equatorial Pacific compiled by Filippelli 1997a). 

Deep-sea manganese nodules represent a significant potential mineral resource. Whereas the principal constituent of these deposits is manganese, the primary interest has come from the associated metals that the nodules can also contain (see Ocean rawmaterials). For example, metals can range from 0.01—2.0% nickel, 0.01—2.0% copper, and 0.01—2.25% cobalt (12). Recovery is considered an economic potential in the northwestern equatorial Pacific, and to a lesser degree in the southern and western Pacific and Indian Oceans (13—18). 

Biogenic Ma.teria.ls, Deep ocean calcareous or siUceous oo2es are sediments containing >30% of biogenic material. Foraminifera, the skeletal remains of calcareous plankton, are found extensively in deep equatorial waters above the calcium carbonate compensation depth of 4000 to 5000 m. 

Solar beating of tropical oceans warms the surface water, promoting evaporation. Where the equatorial surface waters are warmest and the northeast and southeast trade winds meet, a band of cirrostratus and cirrus clouds spreads out from convective precipitation regions. This area is known as the Intertropical Convergence Zone. 

Water of equatorial divergences and oceanic regions of polar zones 200 482 6.31 15.2 HIGH (50-80 ) 7.6-12.1 1... 

Over 20% of the world s open ocean surface waters are replete in light and major nutrients (nitrate, phosphate, and silicate), yet chlorophyll and productivity values remain low. These so-called "high-nitrate low-chlorophyll" or HNLC regimes (Chisholm and Morel, 1991) include the sub-arctic North Pacific (Martin and Fitzwater, 1988 Martin et al, 1989 Miller et al, 1991), the equatorial Pacific (Murray et al, 1994 Fitzwater et al, 1996) and the southern Ocean (Martin et al.,... 

Coale, K. H., Johnson, K. S., Fitzwater, S. E. et al. (1996). A massive phytoplankton bloom induced by an ecosystem-scale iron fertilization experiment in the equatorial Pacific Ocean. Nature 383, 495-501. 

Hansell, D. A., Bates, N. R. and Carlson, C. A. (1997). Predominance of vertical loss of carbon from surface waters of the equatorial Pacific Ocean. Nature 386,59-61. 

Martin, J. H. et al. (1994). Testing the iron hypothesis in ecosystems of the equatorial Pacific Ocean. Nature 371,123-129. 

Peltzer, E. T. and Hayward, N. A. (1996). Spatial and temporal variability of total organic carbon along 140 W in the equatorial Pacific Ocean in 1992. Deep-Sea Res. II43, 1155-1180. 

Fig. 11-16 Partial pressure of CO2 in surface ocean water along the GEOSECS tracks (a) the Atlantic western basin data obtained between August 1972 and January 1973 (b) the central Pacific data along the 180° meridian from October 1973 to February 1974. The dashed line shows atmospheric CO2 for comparison. The equatorial areas of both oceans release CO2 to the atmosphere, whereas the northern North Atlantic is a strong sink for CO2. (Modified with permission from W. S. Broecker et al. (1979). Fate of fossil fuel carbon dioxide and the global carbon budget, Science 206,409 18, AAAS.)...

Charette MA, Moran SB (1999) Rates of particle scavenging and particulate oiganic carbon export estimated using as a tracer in the subtropical and equatorial Atlantic Ocean. Deep-Sea Res II 46 885-906... 

Clegg SL, Bacon MP, Whitfield M (1991) Application of a generalized scavenging model to thorium isotope and particle data at equatorial and high-latitude sites in the Pacific Ocean. J Geophys Res 96 20655-20670... 

Duime JP, Murray JW, Rodier M, Hansell DA (2000) Export flux in the western and central equatorial Pacific zone and temporal variability. Deep-Sea Res 147 901-936 Eppley RW, Peterson BJ (1979) Particulate organic matter flux and planktonic new production in the deep ocean. Nature 282 670-680... 

Cochran JK, Krishnaswami S (1980) Radium, thorium, uranium and °Pb in deep-sea sediments and sediment pore waters from the north equatorial Pacific. Am J Sci 280 849-889 Cochran JK, Masque P (2003) Short-lived U/Th-series radionuchdes in the ocean tracers for scavenging rates, export fluxes and particle dynamics. Rev Mineral Geochem 52 461-492 Colley S, Thomson J, Newton PP (1995) Detailed °Th, Th and °Pb fluxes recorded by the 1989/90 BQFS sediment trap time-series at 48°N, 20°W. Deep-Sea Res 42(6) 833-848... 

Marcantonio F, Anderson RF, Higgins S, Stute M, Schlosser P, Kubik PW (2001b) Sediment focusing in the central equatorial Pacific Ocean. Paleoceanography 16(3) 260-267 Marcantonio F, Kumar N, Stute M, Anderson RF, Seidl MA, Schlosser P, Mix A (1995) A comparative study of accumulation rates derived by He and Th isotope analysis of marine sediments. Earth Planet. Sci. Letters 133 549-555... 

Murray RW, Knowlton C, Leinen M, Mix AC, Polsky CH (2000) Export production and carbonate dissolution in the central equatorial Pacific Ocean over the past 1 Myr. Paleoceanography 15(6) 570-592... 

Spencer DW, Bacon MP, Brewer PG (1981) Models of the distribution of " b in a section across the North Equatorial Atlantic Ocean. J Mar Res 39(1) 119-137 Staubwasser M, Henderson GM, Berkman PA, Hall BL (in press) Ba, Ra, Th and U in marine mollusc shells and the potential of Ra/Ba dating of Holocene marine carbonate shells. Geochim Cosmochim... 

---