Publication Date:
2024-07-01
Description:
During a R.V. Meteor JGOFS-NABE cruise to a tropical site in the northeast Atlantic in spring 1989, three different vertical regimes with respect to nitrate distribution and availability within the euphotic zone were observed. Besides dramatic variations in the depth of the nitracline, a previously undescribed nose-like nitrate maximum within the euphotic zone was the most prominent feature during this study. Both the vertical structure of phytoplankton biomass and the degree of absolute and relative new production were related to the depth of the nitracline, which in turn was dependent on the occurrence/non-occurrence of the subsurface subtropical salinity maximum (Smax). The mesoscale variability of the nitracline depth, as indicated from a pre-survey grid, and published data on the frequent occurrence of the Smax in tropical waters suggest higher variability of new production and F-ratio than usually expected for oligotrophic oceans. The importance of salt fingering and double diffusion for nitrate transport into the euphotic zone is discussed.
Keywords:
14C uptake; Ammonium; Bacteria; Calculated; Carbon, organic, particulate; Carbon/nitrogen analyser (GF/F filtered); Chemiluminescence (NO2/NO3); Chlorophyll a; Chlorophyll a, fluorometric determination (Grasshoff et al., 1983, Chemie GmbH); Colorometric analysis, manual; Continuous Flow Automated Analysis (Gordon et al., 1993, WOCE Tech Rpt 93-1); CTD; CTD/Rosette; CTD-RO; Cyanobacteria; Date/Time of event; Density, sigma-theta (0); DEPTH, water; Elevation of event; Epifluorescence microscopy; Eukaryotes; Event label; Gravimetric analysis (GF/F filtered); JGOFS; Joint Global Ocean Flux Study; Latitude of event; Longitude of event; M10/1; M10/1-CTD-239_045; M10/1-CTD-241_047; M10/1-CTD-242_048; M10/1-CTD-245_050; M10/1-CTD-247_052; M10/1-CTD-249_053; M10/1-CTD-252_056; M10/1-CTD-254_058; M10/1-CTD-258_064; M10/1-CTD-260_067; M10/1-CTD-264_075; M10/1-CTD-266_076; M10/1-CTD-270_078; M10/1-CTD-273_079; M10/1-CTD-274_080; M10/1-CTD-277_081; M10/1-CTD-279_083; M10/1-CTD-282_085; M10/1-CTD-283_086; M10/1-CTD-286_089; M10/1-CTD-287_090; M10/1-CTD-290_093; M10/1-CTD-291_095; M10/1-CTD-292_098; M10/1-CTD-295_101; M10/1-CTD-358_164; M10/1-CTD-359_165; M10/1-CTD-361_166; M10/1-CTD-362_168; M10/1-CTD-364_170; M10/1-CTD-366_171; M10/1-CTD-369_174; M10/1-CTD-370_180; M10/1-CTD-374_183; M10/1-CTD-376_185; M10/1-CTD-380_190; M10/1-CTD-382_191; M10/1-CTD-383_193; M10/1-CTD-385_195; M10/1-CTD-387_196; M10/1-CTD-390_200; M10/1-CTD-392_201; M10/1-CTD-396_206; M10/1-CTD-398_208; M10/1-CTD-401_212; M10/1-CTD-403_214; M10/1-CTD-403_508; M10/1-CTD-403_509; M10/1-CTD-406_218; M10/1-CTD-410_219; M10/1-CTD-414_220; M10/1-CTD-418_221; M10/1-CTD-422_222; M10/1-CTD-426_223; Meteor (1986); NABE; Nanoflagellates, heterotrophic; Nitrate and Nitrite; Nitrite; Nitrogen, organic, particulate; North Atlantic Bloom Experiment, 1989-1991; Optical microscopy; Oxygen; Oxygen, Winkler (Culberson, 1991, WOCE Report 68/91); Phosphate; Primary production of carbon per hour; Salinity; Silicate; Suspended matter, total; Temperature, water
Type:
Dataset
Format:
text/tab-separated-values, 3726 data points
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