_version_ 1867170054841303040
author Wasmund, Norbert
author_facet Wasmund, Norbert
collection Datos científicos de ciencias marinas y ambientales
contents Nitrogen fixation data from the cruise number M103/2 with research vessel "Meteor" from 21.01.-11.02.2014 (second leg from Walvis Bay to Walvis Bay) in front of Namibia. Samples taken by CTD- rosette sampler from different depths and incubated in glass bottles (535 ml) at light intensities that resemble the in situ light intensities of the sampling depth after 15N2 gas was injected to the sample. After the incubation time of 24 hours, the complete bottle content was filtered onto a pre-combusted Whatman GF/F filter. Filters were frozen, transported to the institute on dry ice and measured in a mass spectrometer for Delta15N. The principle of the method was described by Montoya et al. (1996) and calculation was done according to their spread sheet. From the data of the single depths, the nitrogen fixation per square meter within the upper 40 m of the water column was calculated. The methods are described in detail in a paper submitted by Wasmund et al. in 2014 to be printed in 2015. Some results are surprisingly below zero. This occurs if the Delta15N of the blank is higher than the measurement after incubation. It indicates that no nitrogen fixation occurred. Due to natural variability, the variability of the nitrogen fixation data is high. In an overall estimate, also over several cruises, negative and positive values compensate more or less, suggesting that nitrogen fixation is insignificant in the waters in front of northern Namibia and southern Angola.
format Dataset Open Access
id pangaea_https___doi_org_10_1594_PANGAEA_843447
institution PANGAEA
language en
publishDate 2015
publisher PANGAEA
record_format pangaea
spellingShingle Depth integrated nitrogen fixation from the northern Benguela upwelling system during METEOR cruise M103/2
Wasmund, Norbert
104; 107; 118; 120; 77; 78; 86; 89; Calculated according to Montoya et al. (1996); CTD/Rosette; CTD-RO; Date/Time of event; Depth, bottom/max; Depth, top/min; DEPTH, water; Event label; GENUS; Geochemistry and ecology of the Namibian upwelling system; Latitude of event; Longitude of event; M103/2; M103/2_104; M103/2_107; M103/2_118; M103/2_120; M103/2_77; M103/2_78; M103/2_86; M103/2_89; Meteor (1986); Nitrogen fixation rate, integrated per hour; off Namibia; Optional event label
Nitrogen fixation data from the cruise number M103/2 with research vessel "Meteor" from 21.01.-11.02.2014 (second leg from Walvis Bay to Walvis Bay) in front of Namibia. Samples taken by CTD- rosette sampler from different depths and incubated in glass bottles (535 ml) at light intensities that resemble the in situ light intensities of the sampling depth after 15N2 gas was injected to the sample. After the incubation time of 24 hours, the complete bottle content was filtered onto a pre-combusted Whatman GF/F filter. Filters were frozen, transported to the institute on dry ice and measured in a mass spectrometer for Delta15N. The principle of the method was described by Montoya et al. (1996) and calculation was done according to their spread sheet. From the data of the single depths, the nitrogen fixation per square meter within the upper 40 m of the water column was calculated. The methods are described in detail in a paper submitted by Wasmund et al. in 2014 to be printed in 2015. Some results are surprisingly below zero. This occurs if the Delta15N of the blank is higher than the measurement after incubation. It indicates that no nitrogen fixation occurred. Due to natural variability, the variability of the nitrogen fixation data is high. In an overall estimate, also over several cruises, negative and positive values compensate more or less, suggesting that nitrogen fixation is insignificant in the waters in front of northern Namibia and southern Angola.
title Depth integrated nitrogen fixation from the northern Benguela upwelling system during METEOR cruise M103/2
topic 104; 107; 118; 120; 77; 78; 86; 89; Calculated according to Montoya et al. (1996); CTD/Rosette; CTD-RO; Date/Time of event; Depth, bottom/max; Depth, top/min; DEPTH, water; Event label; GENUS; Geochemistry and ecology of the Namibian upwelling system; Latitude of event; Longitude of event; M103/2; M103/2_104; M103/2_107; M103/2_118; M103/2_120; M103/2_77; M103/2_78; M103/2_86; M103/2_89; Meteor (1986); Nitrogen fixation rate, integrated per hour; off Namibia; Optional event label
url https://doi.org/10.1594/PANGAEA.843447