Estimating new production in the equatorial Pacific Ocean at 150°W
作者:
Richard C. Dugdale,
Frances P. Wilkerson,
Richard T. Barber,
Francisco P. Chavez,
期刊:
Journal of Geophysical Research: Oceans
(WILEY Available online 1992)
卷期:
Volume 97,
issue C1
页码: 681-686
ISSN:0148-0227
年代: 1992
DOI:10.1029/91JC01533
数据来源: WILEY
摘要:
A major goal of the WEC88 cruise of the R/VWecomato the equatorial Pacific (made in February‐March 1988), was to establish rates of new production along a meridional section at 150°W and to compare these measured rates with the relatively high values for the equatorial Pacific that had been reported previously using indirect methods and models. New production values were obtained from the traditional approach (in the sense of Dugdale and Goering (1967)) using15N labelled nitrate uptake, and by using14C fixation values multiplied by ƒ (proportion of new production) from various sources: from15N data, from a14C fixation versus ƒ relationship (Eppley and Peterson, 1979) or from a nitrate versus ƒ relationship (Platt and Harrison, 1985). The ratios of directly measured nitrate and carbon uptake and the ratios of nitrate to nitrate plus ammonium uptake, i.e., values of ƒ, agree well; values of ƒ calculated from carbon uptake or from nitrate concentration are overestimates for the equatorial upwelling region. Carbon to nitrogen uptake ratios measured with14C and15N, respectively, approximate the Redfield molar ratio, 6.6 C:N. The overall mean value of ƒ (0.17) helps confirm the view that the low primary production in the enriched eastern equatorial Pacific is due to failure of the nitrate uptak
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