Chemical oceanography of the Arabian Sea: Part vi - Relationship between nutrients and dissolved oxygen in the central basin

Abstract

Inorganic nitrate and phosphate relationships with apparent oxygen utilization (AOU) in the Central Arabian Sea were studied using data collected during 103 cruise of R V Gaveshani (Feb. 1982). The consolidated ratio of Delta AOU: Delta NO3: Delta PO4 was 238:14.3:1 Using the ratio, a relationship between reserved phosphate and reserved nitrate was obtained. Vertical distribution of nutrients showed apart from the occurrence of primary and secondary nitrite maxima in the upper 500 m existence of tertiary nitrite maximum associated with lowering of oxygen concentrations in near-bottom waters. Relationships between reserved phosphate and reserved nitrate and Sigma 1 were used to classify the water masses