Temporal variability of nutrients in the upper ocean
Lead Scientist: Ken Johnson
Lead Engineer: Jon Erickson
Project Manager: Hans Jannasch

Long-term monitoring of dissolved chemicals in seawater is crucial to understanding non-steady state biogeochemical processes in the ocean. Many natural biogeochemical processes are known to undergo significant periodic and sporadic changes. Our knowledge is limited mostly due to the lack of data necessary to be able to characterize this variability. This project directly addresses this problem by developing in situ analyzers to continuously monitor chemical concentrations that can operate on unattended oceanographic platforms for extended time periods.

This abstract represents the final year of developing the OsmoAnalyzer. During 2000 we will complete field testing the redesigned OsmoAnalyzer, incorporate a long flowcell for oligotrophic deployments, and test two further adaptations to address reliability issues for nitrate in high-nutrient environments. During 2000 we expect to coordinate deployments in Monterey Bay to compare data and reliability with the UV-sensor and DigiScanner. Deployments in Monterey Bay and on the Hawaii Ocean Timeseries (HOT) mooring will focus on scientific questions regarding the characterization, quantification and effects of nutrient injections into the mixed layer.