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HIGH-RESOLUTION IN SITU PH MEASUREMENTS AT STATION ALOHA USING AN ION-SENSITIVE FIELD EFFECT TRANSISTOR

For 28 years, the Hawaii Ocean Time-series program has been measuring pH as one of the carbonate parameters that characterize the inorganic carbon system at Station ALOHA. This benchmark time-series shows surface pCO2 rising in step with increasing atmospheric CO2 and corresponding acidification of the ocean. While this record has been instrumental for elucidating the physical and biogeochemical processes controlling the inorganic carbon system at Station ALOHA, the approximately monthly sampling is too coarse to explain processes varying daily. Here, we examine pH data collected approximately every two minutes using a Field Effect Transistor (FET) pH sensor. The FET sensor was deployed in the mixed layer on a floating array for periods up to of 72 hours.  The accuracy of the FET measurements was assessed by comparison with spectrophotometric pH measurements on seawater sampled with Niskin bottles. Variations in this high frequency data set are examined for a biological signature alongside concurrent measurements of temperature, salinity, and oxygen concentration.

Authors

Sadler, D. W., Daniel K. Inouye Center for Microbial Oceanography: Research and Education, University of Hawaii, USA, sadler@hawaii.edu

Barone, B., Daniel K. Inouye Center for Microbial Oceanography: Research and Education, University of Hawaii, USA, bbarone@hawaii.edu

Burkitt, J. W., Daniel K. Inouye Center for Microbial Oceanography: Research and Education, University of Hawaii, USA, jburkitt@hawaii.edu

Dore, J. E., Department of Land Resources and Environmental Sciences, Montana State University, jdore@montana.edu

Church, M. J., University of Montana, Flathead Lake Biological Research Station, USA, mjchurch@hawaii.edu

Karl, D. M., Daniel K. Inouye Center for Microbial Oceanography: Research and Education, University of Hawaii, USA, dkarl@hawaii.edu

Details

Poster presentation

Session #:040
Date: 03/01/2017
Time: 15:30 - 16:30
Location: Poster/Exhibit Hall

Presentation is given by student: No

PosterID: 353