In:
Journal of Atmospheric and Oceanic Technology, American Meteorological Society, Vol. 32, No. 12 ( 2015-12), p. 2305-2317
Abstract:
This study investigated the effect of hydrostatic pressure of up to 6000 dbar on Aanderaa and Sea-Bird oxygen optodes both in the laboratory and in the field. The overall pressure response is a reduction in the O 2 reading by 3%–4% per 1000 dbar, which is closely linear with pressure and increases with temperature. Closer inspection reveals two superimposed processes with an opposite effect: an O 2 -independent pressure response on the luminophore that increases optode O 2 readings and an O 2 -dependent change in luminescence quenching that decreases optode O 2 readings. The latter process dominates and is mainly due to a shift in the equilibrium between the sensing membrane and seawater under elevated pressures. If only the dominant O 2 -dependent process is considered, then the Aanderaa and Sea-Bird optodes differ in their pressure response. Compensation of the O 2 -independent process, however, yields a uniform O 2 dependence for Aanderaa optodes with standard foil and fast-response foil as well as for Sea-Bird optodes. A new scheme to calculate optode O 2 from raw data is proposed to account for the two processes. The overall uncertainty of the optode pressure correction amounts to 0.3% per 1000 dbar, which is mainly due to variability between the sensors.
Type of Medium:
Online Resource
ISSN:
0739-0572
,
1520-0426
DOI:
10.1175/JTECH-D-15-0108.1
Language:
Unknown
Publisher:
American Meteorological Society
Publication Date:
2015
detail.hit.zdb_id:
2021720-1
detail.hit.zdb_id:
48441-6
