An Evaluation of an In Situ Fluorometer for the Estimation of Chlorophyll a
Abstract
In situ fluorometers are evaluated in their estimation Of chlorophyll a. Calibrations from at-sea and laboratory data showed linear relationships between fluorescence and chlorophyll a as measured by in situ fluorometers with r 2 > 0.9. Examination of regression residuals showed an increasing error variance with the magnitude of chlorophyll on two of four cruises. The most likely source of this increasing error variance was in one case, a photoadaptation effect and in the other a population shift between the beginning and end of the cruise. Smaller variability was also found in the ratio fluorescence to chlorophyll a traced to sample depth, a time of day, although this variability was not a consistent property of the data. Generally, there was excellent agreement between laboratory and at-sea calibrations for low levels of chlorophyll typical of oceanic environments. The laboratory calibration of these instruments-was stable over time, suggesting that good estimates of chlorophyll a can be made from fluorometers placed on ocean moorings.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1993
- Accession Number
- ADA266652
Entities
People
- Christopher Langdon
- John Marra
Organizations
- Lamont–Doherty Earth Observatory