Document Type

Article

Publication Date

8-1-1997

Department

Marine Science

Abstract

An in situ multisensor fiber-optic fluorometer (MFF) has been developed to acquire long-term chlorophyll fluorescence measurements in the oceanic bottom boundary layer to characterize the finescale pigment structure at vertical spatial scales comparable to physical measurements. The eight fluorescence sensors of the MFF are composed of dual optical fibers of varying lengths (1.5-8 m), with the fiber ends oriented at 30 degrees to each other and enclosed by a small light baffle. Strobe excitation blue light is passed through one of each pair of optical fibers and stimulated chlorophyll fluorescence is carried back to a photomultiplier. Two sets of four fluorescence sensors assigned to high- and low-sensitivity photomultiplier detectors enable chlorophyll a measurements in two ranges, 0-50 mg m(-3) and 0-200 mg m(-3), respectively. Aspects of the design of the fiber-optic sensor are described that were intended to optimize detection of fluorescence signals and minimize interference by ambient light. The fiber-optic sensor outputs were stable with minimal instrument drift during long-term field operations, and measurements were not affected by turbidity and ambient light. A vertical array of fiber-optic fluorescence sensors supported on a tripod has been deployed at coastal sites for up to seven weeks and chlorophyll fluorescence was obtained with sufficiently high vertical spatial and temporal resolution.

Comments

Publisher Version

© Copyright 1997 American Meteorological Society (AMS). Permission to use figures, tables, and brief excerpts from this work in scientific and educational works is hereby granted provided that the source is acknowledged. Any use of material in this work that is determined to be “fair use” under Section 107 of the U.S. Copyright Act or that satisfies the conditions specified in Section 108 of the U.S. Copyright Act (17 USC §108) does not require the AMS’s permission. Republication, systematic reproduction, posting in electronic form, such as on a website or in a searchable database, or other uses of this material, except as exempted by the above statement, requires written permission or a license from the AMS. All AMS journals and monograph publications are registered with the Copyright Clearance Center (http://www.copyright.com). Questions about permission to use materials for which AMS holds the copyright can also be directed to the AMS Permissions Officer at permissions@ametsoc.org. Additional details are provided in the AMS Copyright Policy statement, available on the AMS website (http://www.ametsoc.org/CopyrightInformation).

Publication Title

Journal of Atmospheric and Oceanic Technology

Volume

14

Issue

4

First Page

889

Last Page

896

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