Vertical distribution of fluorescent organic matter in the North Pacific

Hayase, Kohji; Tsubota, Hiroyuki; Sunada, Isao; Goda, Shiro; Yamazaki, Hideo

doi:10.1016/0304-4203(88)90117-x

Cited by 68 publications

(37 citation statements)

References 20 publications

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“…These percentages were estimated considering the conversion factor of FDOM M to DOC obtained with the commercial fulvic acid. As in other marine environments (Hayase et al 1987, 1988, Chen & Bada 1992, Determann et al 1996, FDOM M concentrations were low at the surface and increased with depth. This gradient is created by photodegradation in the surface layer and humification throughout the water column, especially at the BNL and in sediments (Skoog et al 1996, Burdige et al 2004.…”

Section: Seasonal Accumulationsupporting

confidence: 52%

“…In addition to simplicity, sensitivity and quickness, the small sample volume requirement is another attraction of this technique. It was applied first to the study of humic substances (Cabaniss & Shuman 1987, Hayase et al 1988, Chen & Bada 1992. Coble et al (1990) were pioneers in the use of excitation/emission matrices (EEMs) to study DOM fluorescence.…”

Section: Introductionmentioning

confidence: 99%

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DOM fluorescence, a tracer for biogeochemical processes in a coastal upwelling system (NW Iberian Peninsula)

Nieto‐Cid¹,

Álvarez‐Salgado²,

Gago³

et al. 2005

Mar. Ecol. Prog. Ser.

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Section: Seasonal Accumulationsupporting

confidence: 52%

Section: Introductionmentioning

confidence: 99%

DOM fluorescence, a tracer for biogeochemical processes in a coastal upwelling system (NW Iberian Peninsula)

Nieto‐Cid¹,

Álvarez‐Salgado²,

Gago³

et al. 2005

Mar. Ecol. Prog. Ser.

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“…The low fluorescence intensity in the surface layer has been thought to be caused by photobleaching by solar radiation [Kramer, 1979;Hayase et al, 1988;Chen and Bada, 1992]. Since the photobleaching rate of FDOM M depends on the light intensity, the rate is probably maximized in surface waters and exponentially decreases with water depth [Kouassi et al, 1990].…”

Section: Distribution Of Fluorescence Intensity Of Fdom M In Surface mentioning

confidence: 99%

“…Snapshot profiles show that fluorescence intensity is low and uniform within the mixed layer, and this is probably due to photodegradation and vertical mixing [Kramer, 1979;Hayase et al, 1988]. It is well known that the mixed layer depths (MLD) vary considerably with the season; they tend to develop in winter and decay in summer, and the extent of the seasonal change in the MLD depends on the latitude.…”

Section: Introductionmentioning

confidence: 99%

Relationship between the seasonal change in fluorescent dissolved organic matter and mixed layer depth in the subtropical western North Pacific

Omori

Hama

Ishii³

et al. 2010

J. Geophys. Res.

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[1] Spatial and temporal distributions of marine humic-like fluorescent dissolved organic matter (FDOM M ) were determined in the subtropical western North Pacific to evaluate the controlling factors of FDOM M behaviors. The observations were conducted at 4 stations (15-30°N) along 137°E in a subtropical area between January 2006 and April 2007. The florescence intensity of FDOM M was low (0.14-0.25 quinine sulfate units (QSU)) in the surface layer probably due to photodegradation, and increased with depth (0.90-1.10 QSU at 1000 m), irrespective of season and station. In the surface layer, the thickness of the water mass with low fluorescence intensity (<0.3 QSU) showed the seasonal change by being deeper in winter and shallower in summer, depending on the mixed layer depth (MLD). The average fluorescence intensity within the mixed layer also varied seasonally at midlatitudes; the intensity in summer was 40.8-53.8% of that in winter. Since the MLD was very much shallower in summer than in winter, FDOM M in the mixed layer would be kept within a shallow depth during the summer where intensive photodegradation could occur. The concentration of total organic carbon (TOC) was at its maximum at the water surface and decreased with depth, being adverse to FDOM M . Thus, the ratio of fluorescence intensity to TOC concentration was lowest (0.002-0.003) in surface water, which implies that FDOM M is not quantitatively important to the dissolved organic carbon pool. However, considering the possible difference in the stabilities of FDOM M against photochemical and microbial degradation, it is conceivable that photobleached FDOM M is one of the important organic groups constituting marine dissolved organic matter.Citation: Omori, Y., T. Hama, M. Ishii, and S. Saito (2010), Relationship between the seasonal change in fluorescent dissolved organic matter and mixed layer depth in the subtropical western North Pacific,

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“…Fluorescence characterization has proven to be a useful means of characterizing oceanic water masses (e.g., Hayase et al 1988;Coble et al 1990;Mopper and Schultz 1993;Coble 1996). In a study of a freshwater lake, Stewart and Wetzel (1980) showed that larger molecular weight aquatic humic fractions had a greater absorbance but lower fluorescence than smaller molecular weight fractions.…”

mentioning

confidence: 99%

Spectrofluorometric characterization of dissolved organic matter for indication of precursor organic material and aromaticity

McKnight

Boyer

Westerhoff

et al. 2001

Limnology & Oceanography

2,501

1,810

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We studied the fluorescence properties of fulvic acids isolated from streams and rivers receiving predominantly terrestrial sources of organic material and from lakes with microbial sources of organic material. Microbially derived fulvic acids have fluorophores with a more sharply defined emission peak occurring at lower wavelengths than fluorophores in terrestrially derived fulvic acids. We show that the ratio of the emission intensity at a wavelength of 450 nm to that at 500 nm, obtained with an excitation of 370 nm, can serve as a simple index to distinguish sources of isolated aquatic fulvic acids. In our study, this index has a value of ϳ1.9 for microbially derived fulvic acids and a value of ϳ1.4 for terrestrially derived fulvic acids. Fulvic acids isolated from four large rivers in the United States have fluorescence index values of 1.4-1.5, consistent with predominantly terrestrial sources. For fulvic acid samples isolated from a river, lakes, and groundwaters in a forested watershed, the fluorescence index varied in a manner suggesting different sources for the seepage and streamfed lakes. Furthermore, we identified these distinctive fluorophores in filtered whole water samples from lakes in a desert oasis in Antarctica and in filtered whole water samples collected during snowmelt from a Rocky Mountain stream. The fluorescence index measurement in filtered whole water samples in field studies may augment the interpretation of dissolved organic carbon sources for understanding carbon cycling in aquatic ecosystems.Aquatic fulvic acid is a major fraction of dissolved organic matter (DOM) in natural waters. Aquatic fulvic acids are heterogeneous, moderate molecular weight, yellow-colored organic acids. Examples of processes controlled by fulvic acid are (1) chemical speciation and transport of trace metals through complexation reactions (e.g., Breault et al. 1996); (2) formation of trihalomethanes in drinking water by interactions between chlorine and fulvic acid during water AcknowledgmentsWe thank K. Cunningham for help with spectroscopic methods and G. Aiken, J. Debroux, P. Coble, and four anonymous reviewers for valuable comments on the manuscript.

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Vertical distribution of fluorescent organic matter in the North Pacific

Cited by 68 publications

References 20 publications

DOM fluorescence, a tracer for biogeochemical processes in a coastal upwelling system (NW Iberian Peninsula)

DOM fluorescence, a tracer for biogeochemical processes in a coastal upwelling system (NW Iberian Peninsula)

Relationship between the seasonal change in fluorescent dissolved organic matter and mixed layer depth in the subtropical western North Pacific

Spectrofluorometric characterization of dissolved organic matter for indication of precursor organic material and aromaticity

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