Measurement of light absorption by aquatic particles: improvement of the quantitative filter technique by use of an integrating sphere approach

Röttgers, Rüdiger; Gehnke, Steffen

doi:10.1364/ao.51.001336

Cited by 83 publications

(112 citation statements)

References 36 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…3e). The TR method thus yielded slightly flatter phytoplankton absorption spectra, although the comparison was dispersed (R 2 ¼ 0.75) probably because of differences in the amplification factor beta applied for each method, which can also spectrally affect a ph (l) (Röttgers and Gehnke, 2012). Lastly, S det computed for the a det (l) spectra measured by the TR method was also substantially lower, with large discrepancies for very high QFT-S det (Fig.…”

Section: The Qft and Tr Methods For Light Absorption Of Particlesmentioning

confidence: 94%

“…Investigations of the extent to which the TR method improves measurements in waters with high-suspended sediment content (e.g., Ferrari, 2002, 2003;Moate et al, 2012;Röttgers and Gehnke, 2012) have yet to include the possible effects on the spectral shape of the phytoplankton coefficients.…”

Section: The Qft and Tr Methods For Light Absorption Of Particlesmentioning

confidence: 99%

“…No clear trends were found in TR-a ph (l):QFT-a ph (l) and [Chl a], TR-a p (l) or TR-offset (absorption in the red wavebands attributed to detritus by the TR method). Both the correction for scattering errors and the amplification of particulate signal (correction beta), however, impose wavelength-dependent effects (Röttgers and Gehnke, 2012), potentially affecting the retrievals of S det and S f . In general, the TRderived spectra were flatter than those derived by the QFT method.…”

Section: Retrieval Of Light Absorption Parameters By Different Methodsmentioning

confidence: 99%

See 2 more Smart Citations

Variability in the light absorption coefficients of phytoplankton, non-algal particles, and colored dissolved organic matter in a subtropical bay (Brazil)

Ferreira

Ciotti

Giannini

2014

Estuarine, Coastal and Shelf Science

View full text Add to dashboard Cite

Section: The Qft and Tr Methods For Light Absorption Of Particlesmentioning

confidence: 94%

Section: The Qft and Tr Methods For Light Absorption Of Particlesmentioning

confidence: 99%

Section: Retrieval Of Light Absorption Parameters By Different Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Variability in the light absorption coefficients of phytoplankton, non-algal particles, and colored dissolved organic matter in a subtropical bay (Brazil)

Ferreira

Ciotti

Giannini

2014

Estuarine, Coastal and Shelf Science

View full text Add to dashboard Cite

“…where 2.303 is the conversion of from base-10 to a natural logarithm, A is the particulate retention area of the filter (m 2 ), V is the volume filtered (m 3 ), and β is the path length amplification coefficient (4.5; Röttgers and Gehnke, 2012).…”

Section: Absorption Spectramentioning

confidence: 99%

Diurnal variation in the coupling of photosynthetic electron transport and carbon fixation in iron-limited phytoplankton in the NE subarctic Pacific

et al. 2016

View full text Add to dashboard Cite

Abstract. Active chlorophyll a fluorescence approaches, including fast repetition rate fluorometry (FRRF), have the potential to provide estimates of phytoplankton primary productivity at an unprecedented spatial and temporal resolution. FRRF-derived productivity rates are based on estimates of charge separation in reaction center II (ETR RCII ), which must be converted into ecologically relevant units of carbon fixation. Understanding sources of variability in the coupling of ETR RCII and carbon fixation provides physiological insight into phytoplankton photosynthesis and is critical for the application of FRRF as a primary productivity measurement tool. In the present study, we simultaneously measured phytoplankton carbon fixation and ETR RCII in the iron-limited NE subarctic Pacific over the course of a diurnal cycle. We show that rates of ETR RCII are closely tied to the diurnal cycle in light availability, whereas rates of carbon fixation appear to be influenced by endogenous changes in metabolic energy allocation under iron-limited conditions. Unsynchronized diurnal oscillations of the two rates led to 3.5-fold changes in the conversion factor between ETR RCII and carbon fixation (K c /n PSII ). Consequently, diurnal variability in phytoplankton carbon fixation cannot be adequately captured with FRRF approaches if a constant conversion factor is applied. Utilizing several auxiliary photophysiological measurements, we observed that a high conversion factor is associated with conditions of excess light and correlates with the increased expression of non-photochemical quenching (NPQ) in the pigment antenna, as derived from FRRF measurements. The observed correlation between NPQ and K c /n PSII requires further validation but has the potential to improve estimates of phytoplankton carbon fixation rates from FRRF measurements alone.

show abstract

“…This amplification is corrected by an amplification factor. In this study we used the method of measurement and correction described in Röttgers and Gehnke (2012). Measurements were made in a dual-beam UV/VIS spectrophotometer (Lambda 950, Perkin Elmer) that 7084 H. Örek et al: Contribution to a bio-optical model for remote sensing Table 2.…”

Section: Measurements and Post Processingmentioning

confidence: 99%

Contribution to a bio-optical model for remote sensing of Lena River water

et al. 2013

View full text Add to dashboard Cite

Abstract. Bio-optical measurements and sampling were carried out in the delta of the Lena River (northern Siberia, Russia) between 26 June and 4 July 2011. The aim of this study was to determine the inherent optical properties of the Lena water, i.e., absorption, attenuation, and scattering coefficients, during the period of maximum runoff. This aimed to contribute to the development of a biooptical model for use as the basis for optical remote sensing of coastal water of the Arctic. In this context the absorption by CDOM (colored dissolved organic matter) and particles, and the concentrations of total suspended matter, phytoplankton-pigments, and carbon were measured. CDOM was found to be the most dominant parameter affecting the optical properties of the river, with an absorption coefficient of 4.5-5 m −1 at 442 nm, which was almost four times higher than total particle absorption values at visible wavelength range. The wavelenght-dependence of absorption of the different water constituents was chracterized by determining the semi logarithmic spectral slope. Mean CDOM, and detritus slopes were 0.0149 nm −1 (standard deviation (stdev) = 0.0003, n = 18), and 0.0057 nm −1 (stdev = 0.0017, n = 19), respectively, values which are typical for water bodies with high concentrations of dissolved and particulate carbon. Mean chlorophyll a and total suspended matter were 1.8 mg m −3 (stdev = 0.734 n = 18) and 31.9 g m −3 (stdev = 19.94, n = 27), respectively. DOC (dissolved organic carbon) was in the range 8-10 g m −3 and the total particulate carbon (PC) in the range 0.25-1.5 g m −3 . The light penetration depth (Secchi disc depth) was in the range 30-90 cm and was highly correlated with the suspended matter concentration. The period of maximum river runoff in June was chosen to obtain bio-optical data when maximum water constituents are transported into the Laptev Sea. However, we are aware that more data from other seasons and other years need to be collected to establish a general bio-optical model of the Lena water and conclusively characterize the light climate with respect to primary production.

show abstract

Measurement of light absorption by aquatic particles: improvement of the quantitative filter technique by use of an integrating sphere approach

Cited by 83 publications

References 36 publications

Variability in the light absorption coefficients of phytoplankton, non-algal particles, and colored dissolved organic matter in a subtropical bay (Brazil)

Variability in the light absorption coefficients of phytoplankton, non-algal particles, and colored dissolved organic matter in a subtropical bay (Brazil)

Diurnal variation in the coupling of photosynthetic electron transport and carbon fixation in iron-limited phytoplankton in the NE subarctic Pacific

Contribution to a bio-optical model for remote sensing of Lena River water

Contact Info

Product

Resources

About