Temat: coloured dissolved organic matter - Katalog OPAC zbiorów

Skocz do pozycji: 1.

Tytuł:: Surface desalinated layer distribution in the Kara Sea determined by shipboard and satellite data
Autorzy:: Glukhovets, D.L.
Goldin, Y.A.
Powiązania:: https://bibliotekanauki.pl/articles/2079196.pdf
Data publikacji:: 2020
Wydawca:: Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:: surface layer
desalination
satellite data
coloured dissolved organic matter
interannual variability
Kara Sea
Opis:: This study reports the propagation dynamics of the Kara Sea surface desalinated layer (SDL) during the summer and autumn seasons. We analysed shipboard measurements data collected in 2013–2018 and MODIS ocean colour data that correlated with the shipboard ones. We formulated a comparatively strict criterion to determine the SDL border based on satellite data. For that, we analyzed the shipboard flow-through measuring system data obtained while crossing the surface desalinated layer border. Further, we used a regional algorithm to process the satellite data and estimate the coloured dissolved organic matter absorption coefficient for the Kara Sea. The results demonstrate a significant effect of the wind regime on the interseasonal and interannual variability of the transformation of the SDL boundaries. The positions of the surface desalinated layer boundaries at different times during 2013–2018 are given. The obtained results are important for calculating the heat balance and analyzing the Kara Sea bio-productivity.
Źródło:: Oceanologia; 2020, 62, 3; 364-373
0078-3234
Pojawia się w:: Oceanologia
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:: Measurements of light transfer through drift ice and landfast ice in the Northern Baltic Sea
Autorzy:: Kari, E.
Jutila, A.
Friedrichs, A.
Lepparanta, M.
Kratzer, S.
Powiązania:: https://bibliotekanauki.pl/articles/2079188.pdf
Data publikacji:: 2020
Wydawca:: Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:: light transfer
measurement
sea ice
landfast ice
coloured dissolved organic matter
Baltic Sea
Opis:: The aim of this study was to investigate the light transfer through sea ice with a focus on bio-optical substances both in fast ice and in the drift ice zones in the northern Baltic Sea. The measurements included snow and ice structure, spectral irradiance and photosynthetically active radiation below the sea ice. We also measured the concentrations of the three main bio-optical substances which are chlorophyll-a, suspended particulate matter, and coloured dissolved organic matter (CDOM). These bio-optical substances were determined for melted ice samples and for the underlying sea water. The present study provides the first spectral light transfer data set for drift ice in the Baltic Sea. We found high CDOM absorption values typical to the Baltic Sea waters also within sea ice. Our results showed that the transmittance through bare ice was lower for the coastal fast ice than for the drift ice sites. Bio-optical substances, in particular CDOM, modified the spectral distribution of light penetrating through the ice cover. Differences in crystal structure and the amount of gas inclusions in the ice caused variation in the light transfer. Snow cover on ice was found to be the dominant factor influencing the light field under ice, confirming previous studies. In conclusion, snow cover dominated the amount of light under the ice, but did not modify its spectral composition. CDOM in the ice absorbs strongly in the short wavelengths. As pure water absorbs most in the long wavelengths, the light transfer through ice was highest in the green (549–585 nm).
Źródło:: Oceanologia; 2020, 62, 3; 347-363
0078-3234
Pojawia się w:: Oceanologia
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 3.

Tytuł:: Performance evaluation of non-water absorption coefficient partitioning algorithms in optically complex coastal waters of Kochi and Goa, India
Autorzy:: Kolluru, S.
Gedam, S.S.
Inamdar, A.B.
Powiązania:: https://bibliotekanauki.pl/articles/2078824.pdf
Data publikacji:: 2021
Wydawca:: Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:: absorption coefficient
phytoplankton
coloured dissolved organic matter
partitioning
algorithm
coastal water
particulate matter
optical property
India
Opis:: Absorption coefficient partitioning algorithms (APAs) were developed to partition the total absorption coefficient (a(λ)) or total non-water absorption coefficient (anw (λ)) into the absorption subcomponents, i.e., absorption due to phytoplankton aph(λ), colored dissolved organic matter (CDOM) ag(λ) and non-algal particulate matter ad (λ), λ is the wavelength. Absorption coefficients of CDOM and non-algal particulate matter are generally combined due to a similarity in exhibited spectral shape and represented as colored detrital matter (CDM) absorption coefficient, adg(λ). This study focuses on the applicability of five APAs Schofield’s, Lin’s, Zhang’s, Stacked Constraints Model (SCM) and Generalized Stacked Constraints Model (GSCM), in deriving the absorption subcomponents from anw (λ) in optically complex coastal waters of Kochi and Goa, India. The average spectral Mean Absolute Percentage Errors (MAPE) obtained for all models in the retrieval of aph(λ), ad (λ), ag(λ) and adg(λ) lie in the ranges of 26—44%, 37—45%, 34—65% and 42—56%. Slopes of adg(λ), ag(λ) and ad (λ) as indicated by Sdg, Sg and Sd are derivable from GSCM, Schofield and Lin’s models only. GSCM model exhibited good retrieval capability of Sd with MAPE values of 22% and a correlation coefficient of 0.74. In retrieval of Sg parameter, none of the models demonstrated satisfactory performance. Overall, the GSCM and Schofield’s models demonstrated good performance in the retrieval of absorption subcomponents, aph(λ), adg(λ), ad (λ) and Sd. Effect of applying baseline correction to ad (λ) on model performance is studied. Tuning with in situ data can further improve the absorption subcomponent and slope parameter retrieval capability of the models.
Źródło:: Oceanologia; 2021, 63, 4; 420-437
0078-3234
Pojawia się w:: Oceanologia
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 4.

Tytuł:: Narrowband shortwave minima of multispectral reflectance as indication of algal blooms associated with the mesoscale variability in the Brazil-Malvinas Confluence
Autorzy:: Karabashev, G.S.
Evdoshenko, M.A.
Powiązania:: https://bibliotekanauki.pl/articles/48026.pdf
Data publikacji:: 2018
Wydawca:: Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:: algal bloom
pigment
reflectance
confluence zone
Brazil-Malvinas confluence
coloured dissolved organic matter
MODIS satellite image
Źródło:: Oceanologia; 2018, 60, 4
0078-3234
Pojawia się w:: Oceanologia
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 5.

Tytuł:: Validation of empirical and semi-analytical remote sensing algorithms for estimating absorption by Coloured Dissolved Organic Matter in the Baltic Sea from SeaWiFS and MODIS imagery
Autorzy:: Kowalczuk, P.
Darecki, M.
Zablocka, M.
Gorecka, I.
Powiązania:: https://bibliotekanauki.pl/articles/47876.pdf
Data publikacji:: 2010
Wydawca:: Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:: validation
remote sensing
Ocean colour
satellite validation
coloured dissolved organic matter
organic matter
absorption
Baltic Sea
Gdansk Gulf
Vistula River
Opis:: An extensive bio-optical data set obtained from field measurements was used to evaluate the performance of an empirical (Kowalczuk et al. 2005) and two semi- analytical algorithms: Carder et al. (1999) and GSM01 (Maritorena et al. 2002) for estimating CDOM absorption in the Baltic Sea. The data set includes coincident measurements of radiometric quantities and absorption coefficients of CDOM made during 43 cruises between 2000 and 2008. In the first stage of the analysis, the accuracy of the empirical algorithm by Kowalczuk et al. (2005) was assessed using in situ measurements of remote sensing reflectance. Validation results improved when matching points located in Gulf of Gdańsk close to the Vistula River mouth were eliminated from the data set. The calculated errors in the estimation of aCDOM(400) in the first phase of the analysis were Bias = −0.02, RMSE = 0.46 and R2 = 0.70. In the second stage, the empirical algorithm was tested on satellite data from SeaWiFS and MODIS imagery. The satellite data were corrected atmospherically with the MUMM algorithm designed for turbid coastal and inland waters and implemented in the SeaDAS software. The results of the best case scenario for estimating the CDOM absorption coefficient aCDOM(400), based on SeaWiFS data, were Bias = −0.02, RMSE = 0.23 and R2 = 0.40. The validation of the Kowalczuk et al. (2005) empirical algorithm applied to MODIS data led to a less accurate estimate of aCDOM(400): Bias = −0.03, RMSE = 0.19 and R2 = 0.29. This assessment of the accuracy of standard semi-analytical algorithms available in the SeaWiFS and MODIS imagery processing software revealed that both algorithms (GSM 01 and Carder) underestimate CDOM absorption in the Baltic Sea with mean systematic and random errors in excess of 70%. The paper presents examples of the application of the Kowalczuk et al. (2005) empirical algorithm for producing maps of the seasonal distribution of aCDOM(400) in the Baltic Sea between 2004 and 2008.
Źródło:: Oceanologia; 2010, 52, 2; 171-196
0078-3234
Pojawia się w:: Oceanologia
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 6.

Tytuł:: Two models for absorption by coloured dissolved organic matter (CDOM)
Autorzy:: Schwarz, J.N.
Kowalczuk, P.
Kaczmarek, S.
Cota, G.F.
Mitchell, B.G.
Kahru, M.
Chavez, F.P.
Cunningham, A.
McKee, D.
Gege, P.
Kishino, M.
Phinney, D.A.
Raine, R.
Powiązania:: https://bibliotekanauki.pl/articles/47774.pdf
Data publikacji:: 2002
Wydawca:: Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:: ocean colour
coloured dissolved organic matter
surface water
coastal water
spectrophotometric measurement
ultraviolet absorption
absorption
Vistula River
Opis:: The standard exponential model for CDOM absorption has been applied to data from diverse waters. Absorption at 440 nm (ag440) ranged between close to zero and 10 m−1, and the slope oft he semilogarithmic absorption spectrum over a minimum range of400 to 440 nm (s440) ranged between <0.01 and 0.04 nm−1. No relationship was found between ag440 or s440 and salinity. Except in the southern Baltic, s440 was found to have a broad distribution (0.0165 ± 0.0035), suggesting that it should be introduced as an additional variable in bio-optical models when ag440 is large. An alternative model for CDOM absorption was applied to available high quality UV-visible absorption spectra from the WisGla river (Poland). This model assumes that the CDOM absorption spectrum comprises distinct Gaussian absorption bands in the UV, similar to those ofb enzene. Five bands were fit to the data. The mean central energy ofal l bands was higher in early summer (E ∼7.2, 6.6, 6.4, 6.2 and 5.5 eV or 172, 188, 194, 200 and 226 nm) than in winter. The higher energy bands were found to decay in both height and width with increasing salinity, while lower energy bands broadened with increasing salinity. s440 was found to be correlated with shape parameters of the bands centred at 6.4 and 5.5 eV. While the exponential model is convenient for optical modelling and remote sensing applications, these results suggest that the Gaussian model offers a deeper understanding ofc hemical interactions affecting CDOM molecular structure.
Źródło:: Oceanologia; 2002, 44, 2
0078-3234
Pojawia się w:: Oceanologia
Dostawca treści:: Biblioteka Nauki