Details

Autor(en) / Beteiligte

• Lund-Hansen, Lars Chresten
• Andersen, Thorbjørn Joest
• Nielsen, Morten Holtegaard
• Pejrup, Morten

Titel

Suspended Matter, Chl-a, CDOM, Grain Sizes, and Optical Properties in the Arctic Fjord-Type Estuary, Kangerlussuaq, West Greenland During Summer

Ist Teil von

• Estuaries and coasts, 2010-11, Vol.33 (6), p.1442-1451

Ort / Verlag

New York: Spring Science + Business Media

Erscheinungsjahr

2010

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Optical constituents as suspended particulate matter (SPM), chlorophyll (Chl-a), colored dissolved organic matter (CDOM), and grain sizes were obtained on a transect in the arctic fjord-type estuary Kangerlussuaq (66°) in August 2007 along with optical properties. These comprised diffuse attenuation coefficient of downwelling PAR (K d (PAR)), upwelling PAR (K u (PAR)), particle beam attenuation coefficient (c p ), and irradiance reflectance R (-0, PAR). PAR is white light between 400 and 700 nm. The estuary receives melt water from the Greenland Inland Ice and stations covered a transect from the very high turbid melt water outlet to clear marine waters. Results showed a strong spatial variation with high values as for suspended matter concentrations, CDOM, diffuse attenuation coefficient K d (PAR), particle beam attenuation coefficients (c p ), and reflectance R(-0, PAR) at the melt water outlet. Values of optical constituents and properties decreased with distance from the melt water outlet to a more or less constant level in central and outer part of the estuary. There was a strong correlation between inorganic suspended matter (SPMI) and diffuse attenuation coefficient K d (PAR) (r²=0.92) and also for particle beam attenuation coefficient (c p ; r²=0.93). The obtained SPMI specific attenuation—K d *(PAR)= 0.13 m² g⁻¹ SPMI—and the SPMI specific particle beam attenuation— c p *=0.72 m² g⁻¹—coefficients were about two times higher than average literature values. Irradiance reflectance R(—0, PAR) was comparatively high (0.09-0.20) and showed a high (r² = 0.80) correlation with K u (PAR). Scattering dominated relative to absorption—b(PAR)/a(PAR)= 12.3. Results strongly indicated that the high values in the optical properties were related to the very fine particle sizes (mean= 2-6 μm) of the suspended sediment. Data and results are discussed and compared to similar studies from both temperate and tropical estuaries.