Premium
Bio‐optical Properties of Surface Waters in the Atlantic Water Inflow Region off Spitsbergen (Arctic Ocean)
Author(s) -
Kowalczuk Piotr,
Sagan Sławomir,
Makarewicz Anna,
Meler Justyna,
Borzycka Karolina,
Zabłocka Monika,
Zdun Agnieszka,
Konik Marta,
Darecki Mirosław,
Granskog Mats A.,
Pavlov Alexey K.
Publication year - 2019
Publication title -
journal of geophysical research: oceans
Language(s) - English
Resource type - Journals
eISSN - 2169-9291
pISSN - 2169-9275
DOI - 10.1029/2018jc014529
Subject(s) - colored dissolved organic matter , phytoplankton , chlorophyll a , water column , oceanography , dissolved organic carbon , absorption (acoustics) , environmental science , arctic , meltwater , sea ice , surface water , water mass , chemistry , geology , materials science , snow , geomorphology , nutrient , biochemistry , organic chemistry , environmental engineering , composite material
Bio‐optical properties of surface waters were characterized off western and northern Spitsbergen in the summers of 2013, 2014, and 2015. We observed statistically significant year‐to‐year differences in spatial distribution of spectral absorption ( a ( λ )) and beam attenuation ( c ( λ )). Highest a ( λ ) and c ( λ ) were located in the frontal zone between water masses and co‐varied strongly with chlorophyll a fluorescence. Phytoplankton pigments dominated the absorption budget at 443 nm (50%). The contribution of chromophoric dissolved organic matter to total nonwater absorption was highest at 412 nm (42%), and detrital absorption contributed most at 550 nm (37%). Almost all inherent optical properties, except chromophoric dissolved organic matter, were highly correlated with the chlorophyll a concentration ( Chla , R 2 > 0.81). Relationships between Chl a and the particulate and phytoplankton pigments absorption coefficients at 443 and 676 nm were characterized by significant determination coefficients ( R 2 > 0.73). The phytoplankton pigments line height absorption a LH (676) was found to be the most reliable optical proxy for determination of Chl a , compared to total nonwater absorption, a pg (676), and stimulated in situ chlorophyll a fluorescence intensity, I Chl a . In the presence of sea ice melt the water column was stratified and the vertical distribution of inherent optical properties was characterized by a surface minimum followed by a distinct subsurface maximum, aligned with a subsurface chlorophyll a maximum. We surmise that prevailing regional wind patterns affect sea ice and surface drift in central Fram Strait, and thus the location of sea ice meltwater, which affects the vertical stratification and occurrence of subsurface chlorophyll a maximum.