Effect of sea‐ice melt on inherent optical properties and vertical distribution of solar radiant heating in Arctic surface waters

AbstractAbsorption and fluorescence of chromophoric dissolved organic matter (CDOM) in sea ice and surface waters in the southern Sea of Okhotsk was examined. Sea-water CDOM had featureless absorption increasing exponentially with shorter wavelengths. Sea ice showed distinct absorption peaks in the ultraviolet, especially in younger ice. Older first-year sea ice had relatively flat absorption spectra in the ultraviolet range. Parallel factor analysis (PARAFAC) identified five fluorescent CDOM components, two humic-like and three protein-like. Sea water was largely governed by humic-like fluorescence. In sea ice, protein-like fluorescence was found in considerable excess relative to sea water. The accumulation of protein-like CDOM fluorescence in sea ice is likely a result of biological activity within the ice. Nevertheless, sea ice does not contribute excess CDOM during melt, but the material released will be of different composition than that present in the underlying waters. Thus, at least transiently, the CDOM introduced during sea-ice melt might provide a more labile source of fresher protein-like DOM to surface waters in the southern Sea of Okhotsk.

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Impact of sea ice on the retrieval of water-leaving reflectance, chlorophyll a concentration and inherent optical properties from satellite ocean color data

Remote Sensing of Environment ◽

10.1016/j.rse.2007.03.013 ◽

2007 ◽

Vol 111 (1) ◽

pp. 51-68 ◽

Cited By ~ 62

Author(s):

Simon Bélanger ◽

Jens K. Ehn ◽

Marcel Babin

Keyword(s):

Optical Properties ◽

Sea Ice ◽

Chlorophyll A ◽

Ocean Color ◽

Chlorophyll A Concentration ◽

Inherent Optical Properties ◽

Color Data ◽

Satellite Ocean Color

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Development of a Diffuse Reflectance Probe for In Situ Measurement of Inherent Optical Properties in Sea Ice

10.5194/tc-2021-104 ◽

2021 ◽

Author(s):

Christophe Perron ◽

Christian Katlein ◽

Simon Lambert-Girard ◽

Edouard Leymarie ◽

Louis-Philippe Guinard ◽

...

Keyword(s):

Monte Carlo ◽

Optical Properties ◽

Sea Ice ◽

Phase Function ◽

Diffuse Reflectance ◽

Scattering Coefficient ◽

Scattering Medium ◽

Inherent Optical Properties ◽

Reduced Scattering Coefficient

Abstract. Detailed characterization of the spatially and temporally varying inherent optical properties (IOPs) of sea ice is necessary to better predict energy and mass balances, as well as ice-associated primary production. Here we present the development of an active optical probe to measure IOPs of a small volume of sea ice (dm3) in situ and non-destructively. The probe is derived from the diffuse reflectance method used to measure the IOPs of human tissues. The instrument emits light into the ice by the use of optical fibre. Backscattered light is measured at multiple distances away from the source using several receiving fibres. Comparison to a Monte Carlo simulated lookup table allows to retrieve the absorption coefficient, the reduced scattering coefficient and a phase function similarity parameter γ, introduced by Bevilacqua and Depeursinge (1999), depending on the two first moments of the Legendre polynomials, allowing to analyze the backscattered light not satisfying the diffusion regime. Monte Carlo simulations showed that the depth cumulating 95% of the signal is between 40±2 mm and 270±20 mm depending on the source-detector distance and on the ice scattering properties. The magnitude of the instrument validation error on the reduced scattering coefficient ranged from 0.07% for the most scattering medium to 35% for the less scattering medium over the two orders of magnitude we validated. Vertical profiles of the reduced scattering coefficient were obtained with decimeter resolution on first-year Arctic interior sea ice on Baffin Island in early spring 2019. We measured values of up to 7.1 m−1 for the uppermost layer of interior ice and down to 0.15±0.05 m−1 for the bottommost layer. These values are in the range of polar interior sea ice measurements published by other authors. The inversion of the reduced scattering coefficient at this scale was strongly dependent of γ, highlighting the need to define the higher moments of the phase function. This novel developed probe provides a fast and reliable means for measurement of scattering into sea ice.

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Impact of rapid sea-ice reduction in the Arctic Ocean on the rate of ocean acidification

Biogeosciences Discussions ◽

10.5194/bgd-8-10617-2011 ◽

2011 ◽

Vol 8 (5) ◽

pp. 10617-10644

Author(s):

A. Yamamoto ◽

M. Kawamiya ◽

A. Ishida ◽

Y. Yamanaka ◽

S. Watanabe

Keyword(s):

Sea Ice ◽

Arctic Ocean ◽

Surface Waters ◽

Co2 Concentration ◽

The Arctic ◽

Saturation State ◽

Aragonite Saturation ◽

The Arctic Ocean ◽

Arctic Surface ◽

Sea Ice Reduction

Abstract. The largest pH decline and widespread undersaturation with respect to aragonite in this century due to uptake of anthropogenic carbon dioxide in the Arctic Ocean have been projected. The reductions in pH and aragonite saturation state have been caused primarily by an increase in the concentration of atmospheric carbon dioxide. However, in a previous study, simulations with and without warming showed that these reductions in the Arctic Ocean also advances due to the melting of sea ice caused by global warming. Therefore, future projections of pH and aragonite saturation in the Arctic Ocean will be affected by how rapidly the reduction in sea ice occurs. In this study, the impact of sea-ice reduction rate on projected pH and aragonite saturation state in the Arctic surface waters was investigated. Reductions in pH and aragonite saturation were calculated from the outputs of two versions of an earth system model (ESM) with different sea-ice reduction rates under similar CO2 emission scenarios. The newer model version projects that Arctic summer ice-free condition will be achieved by the year 2040, and the older version predicts ice-free condition by 2090. The Arctic surface water was projected to be undersaturated with respect to aragonite in the annual mean when atmospheric CO2 concentration reached 480 (550) ppm in year 2040 (2048) in new (old) version. At an atmospheric CO2 concentration of 520 ppm, the maximum differences in pH and aragonite saturation state between the two versions were 0.08 and 0.15, respectively. The analysis showed that the decreases in pH and aragonite saturation state due to rapid sea-ice reduction were caused by increases in both CO2 uptake and freshwater input. Thus, the reductions in pH and aragonite saturation state in the Arctic surface waters are significantly affected by the difference in future projections for sea-ice reduction rate. The critical CO2 concentration, at which the Arctic surface waters become undersaturated with respect to aragonite on annual mean bias, would be lower by 70 ppm in the version with the rapid sea-ice reduction.

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Direct contribution of phytoplankton-sized particles to optical backscattering in the open ocean

Biogeosciences Discussions ◽

10.5194/bgd-6-291-2009 ◽

2009 ◽

Vol 6 (1) ◽

pp. 291-340 ◽

Cited By ~ 4

Author(s):

G. Dall'Olmo ◽

T. K. Westberry ◽

M. J. Behrenfeld ◽

E. Boss ◽

W. H. Slade

Keyword(s):

Optical Properties ◽

Surface Waters ◽

Phytoplankton Biomass ◽

Field Studies ◽

Open Ocean ◽

Chl A ◽

Inherent Optical Properties ◽

Similar Information ◽

The Relationship ◽

Beam Attenuation Coefficient

Abstract. Light scattering properties of oceanic particles have been suggested as an alternative index of phytoplankton biomass than chlorophyll-a concentration (chl-a), with the benefit of being less sensitive to physiological forcings (e.g., light and nutrients) that alter the intracellular pigment concentrations. The drawback of particulate scattering is that it is not unique to phytoplankton. Nevertheless, field studies have demonstrated that, to first order, the particulate beam-attenuation coefficient (cp) can track phytoplankton abundance. The relationship between cp and the particulate backscattering coefficient (bbp), a property retrievable from space, has not been fully evaluated, largely due to a lack of open-ocean field observations. Here, we present extensive data on inherent optical properties from the Equatorial Pacific surface waters and demonstrate a remarkable coherence in bbp and cp. Coincident measurements of particle size distributions (PSDs) and optical properties of size-fractionated samples indicate that this covariance is due to both the conserved nature of the PSD and a greater contribution of phytoplankton-sized particles to bbp than theoretically predicted. These findings suggest that satellite-derived bbp could provide similar information on phytoplankton biomass in the open ocean as cp.

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Impact of sea-ice melt on dimethyl sulfide (sulfoniopropionate) inventories in surface waters of Marguerite Bay, West Antarctic Peninsula

Philosophical Transactions of The Royal Society A Mathematical Physical and Engineering Sciences ◽

10.1098/rsta.2017.0169 ◽

2018 ◽

Vol 376 (2122) ◽

pp. 20170169 ◽

Cited By ~ 9

Author(s):

Jacqueline Stefels ◽

Maria A. van Leeuwe ◽

Elizabeth M. Jones ◽

Michael P. Meredith ◽

Hugh J. Venables ◽

...

Keyword(s):

Sea Ice ◽

Antarctic Peninsula ◽

Surface Waters ◽

Dimethyl Sulfide ◽

Organic Sulfur Compound ◽

The West ◽

Ice Melt ◽

West Antarctic ◽

Marguerite Bay ◽

West Antarctic Peninsula

The Southern Ocean is a hotspot of the climate-relevant organic sulfur compound dimethyl sulfide (DMS). Spatial and temporal variability in DMS concentration is higher than in any other oceanic region, especially in the marginal ice zone. During a one-week expedition across the continental shelf of the West Antarctic Peninsula (WAP), from the shelf break into Marguerite Bay, in January 2015, spatial heterogeneity of DMS and its precursor dimethyl sulfoniopropionate (DMSP) was studied and linked with environmental conditions, including sea-ice melt events. Concentrations of sulfur compounds, particulate organic carbon (POC) and chlorophyll a in the surface waters varied by a factor of 5–6 over the entire transect. DMS and DMSP concentrations were an order of magnitude higher than currently inferred in climatologies for the WAP region. Particulate DMSP concentrations were correlated most strongly with POC and the abundance of haptophyte algae within the phytoplankton community, which, in turn, was linked with sea-ice melt. The strong sea-ice signal in the distribution of DMS(P) implies that DMS(P) production is likely to decrease with ongoing reductions in sea-ice cover along the WAP. This has implications for feedback processes on the region's climate system. This article is part of the theme issue ‘The marine system of the West Antarctic Peninsula: status and strategy for progress in a region of rapid change’.

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Two Decades of Ocean Acidification in the Surface Waters of the Beaufort Gyre, Arctic Ocean: Effects of Sea Ice Melt and Retreat From 1997–2016

Geophysical Research Letters ◽

10.1029/2019gl086421 ◽

2020 ◽

Vol 47 (3) ◽

Cited By ~ 1

Author(s):

Y. Zhang ◽

M. Yamamoto‐Kawai ◽

W.J. Williams

Keyword(s):

Sea Ice ◽

Ocean Acidification ◽

Arctic Ocean ◽

Surface Waters ◽

Ice Melt ◽

Beaufort Gyre

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Diazotroph Diversity in the Sea Ice, Melt Ponds, and Surface Waters of the Eurasian Basin of the Central Arctic Ocean

Frontiers in Microbiology ◽

10.3389/fmicb.2016.01884 ◽

2016 ◽

Vol 7 ◽

Cited By ~ 16

Author(s):

Mar Fernández-Méndez ◽

Kendra A. Turk-Kubo ◽

Pier L. Buttigieg ◽

Josephine Z. Rapp ◽

Thomas Krumpen ◽

...

Keyword(s):

Sea Ice ◽

Arctic Ocean ◽

Surface Waters ◽

Central Arctic Ocean ◽

Ice Melt ◽

Melt Ponds ◽

Eurasian Basin

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Development of a diffuse reflectance probe for in situ measurement of inherent optical properties in sea ice

The Cryosphere ◽

10.5194/tc-15-4483-2021 ◽

2021 ◽

Vol 15 (9) ◽

pp. 4483-4500

Author(s):

Christophe Perron ◽

Christian Katlein ◽

Simon Lambert-Girard ◽

Edouard Leymarie ◽

Louis-Philippe Guinard ◽

...

Keyword(s):

Monte Carlo ◽

Optical Properties ◽

Absorption Coefficient ◽

Sea Ice ◽

Diffuse Reflectance ◽

Scattering Coefficient ◽

Scattering Medium ◽

Inherent Optical Properties ◽

Reduced Scattering Coefficient

Abstract. Detailed characterization of the spatially and temporally varying inherent optical properties (IOPs) of sea ice is necessary to better predict energy and mass balances, as well as ice-associated primary production. Here we present the development of an active optical probe to measure IOPs of a small volume of sea ice (dm3) in situ and non-destructively. The probe is derived from the diffuse reflectance method used to measure the IOPs of human tissues. The instrument emits light into the ice by the use of an optical fibre. Backscattered light is measured at multiple distances away from the source using several receiving fibres. Comparison to a Monte Carlo simulated lookup table allows, in theory, retrieval of the absorption coefficient, the reduced scattering coefficient and a phase function similarity parameter γ, introduced by Bevilacqua and Depeursinge (1999). γ depends on the two first moments of the Legendre polynomials, allowing the analysis of the backscattered light not satisfying the diffusion regime. The depth reached into the medium by detected photons was estimated using Monte Carlo simulations: the maximum depth reached by 95 % of the detected photons was between 40±2 and 270±20 mm depending on the source–detector distance and on the ice scattering properties. The magnitude of the instrument validation error on the reduced scattering coefficient ranged from 0.07 % for the most scattering medium to 35 % for the less scattering medium over the 2 orders of magnitude we validated. Fixing the absorption coefficient and γ, which proved difficult to measure, vertical profiles of the reduced scattering coefficient were obtained with decimetre resolution on first-year Arctic interior sea ice on Baffin Island in early spring 2019. We measured values of up to 7.1 m−1 for the uppermost layer of interior ice and down to 0.15±0.05 m−1 for the bottommost layer. These values are in the range of polar interior sea ice measurements published by other authors. The inversion of the reduced scattering coefficient at this scale was strongly dependent on the value of γ, highlighting the need to define the higher moments of the phase function. This newly developed probe provides a fast and reliable means for measurement of scattering in sea ice.

Download Full-text