The effect of measurement geometry on recording solar radiation attenuation in snowpack (e-folding depth) using fibre-optic probes

France, James L.; King, Martin D.

doi:10.3189/2012jog11j227

Cited by 12 publications

(7 citation statements)

References 14 publications

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“…Downwelling spectral irradiance [E d (λ)] was measured as a function of snow depth and underneath the sea ice from 320 to 950 nm with a 3.3 nm spectral resolution, using a spectroradiometer (RAMSES ACC‐VIS, TriOS, Germany). Vertical profiles of downwelling spectral irradiance were measured through the snow pack after digging a snow‐pit allowing for a vertical positioning of the spectral irradiance sensor, 30 cm ‘inside’ the southern wall of the snowpit, after characterizing the physical properties of the snow (France & King, ). The vertical resolution of the profiles was 5 to 20 cm following the snow layers with different densities.…”

Section: Methodsmentioning

confidence: 99%

Extreme Low Light Requirement for Algae Growth Underneath Sea Ice: A Case Study From Station Nord, NE Greenland

et al. 2018

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Microalgae colonizing the underside of sea ice in spring are a key component of the Arctic foodweb as they drive early primary production and transport of carbon from the atmosphere to the ocean interior. Onset of the spring bloom of ice algae is typically limited by the availability of light, and the current consensus is that a few tens‐of‐centimeters of snow is enough to prevent sufficient solar radiation to reach underneath the sea ice. We challenge this consensus, and investigated the onset and the light requirement of an ice algae spring bloom, and the importance of snow optical properties for light penetration. Colonization by ice algae began in May under >1 m of first‐year sea ice with ∼1 m thick snow cover on top, in NE Greenland. The initial growth of ice algae began at extremely low irradiance (<0.17 μmol photons m−2 s−1) and was documented as an increase in Chlorophyll a concentration, an increase in algal cell number, and a viable photosynthetic activity. Snow thickness changed little during May (from 110 to 91 cm), however the snow temperature increased steadily, as observed from automated high‐frequency temperature profiles. We propose that changes in snow optical properties, caused by temperature‐driven snow metamorphosis, was the primary driver for allowing sufficient light to penetrate through the thick snow and initiate algae growth below the sea ice. This was supported by radiative‐transfer modeling of light attenuation. Implications are an earlier productivity by ice algae in Arctic sea ice than recognized previously.

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Section: Methodsmentioning

confidence: 99%

Extreme Low Light Requirement for Algae Growth Underneath Sea Ice: A Case Study From Station Nord, NE Greenland

et al. 2018

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“…19,50 Such studies often assume a single, unidirectional photolysis reaction of nitrate with a constant quantum yield in order to predict NO x emissions out of the snow. They therefore ignore secondary chemistry and the different active domains of nitrate.…”

Section: Discussionmentioning

confidence: 99%

Laboratory study of nitrate photolysis in Antarctic snow. I. Observed quantum yield, domain of photolysis, and secondary chemistry

Meusinger

Berhanu

Erbland

et al. 2014

The Journal of Chemical Physics

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“…The albedos are reported for diffuse solar radiation to demonstrate the effect of increasing black carbon on snowpack albedo and not the effect of solar zenith angle on snowpack albedo. The calculation of the e ‐folding depth is independent of the absolute values of irradiance incident on the snow surface and independent of the solar zenith angle as the e ‐folding depth is only measured in the asymptotic zone of the snowpack (i.e., below the top few cm) where all solar direct radiation has been converted to diffuse radiation by multiple scattering in the top few cm of snow [ France and King , 2012; King and Simpson , 2001; Lee‐Taylor and Madronich , 2002]. Depth‐integrated production rates for the photolysis of H 2 O 2 and NO 3 − (reactions (2) and (4)) were calculated for clear skies at four solar zenith angles: 60°, 69°, 75°, 86°.…”

Section: Modeling Proceduresmentioning

confidence: 99%

Decreased albedo, e‐folding depth and photolytic OH radical and NO₂ production with increasing black carbon content in Arctic snow

2012

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The contribution of snow photochemistry to snow and atmospheric oxidative capacity is controlled, in part, by snow albedo and e‐folding depths in snow. Albedo ande‐folding depths (and thus snow photochemistry) are a function of black carbon concentration in snow. The paper presented here demonstrates the complicated response of albedo, e‐folding depth (wavelengths 300–600 nm) and depth‐integrated production rates of NO2and OH radicals to increasing black carbon concentration in well‐characterized snowpacks of the Barrow OASIS campaign, Alaska. All snowpacks were reworked layered windpacks and were found to have similar responses to changes in black carbon concentration. The radiative‐transfer calculations demonstrate two light absorption regimes: ice‐dominated and black carbon dominated. The ice‐dominated and black carbon dominated behavior of albedo,e‐folding depth and depth‐integrated production rates with increasing black carbon concentrations are presented. For black carbon concentrations greater than 20 ng g−1 (wavelength range of 300–600 nm), e‐folding depth and depth‐integrated production rate have an inverse power law relationship with black carbon concentration. Doubling the black carbon concentration decreases thee‐folding depth to ∼70% of the initial value and for solar zenith angles greater than 60°, doubling the black carbon concentration decreases depth‐integrated production rates of NO2 and OH to ∼70% and ∼65% of their original values respectively.

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The effect of measurement geometry on recording solar radiation attenuation in snowpack (e-folding depth) using fibre-optic probes

Cited by 12 publications

References 14 publications

Extreme Low Light Requirement for Algae Growth Underneath Sea Ice: A Case Study From Station Nord, NE Greenland

Extreme Low Light Requirement for Algae Growth Underneath Sea Ice: A Case Study From Station Nord, NE Greenland

Laboratory study of nitrate photolysis in Antarctic snow. I. Observed quantum yield, domain of photolysis, and secondary chemistry

Decreased albedo, e‐folding depth and photolytic OH radical and NO₂ production with increasing black carbon content in Arctic snow

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The effect of measurement geometry on recording solar radiation attenuation in snowpack (e-folding depth) using fibre-optic probes

Cited by 12 publications

References 14 publications

Extreme Low Light Requirement for Algae Growth Underneath Sea Ice: A Case Study From Station Nord, NE Greenland

Extreme Low Light Requirement for Algae Growth Underneath Sea Ice: A Case Study From Station Nord, NE Greenland

Laboratory study of nitrate photolysis in Antarctic snow. I. Observed quantum yield, domain of photolysis, and secondary chemistry

Decreased albedo, e‐folding depth and photolytic OH radical and NO2 production with increasing black carbon content in Arctic snow

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Decreased albedo, e‐folding depth and photolytic OH radical and NO₂ production with increasing black carbon content in Arctic snow