A solid-phase chemical actinometer film for measurement of solar UV penetration into snowpack

Rowland, G. A.; Grannas, A. M.

doi:10.1016/j.coldregions.2011.01.009

Cited by 9 publications

(11 citation statements)

References 31 publications

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“…: ALASKAN SNOW OPTICS AND PHOTOCHEMISTRY D00R12 D00R12 of 7-12 cm. Thus the values of measured e-folding depths presented here are consistent with those of Rowland and Grannas [2011] for Spring snowpacks. Previous analysis of the error in determining e-folding depths using a fiber optic probe placed horizontally into a snowpack determined an uncertainty in e-folding depth of AE 20% [France et al, 2011a].…”

Section: Comparison With Previous Worksupporting

confidence: 87%

“…The shortest wavelength at which e ‐folding depths are reported in this work is at 350 nm, with e ‐folding depths for four Barrow snowpacks of 7–12 cm. Thus the values of measured e ‐folding depths presented here are consistent with those of Rowland and Grannas [2011] for Spring snowpacks. Previous analysis of the error in determining e ‐folding depths using a fiber optic probe placed horizontally into a snowpack determined an uncertainty in e ‐folding depth of ± 20% [ France et al , 2011a].…”

Section: Discussionmentioning

confidence: 94%

“…Previous measurements of e ‐folding depths in snowpack at Barrow gave values of 8 cm and 26 cm for spring and summer respectively [ Rowland and Grannas , 2011]. Those results were obtained using a solid‐state chemical actinometry method and e ‐folding depths calculated using only 3 depth measurements of in‐snow actinometry with the wavelength peak of the action spectrum at ∼340 nm [ Rowland and Grannas , 2011].…”

Section: Discussionmentioning

confidence: 99%

“…[39] Previous measurements of e-folding depths in snowpack at Barrow gave values of 8 cm and 26 cm for spring and summer respectively [Rowland and Grannas, 2011]. Those results were obtained using a solid-state chemical actinometry method and e-folding depths calculated using only 3 depth measurements of in-snow actinometry with the wavelength peak of the action spectrum at $340 nm [Rowland and Grannas, 2011]. The shortest wavelength at which e-folding depths are reported in this work is at 350 nm, with e-folding depths for four Barrow snowpacks Depth-integrated production (maximum fluxes) of NO x and NO 2 in the snowpack for the duration of the Barrow OASIS campaign, assuming all in-snow photolytic production of NO x from nitrate and nitrite is liberated from the snowpack.…”

Section: Comparison With Previous Workmentioning

confidence: 99%

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Hydroxyl radical and NO_x production rates, black carbon concentrations and light‐absorbing impurities in snow from field measurements of light penetration and nadir reflectivity of onshore and offshore coastal Alaskan snow

et al. 2012

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[1] Photolytic production rates of NO, NO 2 and OH radicals in snow and the total absorption spectrum due to impurities in snowpack have been calculated for the Ocean-Atmosphere-Sea-Ice-Snowpack (OASIS) campaign during Spring 2009 at Barrow, Alaska. The photolytic production rate and snowpack absorption cross-sections were calculated from measurements of snowpack stratigraphy, light penetration depths (e-folding depths), nadir reflectivity (350-700 nm) and UV broadband atmospheric radiation. Maximum NO x fluxes calculated during the campaign owing to combined nitrate and nitrite photolysis were calculated as 72 nmol m À2 h À1 for the inland snowpack and 44 nmol m À2 h À1 for the snow on sea-ice and snowpack around the Barrow Arctic Research Center (BARC). Depth-integrated photochemical production rates of OH radicals were calculated giving maximum OH depth-integrated production rates of $160 nmol m À2 h À1 for the inland snowpack and $110-120 nmol m À2 h À1 for the snow around BARC and snow on sea-ice. Light penetration (e-folding) depths at a wavelength of 400 nm measured for snowpack in the vicinity of Barrow and snow on sea-ice are $9 cm and 14 cm for snow 15 km inland. Fitting scaled HULIS (HUmic-LIke Substances) and black carbon absorption cross-sections to the determined snow impurity absorption cross-sections show a "humic-like" component to snowpack absorption, with typical concentrations of 1.2-1.5 mgC g À1 . Estimates of black carbon concentrations for the four snowpacks are $40 to 70 ng g À1 for the terrestrial Arctic snowpacks and $90 ng g À1 for snow on sea-ice.Citation: France, J. L., H. J. Reay, M. D. King, D. Voisin, H. W. Jacobi, F. Domine, H. Beine, C. Anastasio, A. MacArthur, and J. Lee-Taylor (2012), Hydroxyl radical and NO x production rates, black carbon concentrations and light-absorbing impurities in snow from field measurements of light penetration and nadir reflectivity of onshore and offshore coastal Alaskan snow,

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Section: Comparison With Previous Worksupporting

confidence: 87%

Section: Discussionmentioning

confidence: 94%

Section: Discussionmentioning

confidence: 99%

Section: Comparison With Previous Workmentioning

confidence: 99%

See 2 more Smart Citations

Hydroxyl radical and NO_x production rates, black carbon concentrations and light‐absorbing impurities in snow from field measurements of light penetration and nadir reflectivity of onshore and offshore coastal Alaskan snow

et al. 2012

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“…Fe 3+ + e − Fe 2+ 5UV radiation can penetrate to depths of 5-10 cm into ice depending on ice crystallinity, sediment content etc. (Rowland and Grammas, 2011). The resulting ferrous iron may be incorporated into ice during freeze/thaw cycles (see Freeze-thaw reactions in ice) although ferrous iron at shallow depths in ice will be rapidly re-oxidized to (oxyhydr)oxide minerals where ice becomes permeable or melts.…”

Section: Dissolution and Reduction Of Fe(iii) Oxidesmentioning

confidence: 99%

Iron in Glacial Systems: Speciation, Reactivity, Freezing Behavior, and Alteration During Transport

et al. 2018

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A more insightful view of iron in glacial systems requires consideration of iron speciation and mineralogy, the potential for iron minerals to undergo weathering in ice-water environments, the impact of freezing on concentration and speciation, and potential for glacial delivery to undergo alteration during transport into the ocean. A size fractionation approach improves recognition of iron speciation by separating dissolved Fe (<0.2 or <0.45 µm) into soluble Fe (<0.02 µm) and colloidal/nanoparticulate Fe (0.02 to 0.2 or 0.45 µm). The ranges of soluble Fe concentrations in icebergs and meltwaters are similar (tens of nanomolar). The range of colloidal/nanoparticulate Fe concentrations in icebergs are an order of magnitude higher (hundreds of nanomolar) and up to thousands of nanomolar in meltwaters. The importance of particulate iron speciation in glacial sediments is also recognized by using carefully calibrated sequential extractions with ascorbic acid (FeA comprising fresh ferrihydrite which is potentially bioavailable) and dithionite (FeD comprising all remaining (oxyhydr)oxide Fe). Iceberg and glacier sediments contain lower concentrations of FeA (0.032 ± 0.024 and 0.042 ± 0.059 wt. %) than meltwater suspended sediments (FeA 0.12 ± 0.09 wt. %). Glacier sediments also contain low concentrations of FeD (0.060 ± 0.036) but concentrations of FeD are comparable in iceberg and meltwater sediments (0.38 ± 0.24 wt. % compared to 0.31 ± 0.09 wt.%). Reactions in ice-water systems produce potentially bioavailable Fe(II) and ferrihydrite by pyrite oxidation, iron mineral dissolution (aided by low pH and organic complexes) and reduction (aided by UV radiation). Some icebergs contain high concentrations of FeA (>0.1 wt. %) which represent samples in which the ongoing transformation of ferrihydrite to goethite/hematite is incomplete. Numerical models of freezing in subglacial systems show that the nanomolar levels of soluble Fe in icebergs cannot be achieved solely by freezing, and must indicate the presence of nanoparticulate Fe and/or iron desorbed from ice or sediments during melting. Models of freezing effects in sea ice show that nanomolar levels of soluble Fe are achievable because high concentrations of hydroxide and chloride ions maintain dissolved iron as soluble complexes. Delivery of iron through fjords is temporally and spatially variable due to circulation patterns, mixing of different sources, and aggregation through salinity gradients.

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Actinometry and Radiometry

2022

Photochemical Reactors

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A solid-phase chemical actinometer film for measurement of solar UV penetration into snowpack

Cited by 9 publications

References 31 publications

Hydroxyl radical and NO_x production rates, black carbon concentrations and light‐absorbing impurities in snow from field measurements of light penetration and nadir reflectivity of onshore and offshore coastal Alaskan snow

Hydroxyl radical and NO_x production rates, black carbon concentrations and light‐absorbing impurities in snow from field measurements of light penetration and nadir reflectivity of onshore and offshore coastal Alaskan snow

Iron in Glacial Systems: Speciation, Reactivity, Freezing Behavior, and Alteration During Transport

Actinometry and Radiometry

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A solid-phase chemical actinometer film for measurement of solar UV penetration into snowpack

Cited by 9 publications

References 31 publications

Hydroxyl radical and NOx production rates, black carbon concentrations and light‐absorbing impurities in snow from field measurements of light penetration and nadir reflectivity of onshore and offshore coastal Alaskan snow

Hydroxyl radical and NOx production rates, black carbon concentrations and light‐absorbing impurities in snow from field measurements of light penetration and nadir reflectivity of onshore and offshore coastal Alaskan snow

Iron in Glacial Systems: Speciation, Reactivity, Freezing Behavior, and Alteration During Transport

Actinometry and Radiometry

Contact Info

Product

Resources

About

Hydroxyl radical and NO_x production rates, black carbon concentrations and light‐absorbing impurities in snow from field measurements of light penetration and nadir reflectivity of onshore and offshore coastal Alaskan snow

Hydroxyl radical and NO_x production rates, black carbon concentrations and light‐absorbing impurities in snow from field measurements of light penetration and nadir reflectivity of onshore and offshore coastal Alaskan snow