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Nordblad, Fredrik
Publications (7 of 7) Show all publications
Conrad, S., Ingri, J., Gelting, J., Nordblad, F., Engström, E., Rodushkin, I., . . . Öhlander, B. (2019). Distribution of Fe isotopes in particles and colloids in the salinity gradient along the Lena River plume, Laptev Sea. Biogeosciences, 16(6), 1305-1319
Open this publication in new window or tab >>Distribution of Fe isotopes in particles and colloids in the salinity gradient along the Lena River plume, Laptev Sea
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2019 (English)In: Biogeosciences, ISSN 1726-4170, E-ISSN 1726-4189, Vol. 16, no 6, p. 1305-1319Article in journal (Refereed) Published
Abstract [en]

 Riverine Fe input is the primary Fe source for the ocean. This study is focused on the distribution of Fe along the Lena River freshwater plume in the Laptev Sea using samples from a 600 km long transect in front of the Lena River mouth. Separation of the particulate ( >  0.22 μm), colloidal (0.22 μm–1 kDa), and truly dissolved (<  1 kDa) fractions of Fe was carried out. The total Fe concentrations ranged from 0.2 to 57μM with Fe dominantly as particulate Fe. The loss of >  99% of particulate Fe and about 90% of the colloidal Fe was observed across the shelf, while the truly dissolved phase was almost constant across the Laptev Sea. Thus, the truly dissolved Fe could be an important source of bioavailable Fe for plankton in the central Arctic Ocean, together with the colloidal Fe. Fe-isotope analysis showed that the particulate phase and the sediment below the Lena River freshwater plume had negative δ56Fe values (relative to IRMM-14). The colloidal Fe phase showed negative δ56Fe values close to the river mouth (about -0.20 ‰) and positive δ56Fe values in the outermost stations (about +0.10 ‰). We suggest that the shelf zone acts as a sink for Fe particles and colloids with negative δ56Fe values, representing chemically reactive ferrihydrites. The positive δ56Fe values of the colloidal phase within the outer Lena River freshwater plume might represent Fe oxyhydroxides, which remain in the water column, and will be the predominant δ56Fe composition in the Arctic Ocean.

Place, publisher, year, edition, pages
European Geosciences Union (EGU), 2019
Keywords
iron isotopes, estuarine mixing, iron particles, truly dissolved iron
National Category
Natural Sciences Geochemistry
Research subject
Applied Geochemistry
Identifiers
urn:nbn:se:ltu:diva-73352 (URN)10.5194/bg-16-1305-2019 (DOI)000462793900001 ()2-s2.0-85063632617 (Scopus ID)
Funder
Knut and Alice Wallenberg FoundationSwedish Research Council for Environment, Agricultural Sciences and Spatial Planning, 621-2004-4039Swedish Research Council for Environment, Agricultural Sciences and Spatial Planning, 211-621-2007Swedish Polar Research SecretariatSwedish Research Council for Environment, Agricultural Sciences and Spatial Planning, 2017-05687EU, European Research Council, ERC-AdG CCTOP project #695331
Note

Validerad;2019;Nivå 2;2019-04-03 (johcin)

Available from: 2019-03-29 Created: 2019-03-29 Last updated: 2019-04-25Bibliographically approved
Öhlander, B., Nordblad, F., Lax, K., Ecke, F. & Ingri, J. (2014). Biogeochemical mapping of stream plants to trace acid sulphate soils: A comparison between water geochemistry and metal content in macrophytes (ed.). Paper presented at . Geochemistry: Exploration, Environment, Analysis, 14(1), 85-94
Open this publication in new window or tab >>Biogeochemical mapping of stream plants to trace acid sulphate soils: A comparison between water geochemistry and metal content in macrophytes
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2014 (English)In: Geochemistry: Exploration, Environment, Analysis, ISSN 1467-7873, E-ISSN 2041-4943, Vol. 14, no 1, p. 85-94Article in journal (Refereed) Published
Abstract [en]

The efficiency of biogeochemical mapping for identifying acid sulphate soils (AS soils) was studied by sampling and analysing water, transplanted aquatic moss (Fontinalis antipyretica) and leaves of the vascular plant Calamagrostis purpurea at two sites in a stream in northern Sweden with AS soils in its drainage area. One upstream sampling station (Mårtsmarken) was situated in an area dominated by till, and a downstream station (Persraningen) was situated in an area where AS soils are common. Metal contents in F. antipyretica and C. purpurea at these sites were compared to those in water (both unfiltered samples, and samples subjected to 0.22 μm membrane filtration and 1 kDa ultrafiltration to obtain data on metal speciation and its effects on uptake). Oxidation of sulphides with associated increases in acidity and release of metals were clearly reflected by differences in the water samples. At Persraningen the pH was lower than at Mårtsmarken, and the unfiltered concentrations of Al, Ca, Cd, Co, Cu, K, Mg, Mn, Ni, P, S, Sr, Y and Zn were higher. At the upstream station, Mårtsmarken, the suspended fraction was an important carrier of Fe and P, and the colloidal concentrations were higher than or similar to the dissolved concentrations for all determined elements except Na and K. At Persraningen the low pH resulted in changes of speciation, so that the dissolved concentrations were higher than the colloidal concentrations for most elements. For Al, As, Cr, Cu, Pb and Y, the dissolved and colloidal concentrations were similar. For Fe, the colloidal concentration was usually higher than the dissolved concentration, and suspended Fe was detected. Aluminium, Cr, Cu, Fe and Y concentrations were significantly higher in Fontinalis antipyretica at Persraningen than at Mårtsmarken. In addition, concentrations of Al and Fe in C. purpurea were significantly higher at Persraningen. Our results highlight the potential of biogeochemical mapping for predicting the occurrence of AS soils. A limitation is the strong pH dependence of the uptake of metals in the aquatic mosses resulting in that only a few of the elements typically occurring at high concentrations in waters draining AS soils are enriched in the macrophytes. A combination of maps showing both absolute concentrations and elemental ratios would be useful for this, including not only ratios of previously suggested utility (e.g. Y:Pb and Ni:Pb), but also others, such as Y:Ca, Al:Ca, Cu:Ca, Y:Mg, Al:Mg and Cu:Mg. © 2014 AAG/The Geological Society of London.

National Category
Geochemistry
Research subject
Applied Geology
Identifiers
urn:nbn:se:ltu:diva-11560 (URN)10.1144/geochem2013-206 (DOI)000331213200008 ()2-s2.0-84893563936 (Scopus ID)a8fd0f0f-b815-4144-8851-59493852601d (Local ID)a8fd0f0f-b815-4144-8851-59493852601d (Archive number)a8fd0f0f-b815-4144-8851-59493852601d (OAI)
Note
Validerad; 2014; 20140225 (andbra)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Österlund, H., Gelting, J., Nordblad, F., Baxter, D. & Ingri, J. (2012). Copper and nickel in ultrafiltered brackish water: labile or non-labile? (ed.). Paper presented at . Marine Chemistry, 132-133(1), 34-43
Open this publication in new window or tab >>Copper and nickel in ultrafiltered brackish water: labile or non-labile?
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2012 (English)In: Marine Chemistry, ISSN 0304-4203, E-ISSN 1872-7581, Vol. 132-133, no 1, p. 34-43Article in journal (Refereed) Published
Abstract [en]

Copper and nickel were sampled at three stations in the Baltic Sea using diffusive gradients in thin films (DGT) passive samplers and ultrafiltration (< 1 kDa). Two versions of DGT devices were used, the normal open pore (OP) and a restricted pore (RP). The OP DGT and RP DGT concentrations closely followed each other both in depth profiles and time series. The lack of significant difference between OP and RP DGT suggests that the labile complexes were smaller than the pore size of the RP gel (approximately 1 nm). These data, together with OP DGT measurements at the same location in two different years, clearly demonstrate that the DGT method is robust and indicates reproducible results during routine field conditions.Between 50 and 80% of the ultrafiltered fractions for Ni and Cu could not be detected by the DGT method, using standard procedures. This suggests the presence of complexing ligands for Cu and Ni. Assuming 100% complexation of Ni to fulvic acid ligand gave DGT concentrations similar to ultrafiltered Ni concentrations. The equivalent calculation for Cu indicates that up to 75% of the ultrafiltered Cu fraction is non-labile. The non-labile Cu complexes are proposed to be produced at sea since the fraction increases with decreasing terrestrial influence.

National Category
Geochemistry
Research subject
Applied Geology
Identifiers
urn:nbn:se:ltu:diva-11162 (URN)10.1016/j.marchem.2012.02.002 (DOI)000302929700005 ()2-s2.0-84857987453 (Scopus ID)a1182336-9740-4fbe-9847-32a86145dd86 (Local ID)a1182336-9740-4fbe-9847-32a86145dd86 (Archive number)a1182336-9740-4fbe-9847-32a86145dd86 (OAI)
Note
Validerad; 2012; 20120214 (andbra)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Nordblad, F., Ecke, F. & Ingri, J. (2011). Geochemistry in a boreal stream after a major forest fire: implications for a changing climate (ed.). Paper presented at Annual V.M. Goldschmidt Conference : 14/08/2011 - 19/08/2011. Paper presented at Annual V.M. Goldschmidt Conference : 14/08/2011 - 19/08/2011.
Open this publication in new window or tab >>Geochemistry in a boreal stream after a major forest fire: implications for a changing climate
2011 (English)Conference paper, Oral presentation only (Other academic)
National Category
Geochemistry
Research subject
Applied Geology
Identifiers
urn:nbn:se:ltu:diva-27746 (URN)149127bf-15a9-4113-9a1e-a2e407fddd2b (Local ID)149127bf-15a9-4113-9a1e-a2e407fddd2b (Archive number)149127bf-15a9-4113-9a1e-a2e407fddd2b (OAI)
Conference
Annual V.M. Goldschmidt Conference : 14/08/2011 - 19/08/2011
Note
Godkänd; 2011; 20111007 (andbra)Available from: 2016-09-30 Created: 2016-09-30 Last updated: 2017-11-25Bibliographically approved
Nordblad, F. (2011). Wildfire influences on stream water geochemistry in a boreal catchment (ed.). (Licentiate dissertation). Paper presented at . Luleå: Luleå tekniska universitet
Open this publication in new window or tab >>Wildfire influences on stream water geochemistry in a boreal catchment
2011 (English)Licentiate thesis, comprehensive summary (Other academic)
Abstract [en]

Forest wildfires are important for the structure and functioning of boreal ecosystems including biogeochemical processes. During the last decades, natural forest fires have been successfully suppressed in Fennoscandia. Therefore, our knowledge on the biogeochemical effects of forest fires is limited. In August 2006, a 1500 ha forest fire occurred near Bodträskfors, northern Sweden. The intensity of the fire varied among vegetation types. Especially in areas dominated by pine forest of the lichen type, vegetation and the humus layer were burnt to a large extent whereas the impact in moist-wet forest patches was less pronounced. Burning and subsequent leaching of plant remainders was expected to affect local surface waters. The main objectives with this thesis were to: 1) investigate the behavior of water quality parameters (pH, conductivity) and dissolved major elements including TOC (Total Organic Carbon) due to leaching of burnt plant remainders and, 2) measure the dissolved concentration and isotopic composition of boron as a potential tracer of forest fires. The project was performed in 2007 – 2009 in a creek draining the burnt area. A creek in a neighboring catchment not affected by the fire was sampled as a reference. Both catchments are characterized by the same type of bedrock and soil cover.The results indicate that leaching of the burnt plant remainders was mainly contributing P, K, Ca and Mg to creek water run-off. This is consistent with the naturally high concentrations of these elements in plant tissue. Na was not leached to any greater extent. Compared to the reference creek, burnt creek concentrations of N were slightly higher and slightly lower for TOC. The pH was ~ 0.5 units lower in the burnt creek during all years of measurement. Conductivity was higher in the burnt creek in 2007 but had decreased to the levels of the reference creek in 2009. Conductivity appeared to be controlled by Ca and Mg concentration as the temporal variations of these parameters/elements were closely correlated. During leaching from burnt plant remainders, P and K concentrations showed similar variation with time. The co-variation of Ca and Mg concentrations marks another behavior but TOC and N each exhibit unique changes of concentration with time. P and K are important nutrients associated to the burnt biomass. This caused extensive leaching of these elements for more than three years after the fire. Ca and Mg are contributed from groundwater to a great extent which was the likely reason for the more short-term post-fire leaching of these elements. As N is also considered an important nutrient it was unexpected that leaching was not as extensive as for P or K. However, the release of N after disturbances in boreal forest catchments has previously been observed to be erratic and depends greatly on the properties of the soil. The hypothesized inhibited release of TOC to the burnt creek was not obvious and the pH difference between both catchments was not considered an effect of the fire. However, since sampling was not conducted for longer than three years after the fire it could not be ruled out that TOC and pH were influenced on a longer term than that.The dissolved B concentrations were substantially higher in the burnt creek in 2007 compared to the reference creek and the isotopic composition (δ11B) was lighter. δ11B was not measured in 2009 but the burnt creek B concentrations were only slightly lower relative to 2007. The measured concentration and isotopic composition of dissolved B in the burnt creek were in line with anomalies of B measured in lake sediments. These anomalies were concluded to be the result of leaching of burnt wood remainders. The lighter B isotopic composition detected in both the present and the previous studies is in line with other findings concluding that forest plants utilize mainly the lighter B isotope (10B) during nutrient uptake from the soil solution. This B is normally released during the winter season inducing a seasonal oscillation of δ11B in the soil solution. The seasonal variation of δ11B was observed in the results from the reference creek. The more extensive leaching of lighter B from the burnt plant remainders most likely caused the overall lighter B isotopic composition and higher B concentrations in the burnt creek relative to the reference creek.

Place, publisher, year, edition, pages
Luleå: Luleå tekniska universitet, 2011
Series
Licentiate thesis / Luleå University of Technology, ISSN 1402-1757
National Category
Geochemistry
Research subject
Applied Geology
Identifiers
urn:nbn:se:ltu:diva-17094 (URN)18d5c4a1-44eb-46fd-95d2-14c91817eb92 (Local ID)978-91-7439-355-2 (ISBN)18d5c4a1-44eb-46fd-95d2-14c91817eb92 (Archive number)18d5c4a1-44eb-46fd-95d2-14c91817eb92 (OAI)
Note
Godkänd; 2011; 20111114 (frenor); LICENTIATSEMINARIUM Ämnesområde: Tillämpad geologi/Applied Geology Examinator: Professor Johan Ingri, Institutionen för samhällsbyggnad och naturresurser, Luleå tekniska universitet Diskutant: Professor Hjalmar Laudon, Inst för Skogens Ekologi & Skötsel, Sveriges lantbruksuniversitet, Umeå Tid: Tisdag den 20 december 2011 kl 13.00 Plats: F531, Luleå tekniska universitetAvailable from: 2016-09-29 Created: 2016-09-29 Last updated: 2017-11-24Bibliographically approved
Ingri, J., Gelting, J., Nordblad, F., Engström, E., Rodushkin, I., Andersson, P., . . . Öhlander, B. (2009). Fractionation of iron isotopes during estuarine mixing in Ob, Yenisey and Lena freshwater plumes (ed.). Paper presented at Annual V.M. Goldschmidt Conference : 21/06/2009 - 26/06/2009. Geochimica et Cosmochimica Acta, 73(13, Suppl. S), A569
Open this publication in new window or tab >>Fractionation of iron isotopes during estuarine mixing in Ob, Yenisey and Lena freshwater plumes
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2009 (English)In: Geochimica et Cosmochimica Acta, ISSN 0016-7037, E-ISSN 1872-9533, Vol. 73, no 13, Suppl. S, p. A569-Article in journal, Meeting abstract (Other academic) Published
Abstract [en]

Iron isotopes were measured in suspended matter (>0.2 µm) in the Ob, Yenisey and Lena River freshwater plumes during the International Siberian Shelf Study 2008 (ISSS-08). The δ56Fe value was around zero within the Lena River and close to the river mouth, but changed to more negative values in the outer parts of the plume. In both the Ob and Yenisey plumes suspended matter in the surface water had clearly negative values whereas samples close to the bottom showed values close to zero.It has previously been suggested that total Fe in river suspended matter (>0.2µm) in boreal regions is roughly a mixture of three phases, detrital particles (δ56Fe around zero), oxyhydroxide particles (δ56Fe positive) and C-Fe particles (δ56Fe negative). We suggest that the δ56Fe pattern observed in this study is the result of relatively rapid removal of detrital particles and Fe-oxyhydroxides, leaving a suspended fraction with negative values in the surface water in the outer parts of the freshwater plumes. Hence, during estuarine mixing of suspended particles heavy iron isotopes are deposited close to the river mouth, whereas light isotopes are exported to open ocean water.

Keywords
Natural sciences - Earth sciences, Naturvetenskap - Geovetenskap
National Category
Geochemistry
Research subject
Applied Geology
Identifiers
urn:nbn:se:ltu:diva-32058 (URN)66ab1020-7dab-11de-8da0-000ea68e967b (Local ID)66ab1020-7dab-11de-8da0-000ea68e967b (Archive number)66ab1020-7dab-11de-8da0-000ea68e967b (OAI)
Conference
Annual V.M. Goldschmidt Conference : 21/06/2009 - 26/06/2009
Note
Godkänd; 2009; 20090731 (ysko)Available from: 2016-09-30 Created: 2016-09-30 Last updated: 2018-02-26Bibliographically approved
Nordblad, F., Rodushkin, I., Engström, E., Ecke, F., Öhlander, B. & Ingri, J. (2009). Stream water geochemistry of boron and boron isotopes in a small boreal catchment affected by a major forest fire (ed.). Paper presented at Annual V.M. Goldschmidt Conference : 21/06/2009 - 26/06/2009. Geochimica et Cosmochimica Acta, 73(13, Supp. S), A952
Open this publication in new window or tab >>Stream water geochemistry of boron and boron isotopes in a small boreal catchment affected by a major forest fire
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2009 (English)In: Geochimica et Cosmochimica Acta, ISSN 0016-7037, E-ISSN 1872-9533, Vol. 73, no 13, Supp. S, p. A952-Article in journal, Meeting abstract (Other academic) Published
Abstract [en]

Previous research [1] has suggested that the boron (B) isotope system has a potential to be used as a tracer for detecting historic wood fire events. It was hypothesized that highly elevated B concentrations in sediments of a lake, accompanied by an enrichment of 10B, were a result of an urban wood fire event in the 19th century. The δ11B decrease in these sediments exceeded 9 ., coinciding with a peak in the B concentration.To evaluate this hypothesis, seasonal isotopic pattern of boron (B) was investigated during spring and summer 2007 in a small stream draining a boreal forest area which was severely burnt in a major forest fire in the summer of 2006. Dissolved (< 0.22 µm) boron concentrations of the burnt area were significantly higher compared to a non-burnt reference stream, while 11B/10B ratios were significantly lower. Dissolved δ11B differences between the reference and the burnt area stream were found to be -9 to -22 .. We interpret the elevated B concentrations, accompanied by enrichment of 10B, in the burnt stream as wood and plant ash leaching of biogenic B from the burnt forest by surface run-off. Our results suggest that a boreal forest fire event significantly increases the leached amount of isotopically lighter B in the dissolved phase of stream run-off.[1] Peltola & Åström (2006), Appl. Geochem. 21 (2006) 941-948.

Keywords
Natural sciences - Earth sciences, Naturvetenskap - Geovetenskap
National Category
Ecology Geochemistry
Research subject
Landscape Ecology; Applied Geology
Identifiers
urn:nbn:se:ltu:diva-34020 (URN)81d62490-7dae-11de-8da0-000ea68e967b (Local ID)81d62490-7dae-11de-8da0-000ea68e967b (Archive number)81d62490-7dae-11de-8da0-000ea68e967b (OAI)
Conference
Annual V.M. Goldschmidt Conference : 21/06/2009 - 26/06/2009
Note
Godkänd; 2009; 20090731 (ysko)Available from: 2016-09-30 Created: 2016-09-30 Last updated: 2018-02-26Bibliographically approved
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