4 research outputs found

    A First Global Oceanic Compilation of Observational Dissolved Aluminum Data With Regional Statistical Data Treatment

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    Large national and international observational efforts over recent decades have provided extensive and invaluable datasets of a range of ocean variables. Compiled large datasets, structured, or unstructured, are a powerful tool that allow scientists to access and synthesize data collected over large spatial and temporal scales. The data treatment approaches for any element in the ocean could lead to new global perspectives of their distribution patterns and to a better understanding of large-scale oceanic processes and their impact on other biogeochemical cycles, which may not be evident otherwise. Ocean chemistry Big Data analysis may not just be limited to distribution patterns, but may be used to assess how sampling efforts and analytical methodologies can be improved. Furthermore, a systematic global scale assessment of data is important to evaluate the gaps in knowledge and to provide avenues for future research. In this context, here we provide an extensive compilation of oceanic aluminum (Al) concentration data from global ocean basins, including data available in the GEOTRACES Intermediate Data product (Schlitzer et al., 2018), but also thus far unpublished data

    Fluxes of particles and soluble elements in dry and wet deposition samples collected between September 2012 and April 2016 at Gran Canaria, Canary Islands.

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    Steps to reproduce - Sampling sites and aerosol collection Tafira (TF) station (28º 06' N, 15º 24' W; 269 m a.s.l) is an urban background site subject to anthropogenic influence and situated within the marine boundary layer (<1800 m a.s.l). A Total Suspended particles (TSP) concentration Time-series has been recorded since 1 December 2003(see Gelado-Caballero et al., 2012; López-García et al., 2013). High volume (60 m3 h-1) aerosol collectors (MCV, model CAV-A/M) were used to collect aerosol samples for TSP in air on glass fibre filters (Whatman GF/A). TSP concentrations were measured following the procedure described in Gelado-Caballero et al. (2012). For deposition measurements, an automatic wet and dry sampler (ARS 1000, MTX Italy) with cubic containers having a surface area of 490 and 660 cm2, respectively was used. The instrument is equipped with a rain sensor. The aerosols collected in the deposition samples were quantified by gravimetry after filtering. Nucleopore filters were dried under a Class100 horizontal laminar flow bench and weighed with an accuracy of ±0.01 mg (Sartorius CP225D), before washing with 0.1 M hydrochloric acid (Suprapure, Merck) prior to use. Dry deposition (DD) samples were collected throughout the period from September 2012 to April 2016 at Tafira, in 92 samples representing average time periods ranging of 11 days but only since February 2013 soluble elements were analysed. Wet deposition (WD) samples were collected after each rainfall over the same period (n=125) representing average sampling periods of 2 days. - Chemical Analysis Soluble major ions, soluble Fe and pH were determined in the deposition samples. For DD samples, 150 mL was added to the bucket trying to wash all the particles deposited on the walls. The bucket was placed in an orbital shaker for 15 minutes to extract all the soluble elements, after that, the pH was measured and the sample was filtered using an acid clean Nucleopore filter (47 mm diameter and 0.2 µm pore size). WD samples were analysed just after the rain event and the same type of filter was used. pH in wet and dry deposition unfiltered samples were determined using a combined electrode (Aquatrode Plus, Metrohm). Soluble major ions were determined using two ion chromatographers (883 Basic IC Plus, Metrohm), a Metrosep ASupp 4 column for anion separation (fluoride, formate, chloride, bromide, nitrite, nitrate, phosphate, sulphate, and oxalate) and a Metrosep C4 column for cation separation (sodium, ammonium, potassium, calcium and magnesium) with a detection limit of 1 µg L-1. Because most of the phosphate concentrations in wet and dry deposition samples were below the detection limits of the IC, a nanomolar nutrient system was used (Patey et al., 2008). Soluble Fe was measured using a FiALab-3500 flow-injection analysis (FIA) system adapted to measure Fe using luminol chemiluminescence
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