| 1. |
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| 2. |
- Arwidsson, Zandra, et al.
(author)
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Remediation of heavy metal contaminated soil washing residues with amino polycarboxylic acids
- 2010
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In: Journal of Hazardous Materials. - : Elsevier BV. - 0304-3894 .- 1873-3336. ; 173:1-3, s. 697-704
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Journal article (peer-reviewed)abstract
- Removal of Cu, Pb, and Zn by the action of the two biodegradable chelating agents [S,S]-ethylenediaminedisuccinic acid (EDDS) and methylglycinediacetic acid (MGDA), as well as citric acid, was tested. Three soil samples, which had previously been treated by conventional soil washing (water), were utilized in the leaching tests. Experiments were performed in batches (0.3 kg-scale) and with a WTC-mixer system (Water Treatment Construction, 10 kg-scale). EDDS and MGDA were most often equally efficient in removing Cu, Pb, and Zn after 10-60 min. Nonetheless, after 10 d, there were occasionally significant differences in extraction efficiencies. Extraction with citric acid was generally less efficient, however equal for Zn (mainly) after 10 d. Metal removal was similar in batch and WTC-mixer systems, which indicates that a dynamic mixer system could be used in full-scale. Use of biodegradable amino polycarboxylic acids for metal removal, as a second step after soil washing, would release most remaining metals (Cu, Pb and Zn) from the present soils, however only after long leaching time. Thus, a full-scale procedure, based on enhanced metal leaching by amino polycarboxylic acids from soil of the present kind, Would require a pre-leaching step lasting several days in order to be efficient. (C) 2009 Elsevier B.V. All rights reserved.
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| 3. |
- Arwidsson, Zandra, et al.
(author)
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Remediation of Metal Contaminated Soil by Organic Metabolites from Fungi I—Production of Organic Acids
- 2008
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In: Water, Air and Soil Pollution. - Berlin, Germany : Springer. - 0049-6979 .- 1573-2932. ; 205:1-4, s. 215-226
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Journal article (peer-reviewed)abstract
- Investigations were made on living strains offungi in a bioremediation process of three metal (lead)contaminated soils. Three saprotrophic fungi (Aspergillusniger, Penicillium bilaiae, and a Penicillium sp.) wereexposed to poor and rich nutrient conditions (no carbonavailability or 0.11 M D-glucose, respectively) andmetal stress (25 μM lead or contaminated soils) for5 days. Exudation of low molecular weight organicacids was investigated as a response to the metal andnutrient conditions. Main organic acids identified wereoxalic acid (A. niger) and citric acid (P. bilaiae).Exudation rates of oxalate decreased in response tolead exposure, while exudation rates of citrate were lessaffected. Total production under poor nutrient conditionswas low, except for A. niger, for which nosignificant difference was found between the poor andrich control. Maximum exudation rates were 20 μmoloxalic acid g^−1 biomass h^−1 (A. niger) and 20 μmolcitric acid g^−1 biomass h^−1 (P. bilaiae), in the presenceof the contaminated soil, but only 5 μmol organic acidsg^−1 biomass h^−1, in total, for the Penicillium sp. Therewas a significant mobilization of metals from the soilsin the carbon rich treatments and maximum release ofPb was 12% from the soils after 5 days. This was notsufficient to bring down the remaining concentration tothe target level 300 mg kg^−1 from initial levels of 3,800,1,600, and 370 mg kg^−1in the three soils. Target levelsfor Ni, Zn, and Cu, were 120, 500, and 200 mg kg^−1,respectively, and were prior to the bioremediationalready below these concentrations (except for Cu Soil1). However, maximum release of Ni, Zn, and Cu was28%, 35%, and 90%, respectively. The release of metalswas related to the production of chelating acids, but alsoto the pH-decrease. This illustrates the potential to usefungi exudates in bioremediation of contaminated soil.Nonetheless, the extent of the generation of organicacids is depending on several processes and mechanismsthat need to be further investigated.
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| 4. |
- Arwidsson, Zandra, et al.
(author)
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Remediation of soils and sludges containing organic contaminants as well as metals – soil-wash procedures combining biodegradation, chemical complexation and mechanical separation of particulate matter
- 2009
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Conference paper (peer-reviewed)abstract
- Soil contamination is an urgent issue world wide. More than 83,000 contaminated sites have been identified in Sweden alone, of which approximately some 4,000 require treatment in the near future. Most of the sites carry a mixture of contaminants, metals as well as persistent organics. Most soil remediation efforts are made ex situ, which means that the soil or sludge is dug up and transported to a facility for treatment, or simply for deposition. The aim of the present project is to design a strategy for ex situ treatment of soils with mixed contaminants. A variety of soils and sludges from different sites (around 10), essentially all with organic as well as inorganic (metallic) contaminants, have been selected for experimental studies in laboratory and pilot scale: Military sites (metals, explosives), wood preservation sites (PAHs, As, metals), industrial sites (metals, hydrocarbons, mercury, dioxins and others). Of particular importance in the present study are:Metals – Pb, Cu, Zn, Cr, Hg, as well as As Organics – PAHs, nitro aromatics, dioxinsA number of processes are selected and applied: •Biodegradation - use of commercially available cultures, as well as bacteria cultivated from the contaminated site itself •Mobilisation of organics - use of surface active agents •Mobilisation of metals - use of (1) complexing microbial metabolites produced in the soil (by fungii in paricular), (2) complexing agents generated by degradation of natural organic products (polyhydroxy carboxylic acids), and (3) artificial complexing agents (polyamino carboxylic acids).Biodegradation is performed in batches (anaerobic in most cases), while release and mobilisation of contaminants from soil aggregates are achieved during soil-wash performed in a dynamic system where wash solution is forced through the soil under high pressure (the WTC-process). The efficiency of biodegradation and subsequent soil-wash under various conditions is evaluated from chemical analysis, but also by several ecotoxicological tests. Some results are given that illustrates suitable strategies for treatment of mixed contaminated soil from real sites (soil) as well as for treatment of residues from industrial production (sludges etc).
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| 5. |
- Coley, Nicola, et al.
(author)
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Plasma p-tau181 as an outcome and predictor of multidomain intervention effects: a secondary analysis of a randomised, controlled, dementia prevention trial
- 2024
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In: The Lancet Healthy Longevity. - 2666-7568. ; 5:2
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Journal article (peer-reviewed)abstract
- Background: It is unknown whether multidomain interventions, which might preserve late-life cognition, affect Alzheimer's disease pathology. Previous studies measured cerebrospinal fluid and imaging Alzheimer's disease biomarkers in small subsamples of multidomain trial participants. Newly developed assays enable the measurement of blood-based Alzheimer's disease biomarkers in larger samples. We aimed to assess whether plasma tau phosphorylated at threonine 181 (p-tau181) was able to detect or predict 3-year multidomain intervention effects. Methods: This is a secondary analysis of the randomised, controlled, Multidomain Alzheimer Prevention Trial (MAPT) testing a 3-year multidomain intervention, omega-3 fatty acid supplementation, or both versus placebo, in individuals aged 70 years and older in 13 memory centres in France and Monaco. Plasma p-tau181 was measured in stored blood samples in a subsample of 527 participants on an intention-to-treat basis. Changes in cognitive score were calculated as a composite measure using the average of Z scores for the following tests: Mini Mental State Examination orientation items, Free and Cued Selective Reminding Test (sum of free and total recall scores), category fluency, and Digit Symbol Substitution Test. Intervention effects on 3-year change in p-tau181 concentration were estimated by use of a linear mixed model with centre-specific random intercepts. Findings: Recruitment took place between May 30, 2008, and Feb 24, 2011. Median baseline plasma p-tau181 was 8·8 pg/mL (IQR 6·7–11·9) in the total sample, and significantly higher in older individuals, men, APOE ε4 carriers, and participants with renal dysfunction or a positive PET amyloid scan. During 3-year follow-up, individuals with raised baseline p-tau181 underwent greater cognitive decline (eg, mean difference in 3-year change on the composite cognitive score between control group participants with normal and abnormal baseline levels of p-tau was −0·34 [effect size −0·52; 95% CI −0·61 to 0·07] in the fully adjusted model using a 12·4 pg/mL cutoff for abnormal baseline p-tau181), but there were no intervention effects on change in p-tau181 either in this subgroup or the total population, and no effect on cognitive change in individuals with raised baseline p-tau181 (eg, in the fully adjusted model using the 12·4 pg/mL cutoff for p-tau181 abnormality, the mean difference [95% CI] in this subgroup in 3-year decline on the composite cognitive score between the control group and the multidomain + omega-3 group, the omega-3 group, and the multidomain intervention group, was, respectively: 0·13 [−0·21 to 0·47], 0·03 [−0·30 to 0·36], and 0·10 [−0·26 to 0·46]). Surprisingly, individuals with raised baseline p-tau181 showed a decrease in p-tau181 during follow-up (eg, unadjusted mean [95% CI] 3-year change was −3·01 pg/mL (−4·45 to −1·56) in control group subjects with abnormal baseline p-tau181 [using the 12·4 pg/mL abnormal p-tau cutoff]). Interpretation: Our results support the utility of p-tau181 as a prognostic biomarker, but it did not predict or detect intervention effects in this study. Further investigation of its usefulness as a prevention trial outcome measure is required.
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| 6. |
- DeAngelis, Nicola, et al.
(author)
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2020 WSES guidelines for the detection and management of bile duct injury during cholecystectomy
- 2021
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In: World Journal of Emergency Surgery. - : BMC. - 1749-7922. ; 16:1
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Research review (peer-reviewed)abstract
- Bile duct injury (BDI) is a dangerous complication of cholecystectomy, with significant postoperative sequelae for the patient in terms of morbidity, mortality, and long-term quality of life. BDIs have an estimated incidence of 0.4-1.5%, but considering the number of cholecystectomies performed worldwide, mostly by laparoscopy, surgeons must be prepared to manage this surgical challenge. Most BDIs are recognized either during the procedure or in the immediate postoperative period. However, some BDIs may be discovered later during the postoperative period, and this may translate to delayed or inappropriate treatments. Providing a specific diagnosis and a precise description of the BDI will expedite the decision-making process and increase the chance of treatment success. Subsequently, the choice and timing of the appropriate reconstructive strategy have a critical role in long-term prognosis. Currently, a wide spectrum of multidisciplinary interventions with different degrees of invasiveness is indicated for BDI management. These World Society of Emergency Surgery (WSES) guidelines have been produced following an exhaustive review of the current literature and an international expert panel discussion with the aim of providing evidence-based recommendations to facilitate and standardize the detection and management of BDIs during cholecystectomy. In particular, the 2020 WSES guidelines cover the following key aspects: (1) strategies to minimize the risk of BDI during cholecystectomy; (2) BDI rates in general surgery units and review of surgical practice; (3) how to classify, stage, and report BDI once detected; (4) how to manage an intraoperatively detected BDI; (5) indications for antibiotic treatment; (6) indications for clinical, biochemical, and imaging investigations for suspected BDI; and (7) how to manage a postoperatively detected BDI.
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| 7. |
- Di Muro, A., et al.
(author)
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Magma degassing at piton de la fournaise volcano
- 2016
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In: Active Volcanoes of the World. - Berlin, Heidelberg : Springer Berlin Heidelberg. - 2195-3589 .- 2195-7029. ; , s. 203-222
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Book chapter (other academic/artistic)abstract
- Since about 1860 AD, magmatic gas release at Piton de la Fournaise volcano is very weak during intra-eruptive phases and essentially occurs during the relatively short-lived eruptions. Recent gas measurements performed during an eruption in October 2010, combined with detailed review of melt and fluid inclusion composition in magmas erupted over the past 50 kyrs, indicate that most PdF eruptions extrude magmas having variably degassed at shallow depth (P < 1 kbar). The average low gas flux results from the low volume of both the magma recharges (from P > 1 kbar) and the shallow magmas, whose fluids are efficiently scrubbed by the hydrothermal system and the water table. Quantification of SO2 fluxes permits to track syn-eruptive magma ascent at shallow level (above sea level). Deeper exsolution of CO2 (below sea level) provides a potential long-term geochemical precursor for the detection of new magma recharges and volcano unrest.
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| 8. |
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| 9. |
- Elgh-Dalgren, Kristin, 1980-, et al.
(author)
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Laboratory and pilot scale soil washing of PAH and arsenic from a wood preservation site : Changes in concentration and toxicity
- 2009
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In: Journal of Hazardous Materials. - Amsterdam : Elsevier. - 0304-3894 .- 1873-3336. ; 172:2-3, s. 1033-1040
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Journal article (peer-reviewed)abstract
- Soil washing of a soil with a mixture of both polycyclic aromatic hydrocarbons (PAH) and As was evaluated in laboratory and pilot scale, utilizing both single and mixtures of different additives. The highest level of decontamination was achieved with a combination of 0.213 M of the chelating agent MGDA and 3.2xCMC* of a nonionic, alkyl glucoside surfactant at pH 12 (Ca(OH)2). This combination managed to reach Swedish threshold values within 10 min of treatment when performed at elevated temperature (50°C), with initial contaminant concentrations of As = 105±4 mg/kg and US-EPA PAH16 = 46.0±2.3 mg/kg. The main mechanisms behind the removal were the pH-effect for As and a combination of SOM-ionization as a result of high pH and micellar solubilization for PAHs. Implementation of the laboratory results utilizing a pilot scale equipment did not improve the performance, which may be due to the shorter contact time between the washing solution and the particles, or changes in physical characteristics of the leaching solution due to the elevated pressure utilized. The ecotoxicological evaluation, Microtox®, demonstrated that all soil washing treatments increased the toxicity of soil leachates, possibly due to increased availability of contaminants and toxicity of soil washing solutions to the test organism.
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| 10. |
- Elgh-Dalgren, Kristin, 1980-
(author)
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Remediation of materials with mixed contaminants : treatability, technology and final disposal
- 2009
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Doctoral thesis (other academic/artistic)abstract
- Contaminated soils are a large issue worldwide and much effort has been made to find efficient remediation methods. At many contaminated sites, mixtures of different contaminants with different properties are present, which may lead to additional problems, and thus additional costs, during the remediation process. This thesis presents the results from soil remediation of two mixed contaminated soils, containing explosives and heavy metals and polycyclic aromatic hydrocarbons (PAH) and arsenic, respectively. The results demonstrate that bioremediation may be an efficient method for moderate explosives concentration, but that too high contaminant concentrations may prevent the biodegradation, measured by both chemical and ecotoxicological analyses. If the contaminant concentration is very high, soil washing with alkaline pH (~12, NaOH) may be a good alternative, which was observed to remove both explosives and heavy metals. For a PAH and arsenic contaminated soil, little degradation of organics was observed during the bioremediation. However, the arsenic present was re-distributed in the soil, which could potentially lead to increased availability and thus increased risk for contaminant spreading. Soil washing at alkaline pH (~12-13; Ca(OH)2) with a combination of a biodegradable non-ionic surfactant and a biodegradable chelating agent, executed at high temperature (50°C), reached treatment goals for both arsenic and PAH after 10 min treatment. Measurement of ecotoxicity using Microtox® demonstrated that remaining surfactant in the soil may lead to increased toxicity despite lower contaminant concentrations. Soil is a basically non-renewable resource and thus re-cycling of remediated soil ought to be commonly occurring. Yet, the re-cycling of remediated masses has so far been limited in Sweden, mainly because of the risk of spreading of pollutant remains. However, a recent proposition from the Swedish EPA opens for re-cycling, even though the thresholds are very conservative. Risk assessment of the remediated soil includes the utilization of leaching tests to estimate the risk of spreading of remaining pollutants. A comparison of the leaching from four remediated soils using three different leaching solutions reveals that leaching of both heavy metals and PAH occurs. In addition, differences between different legislations were observed, which could imply that the same soil could be re-cycled in one country (the Netherlands) but not another (Sweden).
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| 11. |
- Elgh-Dalgren, Kristin, 1980-, et al.
(author)
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Simultaneous remediation of explosives and lead from contaminated soil by pH-adjustment
-
Other publication (other academic/artistic)abstract
- Soil washing with pH-adjusted water was evaluated in two soils containing different concentrations of heavy metals and explosives. Overall, the most efficient treatment was with water adjusted to pH 12 by NaOH. For explosives, pH 12 removed significantly higher amounts (P<0.05) of RDX and TNT compared to pH 4 (adjusted with HNO3) and distilled water in a moderately contaminated soil (230 mg HMX/kg, 1340 mg RDX/kg, 450 mg TNT/kg). In a more highly contaminated soil (6080 mg HMX/kg, 28740 mg RDX/kg, 3120 mg TNT/kg), the pH 12-treatment was the most efficient for removal of TNT and 2,4-DNT. Explosives removal increased with treatment time, probably due to the kinetically slow processes underlying the explosives degradation. Mobilization of heavy metals was strongly dependent on pH, with pH 12 mobilizing more than pH 3. In addition, the change in distribution coefficient (Kd) was more pronounced for local contaminants Pb and Cd in comparison with Cu and Zn, which were present in background concentrations.
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| 12. |
- Fischer, Tobias P., et al.
(author)
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The emissions of CO2 and other volatiles from the world's subaerial volcanoes
- 2019
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In: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322 .- 2045-2322. ; 9:1
-
Journal article (peer-reviewed)abstract
- Volcanoes are the main pathway to the surface for volatiles that are stored within the Earth. Carbon dioxide (CO2) is of particular interest because of its potential for climate forcing. Understanding the balance of CO2 that is transferred from the Earth's surface to the Earth's interior, hinges on accurate quantification of the long-term emissions of volcanic CO2 to the atmosphere. Here we present an updated evaluation of the world's volcanic CO2 emissions that takes advantage of recent improvements in satellite-based monitoring of sulfur dioxide, the establishment of ground-based networks for semi-continuous CO2-SO2 gas sensing and a new approach to estimate key volcanic gas parameters based on magma compositions. Our results reveal a global volcanic CO2 flux of 51.3 +/- 5.7 Tg CO2/y (11.7 x 10(11) mol CO2/y) for non-eruptive degassing and 1.8 +/- 0.9 Tg/y for eruptive degassing during the period from 2005 to 2015. While lower than recent estimates, this global volcanic flux implies that a significant proportion of the surface-derived CO2 subducted into the Earth's mantle is either stored below the arc crust, is efficiently consumed by microbial activity before entering the deeper parts of the subduction system, or becomes recycled into the deep mantle to potentially form diamonds.
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| 13. |
- Fresard, Laure, et al.
(author)
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Identification of rare-disease genes using blood transcriptome sequencing and large control cohorts
- 2019
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In: Nature Medicine. - : NATURE PUBLISHING GROUP. - 1078-8956 .- 1546-170X. ; 25:6, s. 911-919
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Journal article (peer-reviewed)abstract
- It is estimated that 350 million individuals worldwide suffer from rare diseases, which are predominantly caused by mutation in a single gene(1). The current molecular diagnostic rate is estimated at 50%, with whole-exome sequencing (WES) among the most successful approaches(2-5). For patients in whom WES is uninformative, RNA sequencing (RNA-seq) has shown diagnostic utility in specific tissues and diseases(6-8). This includes muscle biopsies from patients with undiagnosed rare muscle disorders(6,9), and cultured fibroblasts from patients with mitochondrial disorders(7). However, for many individuals, biopsies are not performed for clinical care, and tissues are difficult to access. We sought to assess the utility of RNA-seq from blood as a diagnostic tool for rare diseases of different pathophysiologies. We generated whole-blood RNA-seq from 94 individuals with undiagnosed rare diseases spanning 16 diverse disease categories. We developed a robust approach to compare data from these individuals with large sets of RNA-seq data for controls (n = 1,594 unrelated controls and n = 49 family members) and demonstrated the impacts of expression, splicing, gene and variant filtering strategies on disease gene identification. Across our cohort, we observed that RNA-seq yields a 7.5% diagnostic rate, and an additional 16.7% with improved candidate gene resolution.
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| 14. |
- Hagberg, Jessika
(author)
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Capillary zone electrophoresis for the analysis of low molecular weight organic acids in environmental systems
- 2003
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Doctoral thesis (other academic/artistic)abstract
- Capillary zone electrophoretic (CZE) methods were developed to identify and quantify low molecular weight (LMW) organic acids in environmental samples. Sensitivity and selectivity were optimised by adapting the background electrolyte to the characteristics of analytes, and by using different modes of detection and injection. Electrokinetic injection mode in combination with an isotachophoretic state increased the sensitivity remarkably for LMW organic acids using UV detection. Calcium ions were added to the background electrolyte, inducing an on-column complexation between acids and calcium ions, which gave good separation of the acids. Mass spectrometric detection (compared to UV detection) increased the sensitivity when using hydrodynamic injection mode during analysis, and selectivity was improved by mass identification. A CZE method for determination of the dissociation constants of LMW organic acids in the pKa range of 3.54.5 was also developed. The developed procedures were applied to different areas where LMW organic acids play an important environmental role: Low molecular weight organic acids were analysed in rainwater and soil water in the low μg/l range, within ten minutes after sampling. Rapid analysis and high sensitivity are essential when studying samples with rapid turnover due to microbial activity and photodegradation. The use of CZE-ESI-MS proved to be a robust analytical tool for determining LMW organic acids in samples rich in interfering ions. Organic acids excreted by soil fungi as response to metal exposure was easily and rapidly quantified with CZE-ESI-MS compared to HPLC and CZE-UV analysis. Dissociation constants for isosaccharinic acid (ISA) and gluconic acid were determined by CZE to 3.87 and 3.64, respectively. The ability to make the determinations in the presence of impurities as well as not having to know the exact concentration of analyte were identified as the major benefits of CZE. Isosaccharinic acid was identified as the main degradation product from alkaline degradation of cellulose by CZE analysis. Long-term predictions on both cellulose degradation and ISA production were made based on three years of sampling data. A control sampling after seven years indicated that the degradation of cellulose and the production of ISA were lower than predicted.
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| 15. |
- Johansson, Emma M.
(author)
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Impact of root and mycorrhizal exudation on soil carbon fluxes : influence of elevated CO2 and metals
- 2009
-
Doctoral thesis (other academic/artistic)abstract
- The thesis concerns the behavior of root and ectomycorrhizal (ECM) exudates. In particular, the dynamics of soluble low molecular weight (LMW) organic compounds such as organic acids (LMWOAs), amino acids, monosaccharides, and dissolved organic carbon (DOC) have been studied. Our knowledge of exudation rates for tree roots and especially associated ECM is limited, and also factors influencing exudation rates. Two environmental factors, metal stress and elevated atmospheric CO2 level, have been investigated. Both are of great environmental concern, but function in different ways (detoxification and C allocation) and may be highly important for the C flux caused by root/ECM exudation. The project has been carried out with mycorrhizal and nonmycorrhizal (NM) Scots pine seedlings, or saprotrophic fungi, under both sterile and non-sterile (soil) conditions. Analytical determination of exudates and calculation of exudation rates have been major tools for assessment. Assessing the possibility of using naturally occurring chelating agents (e.g. citrate and oxalate) for bioremediation of metals contaminated soils and development and validation of analytical techniques have been additional foci. The results show that from soil-living fungi and ectomycorrhizal roots exudation rates of especially LMWOAs increase significantly at Cd and Pb stress (1-100 μM), while As (as arsenate) and mixtures of metals with As have little effect. The impact of ECM fungi is large and much higher exudation rates are found when the symbionts are present both for controls and metal treatments compared to NM plants. In soil systems there was a significant mobilization of metals from soils under presence of saprotrophic fungi. Both N as well as elevated CO2 (700 ppm) causes sizable increases in exudation rates, independent of biomass, and is a finding that suggests that the availability of easily degradable carbon in soil raises, which may be highly important for the carbon flux in soil. Mycorrhizal seedlings (10 months old) increased total soil respiration ~50% compared to controls without plants in non-sterile soil systems. Key words: amino acids, 13C, carbon cycle, ectomycorrhiza, elevated CO2, exudation, DOC, LMWOA, metal stress, monosaccharides, oxalate, Pinus sylvestris, saprotrophic fungi, soil respiration
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| 16. |
- Smith, Gregory C., et al.
(author)
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Polar ocean observations: A critical gap in the observing system and its effect on environmental predictions from hours to a season
- 2019
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In: Frontiers in Marine Science. - : Frontiers Media SA. - 2296-7745. ; 6
-
Journal article (peer-reviewed)abstract
- There is a growing need for operational oceanographic predictions in both the Arctic and Antarctic polar regions. In the former, this is driven by a declining ice cover accompanied by an increase in maritime traffic and exploitation of marine resources. Oceanographic predictions in the Antarctic are also important, both to support Antarctic operations and also to help elucidate processes governing sea ice and ice shelf stability. However, a significant gap exists in the ocean observing system in polar regions, compared to most areas of the global ocean, hindering the reliability of ocean and sea ice forecasts. This gap can also be seen from the spread in ocean and sea ice reanalyses for polar regions which provide an estimate of their uncertainty. The reduced reliability of polar predictions may affect the quality of various applications including search and rescue, coupling with numerical weather and seasonal predictions, historical reconstructions (reanalysis), aquaculture and environmental management including environmental emergency response. Here, we outline the status of existing near-real time ocean observational efforts in polar regions, discuss gaps, and explore perspectives for the future. Specific recommendations include a renewed call for open access to data, especially real-time data, as a critical capability for improved sea ice and weather forecasting and other environmental prediction needs. Dedicated efforts are also needed to make use of additional observations made as part of the Year of Polar Prediction (YOPP; 2017-19) to inform optimal observing system design. To provide a polar extension to the Argo network, it is recommended that a network of ice-borne sea ice and upper-ocean observing buoys be deployed and supported operationally in ice-covered areas together with autonomous profiling floats and gliders (potentially with ice detection capability) in seasonally-ice covered seas. Finally, additional efforts to better measure and parameterize surface exchanges in polar regions are much needed to improve coupled environmental prediction.
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| 17. |
- Tinetti, G., et al.
(author)
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A chemical survey of exoplanets with ARIEL
- 2018
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In: Experimental Astronomy. - : Springer Science and Business Media LLC. - 0922-6435 .- 1572-9508. ; 46:1, s. 135-209
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Journal article (peer-reviewed)abstract
- Thousands of exoplanets have now been discovered with a huge range of masses, sizes and orbits: from rocky Earth-like planets to large gas giants grazing the surface of their host star. However, the essential nature of these exoplanets remains largely mysterious: there is no known, discernible pattern linking the presence, size, or orbital parameters of a planet to the nature of its parent star. We have little idea whether the chemistry of a planet is linked to its formation environment, or whether the type of host star drives the physics and chemistry of the planet’s birth, and evolution. ARIEL was conceived to observe a large number (~1000) of transiting planets for statistical understanding, including gas giants, Neptunes, super-Earths and Earth-size planets around a range of host star types using transit spectroscopy in the 1.25–7.8 μm spectral range and multiple narrow-band photometry in the optical. ARIEL will focus on warm and hot planets to take advantage of their well-mixed atmospheres which should show minimal condensation and sequestration of high-Z materials compared to their colder Solar System siblings. Said warm and hot atmospheres are expected to be more representative of the planetary bulk composition. Observations of these warm/hot exoplanets, and in particular of their elemental composition (especially C, O, N, S, Si), will allow the understanding of the early stages of planetary and atmospheric formation during the nebular phase and the following few million years. ARIEL will thus provide a representative picture of the chemical nature of the exoplanets and relate this directly to the type and chemical environment of the host star. ARIEL is designed as a dedicated survey mission for combined-light spectroscopy, capable of observing a large and well-defined planet sample within its 4-year mission lifetime. Transit, eclipse and phase-curve spectroscopy methods, whereby the signal from the star and planet are differentiated using knowledge of the planetary ephemerides, allow us to measure atmospheric signals from the planet at levels of 10–100 part per million (ppm) relative to the star and, given the bright nature of targets, also allows more sophisticated techniques, such as eclipse mapping, to give a deeper insight into the nature of the atmosphere. These types of observations require a stable payload and satellite platform with broad, instantaneous wavelength coverage to detect many molecular species, probe the thermal structure, identify clouds and monitor the stellar activity. The wavelength range proposed covers all the expected major atmospheric gases from e.g. H2O, CO2, CH4 NH3, HCN, H2S through to the more exotic metallic compounds, such as TiO, VO, and condensed species. Simulations of ARIEL performance in conducting exoplanet surveys have been performed – using conservative estimates of mission performance and a full model of all significant noise sources in the measurement – using a list of potential ARIEL targets that incorporates the latest available exoplanet statistics. The conclusion at the end of the Phase A study, is that ARIEL – in line with the stated mission objectives – will be able to observe about 1000 exoplanets depending on the details of the adopted survey strategy, thus confirming the feasibility of the main science objectives.
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