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  • Journal article
    Bruneau N, Toumi R, Wang S, 2018,

    Publisher correction: Impact of wave whitecapping on land falling tropical cyclones

    , Scientific Reports, Vol: 8, ISSN: 2045-2322
  • Journal article
    Wang S, Toumi R, 2018,

    A historical analysis of the mature stage of tropical cyclones

    , International Journal of Climatology, Vol: 38, Pages: 2490-2505, ISSN: 0899-8418

    The characteristics of tropical cyclone intensity and size during the mature stage are presented. Rooted in the classic description by Herbert Riehl, the mature stage is identified as the period from the time of lifetime maximum intensity to the time of lifetime maximum size. This study is the first to analyse the global climatology of the mature stage of tropical cyclones in detail. Three basic features at the mature stage are observed: the reduction of intensity, the outward expansion of the eyewall, and the increase of tangential wind in the outer primary circulation. Globally, about a quarter of tropical cyclones undergo the mature stage. High intensity at the end of the immature stage favours the likelihood of the occurrence of the mature stage. The intensity reduction during the mature stage is considerable with nearly three-quarters of cyclones decreasing by more than 10%, which makes the conventional ‘steady-state’ presumption questionable. The increase in the radius of damaging-force wind is typically about 50 km, while the decrease in maximum wind speed is typically 20% at the mature stage. However, the average integrated kinetic energy and hence destructive potential increases substantially by about 70%. This is consistent with our finding that most of the highly damaging landfalling hurricanes undergo a mature stage. Intensity downgrades during the mature stage may be misinterpreted as they are mostly not accompanied by an overall danger reduction.
  • Journal article
    Gang S, Sarah M, Waite C, Buck M, Schumacher Jet al., 2018,

    Mutualism between Klebsiella SGM 81 and Dianthus caryophyllus in modulating root plasticity and rhizospheric bacterial density

    , Plant and Soil, Vol: 424, Pages: 273-288, ISSN: 0032-079X

    AimsDianthus caryophyllus is a commercially important ornamental flower. Plant growth promoting rhizobacteria are increasingly applied as bio-fertilisers and bio-fortifiers. We studied the effect of a rhizospheric isolate Klebsiella SGM 81 strain to promote D. caryophyllus growth under sterile and non-sterile conditions, to colonise its root system endophytically and its impact on the cultivatable microbial community. We identified the auxin indole-3-acetic acid (IAA) production of Klebsiella SGM 81 as major bacterial trait most likely to enhance growth of D. caryophyllus.MethodsipdC dependent IAA production of SGM 81 was quantified using LC-MS/MS and localised proximal to D. caryophyllus roots and correlated to root growth promotion and characteristic morphological changes. SGM 81 cells were localised on and within the plant root using 3D rendering confocal microscopy of gfp expressing SGM 81. Using Salkowski reagent IAA production was quantified and localised proximal to roots in situ. The effect of different bacterial titres on rhizosphere bacterial population was CFU enumerated on nutrient agar. The genome sequence of Klebsiella SGM 81 (accession number PRJEB21197) was determined to validate PGP traits and phylogenic relationships.ResultsInoculation of D. caryophyllus roots with Klebsiella SGM 81 drastically promoted plant growth when grown in agar and soil, concomitant with a burst in root hair formation, suggesting an increase in root auxin activity. We sequenced the Klebsiella SGM 81 genome, identified the presence of a canonical ipdC gene in Klebsiella SGM 81, confirmed bacterial production and secretion of IAA in batch culture using LC-MS/MS and localised plant dependent IAA production by SGM 81 proximal to roots. We found Klebsiella SGM 81 to be a rhizoplane and endophytic coloniser of D. caryophyllus roots in a dose dependent manner. We found no adverse effects of SGM 81 on the overall rhizospheric microbial population unless supplied to soil in very high
  • Journal article
    Konstantinoudis G, Kreis C, Ammann RA, Niggli F, Kuehni CE, Spycher BDet al., 2018,

    Spatial clustering of childhood cancers in Switzerland: a nationwide study

    , CANCER CAUSES & CONTROL, Vol: 29, Pages: 353-362, ISSN: 0957-5243
  • Journal article
    Kuznetsov DA, Han B, Yu Y, Rao RR, Hwang J, Roman-Leshkov Y, Shao-Horn Yet al., 2018,

    Tuning Redox Transitions via Inductive Effect in Metal Oxides and Complexes, and Implications in Oxygen Electrocatalysis

    , JOULE, Vol: 2, Pages: 225-244, ISSN: 2542-4351
  • Journal article
    Bruneau N, Toumi R, Wang S, 2018,

    Impact of wave whitecapping on land falling tropical cyclones

    , Scientific Reports, Vol: 8, ISSN: 2045-2322

    Predicting tropical cyclone structure and evolution remains challenging. Particularly, the surface wave interactions with thecontinental shelf and their impact on tropical cyclones have received very little attention. Through a series of state-of-the-arthigh-resolution, fully-coupled ocean-wave and atmosphere-ocean-wave experiments, we show here, for the first time, thatin presence of continental shelf waves can cause substantial cooling of the sea surface. Through whitecapping there is atransfer of momentum from the surface which drives deeper vertical mixing. It is the waves and not just the wind which becomethe major driver of stratified coastal ocean ahead-of-cyclone cooling. In the fully-coupled atmosphere-ocean-wave model anegative feedback is found. The maximum wind speed is weaker and the damaging footprint area of hurricane-force winds isreduced by up to 50% due to the strong wave induced ocean cooling ahead. Including wave-ocean coupling is important toimprove land falling tropical cyclone intensity predictions for the highly populated and vulnerable coasts.
  • Journal article
    Phillipson L, Toumi R, 2018,

    The Crossover Time as an Evaluation of OceanModels Against Persistence

    , Geophysical Research Letters, Vol: 45, Pages: 250-257, ISSN: 0094-8276

    A new ocean evaluation metric, the crossover time, is defined as the time it takes for a numerical model to equal the performance of persistence. As an example, the average crossover time calculated using the Lagrangian separation distance (the distance between simulated trajectories and observed drifters) for the global MERCATOR ocean model analysis is found to be about six days. Conversely, the model forecast has an average crossover time longer than six days, suggesting limited skill in Lagrangian predictability by the current generation of global ocean models. The crossover time of the velocity error is less than three days, which is similar to the average decorrelation time of the observed drifters. The crossover time is a useful measure to quantify future ocean model improvements.
  • Journal article
    Arcucci R, Carracciuolo L, Toumi R, 2018,

    Toward a preconditioned scalable 3DVAR for assimilating Sea Surface Temperature collected into the Caspian Sea

    , Journal of Numerical Analysis, Industrial and Applied Mathematics, Vol: 12, Pages: 9-28, ISSN: 1790-8140

    © 2018 European Society of Computational Methods in Sciences and Engineering. Data Assimilation (DA) is an uncertainty quantification technique used to incorporate observed data into a prediction model in order to improve numerical forecasted results. As a crucial point into DA models is the ill conditioning of the covariance matrices involved, it is mandatory to introduce, in a DA software, preconditioning methods. Here we present first results obtained introducing two different preconditioning methods in a DA software we are developing (we named S3DVAR) which implements a Scalable Three Dimensional Variational Data Assimilation model for assimilating sea surface temperature (SST) values collected into the Caspian Sea by using the Regional Ocean Modeling System (ROMS) with observations provided by the Group of High resolution sea surface temperature (GHRSST). We present the algorithmic strategies we employ and the numerical issues on data collected in two of the months which present the most significant variability in water temperature: August and March.
  • Conference paper
    D'Amore L, Arcucci R, Li Y, Montella R, Moore A, Phillipson L, Toumi Ret al., 2018,

    Performance Assessment of the Incremental Strong Constraints 4DVAR Algorithm in ROMS

    , 12th International Conference on Parallel Processing and Applied Mathematics (PPAM), Publisher: SPRINGER INTERNATIONAL PUBLISHING AG, Pages: 48-57, ISSN: 0302-9743
  • Journal article
    Chang S, Cao X, Zou Z, Isa M, Guthrie RILet al., 2018,

    Micro-bubble formation under non-wetting conditions in a full-scale water model of a ladle shroud/Tundish system

    , ISIJ International, Vol: 58, Pages: 60-67, ISSN: 0915-1559

    The effect of interfacial wettability on the size of gas bubbles releasing from orifices submerged in high velocity cross flow coupled with strong turbulence, was investigated in a full-scale water model of a commercial ladle/tundish/mold system, located at the McGill Metals Processing Centre. The present work attempted to simulate bubble formation in liquid steel passing through a ceramic (non-wetting) ladle shroud, with a high velocity and strong turbulence. This was accomplished by using a hydrophobic coating, sprayed onto the inner surface of the vertical acrylic ladle shroud, forming a contact angle of 150° at the three-phase line of contact, versus an angle of ~45° on the bare plexiglas surface. As such, the poor wettability of the treated acrylic surface of the ladle shroud led to slight increases in the diameters of micro-bubbles of 8.0%–22.4%, vs wetting systems, depending on gas flow rate and gas injection position. The present results indicate that the cross flows of liquid and their associated kinetic energy of turbulence within a ladle shroud flow can effectively refine bubbles into the micron size range, and prevent bubble growth caused by the poor wettability of liquid steel. Thus, argon gas injection through a ladle shroud could be an effective approach of producing small bubbles in liquid steel, even under the non-wetting conditions associated with such flows, which cannot be achieved by conventional gas curtain technique.
  • Book chapter
    Oluleye G, Allison J, Kelly N, Hawkes Aet al., 2018,

    A Multi-period Mixed Integer Linear Program for Assessing the Benefits of Power to Heat Storage in a Dwelling Energy System

    , Editors: Friedl, Klemes, Radl, Varbanov, Wallek, Publisher: ELSEVIER SCIENCE BV, Pages: 1451-1456
  • Book chapter
    Sechi S, Giarola S, Lanzini A, Gandiglio M, Oluleye G, Santarelli M, Hawkes Aet al., 2018,

    An optimization method to estimate the SOFC market in waste water treatment

    , Editors: Friedl, Klemes, Radl, Varbanov, Wallek, Publisher: ELSEVIER SCIENCE BV, Pages: 415-420
  • Journal article
    Stoerzinger KA, Hong WT, Wang XR, Rao RR, Subramanyam SB, Li C, Ariando, Venkatesan T, Liu Q, Crumlin EJ, Varanasi KK, Shao-Horn Yet al., 2017,

    Decreasing the Hydroxylation Affinity of La<sub>1-<i>x</i></sub>Sr<i><sub>x</sub></i>MnO<sub>3</sub> Perovskites To Promote Oxygen Reduction Electrocatalysis

    , CHEMISTRY OF MATERIALS, Vol: 29, Pages: 9990-9997, ISSN: 0897-4756
    • Cite
    • Citations: 38
  • Journal article
    Rao RM, Kolb MJ, Halck NB, Pedersen AF, Mehta A, You H, Stoerzinger KA, Feng Z, Hansen HA, Zhou H, Giordano L, Rossmeisl J, Vegge T, Chorkendorff I, Stephens IEL, Shao-Horn Yet al., 2017,

    Towards identifying the active sites on RuO2 (110) in catalyzing oxygen evolution

    , Energy and Environmental Science, Vol: 10, Pages: 2626-2637, ISSN: 1754-5692

    While the surface atomic structure of RuO2 has been well studied in ultra high vacuum, much less is known about theinteraction between water and RuO2 in aqueous solution. In this work, in situ surface X-ray scattering measurementscombined with density functional theory (DFT) was used to determine the surface structural changes on single-crystalRuO2 (110) as a function of potential in acidic electrolyte. The redox peaks at 0.7, 1.1 and 1.4 V vs. reversible hydrogenelectrode (RHE) could be attributed to surface transitions associated with the successive deprotonation of -H2O on thecoordinatively unsaturated Ru sites (CUS) and hydrogen adsorbed to the bridging oxygen sites. At potentials relevant tothe oxygen evolution reaction (OER), an –OO species on the Ru CUS sites was detected, which was stabilized by aneighboring -OH group on the Ru CUS or bridge site. Combining potential-dependent surface structures with theirenergetics from DFT led to a new OER pathway, where the deprotonation of the -OH group used to stabilize –OO wasfound to be rate-limiting.
  • Journal article
    Hwang J, Rao RR, Giordano L, Katayama Y, Yu Y, Shao-Horn Yet al., 2017,

    Perovskites in catalysis and electrocatalysis

    , SCIENCE, Vol: 358, Pages: 751-756, ISSN: 0036-8075
  • Journal article
    Riesen M, Konstantinoudis G, Lang P, Low N, Hatz C, Maeusezahl M, Spaar A, Bühlmann M, Spycher BD, Althaus CLet al., 2017,

    Exploring variation in human papillomavirus vaccination uptake: multi-level spatial analysis

    <jats:title>Abstract</jats:title><jats:sec><jats:title>Background</jats:title><jats:p>Understanding the factors that influence human papillomavirus (HPV) vaccination uptake is critically important to design effective vaccination programmes. In Switzerland, completed HPV vaccination by age 16 years among women ranges from 30 to 79% across 26 cantons (states). Our objective was to identify factors that are associated with the spatial variation in HPV vaccination uptake.</jats:p></jats:sec><jats:sec><jats:title>Methods and findings</jats:title><jats:p>We used data from the Swiss National Vaccination Coverage Survey 2009-2016 on HPV vaccination status (≥1 dose) of 14-17 year old girls, their municipality of residence and their nationality for 21 of 26 cantons (N=8,965). We examined covariates at municipality level: language, degree of urbanisation, socio-economic position, religious denomination, results of a vote about vaccination laws; and, at cantonal level, availability of school-based vaccination and survey period. We used a series of conditional auto regressive (CAR) models to assess the effects of covariates while accounting for variability between cantons and municipal-level spatial autocorrelation. In the best-fit model, school-based vaccination (adjusted odds ratio, OR: 2.51, 95% credible interval, CI: 1.77-3.56) was associated with increased uptake, while lower acceptance of vaccination laws was associated with lower HPV vaccination uptake (OR 0.61, 95% CI: 0.50-0.73). Overall, the covariates explained 88% of the municipal-level variation in uptake.</jats:p></jats:sec><jats:sec><jats:title>Conclusions</jats:title><jats:p>In Switzerland, cantons play a prominent role in the variation in HPV vaccination uptake, especially through the provision of school-based vaccination delivery. HPV vaccination uptake is also strongly associated with inhabitants&rsqu
  • Journal article
    Liu F, Fortin C, Campbell PGC, 2017,

    Can freshwater phytoplankton access cadmium bound to low-molecular-weight thiols?

    , LIMNOLOGY AND OCEANOGRAPHY, Vol: 62, Pages: 2604-2615, ISSN: 0024-3590
  • Journal article
    Konstantinoudis G, Kreis C, Ammann RA, Niggli F, Kuehni CE, Spycher BDet al., 2017,

    Spatial clustering of childhood leukaemia in Switzerland: A nationwide study

    , INTERNATIONAL JOURNAL OF CANCER, Vol: 141, Pages: 1324-1332, ISSN: 0020-7136
  • Conference paper
    Sechi S, Giarola S, Lanzini A, Gandiglio M, Oluleye O, Santarelli M, Hawkes Aet al., 2017,

    Techno-economic assessment of the effects of biogas rate fluctuations on industrial applications of solid-oxide fuel cells

    , ESCAPE-27, Publisher: Elsevier, ISSN: 1570-7946

    Wastewater treatment is an energy and greenhouse gas intensive process. An important opportunity to reduce both of these quantities is via the use of biogas in co-generation systems. Solid-oxide fuel cells (SOFCs) are the generator types studied in this work.The feasibility of the retrofitting of a wastewater treatment facility fitted with a SOFC combined heat and power energy provision system is assessed including effects of uncertainties in biogas availability on cost and energy performance. A two-stage stochastic optimization framework is proposed to provide feedback on the energy co-generation system design.Results quantify standard deviations in the biogas rate beyond which the SOFC capacity factor might drop below 80 % and change the optimal size of the modules to install.Keywords: solid-oxide fuel cells, stochastic optimization, wastewater treatment, biogas.
  • Journal article
    bruneau N, zika J, Toumi R, 2017,

    Can the ocean’s heat engine control horizontal circulation? Insights from the Caspian Sea.

    , Geophysical Research Letters, Vol: 44, Pages: 9893-9900, ISSN: 0094-8276

    We investigate the role of the ocean's heat engine in setting horizontal circulation using a numerical model of the Caspian Sea. The Caspian Sea can be seen as a virtual laboratory - a compromise between realistic global models which are hampered by long equilibration times and idealized basin geometry models which are not constrained by observations. We find that increases in vertical mixing drive stronger thermally direct overturning and consequent conversion of available potential to kinetic energy. Numerical solutions with water mass structures closest to observations overturn 0.02 − 0.04 x 106m3/s(Sv) representing the first estimate of Caspian Sea overturning. Our results also suggest that the overturning is thermally-forced increasing in intensity with increasing vertical diffusivity. Finally, stronger thermally direct overturning is associated with a stronger horizontal circulation in the Caspian Sea. This suggests the ocean's heat engine can strongly impact broader horizontal circulations in the ocean.
  • Conference paper
    Rao R, Shao-Horn Y, 2017,

    Understanding the active sites and reaction mechanism for oxygen electrocatalysis on ruthenium dioxide surfaces

    , 254th National Meeting and Exposition of the American-Chemical-Society (ACS) on Chemistry's Impact on the Global Economy, Publisher: AMER CHEMICAL SOC, ISSN: 0065-7727
  • Conference paper
    Kuznetsov D, Han B, Rao R, Shao-Horn Yet al., 2017,

    Linking the effect of the metal ion doping to metal oxides redox transitions and OER activity

    , 254th National Meeting and Exposition of the American-Chemical-Society (ACS) on Chemistry's Impact on the Global Economy, Publisher: AMER CHEMICAL SOC, ISSN: 0065-7727
  • Journal article
    Li Y, Toumi R, 2017,

    A balanced Kalman filter ocean data assimilation system with application to the South Australian Sea

    , Ocean Modelling, Vol: 116, Pages: 159-172, ISSN: 1463-5003

    n this paper, an Ensemble Kalman Filter (EnKF) based regional ocean data assimilation system has been developed and applied to the South Australian Sea. This system consists of the data assimilation algorithm provided by the NCAR Data Assimilation Research Testbed (DART) and the Regional Ocean Modelling System (ROMS). We describe the first implementation of the physical balance operator (temperature-salinity, hydrostatic and geostrophic balance) to DART, to reduce the spurious waves which may be introduced during the data assimilation process. The effect of the balance operator is validated in both an idealised shallow water model and the ROMS model real case study. In the shallow water model, the geostrophic balance operator eliminates spurious ageostrophic waves and produces a better sea surface height (SSH) and velocity analysis and forecast. Its impact increases as the sea surface height and wind stress increase. In the real case, satellite-observed sea surface temperature (SST) and SSH are assimilated in the South Australian Sea with 50 ensembles using the Ensemble Adjustment Kalman Filter (EAKF). Assimilating SSH and SST enhances the estimation of SSH and SST in the entire domain, respectively. Assimilation with the balance operator produces a more realistic simulation of surface currents and subsurface temperature profile. The best improvement is obtained when only SSH is assimilated with the balance operator. A case study with a storm suggests that the benefit of the balance operator is of particular importance under high wind stress conditions. Implementing the balance operator could be a general benefit to ocean data assimilation systems.
  • Conference paper
    Arcucci R, Celestino S, Toumi R, Laccetti Get al., 2017,

    Toward the S3DVAR data assimilation software for the Caspian Sea

    , International Conference on Numerical Analysis and Applied Mathematics (ICNAAM), Publisher: AIP Publishing, ISSN: 1551-7616

    Data Assimilation (DA) is an uncertainty quantification technique used to incorporate observed data into a prediction model in order to improve numerical forecasted results. The forecasting model used for producing oceanographic prediction into the Caspian Sea is the Regional Ocean Modeling System (ROMS). Here we propose the computational issues we are facing in a DA software we are developing (we named S3DVAR) which implements a Scalable Three Dimensional Variational Data Assimilation model for assimilating sea surface temperature (SST) values collected into the Caspian Sea with observations provided by the Group of High resolution sea surface temperature (GHRSST). We present the algorithmic strategies we employ and the numerical issues on data collected in two of the months which present the most significant variability in water temperature: August and March.
  • Journal article
    Sparks NJ, Hardwick SR, Schmid M, Toumi Ret al., 2017,

    IMAGE: a multivariate multi-site stochastic weather generator for European weather and climate

    , Stochastic Environmental Research and Risk Assessment, Vol: 32, Pages: 771-784, ISSN: 1436-3240

    Capturing the spatial and temporal correlation of multiple variables in a weather generator is challenging. A new massively multi-site, multivariate daily stochastic weather generator called IMAGE is presented here. It models temperature and precipitation variables as latent Gaussian variables with temporal behaviour governed by an auto-regressive model whose residuals and parameters are correlated through resampling of principle component time series of empirical orthogonal function modes. A case study using European climate data demonstrates the model’s ability to reproduce extreme events of temperature and precipitation. The ability to capture the spatial and temporal extent of extremes using a modified Climate Extremes Index is demonstrated. Importantly, the model generates events covering not observed temporal and spatial scales giving new insights for risk management purposes.
  • Journal article
    Corsaro CM, Toumi R, 2017,

    A self-weakening mechanism for tropical cyclones

    , Quaterly Journal of the Royal Meteological Society, Vol: 143, Pages: 2585-2599, ISSN: 1477-870X

    A mechanism leading to the self-weakening of tropical cyclones is proposed using the Weather and Research and Forecasting model. A comparison between an experiment with variable Coriolis parameter f and one on an f-plane shows that after the initial intensification the former is characterized by a smaller intensity. As opposed to the tropical cyclone on the f-plane, the one with variable f weakens significantly after reaching maturity. Analyses of the 3-D circulation show that the main reason for the weakening is dry intrusion in the mid-upper troposphere from the west. Once the dry intrusion reaches the inner vortex, strong downdrafts reduce the high equivalent potential temperature in the boundary layer inflow. The subsequent updrafts in the eyewall, characterized by lower equivalent potential temperature, are considerably reduced and, consequently, the secondary circulation weakens.Back-trajectories are used to determine the origin of the dry intrusion. It is found that the air parcels expelled from the storm deep convection into the outflow layer recirculate anticyclonically back into the vortex, causing a self-weakening of the tropical cyclone. A time span for the recirculation of at least 48 h allows the air parcels to sink substantially before reaching the vortex circulation. Some implications of the intrinsic nature of this process are briefly discussed.
  • Journal article
    Jovanovic M, Waite C, James E, Synn N, Simpson T, Kotta-Loizou I, Buck Met al., 2017,

    Functional Characterization of Key Residues in Regulatory Proteins HrpG and HrpV of Pseudomonas syringae pv. tomato DC3000

    , Molecular Plant-Microbe Interactions, Vol: 30, Pages: 656-665, ISSN: 0894-0282

    The plant pathogen Pseudomonas syringae pv. tomato DC3000 uses a type III secretion system (T3SS) to transfer effector proteins into the host. The expression of T3SS proteins is controlled by the HrpL σ factor. Transcription of hrpL is σ54-dependent and bacterial enhancer-binding proteins HrpR and HrpS coactivate the hrpL promoter. The HrpV protein imposes negative control upon HrpR and HrpS through direct interaction with HrpS. HrpG interacts with HrpV and relieves such negative control. The sequence alignments across Hrp group I-type plant pathogens revealed conserved HrpV and HrpG amino acids. To establish structure–function relationships in HrpV and HrpG, either truncated or alanine substitution mutants were constructed. Key functional residues in HrpV and HrpG are found within their C-terminal regions. In HrpG, L101 and L105 are indispensable for the ability of HrpG to directly interact with HrpV and suppress HrpV-dependent negative regulation of HrpR and HrpS. In HrpV, L108 and G110 are major determinants for interactions with HrpS and HrpG. We propose that mutually exclusive binding of HrpS and HrpG to the same binding site of HrpV governs a transition from negative control to activation of the HrpRS complex leading to HrpL expression and pathogenicity of P. syringae.
  • Conference paper
    Arcucci R, D'Amore L, Toumi R, 2017,

    Preconditioning of the background error covariance matrix in data assimilation for the Caspian Sea

    , 1st International Conference on Applied Mathematics and Computer Science (ICAMCS), Publisher: AIP Publishing, ISSN: 1551-7616

    Data Assimilation (DA) is an uncertainty quantification technique used for improving numerical forecasted results by incorporating observed data into prediction models. As a crucial point into DA models is the ill conditioning of the covariance matrices involved, it is mandatory to introduce, in a DA software, preconditioning methods. Here we present first studies concerning the introduction of two different preconditioning methods in a DA software we are developing (we named S3DVAR) which implements a Scalable Three Dimensional Variational Data Assimilation model for assimilating sea surface temperature (SST) values collected into the Caspian Sea by using the Regional Ocean Modeling System (ROMS) with observations provided by the Group of High resolution sea surface temperature (GHRSST). We also present the algorithmic strategies we employ.
  • Journal article
    Stoerzinger KA, Rao RR, Wang XR, Hong WT, Rouleau CM, Shao-Horn Yet al., 2017,

    The Role of Ru Redox in pH-Dependent Oxygen Evolution on Rutile Ruthenium Dioxide Surfaces

    , CHEM, Vol: 2, Pages: 668-675, ISSN: 2451-9294
  • Journal article
    Phillipson L, Toumi R, 2017,

    Impact of data assimilation on ocean current forecasts in the Angola Basin

    , OCEAN MODELLING, Vol: 114, Pages: 45-58, ISSN: 1463-5003

    The ocean current predictability in the data limited Angola Basin was investigated using the Regional Ocean Modelling System (ROMS) with four-dimensional variational data assimilation. Six experiments were undertaken comprising a baseline case of the assimilation of salinity/temperature profiles and satellite sea surface temperature, with the subsequent addition of altimetry, OSCAR (satellite-derived sea surface currents), drifters, altimetry and drifters combined, and OSCAR and drifters combined. The addition of drifters significantly improves Lagrangian predictability in comparison to the baseline case as well as the addition of either altimetry or OSCAR. OSCAR assimilation only improves Lagrangian predictability as much as altimetry assimilation. On average the assimilation of either altimetry or OSCAR with drifter velocities does not significantly improve Lagrangian predictability compared to the drifter assimilation alone, even degrading predictability in some cases. When the forecast current speed is large, it is more likely that the combination improves trajectory forecasts. Conversely, when the currents are weaker, it is more likely that the combination degrades the trajectory forecast.

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