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  • CONFERENCE PAPER
    Abolghasemi M, Piggott MD, Spinneken J, Vire A, Cotter CJ, Crammond Set al.,

    Simulating tidal turbines with mesh optimisation and RANS turbulence models

    , 2015 European Wave and Tidal Energy Conference
  • CONFERENCE PAPER
    Ahmad F, Murphy W, Lawrence JA, Hencher Set al.,

    Strength Mobilisation of Rock Masses in Relation to Deep Seated Landslide

    , Geophysical Research Abstracts 17, EGU2015, 8151
  • JOURNAL ARTICLE
    Barral N, Knepley MG, Lange M, Piggott MD, Gorman GJet al.,

    Anisotropic mesh adaptation in Firedrake with PETSc DMPlex

    Despite decades of research in this area, mesh adaptation capabilities arestill rarely found in numerical simulation software. We postulate that theprimary reason for this is lack of usability. Integrating mesh adaptation intoexisting software is difficult as non-trivial operators, such as error metricsand interpolation operators, are required, and integrating available adaptiveremeshers is not straightforward. Our approach presented here is to firstintegrate Pragmatic, an anisotropic mesh adaptation library, into DMPlex, aPETSc object that manages unstructured meshes and their interactions withPETSc's solvers and I/O routines. As PETSc is already widely used, this willmake anisotropic mesh adaptation available to a much larger community. As ademonstration of this we describe the integration of anisotropic meshadaptation into Firedrake, an automated Finite Element based system for theportable solution of partial differential equations which already uses PETScsolvers and I/O via DMPlex. We present a proof of concept of this integrationwith a three-dimensional advection test case.

  • CONFERENCE PAPER
    Busby JP, Senfaute G, Gourry JC, Lawrence JA, Pederson SAS, Mortimore RNet al.,

    Developing tools for the prediction of catastrophic coastal cliff collapse

    , In: Proceedings of the 7th International Symposium – Delivering Sustainable Coasts: Connecting Science and Policy, Pages: 596-601
  • JOURNAL ARTICLE
    Funke SW, Farrell PE, Piggott MD,

    Reconstructing wave profiles from inundation data

    This paper applies variational data assimilation to inundation problemsgoverned by the shallow water equations with wetting and drying. The objectiveof the assimilation is to recover an unknown time-varying wave profile at anopen ocean boundary from inundation observations. This problem is solved withderivative-based optimisation and an adjoint wetting and drying scheme toefficiently compute sensitivity information. The capabilities of this approachare demonstrated on an idealised sloping beach setup in which the profile of anincoming wave is reconstructed from wet/dry interface observations. The methodis robust against noisy observations if a regularisation term is added to theoptimisation objective. Finally, the method is applied to a laboratoryexperiment of the Hokkaido-Nansei-Oki tsunami, where the wave profile isreconstructed with an error of less than 1% of the reference wave signal.

  • JOURNAL ARTICLE
    Lawrence JA,

    Soil and Rock Description in Engineering Practice, D. Norbury: Book review

    , International Journal of Rock Mechanics & Mining Sciences, Pages: 1381-1381
  • JOURNAL ARTICLE
    Lawrence JA,

    Informing chalk cliff recession management decisions

    , Civil Engineering Year Book 2010, Pages: 17-18
  • JOURNAL ARTICLE
    Nixon CW, McNeill LC, Bull JM, Bell RE, Gawthorpe RL, Henstock TJ, Christodoulou, Ford M, Taylor B, Sakellariou D, Ferentinos G, Papatheodorou G, Leeder M, Collier RELI, Goodliffe A, Sachpazi M, Kranis Het al.,

    Rapid spatio-temporal variations in rift structure during development of the Corinth Rift, central Greece

    , Tectonics, ISSN: 1944-9194
  • JOURNAL ARTICLE
    Shevchenko I, Berloff P,

    On the roles of baroclinic modes in eddy-resolving midlatitude ocean dynamics

    , Ocean Modelling, ISSN: 1463-5011

    This work concerns how different baroclinic modes interact and influence solutions of the midlatitude oceandynamics described by the eddy-resolving quasi-geostrophic model of wind-driven gyres. We developedmulti-modal energetics analysis to illuminate dynamical roles of the vertical modes, carried out a systematicanalysis of modal energetics and found that the eddy-resolving dynamics of the eastward jet extension of thewestern boundary currents, such as the Gulf Stream or Kuroshio, is dominated by the barotropic, and thefirst and second baroclinic modes, which become more energized with smaller eddy viscosity. In the absenceof high baroclinic modes, the energy input from the wind is more efficiently focused onto the lower modes,therefore, the eddy backscatter maintaining the eastward jet and its adjacent recirculation zones is thestrongest and overestimated with respect to cases including higher baroclinic modes. In the presence of highbaroclinic modes, the eddy backscatter effect on the eastward jet is much weaker. Thus, the higher baroclinicmodes play effectively the inhibiting role in the backscatter, which is opposite to what has been previouslythought. The higher baroclinic modes are less energetic and have progressively decreasing effect on the flowdynamics; nevertheless, they still play important roles in inter-mode energy transfers (by injecting energyinto the region of the most intensive eddy forcing, in the neighborhood of the eastward jet) that have to betaken into account for correct representation of the backscatter and, thus, for determining the eastward jetextension.

  • JOURNAL ARTICLE
    Stucky de Quay G, Roberts GG, Watson J, Jackson CA-Let al.,

    Incipient mantle plume evolution: Constraints from ancient landscapes buried beneath the North Sea

    , Geochemistry, Geophysics, Geosystems, ISSN: 1525-2027

    Geological observations that constrain the history of mantle convection are sparse despite its importance in determining vertical and horizontal plate motions, plate rheology, and magmatism. We use a suite of geological and geophysical observations from the northern North Sea to constrain evolution of the incipient Paleocene-Eocene Icelandic plume. Well data and a three-dimensional seismic survey are used to reconstruct a 58–55 Ma landscape now buried ∼1.5 km beneath the seabed in the Bressay region. Geochemical analyses of cuttings from wells that intersect the landscape indicate the presence of angiosperm debris. These observations, combined with presence of coarse clastic material, interpreted beach ridges, and a large dendritic drainage network, indicate that this landscape formed subaerially. Longitudinal profiles of palaeo-rivers were extracted and inverted for an uplift rate history, indicating three distinct phases of uplift and total cumulative uplift of ∼350 m. Dinoflagellate cysts in the surrounding marine stratigraphy indicate that this terrestrial landscape formed in <3 Ma and was rapidly drowned. This uplift history is similar to that of a slightly older buried landscape in the Faeroe-Shetland basin ∼400 km to the west. These records of vertical motion are consistent with pulses of anomalously hot asthenosphere spreading out from the incipient Icelandic plume. Using simple isostatic calculations we estimate that the maximum thermal anomaly beneath Bressay was 50–100◦C. Our observations suggest that a thermal anomaly departed the Icelandic plume around 57.4±2.2 Ma at the latest, and travelled with a velocity >∼150 km/Ma.

  • JOURNAL ARTICLE
    Thomas RT, Prentice IC, Graven H, Ciais P, Fisher JB, Hayes DJ, Huang M, Huntzinger DN, Ito A, Jain A, Mao J, Michalak AM, Peng S, Poulter B, Ricciuto DM, Shi X, Schwalm C, Tian H, Zeng Net al.,

    Increased light-use efficiency in northern terrestrial ecosystems indicated by CO2 and greening observations.

    , Geophysical Research Letters, ISSN: 1944-8007
  • JOURNAL ARTICLE
    Davis T, Prentice IC, Stocker BD, Thomas RT, Whitley RJ, Wang H, Evans BJ, Gallego-Sala AV, Sykes MT, Cramer Wet al., 2017,

    Simple process-led algorithms for simulating habitats (SPLASH v.1.0): robust indices of radiation, evapotranspiration and plant-available moisture

    , GEOSCIENTIFIC MODEL DEVELOPMENT, Vol: 10, ISSN: 1991-959X
  • JOURNAL ARTICLE
    Dong N, Colin Prentice I, Evans BJ, Caddy-Retalic S, Lowe AJ, Wright IJet al., 2017,

    Leaf nitrogen from first principles: Field evidence for adaptive variation with climate

    , Biogeosciences, Vol: 14, Pages: 481-495, ISSN: 1726-4170

    © Author(s) 2017.Nitrogen content per unit leaf area (Narea) is a key variable in plant functional ecology and biogeochemistry. Narea comprises a structural component, which scales with leaf mass per area (LMA), and a metabolic component, which scales with Rubisco capacity. The co-ordination hypothesis, as implemented in LPJ and related global vegetation models, predicts that Rubisco capacity should be directly proportional to irradiance but should decrease with increases in ci:ca and temperature because the amount of Rubisco required to achieve a given assimilation rate declines with increases in both. We tested these predictions using LMA, leaf δ13C, and leaf N measurements on complete species assemblages sampled at sites on a north-south transect from tropical to temperate Australia. Partial effects of mean canopy irradiance, mean annual temperature, and ci:ca (from δ13C) on Narea were all significant and their directions and magnitudes were in line with predictions. Over 80% of the variance in community-mean (ln) Narea was accounted for by these predictors plus LMA. Moreover, Narea could be decomposed into two components, one proportional to LMA (slightly steeper in N-fixers), and the other to Rubisco capacity as predicted by the co-ordination hypothesis. Trait gradient analysis revealed ci:ca to be perfectly plastic, while species turnover contributed about half the variation in LMA and Narea. Interest has surged in methods to predict continuous leaf-trait variation from environmental factors, in order to improve ecosystem models. Coupled carbon-nitrogen models require a method to predict Narea that is more realistic than the widespread assumptions that Narea is proportional to photosynthetic capacity, and/or that Narea (and photosynthetic capacity) are determined by N supply from the soil. Our results indicate that Narea has a useful degree of predictability, from a combination of LMA and ci:ca - themselves in part environmentally determined -

  • JOURNAL ARTICLE
    Prentice IC, Cleator SF, Huang YH, Harrison SP, Roulstone Iet al., 2017,

    Reconstructing ice-age palaeoclimates: Quantifying low-CO<inf>2</inf> effects on plants

    , Global and Planetary Change, Vol: 149, Pages: 166-176, ISSN: 0921-8181

    © 2017 Elsevier B.V.We present a novel method to quantify the ecophysiological effects of changes in CO2 concentration during the reconstruction of climate changes from fossil pollen assemblages. The method does not depend on any particular vegetation model. Instead, it makes use of general equations from ecophysiology and hydrology that link moisture index (MI) to transpiration and the ratio of leaf-internal to ambient CO2 (χ). Statistically reconstructed MI values are corrected post facto for effects of CO2 concentration. The correction is based on the principle that e, the rate of water loss per unit carbon gain, should be inversely related to effective moisture availability as sensed by plants. The method involves solving a non-linear equation that relates e to MI, temperature and CO2 concentration via the Fu-Zhang relation between evapotranspiration and MI, Monteith's empirical relationship between vapour pressure deficit and evapotranspiration, and recently developed theory that predicts the response of χ to vapour pressure deficit and temperature. The solution to this equation provides a correction term for MI. The numerical value of the correction depends on the reconstructed MI. It is slightly sensitive to temperature, but primarily sensitive to CO2 concentration. Under low LGM CO2 concentration the correction is always positive, implying that LGM climate was wetter than it would seem from vegetation composition. A statistical reconstruction of last glacial maximum (LGM, 21±1 kyr BP) palaeoclimates, based on a new compilation of modern and LGM pollen assemblage data from Australia, is used to illustrate the method in practice. Applying the correction brings pollen-reconstructed LGM moisture availability in southeastern Australia better into line with palaeohydrological estimates of LGM climate.

  • JOURNAL ARTICLE
    Rogers A, Medlyn BE, Dukes JS, Bonan G, von Caemmerer S, Dietze MC, Kattge J, Leakey ADB, Mercado LM, Niinemets U, Prentice IC, Serbin SP, Sitch S, Way DA, Zaehle Set al., 2017,

    A roadmap for improving the representation of photosynthesis in Earth system models

    , NEW PHYTOLOGIST, Vol: 213, Pages: 22-42, ISSN: 0028-646X
  • JOURNAL ARTICLE
    Terrer C, Vicca S, Hungate BA, Phillips RP, Reich PB, Franklin O, Stocker BD, Fisher JB, Prentice ICet al., 2017,

    Response to Comment on "Mycorrhizal association as a primary control of the CO2 fertilization effect".

    , Science, Vol: 355

    Norby et al center their critique on the design of the data set and the response variable used. We address these criticisms and reinforce the conclusion that plants that associate with ectomycorrhizal fungi exhibit larger biomass and growth responses to elevated CO2 compared with plants that associate with arbuscular mycorrhizae.

  • JOURNAL ARTICLE
    Wang H, Prentice IC, Davis TW, Keenan TF, Wright IJ, Peng Cet al., 2017,

    Photosynthetic responses to altitude: an explanation based on optimality principles

    , NEW PHYTOLOGIST, Vol: 213, Pages: 976-982, ISSN: 0028-646X
  • JOURNAL ARTICLE
    Aitken ARA, Betts PG, Young DA, Blankenship DD, Roberts JL, Siegert MJet al., 2016,

    The Australo-Antarctic Columbia to Gondwana transition

    , GONDWANA RESEARCH, Vol: 29, Pages: 136-152, ISSN: 1342-937X
  • JOURNAL ARTICLE
    Aitken ARA, Roberts JL, van Ommen TD, Young DA, Golledge NR, Greenbaum JS, Blankenship DD, Siegert MJet al., 2016,

    Repeated large-scale retreat and advance of Totten Glacier indicated by inland bed erosion

    , NATURE, Vol: 533, Pages: 385-+, ISSN: 0028-0836
  • JOURNAL ARTICLE
    Ang CDE, Rein G, Peiro J, Harrison Ret al., 2016,

    Simulating longitudinal ventilation flows in long tunnels: Comparison of full CFD and multi-scale modelling approaches in FDS6

    , TUNNELLING AND UNDERGROUND SPACE TECHNOLOGY, Vol: 52, Pages: 119-126, ISSN: 0886-7798
  • JOURNAL ARTICLE
    Ball WT, Haigh JD, Rozanov EV, Kuchar A, Sukhodolov T, Tummon F, Shapiro AV, Schmutz Wet al., 2016,

    High solar cycle spectral variations inconsistent with stratospheric ozone observations

    , Nature Geoscience, ISSN: 1752-0894
  • JOURNAL ARTICLE
    Bantges RJ, Brindley HE, Chen XH, Huang XL, Harries JE, Murray JEet al., 2016,

    On the Detection of Robust Multidecadal Changes in Earth's Outgoing Longwave Radiation Spectrum

    , JOURNAL OF CLIMATE, Vol: 29, Pages: 4939-4947, ISSN: 0894-8755
  • JOURNAL ARTICLE
    Bercea G-T, McRae ATT, Ham DA, Mitchell L, Rathgeber F, Nardi L, Luporini F, Kelly PHJet al., 2016,

    A structure-exploiting numbering algorithm for finite elements on extruded meshes, and its performance evaluation in Firedrake

    , GEOSCIENTIFIC MODEL DEVELOPMENT, Vol: 9, Pages: 3803-3815, ISSN: 1991-959X
  • JOURNAL ARTICLE
    Bercea G-T, McRae ATT, Ham DA, Mitchell L, Rathgeber F, Nardi L, Luporini F, Kelly PHJet al., 2016,

    A structure-exploiting numbering algorithm for finite elements on extruded meshes, and its performance evaluation in Firedrake

    , Geoscientific Model Development, Vol: 9, Pages: 3803-3815
  • JOURNAL ARTICLE
    Bridgestock L, van de Flierdt T, Rehkamper M, Paul M, Middag R, Milne A, Lohan MC, Baker AR, Chance R, Khondoker R, Strekopytov S, Humphreys-Williams E, Achterberg EP, Rijkenberg MJA, Gerringa LJA, de Baar HJWet al., 2016,

    Return of naturally sourced Pb to Atlantic surface waters

    , NATURE COMMUNICATIONS, Vol: 7, ISSN: 2041-1723
  • JOURNAL ARTICLE
    Brindley HE, Bantges RJ, 2016,

    The Spectral Signature of Recent Climate Change

    , Current Climate Change Reports, Vol: 2, Pages: 112-126
  • JOURNAL ARTICLE
    Cavitte MGP, Blankenship DD, Young DA, Schroeder DM, Parrenin F, Lemeur E, Macgregor JA, Siegert MJet al., 2016,

    Deep radiostratigraphy of the East Antarctic plateau: connecting the Dome C and Vostok ice core sites

    , JOURNAL OF GLACIOLOGY, Vol: 62, Pages: 323-334, ISSN: 0022-1430
  • JOURNAL ARTICLE
    Chen C, Kamenkovich I, Berloff P, 2016,

    Eddy Trains and Striations in Quasigeostrophic Simulations and the Ocean

    , JOURNAL OF PHYSICAL OCEANOGRAPHY, Vol: 46, Pages: 2807-2825, ISSN: 0022-3670
  • JOURNAL ARTICLE
    Cooper MA, Michaelides K, Siegert MJ, Bamber JLet al., 2016,

    Paleofluvial landscape inheritance for Jakobshavn Isbrae catchment, Greenland

    , GEOPHYSICAL RESEARCH LETTERS, Vol: 43, Pages: 6350-6357, ISSN: 0094-8276
  • JOURNAL ARTICLE
    Cotter CJ, Kirby RC, 2016,

    Mixed finite elements for global tide models

    , NUMERISCHE MATHEMATIK, Vol: 133, Pages: 255-277, ISSN: 0029-599X

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