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Journal articles on the topic 'Global parametrization'

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Author: Grafiati

Published: 8 June 2024

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1

Shen, Hanxiao, Leyi Zhu, Ryan Capouellez, Daniele Panozzo, Marcel Campen, and Denis Zorin. "Which cross fields can be quadrangulated?" ACM Transactions on Graphics 41, no. 4 (July 2022): 1–12. http://dx.doi.org/10.1145/3528223.3530187.

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We describe a method for the generation of seamless surface parametrizations with guaranteed local injectivity and full control over holonomy. Previous methods guarantee only one of the two. Local injectivity is required to enable these parametrizations' use in applications such as surface quadrangulation and spline construction. Holonomy control is crucial to enable guidance or prescription of the parametrization's isocurves based on directional information, in particular from cross-fields or feature curves, and more generally to constrain the parametrization topologically. To this end we investigate the relation between cross-field topology and seamless parametrization topology. Leveraging previous results on locally injective parametrization and combining them with insights on this relation in terms of holonomy, we propose an algorithm that meets these requirements. A key component relies on the insight that arbitrary surface cut graphs, as required for global parametrization, can be homeomorphically modified to assume almost any set of turning numbers with respect to a given target cross-field.

2

Campen, Marcel, David Bommes, and Leif Kobbelt. "Quantized global parametrization." ACM Transactions on Graphics 34, no. 6 (November 4, 2015): 1–12. http://dx.doi.org/10.1145/2816795.2818140.

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3

Myles, Ashish, Nico Pietroni, and Denis Zorin. "Robust field-aligned global parametrization." ACM Transactions on Graphics 33, no. 4 (July 27, 2014): 1–14. http://dx.doi.org/10.1145/2601097.2601154.

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4

Myles, Ashish, and Denis Zorin. "Controlled-distortion constrained global parametrization." ACM Transactions on Graphics 32, no. 4 (July 21, 2013): 1–14. http://dx.doi.org/10.1145/2461912.2461970.

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5

Myles, Ashish, and Denis Zorin. "Global parametrization by incremental flattening." ACM Transactions on Graphics 31, no. 4 (August 5, 2012): 1–11. http://dx.doi.org/10.1145/2185520.2185605.

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6

Bright, Alon, Edward Chien, and Ofir Weber. "Harmonic global parametrization with rational holonomy." ACM Transactions on Graphics 36, no. 4 (July 20, 2017): 1–15. http://dx.doi.org/10.1145/3072959.3073646.

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7

Pietroni, Nico, Marco Tarini, Olga Sorkine, and Denis Zorin. "Global parametrization of range image sets." ACM Transactions on Graphics 30, no. 6 (December 2011): 1–10. http://dx.doi.org/10.1145/2070781.2024183.

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8

Veira, A., S. Kloster, N. A. J. Schutgens, and J. W. Kaiser. "Fire emission heights in the climate system – Part 2: Impact on transport, Black Carbon concentrations and radiation." Atmospheric Chemistry and Physics Discussions 15, no. 5 (March 6, 2015): 6695–744. http://dx.doi.org/10.5194/acpd-15-6695-2015.

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Abstract. Wildfires represent a major source for aerosols impacting atmospheric radiation, atmospheric chemistry and cloud micro-physical properties. Although former studies indicated that the height of the aerosol–radiation interaction crucially affects the overall climate impact, the importance of fire emission heights in particular remains to be quantified. In this study we use the general circulation model ECHAM6 extended by the aerosol module HAM2 to investigate the impact of wildfire emission heights on atmospheric long-range transport, Black Carbon (BC) concentrations and atmospheric radiation. We simulate the wildfire aerosol release using either various versions of a semi-empirical plume height parametrization or prescribed standard emission heights in ECHAM6-HAM2. Extreme scenarios of near-surface or free-tropospheric only injections provide lower and upper constraints on the emission height climate impact. We find relative changes in mean global atmospheric BC burden of up to 7.9±4.4% caused by average changes in emission heights of 1.5–3.5 km. Regionally, changes in BC burden exceed 30–40% in the major biomass burning regions. The model evaluation of Aerosol Optical Thickness (AOT) against MODIS, AERONET and CALIOP observations indicates that the implementation of a plume height parametrization slightly reduces the ECHAM6-HAM2 biases regionally, but on the global scale these improvements in model performance are small. For prescribed emission release at the surface, wildfire emissions entail a total sky Top Of Atmosphere (TOA) Radiative Forcing (RF) of −0.16±0.06 W m−2. The application of a plume height parametrization which agrees reasonably well with observations introduces a slightly stronger negative TOA RF of −0.20±0.07 W m−2. The standard ECHAM6-HAM2 model in which 25% of the wildfire emissions are injected into the free troposphere and 75% into the planetary boundary layer, leads to a TOA RF of −0.24±0.06 W m−2. Overall, we conclude that simple plume height parametrizations provide sufficient representations of emission heights for global climate modeling. Significant improvements in aerosol wildfire modeling likely depend on better emission inventories and aerosol process modeling rather than on improved emission height parametrizations.

9

Du, Zhang Peng, Christoph Steindl, and Stefan Jakubek. "Efficient Two-Step Parametrization of a Control-Oriented Zero-Dimensional Polymer Electrolyte Membrane Fuel Cell Model Based on Measured Stack Data." Processes 9, no. 4 (April 18, 2021): 713. http://dx.doi.org/10.3390/pr9040713.

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This paper proposes a new efficient two-step method for parametrizing control-oriented zero-dimensional physical polymer electrolyte membrane fuel cell (PEMFC) models with measured stack data. Parametrizations of these models are computationally intensive due to the numerous unknown parameters and the typically nonlinear, stiff model properties. This work reduces an existing model to decrease its stiffness for accelerated numerical simulations. Subdividing the parametrization into two consecutive subproblems (thermodynamic and electrochemical ones) reduces the solution space significantly. A parameter sensitivity analysis further reduces each sub-solution space by excluding non-significant parameters. The method results in an efficient parametrization process. The two-step approach minimizes each sub-solution space’s dimension by two-thirds, respectively three-fourths, compared to the global one. An achieved R2 value between simulation and measurement of 91% on average provides the required accuracy for control-oriented models.

10

Veira, A., S. Kloster, N. A. J. Schutgens, and J. W. Kaiser. "Fire emission heights in the climate system – Part 2: Impact on transport, black carbon concentrations and radiation." Atmospheric Chemistry and Physics 15, no. 13 (July 1, 2015): 7173–93. http://dx.doi.org/10.5194/acp-15-7173-2015.

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Abstract. Wildfires represent a major source for aerosols impacting atmospheric radiation, atmospheric chemistry and cloud micro-physical properties. Previous case studies indicated that the height of the aerosol–radiation interaction may crucially affect atmospheric radiation, but the sensitivity to emission heights has been examined with only a few models and is still uncertain. In this study we use the general circulation model ECHAM6 extended by the aerosol module HAM2 to investigate the impact of wildfire emission heights on atmospheric long-range transport, black carbon (BC) concentrations and atmospheric radiation. We simulate the wildfire aerosol release using either various versions of a semi-empirical plume height parametrization or prescribed standard emission heights in ECHAM6-HAM2. Extreme scenarios of near-surface or free-tropospheric-only injections provide lower and upper constraints on the emission height climate impact. We find relative changes in mean global atmospheric BC burden of up to 7.9±4.4 % caused by average changes in emission heights of 1.5–3.5 km. Regionally, changes in BC burden exceed 30–40 % in the major biomass burning regions. The model evaluation of aerosol optical thickness (AOT) against Moderate Resolution Imaging Spectroradiometer (MODIS), AErosol RObotic NETwork (AERONET) and Cloud–Aerosol Lidar with Orthogonal Polarization (CALIOP) observations indicates that the implementation of a plume height parametrization slightly reduces the ECHAM6-HAM2 biases regionally, but on the global scale these improvements in model performance are small. For prescribed emission release at the surface, wildfire emissions entail a total sky top-of-atmosphere (TOA) radiative forcing (RF) of −0.16±0.06 W m−2. The application of a plume height parametrization which agrees reasonably well with observations introduces a slightly stronger negative TOA RF of −0.20±0.07 W m−2. The standard ECHAM6-HAM2 model in which 25 % of the wildfire emissions are injected into the free troposphere (FT) and 75 % into the planetary boundary layer (PBL), leads to a TOA RF of −0.24±0.06 W m−2. Overall, we conclude that simple plume height parametrizations provide sufficient representations of emission heights for global climate modeling. Significant improvements in aerosol wildfire modeling likely depend on better emission inventories and aerosol process modeling rather than on improved emission height parametrizations.

11

Nicolis, N. G., and C. A. Papachristodoulou. "Alpha particle transmission coefficients from a global optical potential." HNPS Proceedings 9 (February 11, 2020): 299. http://dx.doi.org/10.12681/hnps.2790.

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Statistical model calculations involving a large number of emitted particles can be greatly facilitated by using transmission coefficients in a parametrized form. Thus, the execution and storage of the results of extensive optical model calculations can be avoided. Along these lines, a parametrization of optical model transmission coefficients, involving n, p, 2H, 3He and 4He on many targets, was produced some years ago. In the present work, we question the validity of this technique in the description of low-energy alpha particle evaporation. We propose a new parametrization with an improved low energy behavior.

12

ROBINSON, JAMES C. "Parametrization of global attractors, experimental observations, and turbulence." Journal of Fluid Mechanics 578 (April 26, 2007): 495–507. http://dx.doi.org/10.1017/s0022112007005137.

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This paper is concerned with rigorous results in the theory of turbulence and fluid flow. While derived from the abstract theory of attractors in infinite-dimensional dynamical systems, they shed some light on the conventional heuristic theories of turbulence, and can be used to justify a well-known experimental method.Two results are discussed here in detail, both based on parametrization of the attractor. The first shows that any two fluid flows can be distinguished by a sufficient number of point observations of the velocity. This allows one to connect rigorously the dimension of the attractor with the Landau–Lifschitz ‘number of degrees of freedom’, and hence to obtain estimates on the ‘minimum length scale of the flow’ using bounds on this dimension. While for two-dimensional flows the rigorous estimate agrees with the heuristic approach, there is still a gap between rigorous results in the three-dimensional case and the Kolmogorov theory.Secondly, the problem of using experiments to reconstruct the dynamics of a flow is considered. The standard way of doing this is to take a number of repeated observations, and appeal to the Takens time-delay embedding theorem to guarantee that one can indeed follow the dynamics ‘faithfully’. However, this result relies on restrictive conditions that do not hold for spatially extended systems: an extension is given here that validates this important experimental technique for use in the study of turbulence.Although the abstract results underlying this paper have been presented elsewhere, making them specific to the Navier–Stokes equations provides answers to problems particular to fluid dynamics, and motivates further questions that would not arise from within the abstract theory itself.

13

Helmke, Uwe. "A global parametrization of asymptotically stable linear systems." Systems & Control Letters 13, no. 5 (December 1989): 383–89. http://dx.doi.org/10.1016/0167-6911(89)90104-7.

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14

Veira, A., S. Kloster, S. Wilkenskjeld, and S. Remy. "Fire emission heights in the climate system – Part 1: Global plume height patterns simulated by ECHAM6-HAM2." Atmospheric Chemistry and Physics Discussions 15, no. 5 (March 6, 2015): 6645–93. http://dx.doi.org/10.5194/acpd-15-6645-2015.

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Abstract. We use the global circulation model ECHAM6 extended by the aerosol module HAM2 to simulate global patterns in wildfire emission heights. Prescribed plume heights in ECHAM6 are replaced by an implementation of a simple, semi-empirical plume height parametrization. In a first step, the global performance of the plume height parametrization is evaluated for plumes reported in the MISR Plume Height Project data set. Our results show that the parametrization simulates a largely reasonable global distribution of plume heights. While the modeled global mean plume height (1411±646 m) is in good agreement with the observed mean (1382±702 m), the upper and lower tails of the plume height distribution tend to be slightly underrepresented. Furthermore, we compare plume heights simulated by the simple parametrization to a more complex, analytical plume model. Major differences in global plume height distributions are found for the lowest 1.5 km, but reasonable agreement is observed for higher plumes. In a second step, Fire Radiative Power (FRP) as reported in the Global Fire Assimilation System (GFAS) is used to simulate plume heights for observed fires globally for the period 2005–2011. The global fraction of simulated daytime plumes injecting emissions into the free troposphere ranges from 3.7±0.7 to 5.2±1.0%. This range is comparable to results from observational studies, but it is much lower than for prescribed plume heights in the ECHAM6-HAM2 standard setup. Nevertheless, occasionally deep emission injections exceeding 5–7 km of height are simulated for intense fires and favorable meteorological conditions. The application of a prescribed diurnal cycle in FRP turns out to be of minor importance. For a hypothetical doubling in FRP, moderate changes in plume heights of 100–400 m are simulated. These small changes indicate that a potential future increase in fire intensity will only slightly impact the emission heights on global scale.

15

Zhao, Yifei. "Spectral decomposition of genuine cusp forms over global function fields." Compositio Mathematica 160, no. 6 (May 6, 2024): 1194–260. http://dx.doi.org/10.1112/s0010437x24007127.

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We prove the geometric Satake equivalence for étale metaplectic covers of reductive group schemes and extend the Langlands parametrization of V. Lafforgue to genuine cusp forms defined on their associated covering groups.

16

CHARNG, YEO-YIE. "WEAK PHASES FROM AMPLITUDE PARAMETRIZATION." International Journal of Modern Physics A 20, no. 15 (June 20, 2005): 3566–68. http://dx.doi.org/10.1142/s0217751x05026996.

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We determine the weak phases and the amplitudes by proposing an parametrization to each topologies of amplitudes in power of Wolfenstein parameter λ ~ 0.22. Comparing this parametrization with the experimental data, we can obtain the phase ϕ3 from the B → Kπ data up to theoretical uncertainty of O(λ3) ~ 5%. We find that these solutions indicate a large color-suppressed tree amplitude. The extraction of the phase ϕ2 and ϕ3 are consistent with the global unitarity triangle fit.

17

Medvigy, David, and Paul R. Moorcroft. "Predicting ecosystem dynamics at regional scales: an evaluation of a terrestrial biosphere model for the forests of northeastern North America." Philosophical Transactions of the Royal Society B: Biological Sciences 367, no. 1586 (January 19, 2012): 222–35. http://dx.doi.org/10.1098/rstb.2011.0253.

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Terrestrial biosphere models are important tools for diagnosing both the current state of the terrestrial carbon cycle and forecasting terrestrial ecosystem responses to global change. While there are a number of ongoing assessments of the short-term predictive capabilities of terrestrial biosphere models using flux-tower measurements, to date there have been relatively few assessments of their ability to predict longer term, decadal-scale biomass dynamics. Here, we present the results of a regional-scale evaluation of the Ecosystem Demography version 2 (ED2)-structured terrestrial biosphere model, evaluating the model's predictions against forest inventory measurements for the northeast USA and Quebec from 1985 to 1995. Simulations were conducted using a default parametrization, which used parameter values from the literature, and a constrained model parametrization, which had been developed by constraining the model's predictions against 2 years of measurements from a single site, Harvard Forest (42.5° N, 72.1° W). The analysis shows that the constrained model parametrization offered marked improvements over the default model formulation, capturing large-scale variation in patterns of biomass dynamics despite marked differences in climate forcing, land-use history and species-composition across the region. These results imply that data-constrained parametrizations of structured biosphere models such as ED2 can be successfully used for regional-scale ecosystem prediction and forecasting. We also assess the model's ability to capture sub-grid scale heterogeneity in the dynamics of biomass growth and mortality of different sizes and types of trees, and then discuss the implications of these analyses for further reducing the remaining biases in the model's predictions.

18

Veira, A., S. Kloster, S. Wilkenskjeld, and S. Remy. "Fire emission heights in the climate system – Part 1: Global plume height patterns simulated by ECHAM6-HAM2." Atmospheric Chemistry and Physics 15, no. 13 (July 1, 2015): 7155–71. http://dx.doi.org/10.5194/acp-15-7155-2015.

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Abstract. We use the global circulation model ECHAM6 extended by the aerosol module HAM2 to simulate global patterns in wildfire emission heights. Prescribed plume heights in ECHAM6 are replaced by an implementation of a simple, semi-empirical plume height parametrization. In a first step, the global performance of the plume height parametrization is evaluated for plumes reported in the Multiangle Imaging Spectroradiometer (MISR) Plume Height Project (MPHP) data set. Our results show that the parametrization simulates a largely reasonable global distribution of plume heights. While the modeled global mean plume height (1411 ± 646 m) is in good agreement with the observed mean (1382 ± 702 m), the upper and lower tails of the plume height distribution tend to be slightly underrepresented. Furthermore, we compare plume heights simulated by the simple parametrization to a more complex, analytical plume model. Major differences in global plume height distributions are found for the lowest 1.5 km, but reasonable agreement is observed for higher plumes. In a second step, fire radiative power (FRP) as reported in the global fire assimilation system (GFAS) is used to simulate plume heights for observed fires globally for the period 2005–2011. The global fraction of simulated daytime plumes injecting emissions into the free troposphere (FT) ranges from 3.7 ± 0.7 to 5.2 ± 1.0 %. This range is comparable to results from observational studies, but it is much lower than results for prescribed plume heights in the ECHAM6-HAM2 standard setup. Nevertheless, occasionally deep emission injections exceeding 5–7 km in height are simulated for intense fires and favorable meteorological conditions. The application of a prescribed diurnal cycle in FRP turns out to be of minor importance. For a hypothetical doubling in FRP, moderate changes in plume heights of 100–400 m are simulated. These small changes indicate that a potential future increase in fire intensity will only slightly impact the emission heights on a global scale.

19

Sun, Zhian, Xianning Zeng, Jingmiao Liu, Hong Liang, and J. Li. "Parametrization of instantaneous global horizontal irradiance: clear-sky component." Quarterly Journal of the Royal Meteorological Society 140, no. 678 (March 21, 2013): 267–80. http://dx.doi.org/10.1002/qj.2126.

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20

Rontu, Laura, and Anders V. Lindfors. "Comparison of radiation parametrizations within the HARMONIE–AROME NWP model." Advances in Science and Research 15 (May 22, 2018): 81–90. http://dx.doi.org/10.5194/asr-15-81-2018.

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Abstract. Downwelling shortwave radiation at the surface (SWDS, global solar radiation flux), given by three different parametrization schemes, was compared to observations in the HARMONIE–AROME numerical weather prediction (NWP) model experiments over Finland in spring 2017. Simulated fluxes agreed well with each other and with the observations in the clear-sky cases. In the cloudy-sky conditions, all schemes tended to underestimate SWDS at the daily level, as compared to the measurements. Large local and temporal differences between the model results and observations were seen, related to the variations and uncertainty of the predicted cloud properties. The results suggest a possibility to benefit from the use of different radiative transfer parametrizations in a NWP model to obtain perturbations for the fine-resolution ensemble prediction systems. In addition, we recommend usage of the global radiation observations for the standard validation of the NWP models.

21

PING, YONGLI, LIXIN XU, CHENGWU ZHANG, and HONGYA LIU. "DARK ENERGY IN GLOBAL BRANE UNIVERSE." International Journal of Modern Physics D 16, no. 10 (October 2007): 1633–40. http://dx.doi.org/10.1142/s0218271807011024.

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We discuss the exact solutions of brane universes and the results indicate that the Friedmann equations on the branes are modified with a new density term. Then, we assume the new term as the density of dark energy. Using Wetterich's parametrization equation of state (EOS) of dark energy, we obtain that the new term varies with the redshift z. Finally, the evolutions of the mass density parameter Ω2, dark energy density parameter Ωx and deceleration parameter q2 are studied.

22

BENAOUM, H. B. "NEW PARAMETRIZATION OF NEUTRINO MIXING MATRIX." Modern Physics Letters A 26, no. 06 (February 28, 2011): 423–31. http://dx.doi.org/10.1142/s021773231103489x.

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Global fits to neutrino oscillation data are compatible with tri-bimaximal mixing pattern, which predict θ23 = π/4, [Formula: see text] and θ13 = 0. We propose here to parametrize the tri-bimaximal mixing matrix V TBM by its hermitian generator H TBM using the exponential map. Then we use the exponential map to express the deviations from tri-bimaximal pattern by deriving the hermitian matrices Hz = 0 and H1. These deviations might come from the symmetry breaking of the neutrino and charged lepton sectors.

23

Okorokov, V. A., and S. D. Campos. "Analysis of pp and p̄p elastic scatterings based on theoretical bounds in high-energy physics: An update." International Journal of Modern Physics A 32, no. 28n29 (October 19, 2017): 1750175. http://dx.doi.org/10.1142/s0217751x17501755.

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In a previous work a novel parametrization was proposed for the [Formula: see text] and [Formula: see text] total cross-sections. Here, results are presented for the updated analysis with taking into account the recent data from accelerator experiments as well as from cosmic ray measurements. The analytic parametrizations suggested within axiomatic quantum field theory (AQFT) provide the quantitative description of energy dependence of global scattering observables with robust values of fit parameters. Based on the fit results the estimations are derived for the total cross-section and the [Formula: see text] parameter in elastic [Formula: see text] scattering at various [Formula: see text] up to energy frontier [Formula: see text] PeV which can be useful for present and future hadron colliders as well as for cosmic ray measurements at ultra-high energies.

24

Reynolds, R. G. "Quaternion parametrization and a simple algorithm for global attitude estimation." Journal of Guidance, Control, and Dynamics 21, no. 4 (July 1998): 669–71. http://dx.doi.org/10.2514/3.22106.

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25

Power, S. B., and A. C. Hirst. "Eddy parametrization and the oceanic response to idealized global warming." Climate Dynamics 13, no. 6 (July 21, 1997): 417–28. http://dx.doi.org/10.1007/s003820050174.

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26

Hagemann, S., and L. D�menil. "A parametrization of the lateral waterflow for the global scale." Climate Dynamics 14, no. 1 (December 16, 1997): 17–31. http://dx.doi.org/10.1007/s003820050205.

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27

Tupas, Mark Edwin, Florian Roth, Bernhard Bauer-Marschallinger, and Wolfgang Wagner. "An Intercomparison of Sentinel-1 Based Change Detection Algorithms for Flood Mapping." Remote Sensing 15, no. 5 (February 22, 2023): 1200. http://dx.doi.org/10.3390/rs15051200.

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With its unrivaled and global land monitoring capability, the Sentinel-1 mission has been established as a prime provider in SAR-based flood mapping. Compared to suitable single-image flood algorithms, change-detection methods offer better robustness, retrieving flood extent from a classification of observed changes. This requires data-based parametrization. Moreover, in the scope of global and automatic flood services, the employed algorithms should not rely on locally optimized parameters, which cannot be automatically estimated and have spatially varying quality, impacting much on the mapping accuracy. Within the recently launched Global Flood Monitoring (GFM) service, we implemented a Bayes-Inference (BI)-based algorithm designed to meet these ends. However, whether other change detection algorithms perform similarly or better is unknown. This study examines four Sentinel-1 change detection models: The Normalized Difference Scattering Index (NDSI), Shannon’s entropy of NDSI (SNDSI), Standardized Residuals (SR), and Bayes Inference over Luzon in the Philippines, which was flood-hit by a typhoon in November 2020. After parametrization assessment against an expert-created Sentinel-1 flood map, the four models are inter-compared against an independent Sentinel-2 classification. The obtained findings indicate that the Bayes change detection profits from its scalable classification rules and shows the least sensitivity to parametrization choices while also performing best in terms of mapping accuracy. For all change detection models, a backscatter seasonality model for the no-flood reference delivered best results.

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Vanderkelen, Inne, Shervan Gharari, Naoki Mizukami, Martyn P. Clark, David M. Lawrence, Sean Swenson, Yadu Pokhrel, Naota Hanasaki, Ann van Griensven, and Wim Thiery. "Evaluating a reservoir parametrization in the vector-based global routing model mizuRoute (v2.0.1) for Earth system model coupling." Geoscientific Model Development 15, no. 10 (June 1, 2022): 4163–92. http://dx.doi.org/10.5194/gmd-15-4163-2022.

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Abstract. Human-controlled reservoirs have a large influence on the global water cycle. While global hydrological models use generic parameterizations to model dam operations, the representation of reservoir regulation is still lacking in many Earth system models. Here we implement and evaluate a widely used reservoir parametrization in the global river-routing model mizuRoute, which operates on a vector-based river network resolving individual lakes and reservoirs and is currently being coupled to an Earth system model. We develop an approach to determine the downstream area over which to aggregate irrigation water demand per reservoir. The implementation of managed reservoirs is evaluated by comparing them to simulations ignoring inland waters and simulations with reservoirs represented as natural lakes using (i) local simulations for 26 individual reservoirs driven by observed inflows and (ii) global-domain simulations driven by runoff from the Community Land Model. The local simulations show the clear added value of the reservoir parametrization, especially for simulating storage for large reservoirs with a multi-year storage capacity. In the global-domain application, the implementation of reservoirs shows an improvement in outflow and storage compared to the no-reservoir simulation, but a similar performance is found compared to the natural lake parametrization. The limited impact of reservoirs on skill statistics could be attributed to biases in simulated river discharge, mainly originating from biases in simulated runoff from the Community Land Model. Finally, the comparison of modelled monthly streamflow indices against observations highlights that including dam operations improves the streamflow simulation compared to ignoring lakes and reservoirs. This study overall underlines the need to further develop and test runoff simulations and water management parameterizations in order to improve the representation of anthropogenic interference of the terrestrial water cycle in Earth system models.

29

Paneitz, Stephen M. "Parametrization of causal actions of universal covering groups and global hyperbolicity." Journal of Functional Analysis 62, no. 3 (July 1985): 337–53. http://dx.doi.org/10.1016/0022-1236(85)90009-6.

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30

Seiffert, Rita, Richard Blender, and Klaus Fraedrich. "Subscale forcing in a global atmospheric circulation model and stochastic parametrization." Quarterly Journal of the Royal Meteorological Society 132, no. 618 (July 1, 2006): 1627–43. http://dx.doi.org/10.1256/qj.05.139.

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31

Shcherbakov, E. A., and M. E. Shcherbakov. "Equilibrium Droplet Shapes and Almost Global Semi-Geodesic Parametrization of Surfaces." Lobachevskii Journal of Mathematics 44, no. 4 (April 2023): 1486–93. http://dx.doi.org/10.1134/s199508022304025x.

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32

Tiba, Dan. "Applications of implicit parametrizations." Studia Universitatis Babes-Bolyai Matematica 66, no. 1 (March 20, 2021): 5–15. http://dx.doi.org/10.24193/subbmath.2021.1.01.

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We review several applications of the implicit parametrization theorem in optimization. In nonlinear programming, we discuss both new forms, with less multipliers, of the known optimality conditions, and new algorithms of global type. For optimal control problems, we analyze the case of mixed equality constraints and indicate an algorithm, while in shape optimization problems the emphasis is on the new penalization approach.

33

Garcia, Ronaldo, and Dimas Tejada. "Principal Lines on an Ellipsoid in a Minkowski Three-Dimensional Space." KoG, no. 27 (2023): 3–13. http://dx.doi.org/10.31896/k.27.1.

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The description of principal lines of the ellipsoid on the 3-dimensional Minkowski space is established. A global principal parametrization of a triple orthogonal system of quadrics is also achieved, and the focal set of the ellipsoid is sketched.

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Jin, Chenyao, Chi-Shung Yip, Young-chul Ghim, Wei Zhang, Di Jiang, and Guo Sheng Xu. "Parametrization of electron sheath expansion for Langmuir probe I-V traces." Journal of Instrumentation 18, no. 07 (July 1, 2023): P07009. http://dx.doi.org/10.1088/1748-0221/18/07/p07009.

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Abstract The Langmuir probe is a common plasma diagnostic widely utilized in various fields of plasma physics, and its associated methods of data analysis remains in active development. In this work, we present an attempt using a power law parametrization model similar to Sheridan's empirical formulation is to describe the sheath expansion effect on electron current in an argon plasma. The fitting results using the power law parametrization method show observably better consistency compared to those using conventional interception method and inflection method. It is also observed that when used to fit the electron saturation current at probe bias voltages well beyond the plasma potential plus the argon ionization energy, resultant curve fitted by power law parametrization, as with that by linear fitting, deviates significantly from the curve fitted at lower bias voltages, albeit the saturation obtained fitted using the power law method remained consistent with that fitted at lower probe bias voltages. Probable causes of this deviation include anode glow or spots near the probe and the changes of the global plasma parameters via electron absorption at very high probe bias. The fact that the resultant electron saturation current remained consistent hints that these non-trival effects can also be approximated by power law parametrization.

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Walters, D. N., K. D. Williams, I. A. Boutle, A. C. Bushell, J. M. Edwards, P. R. Field, A. P. Lock, et al. "The Met Office Unified Model Global Atmosphere 4.0 and JULES Global Land 4.0 configurations." Geoscientific Model Development Discussions 6, no. 2 (May 14, 2013): 2813–81. http://dx.doi.org/10.5194/gmdd-6-2813-2013.

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Abstract. We describe Global Atmosphere 4.0 (GA4.0) and Global Land 4.0 (GL4.0): configurations of the Met Office Unified Model and JULES community land surface model developed for use in global and regional climate research and weather prediction activities. GA4.0 and GL4.0 are based on the previous GA3.0 and GL3.0 configurations, with the inclusion of developments made by the Met Office and its collaborators during its annual development cycle. This paper provides a comprehensive technical and scientific description of GA4.0 and GL4.0 as well as details of how these differ from their predecessors. We also present the results of some initial evaluations of their performance. These show that, overall, performance is comparable with that of GA3.0/GL3.0; the updated configurations do, however, include improvements to the science of several parametrization schemes and will form a baseline for further ongoing development.

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Ilin, N. V., M. V. Shatalina, and N. N. Slyunyaev. "Simulation of seasonal dynamics of the global electric circuit diurnal variation." Известия Российской академии наук. Физика атмосферы и океана 55, no. 5 (November 25, 2019): 76–84. http://dx.doi.org/10.31857/s0002-351555576-84.

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Based on the ionospheric potential (IP) parameterization, the seasonal dynamics of the diurnal variation of IP for 20162017 were modeled for the first time using the numerical weather forecast model WRF-ARW. The diurnal variation of the IP, averaged over the annual simulation periods, shows good agreement with the classical Carnegie curve. The proposed parametrization correctly reproduces the basic characteristics of the stationary global electric circuit generators. The annual variation does not show a precise repeatability from year to year, but in the winter season of the Northern Hemisphere a lower IP value was obtained, and in the summer - an increased one. The model diurnal variation demonstrates stable seasonal trends, and in the northern hemisphere, the variation is characterized by only one strongly distinguished maximum IP in the 16-18 UTC area of ~120% of the average value, while in the summer season the daily variation curve has two maxima with smaller value (~ 107% of average): morning at 89 UTC and evening at 1820 UTC. The model annual variation of the diurnal variation agrees with the experimental data of the surface field measuring in Antarctica in the period 20062011. The proposed parametrization and modeling technique made possible the accurate reproduction of the IP variation maximums times, their seasonal variability, and decreasing of the amplitude of variation in the summer period of the Northern Hemisphere.

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Kukavica, Igor. "On Fourier parametrization of global attractors for equations in one space dimension." Discrete & Continuous Dynamical Systems - A 13, no. 3 (2005): 553–60. http://dx.doi.org/10.3934/dcds.2005.13.553.

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Lu, Xin-Wei, and Ke-Cun Zhang. "An application of a global optimization parametrization method on macromolecular structure problem." Applied Mathematics and Computation 193, no. 1 (October 2007): 127–34. http://dx.doi.org/10.1016/j.amc.2007.03.070.

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Ehrt, Julia. "Parametrizations of sub-attractors in hyperbolic balance laws." Proceedings of the Royal Society of Edinburgh: Section A Mathematics 142, no. 3 (June 2012): 563–83. http://dx.doi.org/10.1017/s030821051000096x.

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We investigate the properties of the global attractor of hyperbolic balance laws on the circle, given byut + f(u)x = g(u).The new tool of sub-attractors is introduced. They contain all solutions on the global attractor up to a given number of zeros. The paper proves finite dimensionality of all sub-attractors, provides a full parametrization of all sub-attractors and derives a system of ordinary differential equations for the embedding parameters that describe the full partial differential equation dynamics on the sub-attractor.

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BLOCK, MARTIN M., and KYUNGSIK KANG. "A GLOBAL TEST OF FACTORIZATION FOR NUCLEON–NUCLEON, γp AND γγ SCATTERING." International Journal of Modern Physics A 20, no. 13 (May 20, 2005): 2781–93. http://dx.doi.org/10.1142/s0217751x05024936.

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The purpose of this paper is to show that the cross-section factorization relation σnn(s)/σγp(s) = σγp(s)/σγγ(s) is satisfied experimentally in the energy domain [Formula: see text], where the σ's are total cross-sections and nn denotes the even portion of the pp and [Formula: see text] total cross-section. A convenient phenomenological parametrization for a global simultaneous fit to the pp, [Formula: see text], γp and γγ total cross-section data together with the ρ-value data for pp and [Formula: see text] is provided by using real analytic amplitudes. Within experimental errors, we show that factorization is satisfied when we unfold the published γγ data which had averaged the cross-sections obtained by using the two different PHOJET and PYTHIA Monte Carlo results. Our analysis clearly favors the PHOJET results and suggests that the additive quark model, together with vector meson dominance, allows one to compute σγp(s) and σγγ(s) from σnn(s) with essentially no free parameters. The universal ρ-value predicted by our fit, i.e. ρnn = ργp = ργγ, is compared to the ρ-value obtained by a QCD-inspired analysis of [Formula: see text] and pp data, including the p-air cross-sections from cosmic rays. The ρ-values obtained from the two techniques are essentially indistinguishable in the energy region [Formula: see text], giving us increased confidence in our parametrization of the cross-sections needed for the factorization relation.

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Magyari-Köpe, B., L. Vitos, B. Johansson, and J. Kollár. "Parametrization of perovskite structures: an ab initio study." Acta Crystallographica Section B Structural Science 57, no. 4 (July 24, 2001): 491–96. http://dx.doi.org/10.1107/s010876810100893x.

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An overview of the pressure, temperature and chemical composition dependence of the lattice distortion in orthorhombic ABO3 perovskite structures is presented. Within the framework of the so-called global parametrization method (GPM) [Thomas (1998). Acta Cryst. B54, 585–599] an improved description for the position of the A cation in terms of the AO_{12} and BO_6 polyhedral volume ratio is proposed. The relationship is derived from an extensive ab initio study based on the density functional theory. The applicability of the improved GPM in combination with ab initio total energy calculations in the prediction of changes in the structural distortion under increasing hydrostatic pressure is investigated. Test calculations are performed for the geophysically important magnesium silicate perovskite and the results are compared with the available theoretical and experimental data.

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Baumgaertner, A. J. G., G. M. Lucas, J. P. Thayer, and S. A. Mallios. "On the role of non-electrified clouds in the Global Electric Circuit." Atmospheric Chemistry and Physics Discussions 14, no. 7 (April 15, 2014): 9815–47. http://dx.doi.org/10.5194/acpd-14-9815-2014.

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Abstract. Non-electrified clouds in the fair-weather part of the Global Electric Circuit (GEC) reduce conductivity because of the limited mobility of charge due to attachment to cloud water droplets, effectively leading to a loss of ions. A high-resolution GEC model, which numerically solves the Poisson equation, is used to show that in the fair-weather region currents partially flow around non-electrified clouds, with current divergence above the cloud, and convergence below the cloud. An analysis of this effect is presented for various types of non-electrified clouds, i.e. for different altitude extents, and for different horizontal dimensions, finding that the effect is most pronounced for high clouds with a diameter below 100 km. Based on these results, a method to calculate column and global resistance is developed that can account for all cloud sizes and altitudes. The CESM1(WACCM) Earth System Model as well as ISCCP cloud data are used to calculate the effect of this phenomenon on global resistance. From CESM1(WACCM), it is found that when including non-electrified clouds in the fair-weather estimate of resistance the global resistance increases by up to 73%, depending on the parameters used. Using ISCCP cloud cover leads to an even larger increase, which is likely to be overestimated because of time-averaging of cloud cover. Neglecting current divergence/convergence around small clouds overestimates global resistance by up to 20%, whereas the method introduced by previous studies underestimates global resistance by up to 40%. For global GEC models, a conductivity parametrization is developed to account for the current divergence/convergence phenomenon around non-electrified clouds. Conductivity simulations from CESM1(WACCM) using this parametrization are presented.

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Sim, Inbo, and Satoshi Tanaka. "Symmetry-breaking bifurcation for the one-dimensional Hénon equation." Communications in Contemporary Mathematics 21, no. 01 (January 28, 2019): 1750097. http://dx.doi.org/10.1142/s0219199717500973.

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We show the existence of a symmetry-breaking bifurcation point for the one-dimensional Hénon equation [Formula: see text] where [Formula: see text] and [Formula: see text]. Moreover, employing a variant of Rabinowitz’s global bifurcation, we obtain the unbounded connected set (the first of the alternatives about Rabinowitz’s global bifurcation), which emanates from the symmetry-breaking bifurcation point. Finally, we give an example of a bounded branch connecting two symmetry-breaking bifurcation points (the second of the alternatives about Rabinowitz’s global bifurcation) for the problem [Formula: see text] where [Formula: see text] is a specified continuous parametrization function.

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EMRE, E. "Explicit (global) parametrization of all stabilizing compensators and observers for linear feedback systems." International Journal of Control 48, no. 2 (August 1988): 625–40. http://dx.doi.org/10.1080/00207178808906201.

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Mandad, Manish, and Marcel Campen. "Efficient piecewise higher-order parametrization of discrete surfaces with local and global injectivity." Computer-Aided Design 127 (October 2020): 102862. http://dx.doi.org/10.1016/j.cad.2020.102862.

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Müller-Stoffels, M., and R. Wackerbauer. "Albedo parametrization and reversibility of sea ice decay." Nonlinear Processes in Geophysics 19, no. 1 (February 9, 2012): 81–94. http://dx.doi.org/10.5194/npg-19-81-2012.

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Abstract. The Arctic's sea ice cover has been receding rapidly in recent years, and global climate models typically predict a further decline over the next century. It is an open question whether a possible loss of Arctic sea ice is reversible. We study the stability of Arctic model sea ice in a conceptual, two-dimensional energy-based regular network model of the ice-ocean layer that considers ARM's longwave radiative budget data and SHEBA albedo measurements. Seasonal ice cover, perennial ice and perennial open water are asymptotic states accessible by the model. We show that the shape of albedo parameterization near the melting temperature differentiates between reversible continuous sea ice decrease under atmospheric forcing and hysteresis behavior. Fixed points induced solely by the surface energy budget are essential for understanding the interaction of surface energy with the radiative forcing and the underlying body of ice/water, particularly close to a bifurcation point. Future studies will explore ice edge stability and reversibility in this lattice model, generalized to a latitudinal transect with spatiotemporal lateral atmospheric heat transfer and high spatial resolution.

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CIMA, ANNA, ARMENGOL GASULL, and VÍCTOR MAÑOSA. "GLOBAL PERIODICITY CONDITIONS FOR MAPS AND RECURRENCES VIA NORMAL FORMS." International Journal of Bifurcation and Chaos 23, no. 11 (November 2013): 1350182. http://dx.doi.org/10.1142/s0218127413501824.

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We face the problem of characterizing the periodic cases in parametric families of rational diffeomorphisms of 𝕂k, where 𝕂 is ℝ or ℂ, having a fixed point. Our approach relies on the Normal Form Theory, to obtain necessary conditions for the existence of a formal linearization of the map, and on the introduction of a suitable rational parametrization of the parameters of the family. Using these tools we can find a finite set of values p for which the map can be p-periodic, reducing the problem of finding the parameters for which the periodic cases appear to simple computations. We apply our results to several two- and three-dimensional classes of polynomial or rational maps. In particular, we find the global periodic cases for several Lyness-type recurrences.

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TIBA, DAN. ""Periodic solutions for certain Hamiltonian systems in arbitrary dimension and global parametrization of some manifolds"." Carpathian Journal of Mathematics 38, no. 3 (July 26, 2022): 631–40. http://dx.doi.org/10.37193/cjm.2022.03.09.

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"t has been recently shown that the limit cycle situation is not valid for Hamiltonian systems in dimension two, under appropriate conditions. The applications concern global parametrizations of closed curves in the plane and optimal design problems. Here, we discuss a partial extension of this result, for certain Hamiltonian-type systems in higher dimension."

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Nassar, H., A. Lebée, and L. Monasse. "Curvature, metric and parametrization of origami tessellations: theory and application to the eggbox pattern." Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences 473, no. 2197 (January 2017): 20160705. http://dx.doi.org/10.1098/rspa.2016.0705.

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Origami tessellations are particular textured morphing shell structures. Their unique folding and unfolding mechanisms on a local scale aggregate and bring on large changes in shape, curvature and elongation on a global scale. The existence of these global deformation modes allows for origami tessellations to fit non-trivial surfaces thus inspiring applications across a wide range of domains including structural engineering, architectural design and aerospace engineering. The present paper suggests a homogenization-type two-scale asymptotic method which, combined with standard tools from differential geometry of surfaces, yields a macroscopic continuous characterization of the global deformation modes of origami tessellations and other similar periodic pin-jointed trusses. The outcome of the method is a set of nonlinear differential equations governing the parametrization, metric and curvature of surfaces that the initially discrete structure can fit. The theory is presented through a case study of a fairly generic example: the eggbox pattern. The proposed continuous model predicts correctly the existence of various fittings that are subsequently constructed and illustrated.

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Malardel, Sylvie, and Nils P. Wedi. "How does subgrid-scale parametrization influence nonlinear spectral energy fluxes in global NWP models?" Journal of Geophysical Research: Atmospheres 121, no. 10 (May 21, 2016): 5395–410. http://dx.doi.org/10.1002/2015jd023970.

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