Article
Engineering, Civil
Zhendong Cao, Yu Zhang, Phillip J. Wolfram, Steven R. Brus, Joel C. Rowland, Chonggang Xu, Donatella Pasqualini, Carolyn B. Begeman, Mark R. Petersen
Summary: Vegetation drag is a crucial factor influencing coastal marsh and geomorphological studies. Different parameterizations have been used to model vegetation drag, but their effects on tidal propagation and flooding depth vary. The selection of vegetation drag parameterization is essential for accurately predicting the long-term evolution of coastal marshes and morphology.
JOURNAL OF HYDROLOGY
(2021)
Article
Automation & Control Systems
Belmiro P. M. Duarte, Anthony C. Atkinson, Nuno M. C. Oliveira
Summary: Nonlinear regression is commonly used to fit nonlinear relationships between response variables and regressors. This paper presents a systematic strategy for model reparameterization using a carefully chosen set of support points. The approach is tested with both linear and nonlinear models and evaluated using various metrics.
CHEMOMETRICS AND INTELLIGENT LABORATORY SYSTEMS
(2023)
Article
Astronomy & Astrophysics
Rupert Coy, Michele Frigerio
Summary: New physics in the lepton sector has implications for neutrino masses, electroweak precision observables, charged-lepton flavor violation, and dipole moments. Effective field theory is a convenient formalism for comparing low-energy predictions of different models. By deriving the Wilson coefficients for representative models and considering various lepton observables, it becomes straightforward to understand the allowed parameter space for each model and discriminate between them. The Zee and leptoquark models are particularly relevant for explaining the muon g-2 anomaly.
Article
Meteorology & Atmospheric Sciences
Shanning Bao, Lazaro Alonso, Siyuan Wang, Johannes Gensheimer, Ranit De, Nuno Carvalhais
Summary: Parameters in a system model can affect the accuracy and uncertainty of the model by representing system sensitivities and unresolved processes. We propose a Simultaneous Parameter Inversion and Extrapolation approach (SPIE) to overcome issues with plant-functional-type (PFT)-dependent parameterizations. By using an artificial neural network, SPIE predicts model parameters based on collected variables, resulting in better performance compared to other parameter extrapolation methods.
JOURNAL OF ADVANCES IN MODELING EARTH SYSTEMS
(2023)
Article
Engineering, Civil
Zhipeng Xie, Yaoming Ma, Weiqiang Ma, Zeyong Hu, Genhou Sun
Summary: Blowing snow greatly influences the spatial-temporal evolution of snow cover. accurately predicting the initiation of snow particle movement is a prerequisite for blowing snow modeling. Previous studies lack a quantitative evaluation of the performance of different schemes in blowing snow identification, especially outside the regions where empirical schemes were proposed.
JOURNAL OF HYDROLOGY
(2023)
Article
Meteorology & Atmospheric Sciences
Douglas C. Stolz, Kelsey R. Bilsback, Jeffrey R. Pierce, Steven A. Rutledge
Summary: Lightning plays a fundamental role in atmospheric chemistry as the largest natural source of NOx in the upper troposphere. Global models rely on experimental parameterizations to include lightning, with different parameterizations showing varying degrees of correlation and bias compared to observations. Utilizing environmental factors with aerosols for lightning parameterization yields the highest correlation and the smallest error bias, while biases in lightning estimates are shown to be sensitive to uncertainties in convective area.
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
(2021)
Article
Physics, Fluids & Plasmas
Benjamin J. Walker, Kenta Ishimoto, Eamonn A. Gaffney
Summary: Simple models are commonly used in the physical sciences to gain intuition, capture phenomena, and qualitatively reproduce observations. In the study of microswimmers, simple force-dipole models are prevalent and serve as far-field descriptions of complex swimmers. However, the use of constant, averaged parameters in these models may lead to qualitatively incorrect conclusions and alter our intuition for microscale swimming. Through a multitimescale analysis, we investigate the validity of a priori-averaged parameters and explore models that incorporate rapid temporal variation through simple extensions. We demonstrate how asymptotic analysis of non-autonomous models can lead to effective parametrizations of minimal microswimmer models.
PHYSICAL REVIEW FLUIDS
(2023)
Article
Energy & Fuels
Stuart R. J. R. Walker, Philipp R. Thies
Summary: Electricity generated from tidal streams using underwater turbines has lower greenhouse gas emissions compared to electricity derived from fossil fuels. However, the conventional materials used for tidal stream turbine blades are non-recyclable and contribute to a significant amount of waste. This study explores alternative materials and manufacturing methods, considering their environmental impact and cost. The results suggest that flax fiber composite materials provide the best environmental performance, offering lower greenhouse gas emissions compared to traditional glass fiber materials.
Article
Mathematics, Applied
Wei-Hung Liao, Mei-Heng Yueh
Summary: In this paper, an efficient algorithm for computing disk conformal parameterizations of simply connected open surfaces is proposed, which combines the spherical harmonic mapping and the geodesic algorithm. The algorithm reduces the number of unknowns involved in the computation and shows improved efficiency compared to other state-of-the-art algorithms, while maintaining similar or even slightly better accuracy.
JOURNAL OF SCIENTIFIC COMPUTING
(2022)
Article
Meteorology & Atmospheric Sciences
Wanchen Wu, Wei Huang, Baode Chen
Summary: Idealized supercell storms were simulated using two aerosol-aware bulk microphysics schemes in the Weather Research and Forecast (WRF) model. The study aimed to investigate aerosol effects on cloud and precipitation characteristics, showing significant differences in cloud composition and precipitation between the schemes. Additionally, the fall speed characteristics of graupel and aerosol parameterization uncertainties were found to play important roles in storm dynamics and precipitation.
ADVANCES IN ATMOSPHERIC SCIENCES
(2022)
Article
Astronomy & Astrophysics
Aseem Paranjape
Summary: The study focuses on the non-linear cosmic web environment of dark matter haloes and their impact on growth and evolution, as well as the galaxies within them. An analytical formalism is developed to describe the tidal field of anisotropic halocentric density distributions. Through axisymmetric examples, interesting results are demonstrated that shed light on the dynamics within the cosmic web.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Oceanography
Z. Liu, W. G. Zhang, K. R. Helfrich
Summary: This study reveals the vertical distribution of barotropic-to-baroclinic energy conversion in a slope-shelf setting, showing two hotspots of energy conversion at the bottom and thermocline, respectively. The study also indicates the significance of baroclinic energy generated at the thermocline for onshore energy radiation.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2022)
Article
Geosciences, Multidisciplinary
Ritabrata Thakur, Brian K. Arbic, Dimitris Menemenlis, Kayhan Momeni, Yulin Pan, W. R. Peltier, Joseph Skitka, Matthew H. Alford, Yuchen Ma
Summary: We propose improvements to the modeling of the vertical wavenumber spectrum of internal gravity waves in regional ocean simulations. Our study focuses on the sensitivity of the model to mixing parameters and compares the results to observations. The findings suggest that improving the mixing parameters can enhance the representation of internal wave dynamics.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Environmental Sciences
Andrew Bennett, Bart Nijssen
Summary: By embedding DL methods into PBHM models, it is possible to improve the accuracy of modeling hydrologic processes and achieve better predictive results.
WATER RESOURCES RESEARCH
(2021)
Article
Meteorology & Atmospheric Sciences
T. Waterman, A. D. Bragg, G. Katul, N. Chaney
Summary: Earth system models and mesoscale models have been using increasingly complex parameterization schemes for the atmospheric boundary layer. This study evaluates existing parameterizations for the surface boundary conditions of potential temperature variance (PTV) and finds that the existing schemes are acceptable over a variety of surface conditions. However, they perform poorly over heterogeneous surfaces and rough landscapes. Attempts to improve the results using canopy structure and surface roughness characteristics did not significantly enhance the predictive power of the models. There is no strong evidence indicating that large scale circulations cause substantial deviations from textbook models.
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
(2022)
Article
Oceanography
Filippa Fransner, Erik Gustafsson, Letizia Tedesco, Marcello Vichi, Robinson Hordoir, Fabien Roquet, Kristian Spilling, Ivan Kuznetsov, Kari Eilola, Carl-Magnus Morth, Christoph Humborg, Jonas Nycander
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2018)
Article
Meteorology & Atmospheric Sciences
Magnus Hieronymus, Jonas Nycander, Johan Nilsson, Kristofer Doos, Robert Hallberg
JOURNAL OF CLIMATE
(2019)
Article
Mechanics
Friederike Pollmann, Jonas Nycander, Carsten Eden, Dirk Olbers
JOURNAL OF FLUID MECHANICS
(2019)
Article
Meteorology & Atmospheric Sciences
C. de Lavergne, S. Falahat, G. Madec, F. Roquet, J. Nycander, C. Vic
Article
Meteorology & Atmospheric Sciences
Magnus Hieronymus, Jonas Nycander
JOURNAL OF CLIMATE
(2020)
Article
Environmental Sciences
Aitor Aldama-Campino, Filippa Fransner, Malin Odalen, Sjoerd Groeskamp, Andrew Yool, Kristofer Doos, Jonas Nycander
GLOBAL BIOGEOCHEMICAL CYCLES
(2020)
Article
Meteorology & Atmospheric Sciences
Paolo Ruggieri, Maarten H. P. Ambaum, Jonas Nycander
JOURNAL OF THE ATMOSPHERIC SCIENCES
(2020)
Letter
Mechanics
G. G. Sutyrin, T. Radko, J. Nycander
Summary: This study examines baroclinic vortices embedded in large-scale vertical shear and describes a new class of stable propagating vortices. These vortices can extract potential energy from a large-scale vertically sheared flow by generating Rossby waves, leading to meridional vortex drift and associated heat flux. The theory is confirmed by numerical simulations, showing that reduced potential vorticity gradient in the upper layer provides favorable conditions for eddy persistence and long-range propagation in westward flows in subtropical oceans.
Article
Oceanography
Sara Berglund, Kristofer Doos, Aitor Aldama Campino, Jonas Nycander
Summary: The study explored the warming and salinification of water masses flowing from the Southern Ocean to the tropics using Lagrangian trajectories simulated with an Earth System Model. Results showed that heat gain in the Antarctic Circumpolar Current is mainly due to heat flux from the atmosphere and mixing processes, while the warming and salinification of water masses in the Southern Hemispheric subtropical gyres result from internal mixing with other warmer and more saline water masses.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2021)
Article
Oceanography
Gaspard Geoffroy, Jonas Nycander
Summary: This study uses data from Argo floats to obtain a global map of the total amplitude of the semidiurnal internal tide at a certain depth. The obtained results are compared with data from moored instruments, confirming the accuracy. The study also compares the obtained amplitude with a satellite-based model, showing that the model only captures the stationary component while the present results capture the total amplitude.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2022)
Article
Meteorology & Atmospheric Sciences
Gaspard Geoffroy, Jonas Nycander, Maarten C. Buijsman, Jay F. Shriver, Brian K. Arbic
Summary: The autocovariance of the semidiurnal internal tide (IT) is examined using the HYCOM model, which shows a globally low bias in terms of IT variance and decay of the IT autocovariance. Except in the Southern Ocean, the spatial correlation between the model and observational data suggests that the generation of semidiurnal ITs is well captured by the model.
Article
Physics, Fluids & Plasmas
Lucie Bordois, Jonas Nycander, Alexandre Paci
Article
Ecology
Malin Odalen, Jonas Nycander, Andy Ridgwell, Kevin I. C. Oliver, Carlye D. Peterson, Johan Nilsson
Article
Ecology
Filippa Fransner, Agneta Fransson, Christoph Humborg, Erik Gustafsson, Letizia Tedesco, Robinson Hordoir, Jonas Nycander
Article
Ecology
Malin Odalen, Jonas Nycander, Kevin I. C. Oliver, Laurent Brodeau, Andy Ridgwell
