Article
Environmental Sciences
Debin Lu, Wanliu Mao, Wu Xiao, Liang Zhang
Summary: The research shows that the PM2.5 concentration in China increased annually from 2000 to 2016, with nearly half of the cities having PM2.5 levels exceeding 35 μg/m³. The spatial distribution pattern of PM2.5 exhibits characteristics of regional convergence, being positively correlated with urban and farmland, and negatively correlated with forest, grassland, and unused land. The impact of land use change on PM2.5 is non-linear, with significant differences and spillover effects observed for different land types.
Article
Oceanography
Veit Lueschow, Jochem Marotzke, Jin-Song Von Storch
Summary: This paper compares the overturning responses to wind stress changes between an eddying ocean and a non-eddying ocean, finding differences in the deep overturning cell and the deep western boundary current in the North Atlantic Ocean. The study demonstrates that the slowdown of the DWBC in the eddying configuration is mainly balanced by eddy vorticity fluxes, which may not be captured in non-eddying ocean models, affecting the overall range of overturning responses. It also provides evidence that deep eddies sourced from the upper ocean can actively force the DWBC mean flow to slow down.
JOURNAL OF PHYSICAL OCEANOGRAPHY
(2021)
Article
Water Resources
Xiaojing Zhang, Pan Liu, Lei Cheng, Kang Xie, Dongyang Han, Liting Zhou
Summary: This study evaluates anthropogenic impacts on water yield in the Upper Yangtze River Basin by representing hydrological parameters as functions of socioeconomic factors. The study shows that population and drainage area of reservoirs have significant impacts on hydrological parameters, and the linear functional form effectively improves streamflow simulation.
JOURNAL OF HYDROLOGY-REGIONAL STUDIES
(2021)
Article
Engineering, Marine
S. Bahramiasl, E. de Langre
Summary: This study investigates the vortex-induced vibrations of circular tapered and wavy cylinders under cross-flow, finding that the amplitude of oscillation decreases when reaching critical tapering or wave pattern. The critical diameter ratio is identified as a key factor affecting the vortex shedding behavior of coupled fluid-solid systems along the length of the cylinders.
Article
Environmental Sciences
Xiaorong Huang, Guihua Wang
Summary: When tropical cyclones pass over the world's oceans, they often interact with mesoscale dipole eddies, resulting in amplified cyclonic ocean eddy components and weakened or destroyed anticyclonic ocean eddy components. The interaction leads to changes in the amplitudes, radii, and vertical structures of the eddies, as well as the injection of positive relative vorticity and an upwelling anomaly. After the passage of the tropical cyclone, the dipole eddy gradually stabilizes and recovers through a quasi-geostrophic adjustment process, eventually reaching an equilibrium state.
Article
Biology
Michael A. Barnett, Geoffrey K. Aguirre, David Brainard
Summary: The study found that V1 is most sensitive to L-M contrast modulations and least sensitive to L+M contrast modulations. Additionally, within V1, there was little to no change in chromatic sensitivity as a function of eccentricity.
Article
Environmental Sciences
Bing Li, Guishan Yang, Rongrong Wan, Ligang Xu
Summary: This study examined the variations of Chlorophyll a (Chla) and its relationship with environmental stressors in Poyang Lake over an 11-year period. The results showed that hydrological connectivity had a significant impact on the environmental variables and the growth of phytoplankton in the lake. The study also identified different patterns of hydrological connectivity and their corresponding effects on Chla dynamics.
ENVIRONMENTAL POLLUTION
(2022)
Article
Engineering, Aerospace
Rajesh Vaishnav, Christoph Jacobi, Jens Berdermann, Erik Schmolter, Mihail Codrescu
Summary: The behavior of the ionosphere is strongly dependent on solar activity conditions. A study using IGS and CTIPe data found that the ionospheric time delay is significantly affected by various processes such as diffusion, photodissociation, solar and geomagnetic activities. It was also confirmed that the ionospheric delay increases with increasing solar activity levels.
ADVANCES IN SPACE RESEARCH
(2022)
Article
Engineering, Chemical
Zhaozheng Hou
Summary: Synthetic gene circuits are powerful tools in biological research, but their model calibration is time-consuming. This study proposes two OED approaches to simplify the calibration process while maintaining accuracy, and the results suggest a significant reduction in complexity with improved calibration accuracy.
Article
Multidisciplinary Sciences
Yongzheng Wen, Flavio Giorgianni, Igor Ilyakov, Baogang Quan, Sergey Kovalev, Chen Wang, Carlo Vicario, Jan-Christoph Deinert, Xiaoyu Xiong, Joe Bailey, Min Chen, Alexey Ponomaryov, Nilesh Awari, Andrea Rovere, Jingbo Sun, Roberto Morandotti, Luca Razzari, Gabriel Aeppli, Junjie Li, Ji Zhou
Summary: Non-linear materials, although widely used in optics and electronics, have limitations in extending demanding non-linear effects to widely used centrosymmetric materials (such as silicon) and technologically important spectral domains (such as terahertz frequencies). In this study, the researchers introduce a universal method called non-linear Thomson scattering to efficiently stimulate non-linear responses in linear solid materials, allowing for second-harmonic generation at terahertz frequencies on materials like crystalline silicon. This approach offers a material- and frequency-independent platform for various applications in non-linear optics, terahertz sources, light-solid interactions, and integrated photonic circuits.
NATIONAL SCIENCE REVIEW
(2023)
Article
Physics, Multidisciplinary
Alexandre Vonesch, Cassandre Duhot, Thierry Lelard, Guillaume Leonard, Michalina Blazkiewicz, Harold Mouras
Summary: This study investigated the differential modulation of non-linear measures characterizing postural control in the context of perceiving painful stimuli. The results suggest that active stimulation has a greater impact on Center of Pressure (COP) displacement compared to passive stimulation, and the Lyapunov exponent is useful for assessing postural modulation dynamics in response to painful stimuli perception.
Article
Meteorology & Atmospheric Sciences
Wenhao Dong, Ming Zhao, Yi Ming, V Ramaswamy
Summary: The characteristics of tropical mesoscale convective systems simulated by a finer-resolution version of the GFDL AM4 model were evaluated and found to be reasonably captured, although the simulated MCSs were generally longer-lived, weaker, and larger than observed. Event-scale analysis showed a strong correlation between the duration, intensity, and size of MCSs.
JOURNAL OF CLIMATE
(2021)
Article
Physics, Multidisciplinary
Nahuel Freitas, Gianmaria Falasco, Massimiliano Esposito
Summary: This method provides an effective expression for determining probability distribution away from equilibrium and accurately approximates the rate function through linear response theory at the level of the rate function, applicable to various physical and chemical systems. The approach can be extended to transient probabilities and non-autonomous dynamics, creating a virtual flow in probability space to determine the steady state rate function far from equilibrium.
NEW JOURNAL OF PHYSICS
(2021)
Article
Computer Science, Interdisciplinary Applications
He Zhang, John Harlim, Xiantao Li
Summary: The article discusses a method to estimate parameters of stochastic dynamics based on linear response statistics and addresses the important issue of model error. By fitting the imperfect model to appropriate marginal linear response statistics, the issue of inaccessibility of linear response statistics in high dimensional and non Gaussian equilibrium density functions can be resolved.
JOURNAL OF COMPUTATIONAL PHYSICS
(2021)
Article
Environmental Sciences
Wentian Xu, Lei Yao, Xuecheng Fu, Yixu Wang, Shuo Sun
Summary: This study analyzes the relationship between the variation characteristics of PM2.5 in 264 cities in China and representative socioeconomic indicators in different climate zones. The findings indicate that air quality has significantly improved in most cities over the past few years, with urban development playing a major role in the changes in PM2.5 pollution. Furthermore, there is a potential interaction of different climatic indicators on the environmental effect of the urbanization process in different climate zones.
Article
Engineering, Ocean
Valerian Jewtoukoff, Riwal Plougonven, Albert Hertzog, Chris Snyder, Glen Romine
JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY
(2016)
Article
Meteorology & Atmospheric Sciences
Soyoung Ha, Chris Snyder, William C. Skamarock, Jeffrey Anderson, Nancy Collins
MONTHLY WEATHER REVIEW
(2017)
Article
Meteorology & Atmospheric Sciences
Kathryn R. Fossell, David Ahijevych, Rebecca E. Morss, Chris Snyder, Chris Davis
MONTHLY WEATHER REVIEW
(2017)
Article
Meteorology & Atmospheric Sciences
Matthias Morzfeld, Daniel Hodyss, Chris Snyder
TELLUS SERIES A-DYNAMIC METEOROLOGY AND OCEANOGRAPHY
(2017)
Article
Meteorology & Atmospheric Sciences
William C. Skamarock, Chris Snyder, Joseph B. Klemp, Sang-Hun Park
MONTHLY WEATHER REVIEW
(2019)
Article
Meteorology & Atmospheric Sciences
Anna Shlyaeva, Jeffrey S. Whitaker, Chris Snyder
JOURNAL OF ADVANCES IN MODELING EARTH SYSTEMS
(2019)
Article
Meteorology & Atmospheric Sciences
May Wong, Glen Romine, Chris Snyder
MONTHLY WEATHER REVIEW
(2020)
Article
Geosciences, Multidisciplinary
Gregory J. Hakim, Chris Snyder, Stephen G. Penny, Matthew Newman
Summary: The study shows that a Kalman filter with a linear emulator can efficiently assimilate strongly coupled data, improving the forecast skill of ocean analyses. The experiment results demonstrate that daily assimilation of observations using a linear inverse model reduces the analysis errors of sea-surface temperature by 20% compared to a control experiment. Additionally, it enhances the forecast skill for at least 50 days. However, the assimilation of coupled data leads to an increase in forecast errors of extratropical Northern Hemisphere 2 m air temperature.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Meteorology & Atmospheric Sciences
Chris Snyder, Gregory J. Hakim
Summary: This article introduces a linear transformation in which state variables and observations have uncorrelated errors in the transformed space, with a diagonal gain matrix in the update step. The transformation includes canonical observation operators (COOs) in the update step, which rank pairs of transformed observations and state variables based on their influence.
JOURNAL OF ADVANCES IN MODELING EARTH SYSTEMS
(2022)
Article
Meteorology & Atmospheric Sciences
Richard Rotunno, Chris Snyder, Falko Judt
Summary: Atmospheric predictability is measured by the difference in forecasts generated from slightly different initial conditions. The error field in meteorological applications requires a 2D spectral analysis. Statistical predictability theory reduces 2D spectra to 1D by integrating around a circle in wavenumber polar coordinates. Recent studies have shown that using a theory-consistent method is necessary to transform a 2D error field to a 1D spectrum in order to compare with the predictions of statistical predictability theory.
JOURNAL OF THE ATMOSPHERIC SCIENCES
(2023)
Article
Meteorology & Atmospheric Sciences
Robert G. Nystrom, Chris Snyder, Mohamad EL Gharamti
Summary: In this study, a one-step-ahead ensemble Kalman smoother (EnKS) is introduced for parameter estimation. It is found that the EnKS has the potential to provide new constraints on surface-exchange coefficients of momentum and enthalpy through observing system simulation experiments (OSSEs). The results show that the EnKS can accurately constrain these parameters, but its success varies throughout the tropical cyclone life cycle and is influenced by the ensemble size and smoothing forecast length.
MONTHLY WEATHER REVIEW
(2023)
Article
Geosciences, Multidisciplinary
Zhiquan Liu, Chris Snyder, Jonathan J. Guerrette, Byoung-Joo Jung, Junmei Ban, Steven Vahl, Yali Wu, Yannick Tremolet, Thomas Auligne, Benjamin Menetrier, Anna Shlyaeva, Stephen Herbener, Emily Liu, Daniel Holdaway, Benjamin T. Johnson
Summary: JEDI-MPAS 1.0.0, a new data assimilation (DA) system for MPAS-A, built on the JEDI software framework, was released for community use. With capabilities including 3DVar and EnVar schemes, as well as the EDA technique, JEDI-MPAS operates on the native MPAS unstructured mesh. The system exhibits good performance in forecast verification, particularly with the addition of microwave radiance data, showing potential for both research and operational applications.
GEOSCIENTIFIC MODEL DEVELOPMENT
(2022)
Article
Meteorology & Atmospheric Sciences
Travis Harty, Matthias Morzfeld, Chris Snyder
Summary: A new multiscale covariance localisation method is proposed in this study, which combines eigenvector estimation and projection with traditional spatial localisation to address covariance issues in ensemble data assimilation effectively.
TELLUS SERIES A-DYNAMIC METEOROLOGY AND OCEANOGRAPHY
(2021)
Article
Meteorology & Atmospheric Sciences
Rebecca E. Morss, Julie L. Demuth, Heather Lazrus, Leysia Palen, C. Michael Barton, Christopher A. Davis, Chris Snyder, Olga V. Wilhelmi, Kenneth M. Anderson, David A. Ahijevych, Jennings Anderson, Melissa Bica, Kathryn R. Fossell, Jennifer Henderson, Marina Kogan, Kevin Stowe, Joshua Watts
BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY
(2017)
Article
Meteorology & Atmospheric Sciences
Jordan G. Powers, Joseph B. Klemp, William C. Skamarock, Christopher A. Davis, Jimy Dudhia, David O. Gill, Janice L. Coen, David J. Gochis, Ravan Ahmadov, Steven E. Peckham, Georg A. Grell, John Michalakes, Samuel Trahan, Stanley G. Benjamin, Curtis R. Alexander, Geoffrey J. Dimego, Wei Wang, Craig S. Schwartz, Glen S. Romine, Zhiquan Liu, Chris Snyder, Fei Chen, Michael J. Barlage, Wei Yu, Michael G. Duda
BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY
(2017)