Abstract Predicting forced, long‐term radiative feedbacks from internal climate variability has been a decades‐long quest in science. We train convolutional neural network (CNN) to predict annual‐ and global‐mean top of the atmosphere radiation anomalies time‐varying maps near‐surface temperature models. Trained on alone, nonlinear CNN can under strong change, outperforms regularized linear regression approach, works within across different show with explainable artificial intelligence...

Abstract For the majority of data assimilation (DA) applications, a Gaussian assumption is made to model behaviour errors associated with specific situation. This generally false in geoscience fields, especially for variables that are positive (semi‐)definite. The three‐dimensional variational (3DVar) data‐assimilation method was traditionally generated through Bayes' theorem multivariate probability density functions; however, over last 15 years this has been modified allow lognormal...

The radiative effect of shallow clouds, especially in the subtropical ocean upwelling regions, is very efficient and mostly controlled by local sea surface temperatures lower tropospheric inversion strength. latter caused feedback clouds to switch from positive negative over last couple decades likely controls cloud feedbacks future. Drivers strength are not well understood theoretically vary strongly between reanalyses. We employ convolutional neural networks explainable artificial...

We investigate the effects of quantum fluctuations on low-energy collective modes two-dimensional (2D) $s$-wave Fermi superfluids from BCS to Bose limit. compare our results recent Bragg scattering experiments in 2D box potentials, with very good agreement. show that phase and modulus pairing order parameter are absolutely necessary give physically acceptable chemical potential dispersion relation mode throughout evolution. Furthermore, we demonstrate change concave convex as interactions...

We review aspects of the evolution from Bardeen–Cooper–Schrieffer (BCS) to Bose–Einstein condensation (BEC) in two dimensions, which have now become relevant systems with low densities, such as gated superconductors Li x ZrNCl, magic-angle twisted trilayer graphene, FeSe, FeSe 1− S , and ultracold Fermi superfluids. emphasize important role played by chemical potentials determining crossovers or topological quantum phase transitions during BCS–BEC one-band two-band superfluids...

We theoretically investigate the role of multiple impurity atoms on ground-state properties Bose polarons. The Bogoliubov approximation is applied for description condensate resulting in a Hamiltonian containing terms beyond Fr\"ohlich approximation. many-body nature taken into account by extending polarons, revealing static structure factor impurities as key quantity. Within this formalism various experimentally accessible polaronic are calculated such energy and effective mass. These...

Abstract We derive a generalization of the Kalman filter that allows for non‐Gaussian background and observation errors. The Gaussian assumption is replaced by considering errors come from mixed distribution Gaussian, lognormal, reverse lognormal random variables. detail derivation extend results to distributions, where number state variables can change dynamically every analysis time. test dynamical robustly on two different systems based Lorenz 1963 model, demonstrate techniques generally...

Abstract In this paper we present the derivation of two new forms Kalman filter equations; first is for a pure lognormally distributed random variable, while second set equations will be combination Gaussian and variables. We show that appearance similar to Gaussian-based equations, but analysis state multivariate median not mean. also results mixed distribution with Lorenz 1963 model lognormal errors background observations z component, compare them from traditional extended under certain...

We investigate the fermionic quasiparticle branch of superfluid Fermi gases in Bardeen-Cooper-Schrieffer (BCS) to Bose-Einstein condensation (BEC) crossover and calculate lifetime energy shift due its coupling with collective mode. The only close-to-resonance process that low-energy quasiparticles can undergo at zero temperature is emission a bosonic excitation from phononic branch. Close minimum we find remain undamped, allowing us compute corrections experimentally relevant quantities such...

We discuss a two-band model for two-dimensional superconductors with electron and hole bands separated by an energy gap singlet $d$-wave pairing in each band. This exhibits V-shaped to U-shaped transition the density of states superconductor, which is similar that found recent tunneling experiments magic-angle twisted trilayer graphene [H. Kim et al., Nature 606, 494 (2022)]. qualitative difference behavior occurs when chemical potentials change, leading topological quantum phase transitions...

Abstract We present a non‐Gaussian ensemble data assimilation method based on the maximum‐likelihood filter, which allows for any combination of Gaussian, lognormal, and reverse lognormal errors in both background observations. The technique is fully nonlinear, does not require tangent linear model, uses Hessian preconditioner to minimise cost function efficiently space. When Gaussian assumption relaxed, results show significant improvements analysis skill within two atmospheric toy models,...

Abstract In many applications of data assimilation, especially when the size problem is large, a substantial assumption made: all variables are well‐described by Gaussian error statistics. This has advantage making calculations considerably simpler, but it often not valid, leading to biases in forecasts or, even worse, unphysical predictions. We propose simple, effective, way replacing this assumption, use transforming functions, while remaining consistent with Bayes' theorem. method allows...

Abstract We compare insights provided by local and large‐scale perspectives of extreme heat events in ERA5 near‐surface temperature data. Heat waves where temperatures exceed four standard deviations about the climatological‐mean are expected less than once a century locally but occur roughly every 10 days somewhere Northern Hemisphere midlatitudes. The high frequency occurrence indicated hemispheric perspective is not well represented normal statistics because it strongly depends on shapes...

We study the propagation of dispersive waves in superfluid Fermi gases BEC-BCS crossover. Unlike other systems where have already been studied and observed, can exhibit a subsonic dispersion relation for which wave pattern appears at tail front. show that this property be used to distinguish between supersonic unitarity.

Bicycles with electrically powered pedal assistance (PA) show great potential as ecological alternatives for engine-based vehicles. There is plenty of research available about the influence various bicycle parameters on cycling technique. Though, to best authors’ knowledge, there none PA. In this study, a recreational equipped PA and unique instrumentation measure user-induced loads seat, steer pedals. Joint loading derived in sagittal plane from inverse dynamics muscle activity lower limbs...

We study the fermionic quasiparticle spectrum in a zero-temperature superfluid Fermi gas, and particular how it is modified by different disintegration processes. On top of emission collective boson ( 1\to2 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mn>1</mml:mn><mml:mo>→</mml:mo><mml:mn>2</mml:mn></mml:mrow></mml:math> , subject previous study, PRL 073404), we consider here events where three quasiparticles are emitted 1\to3...

We investigate the effects of quantum fluctuations on low-energy collective modes two-dimensional (2D) $s$-wave Fermi superfluids from BCS to Bose limit. compare our results recent Bragg scattering experiments in 2D box potentials, with very good agreement. show that phase and modulus pairing order parameter are absolutely necessary give physically acceptable chemical potential dispersion relation mode throughout evolution. Furthermore, we demonstrate change concave convex as interactions...