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Related papers: Utilizing wind in spatial covariance

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Analytical expressions for covariances of weak lensing statistics related to the aperture mass $\Map$ are derived for realistic survey geometries such as SNAP for a range of smoothing angles and redshift bins. We incorporate the…

Astrophysics · Physics 2009-11-10 Dipak Munshi , Patrick Valageas

We study the evolution of turbulence in the solar wind by solving numerically the full 3D magneto-hydrodynamic (MHD) equations embedded in a radial mean wind. The corresponding equations (expanding box model or EBM) have been considered…

Solar and Stellar Astrophysics · Physics 2015-06-22 Yue Dong , Andrea Verdini , Roland Grappin

Intensive studies have been conducted to understand the anisotropy of solar wind turbulence. However, the anisotropy of Els\"asser variables ($\textbf{Z}^\pm$) in 2D wave-vector space has yet to be investigated. Here we first verify the…

Solar and Stellar Astrophysics · Physics 2016-05-04 Limei Yan , Jiansen He , Lei Zhang , Chuanyi Tu , Eckart Marsch , Christopher H. K. Chen , Xin Wang , Linghua Wang , Robert T. Wicks

This paper proposes parametric and non-parametric hypothesis testing algorithms for detecting anisotropy -- rotational variance of the covariance function in random fields. Both algorithms are based on resampling mechanisms, which enable…

Methodology · Statistics 2021-06-08 Assaf Rabinowicz , Saharon Rosset

Wind turbine wakes play a central role in determining wind farm performance, yet their spatial organization remains only partially understood. Here, we apply a spatially localized multifractal analysis to quantify the strength of…

For convex univalent functions we give instances where the sharp bound for various coefficient functionals are identical to those for the corresponding bound for the inverse function. We give instances where the sharp bounds differ and also…

Complex Variables · Mathematics 2022-12-12 Derek K. Thomas

When modeling geostatistical or areal data, spatial structure is commonly accommodated via a covariance function for the former and a neighborhood structure for the latter. In both cases the resulting spatial structure is a consequence of…

Methodology · Statistics 2015-04-20 Garritt L. Page , Fernando A. Quintana

Sz\'{e}kely, Rizzo and Bakirov (Ann. Statist. 35 (2007) 2769-2794) and Sz\'{e}kely and Rizzo (Ann. Appl. Statist. 3 (2009) 1236-1265), in two seminal papers, introduced the powerful concept of distance correlation as a measure of dependence…

Statistics Theory · Mathematics 2014-10-17 Johannes Dueck , Dominic Edelmann , Tilmann Gneiting , Donald Richards

Paradoxically, while the assumptions of second-order stationarity and isotropy appear outdated in light of modern spatial data, they remain remarkably robust in practice, as nonstationary methods often provide marginal improvements in…

Methodology · Statistics 2025-11-07 Federico Blasi , Reinhard Furrer

Single point spacecraft observations of the turbulent solar wind flow exhibit a characteristic nonaxisymmetric anisotropy that depends sensitively on the perpendicular power spectral exponent. For the first time we use this nonaxisymmetric…

Solar and Stellar Astrophysics · Physics 2015-05-30 A. J. Turner , G. Gogoberidze , S. C. Chapman

The scaling anisotropy is crucial to interpret the nonlinear interactions in solar wind turbulence. Previous observations provide diverse results and the structure function analyses are also reported to be an approach to investigate the…

Space Physics · Physics 2020-11-23 Honghong Wu , Chuanyi Tu , Xin Wang , Jiansen He , Liping Yang , Linghua Wang

A functional time series approach is proposed for investigating spatial correlation in daily maximum temperature forecast errors for 111 cities spread across the U.S. The modelling of spatial correlation is most fruitful for longer forecast…

Methodology · Statistics 2021-11-23 Phillip A. Jang , David S. Matteson

Cosmological analyses of second-order weak lensing statistics require precise and accurate covariance estimates. These covariances are impacted by two sometimes neglected terms: A negative contribution to the Gaussian covariance due to…

Cosmology and Nongalactic Astrophysics · Physics 2023-12-04 Laila Linke , Pierre A. Burger , Sven Heydenreich , Lucas Porth , Peter Schneider

Spatial phenomena in environmental and biological contexts often involve events that are unevenly distributed across space and carry attributes, whose associations/variations are space-dependent. In this paper, we introduce the class of…

Methodology · Statistics 2025-06-02 Mehdi Moradi , Matthias Eckardt

In practice rarely (if ever) is the spatial covariance known in spatial prediction problems. Often, prediction is performed after estimated spatial covariance parameters are plugged into the prediction equation. The estimated spatial…

Methodology · Statistics 2014-09-11 Roberto Rivera , Wendy Meiring

The self-correlation level contours at the 1010 cm scale reveal a 3D isotropic feature in the slow solar wind and a quasi-anisotropic feature in the fast solar wind. However, the 1010 cm scale is approximately near the lowfrequency break…

Space Physics · Physics 2019-12-18 Honghong Wu , Chuanyi Tu , Xin Wang , Jiansen He , Linghua Wang

The concept of distance covariance/correlation was introduced recently to characterize dependence among vectors of random variables. We review some statistical aspects of distance covariance/correlation function and we demonstrate its…

Methodology · Statistics 2018-07-13 Dominic Edelmann , Konstantinos Fokianos , Maria Pitsillou

Optimal analyses using the 2-point functions of large-scale structure probes require accurate covariance matrices. A covariance matrix of the 2-point function comprises the disconnected part and the connected part. While the connected…

Cosmology and Nongalactic Astrophysics · Physics 2019-01-14 Yin Li , Sukhdeep Singh , Byeonghee Yu , Yu Feng , Uros Seljak

Spatial models are used in a variety research areas, such as environmental sciences, epidemiology, or physics. A common phenomenon in many spatial regression models is spatial confounding. This phenomenon takes place when spatially indexed…

Methodology · Statistics 2021-06-08 Isa Marques , Thomas Kneib , Nadja Klein

We study short-term prediction of wind speed and wind power (every 10 minutes up to 4 hours ahead). Accurate forecasts for these quantities are crucial to mitigate the negative effects of wind farms' intermittent production on energy…