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Advancing Space‐Time Simulation of Random Fields: From Storms to Cyclones and Beyond
Author(s) -
Papalexiou Simon Michael,
Serinaldi Francesco,
Porcu Emilio
Publication year - 2021
Publication title -
water resources research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.863
H-Index - 217
eISSN - 1944-7973
pISSN - 0043-1397
DOI - 10.1029/2020wr029466
Subject(s) - advection , copula (linguistics) , random field , statistical physics , storm , positive definiteness , gaussian , meteorology , computer science , anisotropy , mathematics , physics , econometrics , statistics , positive definite matrix , eigenvalues and eigenvectors , quantum mechanics , thermodynamics
Realistic stochastic simulation of hydro‐environmental fluxes in space and time, such as rainfall, is challenging yet of paramount importance to inform environmental risk analysis and decision making under uncertainty. Here, we advance random fields simulation by introducing the concepts of general velocity fields and general anisotropy transformations. This expands the capabilities of the so‐called Complete Stochastic Modeling Solution (CoSMoS) framework enabling the simulation of random fields (RF's) preserving: (a) any non‐Gaussian marginal distribution, (b) any spatiotemporal correlation structure (STCS), (c) general advection expressed by velocity fields with locally varying speed and direction, and (d) locally varying anisotropy. We also introduce new copula‐based STCS's and provide conditions guaranteeing their positive definiteness. To illustrate the potential of CoSMoS, we simulate RF's with complex patterns and motion mimicking rainfall storms moving across an area, spiraling fields resembling weather cyclones, fields converging to (or diverging from) a point, and colliding air masses. The proposed methodology is implemented in the freely available CoSMoS R package.