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Scale‐wise evolution of rainfall probability density functions fingerprints the rainfall generation mechanism
Author(s) -
Molini Annalisa,
Katul Gabriel G.,
Porporato Amilcare
Publication year - 2010
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2010gl042634
Subject(s) - intermittency , lacunarity , probability density function , asymmetry , statistical physics , scale (ratio) , convective storm detection , probabilistic logic , weibull distribution , probability distribution , power law , storm , meteorology , climatology , geology , atmospheric sciences , physics , turbulence , mathematics , statistics , fractal , fractal dimension , mathematical analysis , quantum mechanics
The cross‐scale probabilistic structure of rainfall intensity records collected over time scales ranging from hours to decades at sites dominated by both convective and frontal systems is investigated. Across these sites, intermittency build‐up from slow to fast time‐scales is analyzed in terms of heavy tailed and asymmetric signatures in the scale‐wise evolution of rainfall probability density functions (pdfs). The analysis demonstrates that rainfall records dominated by convective storms develop heavier‐tailed power law pdfs toward finer scales when compared with their frontal systems counterpart. Also, a concomitant marked asymmetry build‐up emerges at such finer time scales. A scale‐dependent probabilistic description of such fat tails and asymmetry appearance is proposed based on a modified q ‐Gaussian model, able to describe the cross‐scale rainfall pdfs in terms of the nonextensivity parameter q , a lacunarity (intermittency) correction and a tail asymmetry coefficient, linked to the rainfall generation mechanism.