Simple Scaling of Extreme Precipitations over North America

Abstract:

Characterizing extreme precipitations at different spatial and temporal scales is crucial in order to evaluate and predict the impacts of natural hazards on regional ecosystems. Being governed by climate and weather processes acting at different scales, extreme precipitations are highly variable in space and time. As a result, observational scales and measurement techniques have a major impact on the statistical description of extreme precipitation intensity. Equally important, the coverage and the resolution of available data, whether observed at meteorological stations or simulated by weather and climate models, often mismatch the resolution needed in applications.

One interesting paradigm in conducing multi-scale analysis of precipitations is the scaling model framework. In particular, physical evidences of the simple scaling properties of extreme precipitation distribution have been provided by several studies. However, the use of these models has been mainly restricted to specific regions and small observational datasets. A deeper analysis of the effect of geo-climatic factors over large regions and of datasets characteristics [e.g., their temporal and spatial resolution, or spatial coverage] is thus needed.

The present study aims to deepen the knowledge of the spatial distribution over North America of the estimated scaling laws for extreme rainfall intensities. The variability of these laws over various temporal scale ranges is also evaluated. The objective is to present the influence of climatic and geographic characteristics on scaling estimates over this study region for several duration ranges.