Multifractal Properties of Daily Rainfall in Two Different Climates

TLDR

The study examined daily rainfall time series and spatial distributions in an East Asian monsoon and a temperate Swedish climate, applying multifractal analysis to both temporal and spatial data by grouping rainfall mechanisms and analyzing each separately. Daily rainfall in both climates follows a multiplicative cascade over 1–32 days, with scaling moments up to 2.5 in the monsoon and 4.0 in temperate, while spatial rainfall scales up to order 4.0 over 15–180 km (monsoon) and 7.5–90 km (temperate); the multifractal framework fits convective rainfall well but frontal rainfall appears more monofractal.

Abstract

The multifractal properties of daily rainfall were investigated in two contrasting climates: an east Asian monsoon climate (China) with an extreme rainfall variability and a temperate climate (Sweden) with a moderate rainfall variability. First, daily time series were studied. The results showed that daily rainfall in both climates can be viewed as the result of a multiplicative cascade process for the range 1–32 days. The temporal data exhibited scaling for moments of orders up to 2.5 in the monsoon area and up to 4.0 in the temperate area and showed clear multifractal properties in both climates. Second, daily spatial rainfall distributions were pooled into different rainfall‐generating mechanism groups, and each group was analyzed separately. The spatial data for all rainfall mechanisms in the two climates exhibited scaling for moments of orders up to 4.0. The scaling regime was 15–180 km (225–32,400 km 2 ) in the monsoon climate and 7.5–90 km (55–8100 km 2 ) in the temperate climate. A multifractal framework seemed well suited for description of convective‐type rainfall in both climates, but its suitability for frontal rainfall in the two regions was less clear. Although the frontal rainfall exhibited scaling, the almost linear τ( q ) functions suggested monofractality.