Spatial Classification of Diurnal Precipitation Cycle in the Tropical and Subtropical Regions Based on the Circular Statistical Analysis
DOI:
https://doi.org/10.48048/tis.2026.12518Keywords:
Precipitation, Diurnal Cycle, Circular Statistics, Spatial Classification, Tropical Climate, Rainfall Variability, Satellite Observation, Precipitation, Diurnal cycle, Circular statistics, Spatial classification, Tropical climate, Rainfall variability, Satellite observationAbstract
The impact of climate and weather on human existence is of utmost importance, as it shapes several aspects, such as human evolution, migration patterns, and social progress. Observing and comprehending precipitation patterns, especially the diurnal cycle, are imperative for effectively managing everyday activities. This study thoroughly examines diurnal precipitation patterns in tropical and subtropical regions through the utilization of a parametric approach based on the bimodal von Mises distribution. The research effectively creates a spatial classification criterion for diurnal precipitation, offering a simple but helpful tool for meteorological and climatological investigations. It helps identify the spatial extents of convective and stratiform precipitations and reveals the physical mechanisms behind the precipitation, such as over the complex mountaintop terrains. The user-friendliness and capacity to elucidate the bimodal characteristics of diurnal precipitation patterns also render this criterion a significant asset for academia and practitioners.
HIGHLIGHTS
- Introduces a circular statistical framework using the bimodal von Mises distribution to model diurnal precipitation patterns across tropical and subtropical regions.
- Demonstrates that the proposed method effectively captures both unimodal and bimodal rainfall variations, outperforming traditional harmonic approaches, particularly in representing asymmetric or dual-peak behaviors.
- Provides a spatial classification of diurnal precipitation into classes covering convective, orographic, and stratiform regimes, revealing clear land–ocean and topographic contrasts.
- Shows that continental regions exhibit afternoon and evening convective peaks, while oceanic areas are dominated by nocturnal and early-morning stratiform rainfall.
- Offers a quantitative tool for climatological and hydrological applications, supporting improved weather prediction, water-resource management, and climate-resilience planning.
GRAPHICAL ABSTRACT
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