Singular value decomposition (SVD) based correlation analysis of climatic factors and extreme precipitation in Hunan Province, China, during 1960–2009

Abstract

A small change in the mean climate may lead to a dramatic change in the frequency and intensity of extreme climate events. In this study, the relationship between mean temperature (MT) and extreme precipitation and the influence from large-scale circulation were investigated in Hunan Province. The correlation between MT and the frequency of extreme precipitation events in different seasons (spring, summer, and autumn) and time periods (1960–2009) was used to obtain pairs of spatial patterns by the singular value decomposition method. The temporal expansion series displayed a consistent trend of temperature and extreme precipitation, and a mutation was observed to occur approximately during the 1980s–1990s. Temperature exhibited a warming trend after the mutation, but the frequency of extreme precipitation events exhibited obvious spatio-temporal variations. The causes of seasonal differences in the frequency of extreme precipitation events were determined by comparing interdecadal changes in three atmospheric circulation factors (850 hPa winds, the entire layer of vapor transportation fluxes and vapor flux divergence) before and after the mutation was revealed. HIGHLIGHTS The relationship between temperature and extreme rainfall events was investigated using the SVD method.; The temperature exhibited a sudden change during the 1980s–1990s.; The trend of temperature change was widely varied.; The correlation between temperature and extreme rainfall exhibited a significant spatial variation.; The wind anomaly field revealed the opposite trends before and after the abrupt change.;

Keywords

• climate index
• extreme precipitation
• hunan province
• singular value decomposition (svd)