Recent changes in climate seasonality in the inland river basin of Northwestern China

[摘要] Representing regional available water and energy conditions, variations in precipitation (P) and potential evapotranspiration (E-0) have received much attention in current studies on climate change. However, the changes in their mismatch, i.e. climate seasonally, have rarely been investigated. Considering the seasonal amplitudes of P and E-0 (delta(p) and delta(E)0, respectively), as well as their phase difference, a climate seasonally and asynchrony index (SA/) was used to analyze the seasonal distribution of the available water-energy and their mismatch in the inland river basin of Northwestern China (IRB-NWC) during 1960-2017. We found that the annual delta(p), delta(E0), and SAI all decreased during the past few decades, indicating that the mismatch between the seasonal available water and energy in IRB-NWC has improved. Attribution analysis conducted by the elasticity method indicated that the changes in delta(p) controlled the variations in SA/ throughout the area, with a relative contribution of 43.7%. Furthermore, wavelet analysis indicated that large-scale ocean-atmosphere circulation patterns (including EI Nino Southern Oscillation, Indian Ocean Dipole, Pacific Decadal Oscillation and East Asian Summer Monsoon) were significantly linked with SAI on 2-6 years scale. Our findings may provide valuable information regarding the trends and causes of climate seasonally and aid in predicting and mitigating the effects of potential future climate changes in the dry region.

[发布日期] 2020-11-01

[关键词] Climate seasonality;Precipitation;Potential evapotranspiration;Climate elasticity