**Understanding the inter-decadal variability of autumn precipitation over North Central China using model simulations — Australian Meteorological and Oceanographic Society

**Understanding the inter-decadal variability of autumn precipitation over North Central China using model simulations (#1035)

Minhua Qin 1 , Wenjian Hua 1
  1. Nanjing University of Information Science and Technology, Nanjing, JIANGSU, China

Decadal variations in autumn (September–October–November, SON) precipitation over North Central China since the 1940s are investigated using observations and reanalysis data. They are found to be significantly correlated negatively with the Pacific Decadal Oscillation (PDO). However, the physical processes underlying these inter-decadal precipitation variations are not fully understood. Here we analyse multi-member ensembles of atmospheric reanalysis and model simulations to examine the atmospheric and precipitation responses to sea surface temperature (SST) forcing. Despite the large inter-member spread resulting from atmospheric internal variability, the model simulations forced by the observed SSTs show an important role of mid-latitude atmospheric circulation in influencing the inter-decadal precipitation variations over NCC. We also analyse the sensitivity experiments using three atmospheric models forced by the Inter-decadal Pacific Oscillation (IPO)/PDO-like SST fields. The results suggest that the SST anomalies associated with a negative IPO phase can induce anomalous positive pressure anomalies over the East Asia-Japan-North Pacific region, which weakens the East Asian trough (EAT) and produces southerly advection of warm and moist air into NCC, leading to increased precipitation there. This study provides a depiction of how the IPO/PDO-associated SSTs induce inter-decadal oscillations in mid-latitude atmospheric circulations, which in turn cause inter-decadal precipitation variations over NCC.

 

 

 

  1. Qin M., Dai A., Li D., Hua W. 2019. Understanding the inter-decadal variability of autumn precipitation over North Central China using model simulations. International Journal of Climatology, https://doi.org/10.1002/joc.6245
  2. Qin M., Li D., Dai A., Hua W., Ma H. 2018. The influence of the Pacific Decadal Oscillation on North Central China precipitation during boreal autumn. International Journal of Climatology, 38(S1), e821–e831. https://doi.org/10.1002/joc.5410
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