Impact of the Eurasian Wave Train on the Interannual Variability of Autumn Precipitation in the Central Region of China.

Autumn precipitation in the central region of China (APCC) can considerably influence on agricultural production and human livelihood. With reanalysis data from 1979 to 2020, it revealed that APCC is significantly affected by the second mode of the meridional wind field at 200 hPa over the Eurasian continent on the interannual scale, which featured a quasi‐barotropic "+‐+" wave‐like pattern from Europe to China (EC pattern) in extratropical zone. When the EC pattern is in a positive phase, central China lags behind the downstream positive geopotential height (anticyclone) anomaly. In this context, the transport of moisture from the south and east is enhanced and the advancement of the southerly monsoon is blocked, providing sufficient water vapor to support the occurrence of APCC. Further diagnosis revealed that local ascending motion is strengthened owing to the warm advection induced by anomalous southerly and positive vorticity advection associated with the anomalous anticyclone over East Asia. Additionally, wave flux analysis and model simulation suggest that the EC pattern results from the propagation of stationary Rossby wave, which could be excited by dipole sea surface temperature anomalies in the North Atlantic. These discoveries will contribute to improving the predictability of APCC. Plain Language Summary: The interannual variability of autumn precipitation in central China (APCC) is largely affected by a wave train over the Eurasian continent (EC pattern), which can influence the local moisture and dynamic uplift conditions by an anomalous anticyclone over East Asia. The North Atlantic dipole sea surface temperatur anomalies play an important role in the prediction of APCC, and could stimulate an extratropical teleconnection to shape the EC pattern over the Eurasian continent, as confirmed in the linear baroclinic model. Key Points: The autumn rainfall in central China is related to the second mode of V200 (EOF2) over the Eurasian continent on interannual timescaleEOF2 features in a "+‐+" wave‐like pattern, resulting in an anticyclone anomaly over East Asia in its positive phaseExtratropical EOF2 pattern wave train could be excited by the North Atlantic dipole sea surface temperature anomaly [ABSTRACT FROM AUTHOR]