Interdecadal changes in three-dimensional atmospheric circulation patterns related to summer temperature variability in Eastern China modulated by the interdecadal Pacific Oscillation

Abstract

The dynamic effects of three-dimensional atmospheric circulation patterns are critical for regulating both regional and global climates. By using the three-pattern decomposition of global atmospheric circulation (3P-DGAC), this study recognizes the interdecadal changes of three-dimensional atmospheric circulation patterns associated with summer temperature anomalies in the middle and lower reaches of Yangtze River (MLRYR), and further demonstrates that these related changes of atmospheric circulation patterns are modulated by the Interdecadal Pacific Oscillation (IPO). During the positive phase of the IPO, the three-dimensional atmospheric circulation patterns are characterized by the anticyclonic high at the middle and upper troposphere, and anomalous downdrafts along local meridional circulation near MLRYR. Then, in the negative phase of the IPO, alongside the aforementioned atmospheric circulation patterns, there are anomalous downdrafts along the local zonal circulation at the Eastern Tibetan Plateau (ETP). Through statistical and dynamical analysis, the emergence of local zonal circulation is attributed to the influences of positive sea surface temperature anomalies in North Atlantic during the negative phase of the IPO, which propagate to East Asia through intensified jet stream waviness. The findings of this study establish a synchronous linkage between ETP climate and downstream regions, offering significant implications for enhancing seasonal climate forecasting in the future.

Keywords

• middle and lower reaches of Yangtze River
• interdecadal Pacific Oscillation
• three-dimensional atmospheric circulation patterns
• atmospheric teleconnection
• interdecadal variability