Connections between Spring Arctic Ozone and the Summer Circulation and Sea Surface Temperatures over the Western North Pacific

Using various observations, reanalysis datasets, and a general circulation model (CESM-WACCM4), the relationship between the Arctic total column ozone (TCO) and the tropospheric circulation and sea surface temperatures (SSTs) over the western North Pacific (30 degrees-45 degrees N, 130 degrees E-170 degrees W) was investigated. We find that anomalies in the circulation and SSTs over the western North Pacific in June are closely related to anomalies in the Arctic TCO in March; that is, when the Arctic TCO in March decreases, the anomalous tropospheric cyclone and negative SST anomalies (SSTAs) will occur over the western North Pacific in June. Further analysis indicates that the decreased Arctic TCO in March tends to result in positive Victoria mode (VM)-like SSTAs over the North Pacific in April, which persist and develop an anomalous cyclone over the eastern North Pacific in May via atmosphere-ocean coupling. This anomalous cyclone over the eastern North Pacific subsequently induces an anomalous cyclone over the western North Pacific in June via westward-propagating Rossby waves in the lower troposphere. Furthermore, the negative SSTAs over the western North Pacific are enhanced by the anomalous northerly wind related to the anomalous cyclone in June. The effects of increased Arctic TCO in March on the tropospheric circulation and SSTs are almost opposite to those of decreased Arctic TCO. These results are also supported by our numerical simulations. Moreover, 10%-20% of the anomalies in the tropospheric circulation and SSTs over the western North Pacific in June are affected by the anomalies in the Arctic TCO in March.