Change of the CP ENSO’s role in the occurrence frequency of Arctic daily warming events triggered by Atlantic storms

• Published in: npj Climate and Atmospheric Science
• Main Authors: Cen Wang, Baohua Ren, Chengyun Yang, Jianqiu Zheng, Linwei Jiang
• Format: Article in Journal/Newspaper
• Language: English
• Published: Nature Portfolio 2023
• Subjects: Environmental sciences; GE1-350; Meteorology. Climatology; QC851-999; Arctic; Pacific; Iceland
• Online Access: https://doi.org/10.1038/s41612-023-00399-y; https://doaj.org/article/bc87324caafd4bf481b5435919b03dce

Abstract Arctic daily warming is gradually garnering the attention of academics. Here we discuss an interdecadal change around the mid-1980s in the role of the Central Pacific El Niño-Southern Oscillation (CP ENSO) in the occurrence frequency of Arctic daily warming events triggered by Atlantic storms in winter (called the Atlantic pattern-Arctic rapid tropospheric daily warming (A-RTDW) event) and the possible mechanism. Before the mid-1980s, the Central Pacific El Niño/La Niña events weakened/strengthened the Iceland Low (IL); the resulting anomalous northerly/southerly at the east of the IL prevented/favored the A-RTDW event occurrence by leading Atlantic storms away from/into the Arctic. Thus, the CP ENSO could affect the occurrence frequency of A-RTDW events by the CP ENSO/IL teleconnection. In contrast, this role hardly exists after the mid-1980s. Before the mid-1980s, the CP ENSO could affect the polar vortex by planetary wave propagation upwards into the stratosphere to create the CP ENSO/IL teleconnection; thereby, the CP ENSO and A-RTDW could establish a connection. However, after the mid-1980s, the planetary wave associated with CP ENSO could not propagate upwards into the stratosphere; thus, the ENSO/IL teleconnection disappears, resulting in CP ENSO having no effect on the occurrence frequency of A-RTDW events.