EGU2020-2941
https://doi.org/10.5194/egusphere-egu2020-2941
EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

A breakdown of ENSO-North Pacific Teleconnection in early January

Chang-Hyun Park1,2, Seok-Woo Son1,2, and Jung Choi1
Chang-Hyun Park et al.
  • 1School of Earth and Environmental Sciences, Seoul National University, Korea, Republic of (sweetweather@snu.ac.kr)
  • 2Interdisciplinary Graduate Program in Computational Science and Technology, Seoul National University, Korea, Republic of (sweetweather@snu.ac.kr)

During El Niño winters, East Asia and western North America become anomalously warm because of the combined effect of anti-cyclonic circulation anomaly over Kuroshio Extension and Philippine sea, and an enhanced Aleutian Low. However, this El Niño-Southern Oscillation (ENSO)-North Pacific teleconnection disappears in early January. In this study, we suggest that this breakdown in regional teleconnection is partly due to Madden-Julian Oscillation (MJO). In early December of El Niño winters, MJOs frequently form and reach at Western Pacific, causing positive intraseasonal Pacific North American (PNA)-like teleconnection, which is same pattern to the El Niño teleconnection. In mid-December, however, as MJOs are frequently organized over Indian Ocean, it causes a destructive interference, cancelling El Niño teleconnection in early January. Although weak and not statistically significant, this sharp decline of ENSO teleconnection in early January also appears in La Niña winters. A preference of MJO organization and its propagation in ENSO winters are explained by moist static energy anomalies in the west Indian Ocean. This result suggests that MJO is important for predicting ENSO teleconnection on intraseasonal scales.

How to cite: Park, C.-H., Son, S.-W., and Choi, J.: A breakdown of ENSO-North Pacific Teleconnection in early January , EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-2941, https://doi.org/10.5194/egusphere-egu2020-2941, 2020