EGU23-8258, updated on 25 Feb 2023
https://doi.org/10.5194/egusphere-egu23-8258
EGU General Assembly 2023
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

The Winter North Pacific Teleconnection in Response to ENSO and the MJO in Operational Subseasonal Forecasting Models Is Too Weak

Chen Schwartz1, Chaim Garfinkel1, Wen Chen2,3, Yanjie Li2, Priyanka Yadav4, and Daniela I.V. Domeisen4,5
Chen Schwartz et al.
  • 1Fredy and Nadine Herrmann Institute of Earth Sciences, Hebrew University, Jerusalem, Israel (chaim.garfinkel@mail.huji.ac.il), (chen.schwartz1@mail.huji.ac.il)
  • 2College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing, China (cw@post.iap.ac.cn), (lyj@mail.iap.ac.cn)
  • 3State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics (LASG), Institute of Atmospheric Physics, Chinese Academy of Science (cw@post.iap.ac.cn)
  • 4Institute for Atmospheric and Climate Science, ETH Zurich, Zurich, Switzerland (daniela.domeisen@env.ethz.ch), (priyanka.yadav@env.ethz.ch)
  • 5University of Lausanne, Lausanne, Switzerland (daniela.domeisen@unil.ch)

Teleconnection patterns associated with the Madden–Julian oscillation (MJO) and El Niño–Southern Oscillation (ENSO) impact weather and climate phenomena in the Pacific–North American region and beyond, and therefore accurately simulating these teleconnections is of importance for seasonal and subseasonal forecasts. Systematic biases in boreal midwinter ENSO and MJO teleconnections are found in eight subseasonal to seasonal (S2S) forecast models over the Pacific–North America region. All models simulate an anomalous 500-hPa geopotential height response that is too weak. This overly weak response is associated with overly weak subtropical upper-level convergence and a too-weak Rossby wave source in most models, and in several models there is also a biased subtropical Pacific jet, which affects the propagation of Rossby waves. In addition to this overly weak response, all models also simulate ENSO teleconnections that reach too far poleward toward Alaska and northeastern Russia. The net effect is that these models likely underestimate the impacts associated with the MJO and ENSO over western North America, and suffer from a reduction in skill from what could be achieved.

How to cite: Schwartz, C., Garfinkel, C., Chen, W., Li, Y., Yadav, P., and Domeisen, D. I. V.: The Winter North Pacific Teleconnection in Response to ENSO and the MJO in Operational Subseasonal Forecasting Models Is Too Weak, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-8258, https://doi.org/10.5194/egusphere-egu23-8258, 2023.

Supplementary materials

Supplementary material file