Phase-II: MJO Prediction and Teleconnections

During the second phase of the S2S project, the MJO prediction and teleconnections sub-project will focus on two major tasks:

These two tasks will be tackled in parallel and research activities to address related questions will be spread over the course of sub-project. Specific questions to address include:

a. How well do operational S2S models capture the observed relationship between the MJO and high impact weather events?

Current Projects

Publications

Advances in the subseasonal prediction of extreme events

Daniela I.V. Domeisen, Christopher J. White, Hilla Afargan-Gerstman, Ángel G. Muñoz, Matthew A. Janiga, Frédéric Vitart, C. Ole Wulff, Salomé Antoine, Constantin Ardilouze, Lauriane Batté, Hannah C. Bloomfield, David Brayshaw, Suzana J. Camargo, Andrew Charlton-Pérez, Dan Collins, Tim Cowan, Maria del Mar Chaves, Laura Ferranti, Rosario Gómez, Paula L.M. González, Carmen González Romero, Johnna M. Infanti, Stelios Karozis, Hera Kim, Erik W. Kolstad, Emerson LaJoie, Llorenç Lledó, Linus Magnusson, Piero Malguzzi, Andrea Manrique-Suñén, Daniele Mastrangelo, Stefano Materia, Hanoi Medina, Lluís Palma, Luis E. Pineda, Athanasios Sfetsos, Seok-Woo Son, Albert Soret, Sarah Strazzo, Di Tian

Findings: While extreme weather events are often not predicted in a deterministic sense more than a few days in advance, there is potential for probabilistic sub-seasonal prediction on timescales of several weeks for many extreme events. Here we provide an overview of subseasonal predictability for some of the most prominent extreme events on a global scale: heatwaves, cold spells, heavy precipitation events, and tropical and extratropical cyclones. The Madden-Julian Oscillation provides added predictability for several of these extremes, including cold spells, precipitation extremes, and tropical cyclones.

Link to the publication: Bulletin of the American Meteorological Society

Advances in the prediction of MJO-Teleconnections in the S2S forecast systems

Cristiana Stan, Cheng Zheng, Edmund K.-M. Chang, Daniela I. V. Domeisen, Chaim Garfienkel, Andrea M. Jenney, Hyemi Kim, Young-Kwon Lim, Hai Lin, Andrew Robertson, Chen Schwartz, Frederic Vitart, Jiabao Wang, Priyanka Yadav

Findings: state-of-the-art S2S forecast systems have the ability to capture not only the MJO teleconnections but also the mechanisms associated with teleconnections. the newer versions of S2S models use the potential predictability of teleconnections as an opportunity to enhance the forecast skill of weather in the extratropical NH. In addition to the MJO teleconnections to the extratropics, models in the S2S database adequately capture the MJO influence on the vertical wind shear that can potentially influence the Atlantic’s TC activity. There are also persistent problems in the models that have yet to be improved. Beyond week 2, in the current generation of models, the amplitude of MJO teleconnections to the NP and the Euro-Atlantic sector continues to be underestimated. In the newer forecasting systems, the amplitude of teleconnections is overestimated in the first two weeks when considering all MJO phases. Models with a small number of vertical levels show a narrow distribution of wintertime westerly winds in the polar stratosphere in comparison to reanalysis. Some of the models with a low top also show low skill with respect to metrics related to the tropospheric pathways of teleconnections.

Link to the publication: Bulletin of the American Meteorological Society

b. How does the teleconnections depend on the horizontal, vertical and temporal structure of the diabatic heating anomalies associated with the MJO?

Current Projects

Publications

• Wang, J., H. Kim, D. Kim, S. A. Henderson, C. Stan, and E. D. Maloney (2020): MJO teleconnections over PNA region in climate models. Part II: Impacts of MJO and basic state. Journal of Climate, 33, 5081-5101, doi:10.1175/JCLI-D-19-0865.1 

c. Metrics for assessment of model teleconnections and diagnosing sources of errors in teleconnections

Current Projects

Publications

• Wang, J. H. Kim. D. Kim, S. A. Henderson, C.Stan, and E. D. Maloney (2020): MJO teleconnections over PNA region in climate models. Part I: Performance- and process-based skill metrics. Journal of Climate, 33, 1051-1067, doi:10.1175/JCLI-D-17-0269.1

• A. M. Jenney, D. A. Randall, E. A. Barnes  (2019): Quantifying Regional Sensitivities to Periodic Events: Application to the MJO. Journal of Geophysical Research: Atmospheres,  https://doi.org/10.1029/2018JD029457

d. Does the relationship between the MJO and high impact weather events lead to enhanced predictive skill for these events for particular phases of the MJO or whilst there is strong MJO activity?

Current Projects

Publications

• A. M. Jenney, K. M. Nardi, E. A. Barnes, D. A. Randall (2019): The Seasonality and Regionality of MJO Impacts on North American Temperature, Geophysical Research Letters, https://doi.org/10.1029/2019GL083950

e. How do variations in the slowly varying background state effect the Rossby wave source and the subsequent Rossby wave propagation from the source region?

Current Projects

Publications

• R. W. Lee, S. J. Woolnough, A. J. Charlton-Perez, F. Vitart (2019): ENSO modulation of MJO teleconnections to the North Atlantic and Europe. Geophysical Research Letters, https://doi.org/10.1029/2019GL084683

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