10.02.2020

10.02.2020: Ocean Circulation and Climate Dynamics Colloquium

Dr. Robert W. Lee, National Centre for Atmospheric Science, Reading (UK): "Subseasonal Teleconnections from the MJO to the North Atlantic and Europe"

 

11:00 Uhr, Hörsaal, Düsternbrooker Weg 20

 

The teleconnection from the Madden-Julian Oscillation (MJO) provides a source of subseasonal variability and predictability to the North Atlantic-European (NAE) region. The El Niño-Southern Oscillation (ENSO) modulates the seasonal mean state, through which the MJO and its teleconnection pattern propagates; however, its impact on this teleconnection to the NAE region has not been investigated.

In this talk we present evidence of a robust dependence of the teleconnections from the MJO to NAE weather regimes on the phase of ENSO. We demonstrate that the MJO to NAO+ regime tropospheric teleconnection is strongly enhanced during El Niño years, via enhanced Rossby wave activity, and suppressed during La Niña. Conversely the MJO to NAO− regime stratospheric teleconnection is enhanced during La Niña years, and suppressed during El Niño. This dependence on the background state has strong implications for subseasonal predictability, including interannual variations in subseasonal predictive skill.

 

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