Impact of ENSO teleconnections on the probabilistic prediction of the atmosphere at seasonal-to-decadal time scales: A reduced-order model perspective
- Royal Meteorological Institute of Belgium, Meteorological and Climatological Information Service, Brussels, Belgium (svn@meteo.be)
The dynamics of the atmosphere (and of the climate system) is known to display the property of sensitivity to initial conditions. This property has considerable impact on our abilities to make predictions at short and medium-range weather time scale, and at seasonal-to-decadal ranges. This implies that climate predictions are in essence probabilistic problems that should be tackled with appropriate tools. Since the nineties, considerable efforts have been addressed to develop such an information, often through ensemble forecasts based on multiple model integrations starting from different initial or boundary conditions. Such an approach is now well settled for weather forecasts, but still in its infancy for seasonal to decadal forecasts.
The impact of both initial condition and boundary condition errors on ensemble forecasts is extensively explored in a reduced-order coupled extratropical ocean-atmosphere model -- that was developed over the years -- forced by a Tropical model (Vannitsem et al, 2015, 2021), with a particular emphasis on the impact of Tropical teleconnections on extratropical predictability. In this perfect model framework, the analysis reveals that the potential of teleconnections in improving the quality of climate predictions could only be realized provided that the Tropical dynamics is accurately predicted. The improvements that can be expected by ensemble and temporal averages are also explored.
References
Vannitsem, S., J. Demaeyer, L. De Cruz, M Ghil, Low-frequency variability and heat transport in a low-order nonlinear coupled ocean-atmosphere model. Physica D, 309, 71-85, 2015. https://doi.org/10.1016/j.physd.2015.07.006
Vannitsem, S., Demaeyer, J., & Ghil, M. Extratropical low-frequency variability with ENSO forcing: A reduced-order coupled model study. Journal of Advances in Modeling Earth Systems, 13, e2021MS002530, 2021. https://doi.org/10.1029/2021MS002530.
How to cite: Vannitsem, S.: Impact of ENSO teleconnections on the probabilistic prediction of the atmosphere at seasonal-to-decadal time scales: A reduced-order model perspective, EMS Annual Meeting 2023, Bratislava, Slovakia, 4–8 Sep 2023, EMS2023-232, https://doi.org/10.5194/ems2023-232, 2023.
