Subseasonal-to-Seasonal Prediction and Predictability

Subseasonal-to-Seasonal Prediction and Predictability

Subseasonal-to-seasonal (S2S) prediction is a global effort to forecast the state of the atmosphere and ocean with lead times between two weeks and a season. While it is recognized that the ocean directly influences atmospheric predictability on S2S timescales, my research focuses ocean predictability on such lead times.

North Atlantic Ocean Response to the Madden–Julian Oscillation

As part of my dissertation research, I provided an in-depth analysis of North Atlantic Ocean predictability on S2S timescales based on a hierarchy of techniques ranging from statistical analysis of observations to dynamical downscaling using a high-resolution ocean model. I showed that atmospheric perturbations in response to the Madden–Julian Oscillation (MJO) lead to anomalous air-sea heat fluxes in the North Atlantic causing statistically significant, large-scale changes in sea surface temperature (SST), particularly along the eastern seaboard of North America. Regional, high-resolution ocean models are able to capture this relationship and furthermore reveal signals on smaller scales that cannot be identified from global gridded observations (e.g., anomalous upwelling on the Scotian Shelf in response to the MJO).

Merryfield et al. incl. Renkl, C. (2020). Current and Emerging Developments in Subseasonal to Decadal Prediction. Bulletin of the American Meteorological Society, 101(6), E869–E896. https://doi.org/10.1175/BAMS-D-19-0037.1./

Renkl, C., Oliver, E.C.J., Thompson, K.R. (2024). Downscaling the ocean response to the Madden–Julian Oscillation in the Northwest Atlantic and adjacent shelf seas. Climate Dynamics, 62, 6719–6744. https://doi.org/10.1007/s00382-024-07233-y.