extratropical and tropical interaction
By applying idealized thermal forcings in high latitudes in models with various complexity, seek a systematic understanding of processes with different timescales. A more complete picture of the spatial and temporal characteristics of the teleconnection may serve to bridge the gaps between theories, modeling simulations, and observational data.
We are excited to contribute our findings to a cross-discipline working group under WCRP Climate Dynamics Panel - TROPICS (TROpical PacIfiC SST warming patternS) - which aims to resolve the model-observation discrepancy of the long term SST pattern change. See below for our approaches and findings.
Atmospheric dynamics: linking the momentum and the energetics perspectives
Hwang, Y.-T.*, H.-Y. Tseng, K.-C. Li, S.M. Kang, Y.-J. Chen, and J. C. H. Chiang, Relative roles of energy and momentum fluxes in the tropical response to extratropical thermal forcing. Journal of Climate, 34.10, 3771-3786. 2021
Shin, Y., S.M. Kang, K. Takahashi, M. F. Stuecker, Hwang, Y.-T. and D. Kim, Evolution of the Tropical Response to Periodic Extratropical Thermal Forcing, Journal of Climate, 34(15). 2021
Air-sea flux: the energetic framework (established within inter-annual timescale and persisted until equilibrium)
Most of the work on the energetic framework focuses on the annual mean (see four review papers here). We explore the characteristics and the mechanisms of its seasonal sensitivity:
Hwang, Y.-T.* and P.-C. Chung, Seasonal sensitivity of the cross-equatorial Hadley Cell response to extratropical thermal forcing, Journal of Climate, 34.9, 3327-3342. 2021
We also try to extend this zonal mean theory to the 2D spatial pattern:
Hsiao, W. T., Hwang, Y. T.*, Chen, Y. J., & Kang, S. M. The Role of Clouds in Shaping Tropical Pacific Response Pattern to Extratropical Thermal Forcing. Geophysical Research Letter, 2022, https://doi.org/10.1029/2022GL098023
Hwang, Y.-T.*, S. Xie, C. Deser, and S. M. Kang: Connecting tropical climate change with Southern Ocean heat uptake. Geophysical Research Letter. 2017
Kang, S.M., K. Park, Y.-T Hwang, and W.-T. Hsiao: Contrasting climate response to localized thermal forcing over different ocean basins. Geophysical Research Letter. 2018
Oceanic pathways: the enhanced equatorial response (decadal and longer timescale)
Tseng, H.-T., Hwang, Y.-T.*, Xie, S.-P., Tseng, Y.-H., Kang, S. M., Luongo, M. T., and I. Eisenman. Fast and Slow Responses of the Tropical Pacific to Radiative Forcing in Northern High Latitudes, Journal of Climate, 2023
Luongo, M.T., Xie, S.-P., Eisenman, I., Hwang, Y.-T., and H.-Y. Tseng. A Dynamic Pathway by which Northern Hemisphere Extratropical Cooling Elicits a Tropical Response, Geophysical Research Letters, under review. https://doi.org/10.1002/essoar.10512160.1
Kang, S.M., S.P. Xie, Y. Shin, K. Hanjun, Y.-T. Hwang, M. F. Stuecker, B. Xiang, and M. Hawcroft, Walker circulation response to extratropical radiative forcing. Science Advances., 6.47. eabd3021. 2020
Kang, S. M., Hawcroft, M., Xiang, B., Hwang, Y. T., Cazes, G., Codron, F., ... & Kim, J. (2019). ETIN-MIP Extratropical-Tropical Interaction Model Intercomparison Project–Protocol and Initial Results. Bulletin of the American Meteorological Society, 2019