Eastern Tropical Pacific Dynamics

Last updated: February 20, 2026

The Eastern Tropical Pacific plays a central role in the global climate system. Though often thought as a driver of global climate variability through its far-reaching teleconnections, it is also can be sensitive to high-latitude and interhemispheric variability. Paleoclimate archives can help elucidate the role this region plays in responding to and driving climate variability during periods of global change, such as across glacial-interglacial cycles. Yet, paleoclimate records from the northeastern Tropical Pacific, specifically the Eastern Pacific Warm Pool (EPWP), are sparse. 

To address this gap, I have focused on generating and interpreting several novel organic geochemical (including alkenones, GDGTs, leaf wax hydrogen isotopes, and foraminiferal radiocarbon isotopes) proxy records from marine sediment cores located at the northern edge of the EPWP. These reconstructions provide constraints on how the spatial extent and intensity of the warm pool evolved across major climate transitions. These records reveal unexpected patterns of temperature and hydroclimate variability---notably warmer sea surface temperatures during periods of global ice volume growth---offering new insight into how tropical ocean–atmosphere dynamics responded to glacial–interglacial forcing and reorganizations of global circulation. Ongoing work is touching on new foraminiferal radiocarbon and leaf wax hydrogen isotope records from the Gulf of Tehuantepec, which is located in the core of the EPWP. These records provide unique insight into the influence of interhmispheric climate gradients on Central American gap winds and Intertropical Convergence Zone dynamics. 

RELATED PUBLICATIONS:

• Rafter, P.A., Baldwin, J.W., Sanchez, S., Karnauskas, K., Pavia, F., Meegan-Kumar, D. (in prep) Ice age winds: Interhemispheric air-sea connections between the Atlantic and the Pacific. For submission to Science

• Meegan-Kumar, D., Elsaesser, G.S., Battisti, D.S., Colose, C., Wu, J., Sexton, J., Baldwin, J.W. (2025). Optimizing Topographic Boundary Conditions for East Pacific Climate Simulation. Journal of Climate, 38 (11), 2497-2524. DOI: 10.1175/JCLI-D-24-0316.1

• Meegan Kumar, D., Tierney, J. E., Bhattacharya, T., Zhu, J., & Murray, J. W. (2022). Glacial warming in the Eastern Pacific Warm Pool. Geophysical Research Letters, 49(10), DOI: 2022GL098830

• Meegan Kumar, D., Tierney, J. E., Bhattacharya, T., Zhu, J., McCarty, L., & Murray, J. W. (2021). Climatic drivers of deglacial SST variability in the eastern Pacific. Paleoceanography and Paleoclimatology, 36(10), DOI: 2021PA004264