edu.ucar.opensky::articles:13353 UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact 2025-12-26T03:34:01.400167 ISO 19115-2 Geographic Information - Metadata - Part 2: Extensions for Imagery and Gridded Data ISO 19115-2:2009(E) https://n2t.org/ark:/85065/d7dj5gj7 Equatorial signatures of the Pacific Meridional Modes: Dependence on mean climate state 2014-01-28T00:00:00Z publication https://n2t.org/ark:/85065/d7dj5gj7 https://doi.org/10.1002/2013GL058842 Zhang, H. author Deser, Clara author Clement, A. author Tomas, Robert A. author UCAR/NCAR - Library publisher Extratropical atmospheric variability can impact tropical climate in the Pacific sector via the Pacific Meridional Modes (PMMs). The South PMM (SPMM) has a larger equatorial signature than the North PMM (NPMM) for the same amount of extratropical variability. Here we explain this interhemispheric asymmetry using an atmospheric general circulation model coupled to a slab ocean model. By imposing an anomalous interhemispheric heating gradient, we strengthen the northeasterly trades and weaken the southeasterly trades, shifting the Intertropical Convergence Zone south of the equator. As a result, the SPMM no longer influences the equatorial region while the NPMM shows strengthened linkages to the central-western equatorial Pacific. By demonstrating that background winds determine the propagation of the wind-evaporation-sea surface temperature feedback fundamental for the PMMs, we conclude that the interhemispheric asymmetry between the PMMs is largely attributed to the asymmetric mean trades in the Pacific. The results have implications for both paleoclimate studies and model development. UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact PDF Text theme Resource Type 2016-01-01T00:00:00Z publication Copyright 2014 American Geophysical Union. None eng geoscientificInformation