TROPICAL – EXTRATROPICAL LINKAGES IN PATTERNS OF CLIMATE VARIABILITY

The observational record of modern climate variability provides evidence that recurring, prominent patterns (hereafter called modes) of climate variability in the midlatitudes are influenced by forcing from the tropics, and vice versa. I will summarize the observational and modeling evidence that demonstrates the North Atlantic Oscillation/Arctic Oscillation (NAO/AO) and Pacific North American Patterns (PNA) are influenced by forcing from the tropics (e.g., by El Nino/Southern Oscillation; ENSO), and that the tropical modes of variability (ENSO and TAV – aka the Tropical Atlantic dipole) are influenced by the midlatitudes.

I will then discuss the arguments for the robustness of these linkages through the Holocene, and – time permitting – how they might be different during Glacial Times.