1 research outputs found
Obliquity pacing of the western Pacific IntertropicalConvergence Zone over the past 282,000 years
The Intertropical Convergence Zone (ITCZ) encompasses the heaviest rain belt on the Earth.
Few direct long-term records, especially in the Pacific, limit our understanding of long-term
natural variability for predicting future ITCZ migration. Here we present a tropical
precipitation record from the Southern Hemisphere covering the past 282,000 years, inferred
from a marine sedimentary sequence collected off the eastern coast of Papua New Guinea.
Unlike the precession paradigm expressed in its East Asian counterpart, our record shows
that the western Pacific ITCZ migration was influenced by combined precession and obliquity
changes. The obliquity forcing could be primarily delivered by a cross-hemispherical thermal/
pressure contrast, resulting from the asymmetric continental configuration between Asia and
Australia in a coupled East Asian–Australian circulation system. Our finding suggests that the
obliquity forcing may play a more important role in global hydroclimate cycles than previously
thought