Precession phasing offset between Indian summer monsoon and Arabian Sea productivity linked to changes in Atlantic overturning circulation

摘要: Results from transient climate modeling experiments indicate an in-phase relationship between insolation forcing and Indian summer monsoonal precipitation. This is in contrast to high-resolution radioisotopically dated speleothem oxygen isotope (δ18O) records of China, which showed that East Asian Monsoon maxima lag Northern Hemisphere peak by ∼2,700 years, while approximately 8,000-year time was derived late Pleistocene Arabian Sea sediments. Here, we evaluate the precession phase signal comparing a new productivity minimum zone (OMZ) intensity record over past 450,000 years with results experiment includes glacial-bound ice volume variations. The well established tuning technique North Atlantic cold events occurrence deep-dwelling planktonic foraminifera for last glacial cycle used extend chronology, independent orbital tuning. Cross-spectral analysis 224,000 reveals minima ∼6,900 ± 200 i.e., close agreement previous reconstructions. Also our simulations are accord studies indicating maximum monsoon intensity. We argue most likely not main driver changes biological OMZ at frequency band, but meridional overturning circulation (AMOC) have played prominent role controlling nutrient delivery into euphotic layer northern Ocean, hence amount primary Sea. Such mechanism explains large precession-related conditions Sea, since intensified AMOC occurred during maxima.