Search results for "000-year problem"
showing 2 items of 2 documents
Insolation cycles as a major control equatorial Indian Ocean primary production
1997
Analysis of a continuous sedimentary record taken in the Maldives indicates that strong primary production fluctuations (70 to 390 grams of carbon per square meter per year) have occurred in the equatorial Indian Ocean during the past 910,000 years. The record of primary production is coherent and in phase with the February equatorial insolation, whereas it shows diverse phase behavior with δ 18 O, depending on the orbital frequency (eccentricity, obliquity, or precession) examined. These observations imply a direct control of productivity in the equatorial oceanic system by insolation. In the equatorial Indian Ocean, productivity is driven by the wind intensity of westerlies, which is rel…
Orbital insolation forcing of the Indian Monsoon – a motor for global climate changes?
2003
Abstract Both modern and ancient Indian summer monsoons are driven by transequatorial pressure differences, directly coupled with the insolation difference between the Northern and Southern subtropical Hemispheres. A high-resolution record of upwelling and dust flux from the western Arabian Sea resembles an insolation-based Indian Summer Monsoon Index. This index and the observed monsoonal climate variations share major elements on the orbital obliquity and precessional band with the Specmap marine oxygen isotope record, representing global ice volume. The long-term evolution of the index mirrors almost exactly the insolation changes at 65°N, showing that the forcing of low latitude climate…