LATE QUATERNARY CLIMATE CHANGE FROM ARABIA: VARIATIONS IN THE FORCING OF THE INDIAN OCEAN SUMMER MONSOON

The Indian Ocean summer monsoon represents one of the Earth's most dynamic interactions between atmosphere, oceans, and continents affecting climate on a seasonal basis from eastern Africa, through southern Arabia and into central Asia. The climate of the Arabian sub-continent has been strongly influenced by the past changes in the Indian Ocean summer monsoon winds. The position of the Indian Ocean monsoon is governed by the location of the inter-tropical convergence zone (ITCZ). During periods of increased wetness over Arabia there is a shift in the position of the ITCZ to north of its present location forcing the monsoon to bring rainfall into central and northern Arabia. Likewise the reverse occurs during dry phases with the position of the monsoon inversion lying further south than at present with aridity over Arabia being enhanced by the incursion of enhanced north westerlies

Lacustrine sediments from Awafi, Ras al-Khaimah, United Arab Emirates in the northern Arabian peninsula reveal a series of abrupt Holocene climate events related to changes in the position and forcing of the SW Indian Ocean monsoon system. The early Holocene was characterised by a permanent water body, followed by a shallow lake with fluctuations in depth. The Holocene sequence was punctuated by at least three major desiccation events when the lake became dry. The combination of dune evidence and lacustrine deposits indicate that northern Arabia is sensitive to changes in climate between the SW monsoon and the northwesterlies and provide a crucial archive for the reconstruction of high-resolution environmental changes during the Late Quaternary.