Time-slice analysis of the Australian summer monsoon during the late Quaternary using the Fast Ocean Atmosphere Model

Online Access: Get full text
doi: 10.1002/jqs.1063
Author(s): Marshall, A. G.; Lynch, A. H.
Author Affiliation(s): Primary:
Monash University, School of Geography and Environmental Science, Clayton, Victoria, Australia
Monash University, Australia
Volume Title: Integrating high-resolution past climate records for future prediction in the Australasian region
Volume Author(s): Turney, Chris S. M., editor; Kershaw, A. Peter; Lynch, Amanda
Source: JQS. Journal of Quaternary Science, 21(7), p.789-801; Reconstructing past climates for future prediction; integrating high-resolution past climate records for future prediction in the Australasion region, Canberra, A.C.T., Australia, June 27-28, 2006, edited by Chris S. M. Turney, A. Peter Kershaw and Amanda Lynch. Publisher: John Wiley and Sons for the Quaternary Research Association, Chichester, United Kingdom. ISSN: 0267-8179
Note: In English. 77 refs.; illus., incl. 2 tables, sketch map
Summary: We use the Fast Ocean Atmosphere Model (FOAM) to investigate the variation in the Australian summer monsoon over the last 55,000 years. A synthesis of paleoenvironmental observations is used to constrain the model for six time slices: 55, 35, 21, 11, 6 and 0 ka. Both inter-hemispheric forcing and the seasonal timing of local insolation changes play key, and interacting, roles on the evolution and intensity of the monsoon. During the onset to the monsoon, a heat low develops to the west of Australia over the Indian Ocean in all time slices, but with varying strengths. Divergent outflow from Asia converges with the cyclonic flow to bring increased rainfall to northern Australia and the maritime continent. The relative importance of a low pressure "pull" and the high pressure "push" varies according to the strength of the pressure anomalies. Only in the middle Holocene is the low pressure "pull" the dominant forcing mechanism. At 21 ka, the climate shift to colder mean temperatures determines the large-scale dynamics of the monsoon. The general picture that emerges from these results is consistent with available paleodata but highlights the importance of a broad regional perspective to ascribe the driving mechanisms at different times.
Year of Publication: 2006
Research Program: ODP Ocean Drilling Program
Key Words: 24 Surficial Geology, Quaternary Geology; Australasia; Australia; Cenozoic; Fast Ocean Atmosphere Model; Holocene; Indian Ocean; Last glacial maximum; Leg 133; Monsoons; New Zealand; Numerical models; ODP Site 820; Ocean Drilling Program; Paleoclimatology; Paleoenvironment; Pleistocene; Quaternary; Upper Pleistocene
Coordinates: S220300 S220300 E1133000 E1133000
S172200 S172200 E1454200 E1454200
S131000 S131000 E1213500 E1213500
S121900 S121900 E1395900 E1395900
S415300 S415300 E1453600 E1453600
S370600 S370600 E1463000 E1463000
S163814 S163813 E1461814 E1461813
S431500 S431500 E1701300 E1701300
S350900 S350900 E1731300 E1731300
Record ID: 2007004623
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from John Wiley & Sons, Chichester, United Kingdom