Monsoon variability over the past 150,000 years

Journal Article · Mon Jul 20 04:00:00 EDT 1987 · J. Geophys. Res.; (United States)

DOI:https://doi.org/10.1029/JD092iD07p08411· OSTI ID:5988515

Prell, W L; Kutzbach, J E

Paleoclimatic records adjacent to India and Africa show major variability that is related to large fluctuations in the wind and precipitation fields associated with monsoonal circulations. Much of the variability occurs at orbital periodicities, and all of the paleoclimatic time series show four monsoon maxima that occur during interglacial conditions and coincide with precession maxima and maxima of northern hemisphere summer radiation. To identify the processes causing changes in monsoon circulation, we used 13 general circulation model (National Center for Atmospheric Research (NCAR) community climate model (CCM)) simulations that incorporate a large range of solar radiation and surface (modern to full glacial) boundary conditions. Under interglacial conditions increased northern hemisphere solar radiation produced a larger land-ocean pressure gradient, stronger winds, and greater precipitation over southern Asia and North Africa. Simulated records for southern Asia and equatorial North Africa over the past 150,000 years show four monsoon maxima that are related to solar radiation maxima and are observed in the paleoclimatic data. The simulations also indicate that southern Asia is drier than today (weaker monsoon) for the period with extensive glacial boundary conditions, especially between 75,000 and 15,000 years ago. Conversely, equatorial North Africa is simulated to be wetter than today during glacial conditions. Both areas show stronger monsoons with increasing solar radiation during interglacial conditions. Both orbitally produced solar radiation changes and glacial age boundary condition changes are necessary to explain the major regional features of monsoon climates at millennial or longer time scales.

• Research Organization: Department of Geological Sciences, Brown University, Providence, Rhode Island; Center for Climatic Research and Department of Meteorology, University of Wisconsin, Madison
• OSTI ID: 5988515
• Journal Information: J. Geophys. Res.; (United States), Journal Name: J. Geophys. Res.; (United States) Vol. 92:D7; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

500100* -- Environment
Atmospheric-- Basic Studies-- (-1989)
54 ENVIRONMENTAL SCIENCES
AFRICA
ASIA
ATMOSPHERIC PRECIPITATIONS
DEVELOPING COUNTRIES
DISASTERS
DOCUMENTATION
GENERAL CIRCULATION MODELS
HISTORICAL ASPECTS
INDIA
MATHEMATICAL MODELS
MONSOONS
PALEOCLIMATOLOGY
PALEONTOLOGY
RADIATIONS
SOLAR RADIATION
STELLAR RADIATION
STORMS
VARIATIONS
WIND