Tang, Hui et al. (2011): Regional climate model experiments to investigate the Asian monsoon in the late Miocene

Leg/Site/Hole:
ODP 117
ODP 145
ODP 184
ODP 184 1147
ODP 184 1148
ODP 117 722
ODP 145 885
ODP 145 886
Identifier:
2012-046922
georefid

Creator:
Tang, Hui
University of Helsinki, Department of Geosciences and Geography, Helsinki, Finland
author

Micheels, Arne
Biodiversity and Climate Research Centre (LOEWE BiK-F), Germany
author

Eronen, Jussi
author

Fortelius, Mikael
author

Identification:
Regional climate model experiments to investigate the Asian monsoon in the late Miocene
2011
Climate of the Past
Copernicus, Katlenburg-Lindau, International
7
3
847-868
The Late Miocene (11.6-5.3 Ma) is a crucial period in the history of the Asian monsoon. Significant changes in the Asian climate regime have been documented for this period, which saw the formation of the modern Asian monsoon system. However, the spatiotemporal structure of these changes is still ambiguous, and the associated mechanisms are debated. Here, we present a simulation of the average state of the Asian monsoon climate for the Tortonian (11-7 Ma) using the regional climate model CCLM3.2. We employ relatively high spatial resolution (1 degrees X1 degrees ) and adapt the physical boundary conditions such as topography, land-sea distribution and vegetation in the regional model to represent the Late Miocene. As climatological forcing, the output of a Tortonian run with a fully-coupled atmosphere-ocean general circulation model is used. Our regional Tortonian run shows a stronger-than-present East Asian winter monsoon wind as a result of the enhanced mid-latitude westerly wind of our global forcing and the lowered present-day northern Tibetan Plateau in the regional model. The summer monsoon circulation is generally weakened in our regional Tortonian run compared to today. However, the changes of summer monsoon precipitation exhibit major regional differences. Precipitation decreases in northern China and northern India, but increases in southern China, the western coast and the southern tip of India. This can be attributed to the changes in both the regional topography (e.g. the lower northern Tibetan Plateau) and the global climate conditions (e.g. the higher sea surface temperature). The spread of dry summer conditions over northern China and northern Pakistan in our Tortonian run further implies that the monsoonal climate may not have been fully established in these regions in the Tortonian. Compared with the global model, the high resolution regional model highlights the spatial differences of the Asian monsoon climate in the Tortonian, and better characterizes the convective activity and its response to regional topographical changes. It therefore provides a useful and compared to global models, a complementary tool to improve our understanding of the Asian monsoon evolution in the Late Miocene.
English
Coverage:Geographic coordinates:
North:60.0000
West:-168.1619East: 143.0000
South:2.0000

Stratigraphy; Arabian Sea; arid environment; Asia; atmospheric precipitation; atmospheric pressure; Cenozoic; China; climate change; climate forcing; deserts; equatorial climate; Far East; general circulation models; Indian Ocean; Indian Peninsula; Leg 117; Leg 145; Leg 184; Loess Plateau; Miocene; monsoons; Neogene; Nepal; North Pacific; northern China; northern Pakistan; Northwest Pacific; Ocean Drilling Program; ODP Site 1147; ODP Site 1148; ODP Site 722; ODP Site 885; ODP Site 886; orbital forcing; Pacific Ocean; Pakistan; paleoclimatology; paleoecology; paleoenvironment; Pearl River; polar regions; Qin'an China; sea-surface temperature; Sikouzi China; snow; South China Sea; steppes; Surai Khola Nepal; terrestrial environment; Tertiary; Tibetan Plateau; Tortonian; upper Miocene; velocity; West Pacific; winds;

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