Modeling the Miocene Climatic Optimum. Part I: Land and Atmosphere

This study presents results from the Community Climate System Model 3 (CCSM3) forced with early to middle Miocene (∼20–14 Ma) vegetation, topography, bathymetry, and modern CO₂. A decrease in the meridional temperature gradient of 6.5°C and an increase in global mean temperature of 1.5°C are modeled...

Full description

Saved in:
Bibliographic Details
Published in:Journal of climate 2011-12, Vol.24 (24), p.6353-6372
Main Authors: Herold, N., Huber, M., Müller, R. D.
Format: Article
Language:English
Subjects:
Albedo
Atmosphere
Atmospheric models
Bathymetry
Boundary conditions
Carbon dioxide
Climate
Climate change
Climate models
Climate proxies
Climate system
Climatic analysis
Control simulation
Data analysis
Earth, ocean, space
Energy budget
Exact sciences and technology
External geophysics
Global climate models
Global temperatures
Global warming
Global warming effects
Greenhouse gases
Hadley circulation
Heat
Heat transport
Ice sheets
Jet stream
Jet streams (meteorology)
Latitude
Mean temperatures
Meteorology
Miocene
Miocene climates
Modelling
Northern Hemisphere
Ocean circulation
Oceans
Paleoclimatology
Proxies
Sea transportation
Simulation
Southern Hemisphere
Storm tracks
Storms
Stratosphere
Subtropical jet stream
Temperature
Temperature gradients
Topography
Vegetation
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:This study presents results from the Community Climate System Model 3 (CCSM3) forced with early to middle Miocene (∼20–14 Ma) vegetation, topography, bathymetry, and modern CO₂. A decrease in the meridional temperature gradient of 6.5°C and an increase in global mean temperature of 1.5°C are modeled in comparison with a control simulation forced with modern boundary conditions. Seasonal poleward displacements of the subtropical jet streams and storm tracks compared to the control simulation are associated with changes in Hadley circulation and significant cooling of the polar stratosphere, consistent with previously predicted effects of global warming. Energy budget calculations indicate that reduced albedo and topography were responsible for Miocene warmth in the high-latitude Northern Hemisphere while a combination of increased ocean heat transport and reduced albedo was responsible for relative warmth in the high-latitude Southern Hemisphere, compared to the present. Model–data analysis suggests Miocene climate was significantly warmer and wetter than simulated here, consistent with previous uncoupled Miocene models and supports recent reconstructions of Miocene CO₂ substantially higher than present.
ISSN:0894-8755
1520-0442
DOI:10.1175/2011jcli4035.1