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Latitudinal temperature gradients and high-latitude temperatures during the latest Cretaceous: Congruence of geologic data and climate models

2015; Geological Society of America; Volume: 43; Issue: 8 Linguagem: Inglês

10.1130/g36802.1

1943-2682

Garland R. Upchurch, J. T. Kiehl, Christine A. Shields, Jacquelyn Scherer, Christopher R. Scotese,

Geological formations and processes

Research Article| August 01, 2015 Latitudinal temperature gradients and high-latitude temperatures during the latest Cretaceous: Congruence of geologic data and climate models Garland R. Upchurch, Jr; Garland R. Upchurch, Jr * 1Department of Biology, Texas State University, 601 University Drive, San Marcos, Texas 78666, USA *E-mails: gu01@txstate.edu; cscotese@gmail.com. Search for other works by this author on: GSW Google Scholar Jeffrey Kiehl; Jeffrey Kiehl 2Climate Change Research, Climate and Global Dynamics Division, National Center for Atmospheric Research, 1850 Table Mesa Drive, Boulder, Colorado 80307, USA Search for other works by this author on: GSW Google Scholar Christine Shields; Christine Shields 2Climate Change Research, Climate and Global Dynamics Division, National Center for Atmospheric Research, 1850 Table Mesa Drive, Boulder, Colorado 80307, USA Search for other works by this author on: GSW Google Scholar Jacquelyn Scherer; Jacquelyn Scherer 3University College, University of Texas at San Antonio, 1 UTSA Circle, San Antonio, Texas 78249, USA Search for other works by this author on: GSW Google Scholar Christopher Scotese Christopher Scotese * 4Paleomap Program, 134 Dodge Avenue, Evanston, Illinois 60202, USA *E-mails: gu01@txstate.edu; cscotese@gmail.com. Search for other works by this author on: GSW Google Scholar Author and Article Information Garland R. Upchurch, Jr * 1Department of Biology, Texas State University, 601 University Drive, San Marcos, Texas 78666, USA Jeffrey Kiehl 2Climate Change Research, Climate and Global Dynamics Division, National Center for Atmospheric Research, 1850 Table Mesa Drive, Boulder, Colorado 80307, USA Christine Shields 2Climate Change Research, Climate and Global Dynamics Division, National Center for Atmospheric Research, 1850 Table Mesa Drive, Boulder, Colorado 80307, USA Jacquelyn Scherer 3University College, University of Texas at San Antonio, 1 UTSA Circle, San Antonio, Texas 78249, USA Christopher Scotese * 4Paleomap Program, 134 Dodge Avenue, Evanston, Illinois 60202, USA *E-mails: gu01@txstate.edu; cscotese@gmail.com. Publisher: Geological Society of America Received: 19 Mar 2015 Revision Received: 28 May 2015 Accepted: 28 May 2015 First Online: 09 Mar 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 © 2015 Geological Society of America Geology (2015) 43 (8): 683–686. https://doi.org/10.1130/G36802.1 Article history Received: 19 Mar 2015 Revision Received: 28 May 2015 Accepted: 28 May 2015 First Online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Garland R. Upchurch, Jeffrey Kiehl, Christine Shields, Jacquelyn Scherer, Christopher Scotese; Latitudinal temperature gradients and high-latitude temperatures during the latest Cretaceous: Congruence of geologic data and climate models. Geology 2015;; 43 (8): 683–686. doi: https://doi.org/10.1130/G36802.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract A major challenge in paleoclimatology is disagreement between data and models for periods of warm climate. Data generally indicate equable conditions and reduced latitudinal temperature gradients, while models generally produce colder conditions and steeper latitudinal gradients except when using very high CO2. Here we show congruence between temperature indicators and climate model output for the cool greenhouse interval of the latest Cretaceous (Maastrichtian) using a global database of terrestrial and marine indicators and fully coupled simulations with the Community Climate System Model version 3. In these simulations we explore potential roles of greenhouse gases and properties of pre-anthropogenic liquid clouds in creating warm conditions. Our model simulations successfully reproduce warm polar temperatures and the latitudinal temperature gradient without overheating the tropics. Best fits for mean annual temperature are simulations that use 6× preindustrial levels of atmospheric CO2, or 2× preindustrial levels of atmospheric CO2 and liquid cloud properties that may reflect pre-anthropogenic levels of cloud condensation nuclei. The Siberian interior is problematic, but this may relate to reconstructed elevation and the presence of lakes. Data and models together indicate tropical sea-surface temperatures ∼5 °C above modern, an equator-to-pole temperature difference of 25–30 °C, and a mid-latitudinal temperature gradient of ∼0.4 °C per 1° latitude, similar to the Eocene. Modified liquid cloud properties allow successful simulation of Maastrichtian climate at the relatively low levels of atmospheric CO2 indicated by proxies and carbon cycle modeling. This supports the suggestion that altered properties of liquid clouds may be an important mechanism of warming during past greenhouse intervals. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.