Boundary conditions for the Middle Miocene Climate Transition (MMCT v1.0)

Abstract

Abstract. The Middle Miocene Climate Transition was characterized by major Antarctic ice sheet expansion and global cooling during the interval ∼ 15–13 Ma. Here we present two sets of boundary conditions for global general circulation models characterizing the periods before (Middle Miocene Climatic Optimum; MMCO) and after (Middle Miocene Glaciation; MMG) the transition. These boundary conditions include Middle Miocene global topography, bathymetry, and vegetation. Additionally, Antarctic ice volume and geometry, sea level, and atmospheric CO2 concentration estimates for the MMCO and the MMG are reviewed. The MMCO and MMG boundary conditions have been successfully applied to the Community Climate System Model version 3 (CCSM3) to provide evidence of their suitability for global climate modeling. The boundary-condition files are available for use as input in a wide variety of global climate models and constitute a valuable tool for modeling studies with a focus on the Middle Miocene.

Chromosomal dynamics in space and time: evolutionary history of Mycetophylax ants across past climatic changes in the Brazilian Atlantic coast

“…The Miocene was a climatically dynamic interval from Cenozoic, when long-term global climatic cooling was punctuated by extreme climatic optima ( i . e ., MMCO) 59 . After this period of global warming — the warmest one in the last 24 Ma 34 — a climate transition associated with major Antarctic ice sheet expansion and global cooling began, the so-called Middle Miocene Glaciation “MMG” 59 , which drastically extended to the Pleistocene glacial intervals.…”

“…e ., MMCO) 59 . After this period of global warming — the warmest one in the last 24 Ma 34 — a climate transition associated with major Antarctic ice sheet expansion and global cooling began, the so-called Middle Miocene Glaciation “MMG” 59 , which drastically extended to the Pleistocene glacial intervals. As these global climate oscillations were directly associated with marine transgressions and regressions 35 , the evolutionary history of psammophilous Mycetophylax on sand dunes could plausibly be related to the heterogeneity of the Brazilian Atlantic coast as well to their topographic and climatic gradients.…”

Midlatitude Temperature Variations in the Oligocene to Early Miocene

“…Paleoclimate model simulations with relevant paleogeography for the MMCO and 400 ppmv CO 2 do not reproduce the extremely warm temperatures in the extra-tropical North Atlantic sites, and simulate a much stronger latitudinal gradient between the equatorial site and the locations of extratropical records (Frigola et al, 2018;Herold et al, 2012). Simulations of Paleocene Eocene Thermal Maximum, which feature different paleogeography, using 2250 ppmv CO 2 and altered cloud feedbacks, simulate extreme midlatitude temperatures of 30°C at 42°N in the western Atlantic.…”

The first fossil skull of an anteater (Vermilingua, Myrmecophagidae) from northern South America, a taxonomic reassessment ofNeotamanduaand a discussion of the myrmecophagid diversification

“…The vertical dashed line indicates the time of complete formation of the Panama Land Bridge, which represented thereafter a fundamentally continuous physical connection between South- and North America. Palaeocological data used for the plot in ‘B’ is from the following references: Huntley & Webb III (1988); Toby Pennington et al (2000); Williams et al (2004); Williams (2009); Chan et al (2011); Morley (2011); Kay et al (2012); Pound (2012); Pound et al (2012); Forrest et al (2015); Lohmann et al (2015); Dowsett et al (2016); Sniderman et al (2016); Henrot et al (2017); Frigola et al (2018). The temperature curve in ‘C’ is based on Zachos et al (2001, 2008) and it is reproduced with permission.…”