This README.txt file was generated on Feb 9 2021 by Anna Ruth Halberstadt

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GENERAL INFORMATION
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1. Title of Dataset: 

Model data for 'CO2 and Tectonic Controls on Antarctic Climate and Ice-Sheet Evolution in the Mid-Miocene'


2. Author Information

  First Author Contact Information
        Name: Anna Ruth W Halberstadt
           Institution: University of Massachusetts Amherst
           Address: Department of Geosciences, University of Massachusetts, Amherst, Massachusetts 01003, USA
           Email: ahalberstadt@umass.edu



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DATA & FILE OVERVIEW
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Description of Dataset: 

   This dataset contains the source data for the following publication: 'CO2 and Tectonic Controls on Antarctic Climate 
   and Ice-Sheet Evolution in the Mid-Miocene' by Halberstadt et al. [full citation, doi]

   We use an ensemble of asynchronously coupled climate - ice sheet - vegetation model simulations spanning a range of CO2 
   concentrations, Transantarctic Mountain uplift scenarios, and glacial/interglacial climatic conditions to identify climate 
   and ice-sheet conditions consistent with Antarctic mid-Miocene terrestrial and marine geological records. 

   Here we provide the final equilibrated output data for each model ensemble member.


List of Directories:

   A. Directory: ISMs        
      Short description: Ice Sheet Model output
      Header information for model output variables is contained in the text file ISM.example.vars.txt	
        
   B. Directory: GCMs
      Short description: Global Climate Model output 
      Header information for model output variables is contained in the text file GCM.example.vars.txt	
        
   C. Directory: RCMs
      Short description: Regional Climate Model output
      Header information for model output variables is contained in the text file RCM.example.vars.txt	


File Naming Convention:

   All model output is in netcdf format, and is named according to the boundary conditions used: 
   [1. model type][2. CO2][3. topography and orbit]

	1. Model type: refers to either ice sheet model ('ISM'; Pollard and DeConto, 2012), regional climate model ('RCM', 
	   RegCM; Pal et al., 2007), or global climate model ('GCM', GENESIS version 3.0; Thompson and Pollard, 1997). More
	   information about each model and the coupling details can be found in the Supplementary Materials corresponding
	   to the primary publication (listed above). 

	2. CO2: refers to the CO2 boundary condition specified in the RCM and GCM; files are named after the CO2 values
           set in the model where all the radiative forcing is driven by CO2 rather than other greenhouse gases (see
	   discussion of 'model CO2' and 'effective CO2' in the publication main text and Supplementary Materials for more 
	   information). Therefore, file names containing model CO2 ('280','500','840','1000','1200','1500') correspond to 
	   effective CO2 values discussed in the publication of '280','460','690','780','930','1140' ppm, respectively.

	3. Topography and orbit: refers to the input topography where the Transantarctic Mountains are either left 
	   unchanged from the Paxman et al. (2019) reconstruction of 14 Ma median paleotopography ('norm'), hinged downwards
	   by 300m, 500m, or 800m ('h300','h500', or 'h800'), or hinged upwards by 300m ('h300U'). All model data are run 
	   under a 'interglacial' climate favorable for Antarctic deglaciation (a warm astronomical orbit) except for the 
	   model runs named 'ncold' which denotes an unchanged topography and a 'glacial' climate favorable for Antarctic 
	   glaciation (a warm astronomical orbit). See the publication main text and Supplementary Materials for more 
	   information on topopraphic modifications and astronomical orbit.

	For example, an ice-sheet model output with 280ppm CO2, a warm orbit, and topography hinged downwards by 800m is 
	named: 'ISM.280h800.nc'



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REFERENCES
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Pollard, D., DeConto, R.M., 2012. Description of a hybrid ice sheet-shelf model, and application to Antarctica. Geosci. 
Model Dev. 5, 1273–1295. https://doi.org/10.5194/gmd-5-1273-2012

Pal, J.S., Giorgi, F., Bi, X., Elguindi, N., Solmon, F., Gao, X., Rauscher, S.A., Francisco, R., Zakey, A., Winter, J., 
others, 2007. Regional climate modeling for the developing world: the ICTP RegCM3 and RegCNET. Bull. Am. Meteorol. Soc. 88, 
1395–1410.

Thompson, S.L., Pollard, D., 1997. Ice-sheet mass balance at the Last Glacial maximum from the GENESIS version 2 global 
climate model. Ann. Glaciol. 25. https://doi.org/10.3189/s0260305500268109

Paxman, G.J.G., Jamieson, S.S.R., Hochmuth, K., Gohl, K., Bentley, M.J., Leitchenkov, G., Ferraccioli, F., 2019. 
Reconstructions of Antarctic topography since the Eocene–Oligocene boundary. Palaeogeogr. Palaeoclimatol. Palaeoecol. 535, 
109346. https://doi.org/10.1016/j.palaeo.2019.109346