PMIP3 WG - Pre-Pliocene climates

Contact: Dan Lunt, Bette Otto-Bliesner

Group description

To carry out coordinated model simulations of pre-Pliocene time periods, to address key scientific questions related to key intervals, and to evaluate the models by comparisons with palaeo data.

To leverage funding for pre-Pliocene climate modelling through coordinated projects.

To contribute to the IPCC if appropriate.

Questions to be addressed

What are the key scientific questions?

GF: Efficacy of fast feedbacks in a warm world? What feedbacks that operate in warm climates that done operate in more equitable climes? E.g. are their hidden feedbacks and/or sudden jumps in feedback efficacy that lie in wait as we warm the world toward Eocene conditions? Background climate state dependency of feedbacks etc.

YD: It looks like we are unable to melt the Antarctic ice-sheet with reasonable CO2 levels during the Pliocene (unless tuning all the parameters to get it). Conversely, CO2 is sometimes very low before the E-O transition, what does it mean ? Why do we not see changes in d180, I am not convinced that the small geographical changes characterizing the early Cenozoic could explain a lower Earth sensitivity to glaciation.

DN: What is the impact of a warmer climate on biogeochemical cycles (and weathering)? How did the hydrological cycle look like in a warmer world?

What time periods should we target?

GF: We need a big signal and lots of data coverage. Time periods that are easy to spot in the record and have lots (ish) of data already are Eocene climatic optimum, middle Eocene climatic optimum, PETM.

GL: As a focus, I suggest two time intervals: Eocene and Miocene.

BB: Oligocene and Miocene evolution of climate, ice sheets and the carbon cycle.

DN: Miocene (maybe MCO), E/O boundary, ECO, PETM.

What is needed for experimental design – paleogeographies and CO2 primarily – what datasets can we use?

MH: a full set of early Eocene boundary conditions submitted to Geoscientific Model Development which will be freely available (Nick Herold is spearheading this). It will include topo,bathymetry,veg, tidal dissipation, and aerosol forcing files at 1°x1° among other parameters. the DEM is based on a merging of Markwick's topo and Mueller's bathy/rotations…. it should include everything necessary setting up a coupled GCM run (nothing is turnkey of course, but all the fundamentals are there). hopefully it might provide a basis for future intercomparison efforts and provide a baseline for subsequent modification or comparison. the necessary scripts for rotation the topo/veg to earlier and later time intevals (say 65 and 35mya) will also be provided… Once the article is submitted, we will make it available for perusal and criticism…

What are the best datasets for model-data comparisons, and how can these be improved?

GF: More SST and MAT for terrestrial no doubt needed, and CO2 data.

What are the best methodologies for model-data comparisons (close collaboration with the Past2Future working group)

GF: I think a radical way to do this would be to move away from simple difference to modern type studies that have been done to date, instead we could try to look across a number of natural warming events and see whether the models capture the warming the geological record shows. So for instance, pre, peak and post PETM, MECO and EECO - do the models show similar trajectories to the data? CO2 would be much better constrained this way and so will the SSTs (e.g. most of the TEX86 uncertainty in your Eocene paper is due to calibration, for these shorter time periods you could use delta T change which is largely independent of calibration).

How can we fund this?

DS: SCOR: http://www.scor-int.org/wkgrpinfo.htm ?

BO: PAGES.

Members

Eleni Anagnostou
Paul Baker
Bas de Boer
Catherine Bradshaw
Philippe Claeys
Michel Crucifix
Rob DeConto
Henk Dijkstra
Yannick Donnadieu
Tom Dunkley Jones
Kirsty Edgar
Alex Farnsworth
Gavin Foster
Sheri Fritz
Ed Gasson
Julia Hargreaves
Melise Harland
Alan Haywood
Nicholas Herold
Anna von der Heydt
Dan Hill
Sze Ling Ho
Chris Hollis
Matt Huber
Nick Hulton
Jasmin John
Gregor Knorr
Jean-Baptiste Ladant
Petra Langebroek
David Lea
Carrie Lear
Kate Littler
Gerrit Lohmann
Dan Lunt
Ali Marzocchi
Uwe Mikolajewicz
David Naafs
Tim Naish
Kerim Nisancioglu
Bette Otto-Bliesner
Rich Pancost
Wonsun Park
Paul Pearson
Chris Poulsen
Matthias Prange
Stuart Robinson
Francesca Sangiorgi
Dani Schmidt
Birgit Schneider
Lori Sentman
Appy Sluijs
Emma Stone
Jozef Syktus
Ellen Thomas
Jess Tierney
Martin Tranter
Aradhna Tripati
Paul Valdes
David De Vleeschouwer
Jonny Williams
Arne Winguth
Jim Zachos
Richard Zeebe

Meetings

(very) informal meeting at AGU 2013.

(very) informal meeting at Namur, Belgium, 2014

Name suggestions

Tertiary PMIP “TerMIP”
Deep Time PMIP Working Group “DeepMIP”
5Ma+ PMIP Working Group? “5MaMIP” or “5Ma+MIP”
“CenoMIP”
Phanerozoic MIP “PhanMIP”

Freely available Paleogeographies

This is a list of freely-available, global, digital (i.e. in electronic format), paleogeographies (including both topography and bathymetry) of the pre-Pliocene, of which we are aware:

Early Eocene: Herold et al (2014). Available from: http://www.geosci-model-dev-discuss.net/7/529/2014/gmdd-7-529-2014-discussion.html

Middle Miocene: Herold et al (2008). Available from: http://roskilde.eas.purdue.edu/~nick/data/topo02_2deg.grd
and vegetation from: http://roskilde.eas.purdue.edu/~nick/data/veg02_0.3.grd
More information from: http://roskilde.eas.purdue.edu/~nick/datasets.htm

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