We propose a coordinated Aqua-Planet Experiment (APE) based on a set of specified Sea Surface Temperatures (SST) to provide a benchmark of current model behavior, and more importantly, to stimulate research to understand the cause of differences arising from different models, different subgrid-scale parameterization suites, different dynamical cores, and different methods of coupling the two.

The experiment consists of eight, 3.5-year simulations, with data from the last 3 years analyzed. Motivation and the experiment details are provided in Neale, R.B. and B.J. Hoskins, 2000a (A standard test for AGCMs including their physical parameterizations. I: The proposal. Atmos. Sci. Lett, Vol.1, No.2, pp. 101-107.)
This paper along with a companion paper are available for free viewing HERE.

The experiment will consist of a basic simulation set from AMIP type models, augmented by sensitivity experiments and experiments from simple models to aid interpretation.   The basic simulation data will be openly available to all participating modelling groups for comparative analysis.  In fact, it is expected that all participants who submit the basic set will participate in the analysis of selected aspects of all submitted models.  A workshop will be held at the end of the experiment to discuss the results and produce a summary of research questions arising from the experiment.  No results involving comparison of the basic simulation sets will be published until after the workshop where they will be discussed.  Groups are encouraged to perform sensitivity experiments for their own analyses, or to submit them to the archive for group analysis as they see fit.  Likewise, simulations with simple models for interpretation are encouraged.  Such participants will also have access to the basic simulation data base.  Individual model studies may be published at anytime by their developers.

The schedule for the experiment is:

November 1, 2002:   Inform David Williamson of your intention to participate and list which variables from the list (see below) your group is willing to take responsibility for analysis. Please be as general as possible as this might require negotiation to ensure all variables are analyzed. If you think additional data should be collected please provide details with reasons so the organizers can refine the experiment if needed.

January 1, 2003:   Announce final experiment details.

September 30, 2003:   Cutoff date for submission of data to PCMDI in the specified formats.

February 29, 2004:   Analyses exchanged between participants for consideration before the Workshop.

16 March 2004:   Timescales for data submission and processing have slipped significantly.
Data upload and QC of the control-run data are currently ongoing.

24 May 2004:   Launch of a data website for participating groups is imminent.
The workshop, originally scheduled for June 2004, has been re-scheduled.

02 February 2005:   Data archive operational since December; workshop registration open.

20-22 April 2005:   2.5 day workshop in Reading, U.K.

15 November 2006:   Final cut-off date for second round of data submission.

26 January 2007:   Request for Additional Transient Data, with submission deadline 31 May 2007.

13-15 November 2007:   Second/final workshop to be hosted by the AGU consortium
at the Chiba Institute for Science, Choshi, Chiba, Japan.

28 October, 2013:   The formal APE project is complete, but the data archive remains available for continued research.

The design of the experimental suite is specified HERE

The data to be collected, and analyses to be performed by the group on the basic simulations are specified HERE

The acceptable formats for submitting data are described HERE

Experimental data and Quality Control information are available to participating groups HERE