The PMIP 2 water-hosing experiments will follow the guidelines specified in the sensitivity to surface water flux forcing subproject of the CMIP project.
You can find more details in the mail that Ron Stouffer sent to CMIP participants:
CMIP Common Experiments Letter
May 14, 2003
Dear modeler,
Last year, two sets of Coordinated
Coupled Model Experiments were approved by CMIP's Working Group on
Coupled Models.
The goal of the first set
of experiments is to understand the role of the various surface
fluxes in the weakening of the Atlantic meridional overturning
circulation when CO2 increases in the atmosphere. This effort includes
some partially coupled integrations.
The second set of
experiments focus on a so-called water hosing
integration. In this experiment, an external source of freshwater is
applied to the Atlantic Ocean surface from 50N to 70N at a rate of
0.1SV for 100 years. (A third less publicized experiment has been
initiated as an offshoot of the 0.1SV hosing: a 1.0SV hosing in the
same area, for the same length of time). The water hosing effort is
also a PMIP 2 project.
It is time for us to begin collecting and comparing data from these
experiments. It is important to remember that each group is primarily
responsible for analyzing its own integrations. We have planned only a
limited amount of common analysis, but hope that the coordinated
experiments will stimulate coordination among those involved as we
seek to develop a greater understanding of the differences in the
model results.
A few months ago, Keith Dixon and Bill Hurlin agreed to take the lead in collecting
the role of the surface flux data. Ron
Stouffer and Mike Spelman will collect the
water hosing data. This arrangement will continue for the next year or
so.
Those four people plus Jonathan Gregory developed a list of variables
(subproject : [1] - [2]) to be
shared amongst the participants of the two subprojects. The list of
variables and suggested options for how the data can be shared are
described on a web site developed for these Coordinated Coupled
Model Experiments. The options include having the modeling groups
transfer copies of their data to GFDL where it can be stored on a password
protected server accessible to other participants. Alternatively,
groups can place their data files on a distributed data server of
their own.
We have tested this arrangement by having Jonathan Gregory (HadCM3)
and Andrew Weaver/Mike Eby (UVic) send their data to GFDL. It has
worked well and we are now ready to begin the larger effort of
collecting data from all participants. (FYI - Much of Jonathan's CMIP
talk at the recent EGS was prepared using these preliminary data
sets.)
Please complete the integrations and begin the process of transferring
the data as soon as possible. Instructions for the data transfer are
also found on the web site (subproject : [1] - [2]). We
want to have the preliminary analysis of these projects complete by
late summer in time for the mid-September climate meetings in Hamburg
(the Climate Conference and CMIP workshop). For this reason, we would
like to have your model data here at GFDL (or accessible via another
distributed server) as soon as possible. The data we collect will be
available to all participants via a password
protected web site. Our intention is produce Intercomparison papers
of the basic results with joint authorship by the individuals from the
participating centers. The papers will be written some time after the
September meetings.
The main web page for these coordinated experiments is
http://www.gfdl.noaa.gov/~kd/CMIP.html
Keith Dixon will maintain the web pages for the Atlantic Meridional
Overturning Response To Time-Dependent Climate Change On The Century
Time scale subproject (includes the partially-coupled
experiments).
Ron Stouffer will maintain the web pages for the Sensitivity To Surface
Water Flux Forcing subproject (the so-called water-hosing
experiments).
During the analysis phase of this project, access to the individual
subproject web pages and the model data sets will be password
protected. Each participating modeling group will be sent a username
and password that will allow them to access these web pages and data
files. Please contact us if you have questions regarding password
access. We are using this security to limit outside access to our
results. Once papers are published on this data, we plan to revisit
the issue of making the information public.
The desired data format is netCDF, using the CF convention.
Documentation for the CF convention can be found at:
http://www.cgd.ucar.edu/cms/eaton/cf-metadata/CF-1.0.html.
One can also learn about the CF convention by inspecting the CDL
information for defining the variables - information that can be
found on our web site.
Ron Stouffer
Keith Dixon
Jonathan Gregory
Mike Spelman
Bill Hurlin