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WACCM Tech Meeting 2/7/2008 and followup on 2/8/2008
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Present: R. Garcia, Hanli Liu, Doug Kinnison, Dan Marsh, Yaga Richter

Purpose: 

To discuss progress on new gw parameterization
To discuss WACCM3.5.7 setup for future runs under our CSL allocation 
Consider pros/cons of WACCM becoming part officially of CCSM

Summary:

(1) Gravity Wave Parameterization:

Currently testing the Charron+Manzini scheme for extratropical (frontal zone forced) 
gravity waves plus the Beres parameterization for convectively forced gravity waves.

This parameterization is designated Trsnob.X for "Tropospheric sources/no background
spectrum".  The current version is v.11, or Trsnob.11

Results for Trsnob.11 were shown by Yaga Richter.  In summary:

(a) good time-mean zonal-mean wind climatology
(b) reduced westerly bias in SH summer over Antarctica
(c) realistic summer mesopause altitude and temperature

however,

(d) ozone hole over Antarctica fails to develop fully in too high a proportion
of the years simulated (using 1990s chemistry); ascribable to too early termination
of cold temperatures in Antarctic lower stratosphere
(e) too little wintertime variability in NH.  No sudden warmings in 5 years even when
run with variable SSTs

Conclusion:  additional tuning is necessary to correct undesirable features of this
simulation.

[See .pdf file associated with today's meeting showing results described above.]


(2) Running waccm3.5.7 for CSL simulations

After some debate, the following general consensus was reached:

(a) waccm3.5.7 will be used for all CSL simulations in 2008-2009
(b) run the model in the CCSM framework whether coupled or with specified SST/ocean ice;
this means that specified SST/ice runs would be made with a "data ocean" interacting
with the atmosphere through the CCSM coupler.  This was held to be desirable for consistency
between fully-coupled and specified SST-run. [However, see follow-up comments from Fabrizio
Sassi below]
(c) apply run configurations, environmental variables, etc. found to increase model
efficiency [see separate .txt file based on findings by Brian Eaton and experience by
R. Garcia, Y. Richter and F. Sassi]


(3) WACCM as part of CCSM

(a) Consensus needs to be developed prior to meeting of WACCM group with ESSL directors
on March 5, 2008
(b) General consensus at the present meeting was that it is politically important to
become part of CCSM:  greater visibility and better positioning for resources once NCAR
budget situation improves
(c) Drawbacks include making a formal commitment to CCSM structure, including organization
of working group meetings; designating chairs; and naming a community liaison  
[more comments on this issue below, from a follow-up talk with Peter Gent]

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Follow-up to some of these topics on 2/8/2008
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On topic (2): Fabrizio Sassi on running waccm3.5.7 with specified SST:

Fabrizio did not attend the meeting of 2/7/2007 because of illness.

R. Garcia spoke to him on 2/8/2007 about the possibility of running waccm3.5.7 with
specified SST as part of CCSM, specifying the SSTs as a "data ocean" through the ocean-
atmosphere coupler of CCSM.

Fabrizio believes that CAM3.5.7, upon which waccm3.5.7 is based, does not support this
functionality gracefully, so that it would not perform efficiently. It may be better
to do runs with specified SST using waccm3.5.7 as a "stand-alone" atmospheric model.

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On topic (3):  Conversation with Peter Gent (by R. Garcia and D. Marsh)

Peter agreed that the answer to the question of incorporating WACCM into CCSM and having 
a WACCM Working Group is not clearcut.

He recognized the political issues involved, and agreed that becoming an official part
of CCSM may be advantageous to WACCM in the long run, but noted the following:

--Under CCSM WACCM will need to organize WG meetings AND participate in the annual CCSM
meeting;
--A WACCM-WG would have to be approved by the CCSM Scientific Steering Committee (SSC)
--WACCM will need to designate a community liaison.  If there are no resources for hiring
someone to serve in this capacity, the responsibility devolves onto the WACCM-WG chairs;
--WACCM may not fare as well when competing for CSL resources if it is part of CCSM as
opposed to an independent entity (this is borne out by the results of the last two CSL
competitions);
--Agreed with D. Marsh that WACCM should seek to nominate one person to the CCSM Advisory
Board (CAB) familiar and interested in middle/upper atmosphere research;
--CCSM has no SE resources at the moment to dedicate to WACCM.  In addition, a WACCM-WG
implies some minor costs to CCSM (help in organizing an additional WG meeting; financial
support for WG chairs to attend WG and CCSM meetings);
--Nevertheless, Peter is willing to bring up the matter of a WACCM-WG at the next SSC 
meeting (March 2008)