From: David Rogers <dcrogers@lamar.ColoState.EDU>
Date: Wed, 16 Sep 1998 13:23:39 -0600 (MDT)
Subject: feedback, integrating field-lab-modeling

Dear IN-WG members,

Here are a few comments in response to Gabor's request for some feedback.

Gabor's summary notes of our lunch meeting are accurate and succinct.
Thanks, Gabor.  In regards to spreading the word to other researchers, I
passed along a brief description of the germinal ICE initiative to a few
people outside the U.S. who are interested in the activities of this
research, Margit Schwikowski, Jost Heintzenberg, Clive Saunders and
Masataka Murakami.  Margit and Jost are involved in research related to
the Eurotrac/Procloud-2 experiment (description -
http://www.gsf.de/eurotrac).  All four are interested in the topics and
collaborating with U.S. scientists.

Gabor's draft of discussion topics identifies the important issues. The
topic of integration was not formally addressed, and it may be worthwhile
to consider it.  By integration, I mean closely coordinating the field,
lab and modeling aspects of this research, ab initio, so as to focus the
power of these three different approaches on the salient parts of the
problem and to link them together.  It connects with Gabor's items 3, 4
and 7.

An obvious example is the wave cloud experiment, which will have an
aircraft field observation component.  A simulation type lab experiment is
appropriate for mimicking what the aircraft observes in the free
atmosphere, and the lab experiment should use the same range of
thermodynamic and dynamic (kinematic) conditions.  This is fairly obvious,
although it is not so obvious what to use for the lab aerosol.  There are
also advantages for having equivalent airborne and lab instrumentation.  
To insure the necessary observations are obtained in both lab and field
work, a list of required measurements and accuracies should be compiled.  
If the capability to obtain a required measurement does not exist, then it
should go on a priority list for development.

Likewise, the third component, modeling, must meet certain criteria. If
the ice nuclei measurements provide the temperature-dependent fraction of
freezing CCN active above 1% supersaturation, then the model should be
able to utilize this information.  The modeling could also impose some
criteria on the observations.  For example, if an important part of model
input includes CCN size distribution and solubility, then some way to
measure or deduce these quantities should be in place before the field or
lab experiments are performed.  Anyhow, that's what I had in mind with
"integration," and all of this should be tempered to the extent necessary
to achieve the "small victory."

Another thought about topic #4 concerns how to execute the wave cloud
field experiment.  It's easy to draw figures on paper, showing how the
aircraft follows streamlines, but executing this procedure may be a little
tougher.  Operational and navigational guidance are required and should be
built into the experimental procedures.  What about tracing the path of a
virtual aircraft in a simulated wave cloud?  Is that kind of exercise
useful, or needed?

Finally, my name appeared on topics 3 and 6, as a contributor to the
thinking and writing, with Harry and Al (respectively).  These assignments
are good for me.

  ..dave..


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Dave Rogers       Research Scientist
http://lamar.colostate.edu/~dcrogers