From: David Rogers <dcrogers@lamar.ColoState.EDU>
Date: Mon, 28 Sep 1998 10:31:43 -0600 (MDT)
Subject: ideas for wave cloud exp (topics W5, W6?)

Dear WG members-

I was writing up contributions for some of the working group topics and
thinking about how to perform the wave cloud experiment.  A couple of ideas 
came to mind for testing what we think we know about how to perform such 
an experiment and how particle nucleation and growth occur.  

Perhaps these ideas fit within topic W5 (What models could be used for
designing and evaluating the wave cloud experiment?) in the sense of
conceptual, not numercial, models.  Or maybe they fit W6 (What
laboratory experiments make sense as complements - in preparation and
in evaluation - to the field experiment?).  Or maybe this is outside
the scope of what we should be working on now.  Anyhow, it's food for 
thought -

  ..dave..

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For designing and evaluating the wave cloud experiment-

1. Glaciogenic cloud seeding.  How about generating a seeding plume and 
tracking it into and through the cloud?  It would test our ability to 
detect first ice, to discriminate the natural process from the artificial 
one, to detect nuclei that act primarily through known mechanisms (based on 
cloud chamber experiments), to track a parcel in a Lagrangian frame of 
reference, and to model these processes.  Several kinds of seeding could be 
used: dry ice in the ice-supersaturated/water sub-saturated upwind region, 
and some silver iodide complexes chosen to favor one nucleation mechanism. 

2. The same thing, but using a hygroscopic seeding agent instead.  The 
objectives of this experiment would be to examine our ability to measure 
the water cloud by detecting differences in the natural and seeded case, 
and to examine our ability to do the modeling.  The experiment could be 
done in a cloud too warm for significant ice production, but the cold case 
would be interesting too.  It would be a useful sequel to the ice 
experiment, in that CCN instrumentation on the aircraft should detect the 
CCN aerosol changes in the same way that IN instrumentation should detect 
IN and changes of IN.

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