[Dart-dev] [7355] DART/trunk/filter/filter.html: fix the description/ recommendation section for inflation damping,

[nancy at ucar.edu]

Revision: 7355
Author:   nancy
Date:     2015-01-08 13:15:19 -0700 (Thu, 08 Jan 2015)
Log Message:
-----------
fix the description/recommendation section for inflation damping,
which wrongly described it as only applying when the state space inflation
was time-varying.  in fact it applies for any state space inflation
type. it is generally expected to be most useful in the cases
where the inflation is time-evolving but any combination of
damping and state space inflation is legal.

Modified Paths:
--------------
    DART/trunk/filter/filter.html

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Modified: DART/trunk/filter/filter.html
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--- DART/trunk/filter/filter.html	2015-01-08 16:52:37 UTC (rev 7354)
+++ DART/trunk/filter/filter.html	2015-01-08 20:15:19 UTC (rev 7355)
@@ -481,18 +481,20 @@
 <em>&amp;filter_nml :: inf_damping</em><br />
 valid values: 0.0 to 1.0
 <dd>
-Applies if inflation is time-evolving.
+Applies to all state-space inflation types, but most frequently
+used with time-adaptive inflation variants.
 The difference between the current inflation value and 1.0 
 is multiplied by this factor before the next assimilation cycle. 
 0.0 turns all inflation off by clamping the inflation value to 1.0.
 1.0 turns damping off by leaving the original inflation value unchanged.
-We have had good results in large geophysical models setting
-this to a value of 0.9, which damps slowly.  Damping appears to
+We have had good results in large geophysical models using 
+time- and space-adaptive state-space inflation and setting the
+damping to a value of 0.9, which damps slowly.  Damping appears to
 particularly help in cases where there are dense clusters of observations
 at irregular times.  Areas that are heavily observed evolve
-large inflation values to prevent the ensemble members from becoming
-too close to one another.  However once the area is unobserved 
-there was no mechanism to cause the inflation values to drop 
+large inflation values to prevent the ensemble members from losing
+too much spread. However if then the area is unobserved for some
+period of time there was no mechanism to force the inflation values to drop 
 back down to smaller levels.  The damping factor accomplishes this.
 <br /> <br />
 <dt>