Project #2001-161 EPIC 2001

Eastern Pacific Investigation of Climate Processes in the Coupled Ocean-Atmosphere System

Principal Investigators: David Raymond, et al.

NSF/NCAR EC-130Q Hercules (N130AR)

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Dew Point Sensor Dry Bias

From: Allen Schanot
Date: Thu, 11 Apr 2002 08:16:35 MDT
Subject: EPIC2001 C-130 Data

Through an independent calibration of the RAF dew point sensors, I have
confimred the dry bias in the C-130 humidity data.  I ran a multipoint
calibration using a Licor dewpoint generator which tests the system
as a whole, as opposed to the normal resistance box tests of the 
electronics.  The correction is in line with what we discovered via
the intercomparisons between the C-130, P-3 and Dropsondes.  The RAF
will re-run our production data set and replace the archived data.
We need to send out a project wide alert to let people know
about the change.  A great number of variables will be a affected by 
this change, many in very subtle ways.  Everyone should use only the 
new data set FOR ALL VARIABLES after the change occurs.  I expect to
have the new data set available by the end of next week (4/19/02).

Allen Schanot