DQRID : D970318.2
Start DateStart TimeEnd DateEnd Time Data Quality Metric
03/07/1997142703/07/19971427Suspect
more
Subject:
Questionable RH
DataStreams:sgpsondewrpnC1.a1
Description:
DQR No:                               Platform: sgpsondeC1

Subject: Questionable RH: sounding C1 03/07/97:1427

Date Submitted:  3/18/97
Submitted By:                         _X_  Instrument Mentor
                                      ___  EST Member
                                      ___  Science Team Member
                                      ___  Other - Site Ops
 
For questions or problems, please contact the ARM Experiment Center at
509-375-6898 or via email at dqr@arm.gov.

Platform/Measurement: sgpsondewrpnC1.A1/all
    What level data: (raw,a0,a1,b1,c1 etc):

    What location was the data collected at:  CF
 
    Period of time in question
        Begin Date  03/07/97   Time 14:27      (GMT)
        End Date               Time            (GMT)

 Data should be labeled:
 _X__  questionable                      _?_  All data fields affected
 _X__  incorrect                         _X_  Only some data fields affected
 _?_  wrong calibration
 ___  others 
 
 Discussion of Problem:

David Cook pointed out that the RH values for the subject sounding disagree
substantially with values reported at the 60m tower.  Review of the sounding
data shows saturation (100%) values reported at the surface and during
most of the sounding.  The site ops log shows RH values of between 68% (1400) 
and 52% (1500) at the surface.  Surface temperature (8.4) and pressure (983.0)
obtained from the sonde are not substantially different from the surface
observations (7.8/10.8) and (982.7/982.4) at 1400 and 1500 respectively, so
it is unlikely that an incorrect calibration tape was used for the sonde.
I think the conclusion must be that the RH sensor on this sonde was bad.

As an operational issue, this sonde should have been rejected by site ops
because the surface RH value of 100% is more than 7% different than the surface
value obtained from an independent reference instrument.  I will check the 
procedures that I have provided to site ops to be sure that I included this
criterion.  
 
Other observations/measurements impacted by this problem:

None

Suggested Corrections of the Problem: (e.g. change calibration factor and
recompute, flag data with this comment, etc.)

Flag data.
Suggestions: 
Flag Data.
Measurements:sgpsondewrpnC1.a1:
  • v_wind
  • wstat
  • lat
  • base_time
  • alt
  • dp
  • tdry
  • lon
  • deg
  • asc
  • rh
  • wspd
  • u_wind
  • time_offset
  • pres
more

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