SGP/SONDE/B1 - Incorrect surface temperature

The operator entered 8.1 degC as the surface temperature for this sounding instead of -8.1 
degC.  This is the only value affected.

• Dry Bulb Temperature(tdry)

SGP/SONDE/B1 - Bad sounding data (incorrect calibration?)

I'm not sure what happened here but the temperature data for this sounding
clearly are wrong.  Along with the missing humidity data and the problems
the operator reported with his previous sounding it looks as if all the data
in this file are bad.  It may be that the sensor was damaged at launch (it
was very windy).

• Wind speed, S-to-N component, at altitude, derived from ETA model(v_wind)
• wstat
• Dry Bulb Temperature(tdry)
• time_offset
• base_time
• North latitude(lat)
• Humidity, relative, on hybrid-b grid, derived from RUC model(rh)
• Altitude above mean sea level(alt)
• Temperature, dewpoint, at altitude(dp)
• Pressure, atmospheric, constant value of model level, RUC model output(pres)
• East longitude(lon)
• Wind direction, at altitude(deg)
• Wind speed, W-to-E component, at altitude(u_wind)
• asc
• Wind speed, surface, 1-min avg(wspd)

SGP/SONDE/B1 - Temperature sensor failed

It appears that the temperature sensor on this sonde broke shortly after launch with the 
effect that the temperatures read approximately 30 degC too low.  Other measurements that 
do not rely on the temperature, for example pressure and wind velocity, should be OK.

• Temperature, dewpoint, at altitude(dp)
• Dry Bulb Temperature(tdry)
• Humidity, relative, on hybrid-b grid, derived from RUC model(rh)

TWP/SONDE/C1  - Broken Temperature Sensor

The temperature sensor on these radiosondes broke after launch.
All the temperature related data are incorrect.

• Humidity, relative, on hybrid-b grid, derived from RUC model(rh)
• Temperature, dewpoint, at altitude(dp)
• Dry Bulb Temperature(tdry)

TWP/Sonde/C1 - Bad RH Values

The RH values from the surface to approximately 11.5 km oscillate between reasonable 
values and zero.  This is apparently caused by a failure in the RH sensor heating process.  
Although the oscillation stops when the heating stops (at temperatures below ~ -45degC) I 
think the values must be viewed as suspect.

• Humidity, relative, on hybrid-b grid, derived from RUC model(rh)
• Temperature, dewpoint, at altitude(dp)

TWP/SONDE/C1 - Questionable RH

It appears that the RH sensor heating circuit failed during this portion of the sounding 
(approximately between 5km and 10km).  The RH oscillates rapidly between low (~5 %RH) and 
not so low (~50 %RH) and the oscillation seems to stop when the temperature is below ~35 
degC.  According to Vaisala these are symptoms of failure in the ASIC (application 
specific integrated circuit) that controls the heating.

• Humidity, relative, on hybrid-b grid, derived from RUC model(rh)
• Temperature, dewpoint, at altitude(dp)

TWP/SONDE/C1 - Bad RH

The RH sensor heating circuit failed on this radiosonde.  The RH-related values obtained 
between 0 and 10000 meters oscillate between near-zero and reasonable ambient values.  
Above 10000 the RH values are likely correct.

• Humidity, relative, on hybrid-b grid, derived from RUC model(rh)
• Temperature, dewpoint, at altitude(dp)

TWP/SONDE/C1 - Broken temperature sensor

The temperature sensor on this radiosonde broke after launch.  All the temperature-related 
data are incorrect.

• Humidity, relative, on hybrid-b grid, derived from RUC model(rh)
• Temperature, dewpoint, at altitude(dp)
• Dry Bulb Temperature(tdry)

TWP/SONDE/C1 - Broken temperature sensor

The temperature sensor on these radiosondes broke after launch
All the temperature-related data are incorrect.

• Humidity, relative, on hybrid-b grid, derived from RUC model(rh)
• Temperature, dewpoint, at altitude(dp)
• Dry Bulb Temperature(tdry)

TWP/SONDE/C1 - Bad RH sensors

It appears that the RH sensor heating circuit failed during this portion of the sounding 
(approximately between 0km and 12km).  The RH oscillates rapidly in a 20% range and the 
oscillation seems to stop when the temperature is below ~45 degC.  These are symptoms of 
failure in the ASIC (application specific integrated circuit) that controls the heating.

• Humidity, relative, on hybrid-b grid, derived from RUC model(rh)
• Temperature, dewpoint, at altitude(dp)

TWP/SONDE/C1 - Bad RH sensor

It appears that the RH sensor heating circuit failed during this portion of the sounding 
(approximately between the surface and 11km).  The RH oscillates rapidly between low (~0 
%RH) and high (~80 %RH) and the oscillation seems to stop when the temperature is below 
~40 degC.  According to Vaisala these are symptoms of failure in the ASIC (application 
specific integrated circuit) that controls the heating.

• Humidity, relative, on hybrid-b grid, derived from RUC model(rh)
• Temperature, dewpoint, at altitude(dp)

TWP/SONDE/C1 - Bad RH at beginning of sounding

It appears that the RH sensor heating circuit failed during this portion of the sounding 
(approximately between 0km and 11km).  The RH oscillates rapidly between low (~15 %RH) and 
not so low (~50 %RH) and the oscillation seems to stop when the temperature is below ~40 
degC.  According to Vaisala these are symptoms of failure in the ASIC (application 
specific integrated circuit) that controls the heating.

• Humidity, relative, on hybrid-b grid, derived from RUC model(rh)
• Temperature, dewpoint, at altitude(dp)

TWP/SONDE/C1 - Bad RH at beginning of sounding

It appears that the RH sensor heating circuit failed during this portion of the sounding 
(approximately between 0km and 11km).  The RH oscillates rapidly between low (~0 %RH) and 
not so low (~80 %RH) and the oscillation seems to stop when the temperature is below ~40 
degC.  According to Vaisala these are symptoms of failure in the ASIC (application 
specific integrated circuit) that controls the heating.

• Humidity, relative, on hybrid-b grid, derived from RUC model(rh)
• Temperature, dewpoint, at altitude(dp)

TWP/SONDE/C1  - Bad RH in short interval aloft

It appears that the RH sensor heating circuit on this sonde failed about 31 minutes into 
the flight.  The RH values look reasonable from the surface to approximately 8.25 km at 
which point they begin to oscillate between 0 and 40%.  This behavior stops when the sonde 
reaches approximately 11.0km when the air temperature drops below -40 degC.  The 
oscillation stops at that point, though the RH remains higher than might be expected even under 
supersaturated conditions.

• Humidity, relative, on hybrid-b grid, derived from RUC model(rh)
• Temperature, dewpoint, at altitude(dp)

TWP/SONDE/C1 - Bad RH at beginning of sounding

It appears that the RH sensor heating circuit failed during this portion of the sounding 
(approximately between 0km and 11km).  The RH oscillates rapidly between low (~2 %RH) and 
not so low (~90 %RH) and the oscillation seems to stop when the temperature is below ~40 
degC.  According to Vaisala these are symptoms of failure in the ASIC (application 
specific integrated circuit) that controls the heating.

• Humidity, relative, on hybrid-b grid, derived from RUC model(rh)
• Temperature, dewpoint, at altitude(dp)

TWP/SONDE/C1 - Bad RH at beginning of sounding

It appears that the RH sensor heating circuit failed during this portion of the sounding 
(approximately between 0km and 11km).  The RH oscillates rapidly between low (~1 %RH) and 
high (~80 %RH).  According to Vaisala these are symptoms of failure in the ASIC 
(application specific integrated circuit) that controls the heating.

• Humidity, relative, on hybrid-b grid, derived from RUC model(rh)
• Temperature, dewpoint, at altitude(dp)

TWP/SONDE/C1 - Bad RH at beginning of sounding

It appears that the RH sensor heating circuit failed during this portion of the sounding 
(approximately between 0km and 11km).  The RH oscillates rapidly between low (~5 %RH) and 
not so low (~70 %RH) and the oscillation seems to stop when the temperature is below ~40 
degC.  According to Vaisala these are symptoms of failure in the ASIC (application 
specific integrated circuit) that controls the heating.

• Humidity, relative, on hybrid-b grid, derived from RUC model(rh)
• Temperature, dewpoint, at altitude(dp)

TWP/SONDE/C1 - Bad RH at beginning of sounding

It appears that the RH sensor heating circuit failed during this portion of the sounding 
(approximately between 0km and 12km).  The RH oscillates rapidly between low (~2 %RH) and 
not so low (~80 %RH) and the oscillation seems to stop when the temperature is below ~40 
degC.  According to Vaisala these are symptoms of failure in the ASIC (application 
specific integrated circuit) that controls the heating.

• Humidity, relative, on hybrid-b grid, derived from RUC model(rh)
• Temperature, dewpoint, at altitude(dp)

TWP/SONDE/C1 - Surface RH value incorrect

The surface RH value of 77% when the value should have been in the low 60's.  It appears 
the observers did not allow the sonde to equilibrate to ambient conditions before 
collecting the surface data.  This error also caused the dew point to be incorrect.

• Humidity, relative, on hybrid-b grid, derived from RUC model(rh)
• Temperature, dewpoint, at altitude(dp)

TWP/SONDE/C1 - Wind data missing

A GPS problem associated with Vaisala BBSS ground station software issues caused the 
ground stations to enter into an error state when using GPS wind finding. In some instances, 
the flight was aborted due to the error state and not data was collected.  A workaround 
was developed to allow sondes to be launched without collecting wind data.

• Wind speed, S-to-N component, at altitude, derived from ETA model(v_wind)
• wstat
• Wind speed, W-to-E component, at altitude(u_wind)
• Wind speed, surface, 1-min avg(wspd)

TWP/SONDE/C1 - Reprocessing Notice (RID 1122)

See below for details of reprocessing that was completed on 20140708.  Original DQR 
category: 4 (Red, Incorrect).

-----------------------------------------------------------

The operator input an incorrect surface value for relative humidity.

The corrected raw and ptu files need to be reprocessed.

• Humidity, relative, on hybrid-b grid, derived from RUC model(rh)
• Temperature, dewpoint, at altitude(dp)

TWP/SONDE/C1 - Reprocessing Notice (RID 1126)

See below for details of reprocessing that was completed on 20140708.  Original DQR 
category: 4 (Red, Incorrect).

----------------------------------------------------------

Operator entered incorrect surface relative humidity value.

• Humidity, relative, on hybrid-b grid, derived from RUC model(rh)
• Temperature, dewpoint, at altitude(dp)

SGP/SONDE - Dry bias in sonde RH

Vaisala has confirmed ARM findings of an apparent dry bias in the
relative humidity measured by RS-80H radiosondes.  The cause of
the dry bias is thought to be contamination of the humidity sensor
by volatile organic substances originating from some plastic parts
of the radiosonde.  The amount of contamination is a function of
the time between the date of sonde manufacture and its use.  All
RS-80H sondes manufactured before week 34 of 1998 will show this
bias.  After week 34 of 1998 Vaisala changed its packaging to
reduce, but not eliminate the contamination problem.

Starting with RS-80 radiosonde manufactured in late June 2000 Vaisala
enclosed the sensor boom in an inert plastic shield, thereby eliminating
the contamination that caused the dry bias.

Starting in May 2001 at the SGP, May 2002 at the TWP, and later 2002
at the NSA, ARM has moved to using RS-90 radiosondes.  These sondes
are not subject to the contaminatino that caused the dry bias.

Vaisala is in the process of developing an algorithm that can be 
used to estimate the correct RH from knowledge of the sonde age.
All of the ARM sounding data have sufficient metadata available
to apply the correction.

Additionally, ARM has funded a Science Team effort (Milosevich) to
develop a 'best' correction algorithm for the RS-80 radiosonde humidity
data.  When completed this algorithm will allow us to reprocess the
accumulated RS-80 data and produce a new data platform with what we
hope will be more accurate data.

• Temperature, dewpoint, at altitude(dp)
• Humidity, relative, on hybrid-b grid, derived from RUC model(rh)