TWP/SONDE/C2  - Broken Temperature Sensor

The temperature sensors on these radiosondes broke at launch.  All
the temperature-related data are incorrect.

• Humidity, relative, at 21-m height, 30-min avg(rh)
• Dewpoint Temperature(dp)
• Dry bulb temperature(tdry)

TWP/SONDE/C2 - Bad RH Data (AIRS Validation Sonde)

The RH sensor heating circuit failed on this sonde.  This results in
oscillation of reported RH between reasonable values and values near zero.
This was an AIRS validation sounding.

• Humidity, relative, at 21-m height, 30-min avg(rh)
• Dewpoint Temperature(dp)

TWP/SONDE/C2  - Failure of RH sensor

It appears that the RH sensor heating circuit failed during this sounding.  The RH 
oscillates rapidly between low (~0 %RH) and not so low (ambient %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, at 21-m height, 30-min avg(rh)
• Dewpoint Temperature(dp)

TWP/SONDE/C2 - Strange problem with data -

This is very strange.  The data has what appears to be a pressure jump at launch (from 
1007.2 to 956.5 hPa) but the sounding temperature and RH data clearly look to be 
interpolated between the surface and tropopause.  By examining the absolutely raw data, I found that 
the system assigned an elapsed time of 408 seconds (since system start up) to the launch 
point, but there is no raw data between 410 and 532 seconds.  The raw pressure value at 
410 seconds is 1007.6 hPa and that at 532 seconds is 40.9 hPa!  Unless this sounding was 
done by using a rocket-powered balloon (maybe even then), it would be impossible for the 
sonde to get to 40.9 hPa in 2 minutes.  Because the apparent gap is only two minutes, the 
system was able to interpolate but is not sophisticated enough to understand that the 
limits of the interpolation are unreasonable.

I can't imagine what went wrong - I've not seen anything like this before.

• East longitude(lon)
• Wind speed, W-to-E component, at altitude, 915 MHz RWP(u_wind)
• Wind speed, S-to-N component, at altitude, derived from ETA model(v_wind)
• asc
• Humidity, relative, at 21-m height, 30-min avg(rh)
• Dewpoint Temperature(dp)
• base_time
• time_offset
• wstat
• Wind Direction(deg)
• Altitude above mean sea level(alt)
• Wind speed, surface, 1-min avg(wspd)
• Pressure, atmospheric, constant value of model level, RUC model output(pres)
• North latitude(lat)
• Dry bulb temperature(tdry)

TWP/SONDE/C2 - RH sensor bad

It appears that the RH sensor heating circuits failed during these
soundings.  The RH oscillates rapidly between low (~0 %RH) and not
so low (ambient %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, at 21-m height, 30-min avg(rh)
• Dewpoint Temperature(dp)

TWP/SONDE/C2 - Broken temperature sensors

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

• Humidity, relative, at 21-m height, 30-min avg(rh)
• Dewpoint Temperature(dp)
• Dry bulb temperature(tdry)

TWP/SONDE/C2  - Questionable rH data

It appears that the RH sensor heating circuit failed during this sounding.  The RH 
oscillates rapidly between low (~0 %RH) and not so low (ambient %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, at 21-m height, 30-min avg(rh)
• Dewpoint Temperature(dp)

TWP/SONDE/C2  - Bad RH sensor

It appears that the RH sensor heating circuit failed during this sounding.  The RH 
oscillates rapidly between low (~0 %RH) and not so low (ambient %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, at 21-m height, 30-min avg(rh)
• Dewpoint Temperature(dp)

TWP/SONDE/C2 - Bad RH values aloft

It appears that the RH sensor heating circuit on this sonde failed about 24 minutes into 
the flight.  The RH values look reasonable, though somewhat noisy, from the surface to 
approximately 6.9 km (439 hPa) at which point they begin to oscillate between 0 and 100 %.  
This behavior stops when the sonde reaches approximately 11.5km (232 hPa) 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, at 21-m height, 30-min avg(rh)
• Dewpoint Temperature(dp)

TWP/SONDE/C2  - RH sensor failure near surface

It appears that the RH sensor heating circuit failed during this sounding.  The RH 
oscillates rapidly between low (~0 %RH) and not so low (ambient %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, at 21-m height, 30-min avg(rh)
• Dewpoint Temperature(dp)

TWP/SONDE/C2 - Operator used wrong calibration tape

It appears as though the opperator used the wrong calibration tape for this sounding.  The 
primary symptom is a jump in temperature from a surface value of 30.1 degC to the first 
value aloft of 61.0 degC.  Secondly, the recorded serial number for this sounding is 
Z1430179 which is the same serial number recorded for the previous sounding.

This problem points to three failures of procedure (I have notified TWP site ops by 
e-mail).  The first failure is using the wrong tape. The second failure is not checking the 
radiosonde values before launch which relates to the third failure of not entering the 
radiosonde values as the surface values of the sounding.

• East longitude(lon)
• Wind speed, W-to-E component, at altitude, 915 MHz RWP(u_wind)
• Wind speed, S-to-N component, at altitude, derived from ETA model(v_wind)
• asc
• Humidity, relative, at 21-m height, 30-min avg(rh)
• Dewpoint Temperature(dp)
• base_time
• time_offset
• wstat
• Wind Direction(deg)
• Altitude above mean sea level(alt)
• Wind speed, surface, 1-min avg(wspd)
• Pressure, atmospheric, constant value of model level, RUC model output(pres)
• North latitude(lat)
• Dry bulb temperature(tdry)

TWP/SONDE/C2  - RH sensor failure below 9km

It appears that the RH sensor heating circuit failed during this sounding.  The RH 
oscillates rapidly between low (~0 %RH) and not so low (ambient %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, at 21-m height, 30-min avg(rh)
• Dewpoint Temperature(dp)

TWP/SONDE/C2 - Bad RH values aloft

It appears that the RH sensor heating circuit on these sondes failed after launch but 
resume proper operation when the ambient temperature dropped below ~40 degC.

• Humidity, relative, at 21-m height, 30-min avg(rh)
• Dewpoint Temperature(dp)

TWP/SONDE/C2 - Bad RH sensor

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

• Humidity, relative, at 21-m height, 30-min avg(rh)
• Dewpoint Temperature(dp)

TWP/SONDE/C2 - Broken temperature sensor

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

• Humidity, relative, at 21-m height, 30-min avg(rh)
• Dewpoint Temperature(dp)
• Dry bulb temperature(tdry)

TWP/SONDE/C2  - Broken temperature sensor

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

• Humidity, relative, at 21-m height, 30-min avg(rh)
• Dewpoint Temperature(dp)
• Dry bulb temperature(tdry)

TWP/SONDE/C2 - Failure of RH sensor

The RH sensor ASIC that controls the sensor heating failed.  As a result the RH at the 
beginning of the sounding oscillates between near-zero and ambient values.  The RH heating 
cycle stops when the ambient temperature reaches below -30 degC; above this level RH 
values should be valid.

• Humidity, relative, at 21-m height, 30-min avg(rh)
• Dewpoint Temperature(dp)