SGP/SONDE/C1 - Bad temp (other?) data in 12/3/01:2328 sounding

It looks as though the temperature sensor was damaged on launch.  The
recorded temp goes from 16.4 at the surface to -42.6 at 2 seconds into the
flight.  The temperature never exceeds -42 though the RH and pressure look
reasonable, but probably should be considered questionable.

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

SGP/SONDE/C1 - Bad temperature in CF sounding 12/22/01:0527

The temperature data in this sounding look bad after the first value.  The
temperature series is 11.4, 2.6, -14.3, -32.4 in the first 6 seconds of
flight.  I don't know why this occurred, but it obviously is incorrect.
The pressure and RH data look reasonable.

• Dry Bulb Temperature(tdry)
• Temperature, dewpoint, at altitude(dp)

SGP/SONDE/C1 - Bad temperature data CF sounding 12/28/01:2326

The temperature data in this sounding are bad from approximately 16 seconds
into the flight.  The temperature series is 9.9, 10.8, 11.3, 1.5, 11.6, 11.6,
11.6, -32.2 and remains below -30 degC.  I don't know why this occurred, but
it clearly is incorrect.  The pressure data looks OK as does the RH, though
the RH data are missing (probably sensor failure) above roughly 3.5 km.

• Dry Bulb Temperature(tdry)
• Temperature, dewpoint, at altitude(dp)

SGP/SONDE/C1 - Bad temperature in SGP/CF sounding 20020108:0528

Temperature values in this sounding went from 3.5 degC at the surface to
-33.3 degC at the next sample.  It appears that all the remaining
temperature values have an approximate -35 degC offset.  The pressure
and RH values appear reasonable.

• Dry Bulb Temperature(tdry)
• Temperature, dewpoint, at altitude(dp)

SGP/SONDE/C1 - CF sounding 20020522:1130 bad temperature/RH

It appears that the sonde sensor boom was damaged upon launch.  The result
is that no RH data are reported and the reported temperature is something on
the order of 60 degC too low.

• Dry Bulb Temperature(tdry)
• Temperature, dewpoint, at altitude(dp)
• Altitude above mean sea level(alt)
• Humidity, relative, on hybrid-b grid, derived from RUC model(rh)
• asc

SGP/SONDE/C1 - Bad T/RH data in CF sounding 20020523:1129

It appears that the sensor boom was damaged shortly after launch.  The
temperature reading jumps -60 degC and the RH goes to 0.

• Dry Bulb Temperature(tdry)
• Temperature, dewpoint, at altitude(dp)
• Altitude above mean sea level(alt)
• Humidity, relative, on hybrid-b grid, derived from RUC model(rh)
• asc

SGP/SONDE/C1 - CF sounding 20020609:0229 bad temp/rh/etc

The temperature and RH for this sounding look bad, either because of
interference from another sonde or because the temperature sensor was
broken on launch.  The sounding terminated early in any event.

• Dry Bulb Temperature(tdry)
• Temperature, dewpoint, at altitude(dp)
• Altitude above mean sea level(alt)
• Humidity, relative, on hybrid-b grid, derived from RUC model(rh)
• asc

SGP/SONDE/C1 - Incorrect Surface Pressure

It appears that the operator made a typographical error when entering the
surface pressure.  The file has 987.0 hPa and it probably should be 978.0
which would be consistent with the first sample provided by the radiosonde
(977.3 hPa), the surface pressures recorded for the adjacent soundings, and
the THWAPS pressure.

Because the sounding altitude is calculated assuming the surface pressure
is correct, the altitude values for the entire flight and the ascent rate 
values for the first 30 seconds of the sounding will be incorrect.

• Altitude above mean sea level(alt)
• asc

SGP/SONDE/C1 - Bad Temperature Sensor

It appears that the temperature sensor broke shortly after launch.  As a
result, the temperature and dewpoint values are incorrect.

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

SGP/SONDE/C1 - Temperature sensor failure

Temperature sensor broke at launch.  All temperature-related variables
are incorrect.

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

SGP/SONDE/C1 - Bad Temperature Sensor

It appears that the temperature sensor broke upon launch and therefore the reported 
temperature is approximately 40 degC too low.

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

SGP/SONDE/C1 - Bad Temperature Sensor

It appears that the temperature sensor broke shortly after launch. Temperatures are offset 
by approxmiately (but not constantly) 40 degC.

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

Bad temperature sensor

It appears that the temperture sensor broke a few seconds into flight.  This results in an 
unreasonably low temperature for the rest of the flight.  For some reason, the rh values 
also go missing shortly after launch.  Only the wind and pressure data are reliable.

• Dry Bulb Temperature(tdry)
• Temperature, dewpoint, at altitude(dp)
• Altitude above mean sea level(alt)
• Humidity, relative, on hybrid-b grid, derived from RUC model(rh)
• asc

SGP/SONDE/C1 - Questionable RH: CF sounding 11/13/2002:2044

The RH data in this sounding is erratic between 2km and 10 km, oscillating between 
reasonable values (~40%RH) and zero.  I certainly doubt that this is a real, heretofore 
unreported, atmospheric phenomenon so I have to conclude that something is probably wrong with 
the sensor.  I have not seen this behavior before.  One would have to look at the 
absolutely raw RH data to explore further.

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

SGP/SONDE/C1 - Contaminated by interference

These three soundings are contaminated by interference from another radiosonde.  It is not 
clear why; this doesn't usually happen at the CF where the operators are very 
experienced and frequency separation is not usually a problem.

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

SGP/SONDE/C1 - Interference CF sounding 20021120:0225

Like several soundings on 11/19, this sounding was affected by interference from another 
radiosonde.

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

SGP/SONDE/C1 - Questionable RH CF sounding 0211211:1130

The RH samples in this sounding oscillate between reasonable values (60-80%) and zero.  
This may be a problem with the RH sensor or the software that alternates between the heated 
and non-heated RH elements.  In either case, the reported values are questionable.  More 
investigation of the raw binary data would be required to diagnose further.

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

SGP/SONDE/C1 - Bad RH Data

The RH values during the first 15 minutes of this sounding oscillate between reasonable 
values and near-zero values.  The oscillation is irregular and seems to be related to 
failure of the RH sensor heating process.  I have informed Vaisala of the problem and provided 
raw data files to them for analysis.

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

SGP/SONDE/C1 - Broken temperature sensor SGP/CF sounding

The radiosonde temperature sensor apparently broke during launch.  This results in bad 
temperature, dew point, and rh data.

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

SGP/SONDE/C1 - Bad temperature/RH

The temperature sensor broke shortly after launch.  All temperature and RH-related data 
are incorrect.

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

SGP/Sonde/C1 - Bad temperature, RH

These three soundings all show the effects of a temperature sensor broken at launch.  The 
temperature, RH, dew-point values all are incorrect.

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

SGP/Sonde/C1 - Bad RH in sounding

The RH sensor heating circuit was out of synch from about 400 sec after launch until the 
circuit was turned off whent he sounding temperature reached approximately 233 degK (-40 
degC) about 1500 sec after launch.  During this time period the reported RH oscillates 
between reasonable values and near-zero values.

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

SGP/Sonde/C1 - Sondes launched an hour early

It looks like someone forgot to set his/her clock ahead.  The sounding that should have 
been done at 23:30 UTC on 4/6 was done at 22:38 and the following sounding, which should 
have been done at 0530 on 4/7 was done at 04:31.  The subsequent soundings all are done at 
the correct times.

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

SGP/Sonde/C1 - Incorrect surface temperature on CF sounding

It appears that the operator entered an incorrect value for surface temperature.  Rather 
than 43.2 degC in the file, the value is most likely 19. degC (thwaps reading 19.4, first 
sonde reading aloft 18.6).

• Dry Bulb Temperature(tdry)

SGP/Sonde/C1 - Failed Sonde Launches due to Antenna problems

These sonde launches where unsuccessful due to problems
with the antenna configuration resulting in signal loss
before the launch.

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

SGP/SONDE/C1 - Broken Temperature Sensor

The temperature sensor broke shortly after launch as a result all variables that are 
affected by temperature are incorrect.

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

SGP/SONDE/C1 - Broken temperature sensor

The temperature sensor on this radiosonde broke after launch.  All temperature-related 
variables (dp, tdry, rh) are incorrect.

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

SGP/SONDE/C1 - Broken temperature sensors

The temperature sensors broke at launch on both of these soundings.  All of the 
temperature-related data (tdry, rh, dp) are incorrect.

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

SGP/SONDE/C1 - Broken temperature sensor

The temperature sensor broke at launch on this sounding.  All of the temperature-related 
data (tdry, rh, dp) are incorrect.

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

SGP/SONDE/C1 - Incorrect surface RH value.

The surface RH value, reported as 0%RH should be 52%.  This resulted from a typographical 
error by the operator when entering the surface data.

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

SGP/SONDE/C1 - Broken temperature sensor

The temperature sensor broke at launch on this sounding.  All of the temperature-related 
data (tdry, rh, dp) are incorrect.

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

SGP/SONDE/C1 - A few bad temperature values at the beginning of the sounding

I've never seen this before.  The temperature reported by the radiosonde dropped over 30 
degC just after launch (usually a symptom of a broken temperature sensor), but then 
recovered after 14 seconds of bad readings.  The temperatures from 2 seconds through 14 seconds 
after launch are incorrect, the remainder of the sounding looks fine.  I have sent the 
data files to Vaisala for their consideration.

• Dry Bulb Temperature(tdry)
• 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)