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.

• Raw data stream - documentation not supported

• Raw data stream - documentation not supported

• Dry Bulb Temperature(tdry)
• Dewpoint Temperature(dp)
• Humidity, relative(rh)

• Dry Bulb Temperature(tdry)
• Dewpoint Temperature(dp)
• Humidity, relative(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)
• Dewpoint Temperature(dp)

• Dry Bulb Temperature(tdry)
• Dewpoint Temperature(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)
• Dewpoint Temperature(dp)

• Dry Bulb Temperature(tdry)
• Dewpoint Temperature(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)
• Dewpoint Temperature(dp)

• Dry Bulb Temperature(tdry)
• Dewpoint Temperature(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.

• alt
• Dry Bulb Temperature(tdry)
• Dewpoint Temperature(dp)
• Humidity, relative(rh)
• asc

• Dry Bulb Temperature(tdry)
• Dewpoint Temperature(dp)
• alt
• Humidity, relative(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.

• alt
• Dry Bulb Temperature(tdry)
• Dewpoint Temperature(dp)
• Humidity, relative(rh)
• asc

• Dry Bulb Temperature(tdry)
• Dewpoint Temperature(dp)
• alt
• Humidity, relative(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.

• alt
• Dry Bulb Temperature(tdry)
• Dewpoint Temperature(dp)
• Humidity, relative(rh)
• asc

• Dry Bulb Temperature(tdry)
• Dewpoint Temperature(dp)
• alt
• Humidity, relative(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.

• alt
• asc

• 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)
• Dewpoint Temperature(dp)
• Humidity, relative(rh)

• Dry Bulb Temperature(tdry)
• Dewpoint Temperature(dp)
• Humidity, relative(rh)

SGP/SONDE/C1 - Temperature sensor failure

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

• Water vapor, total integrated from radiosonde(integ_vap_sonde)
• integ_vap_sonde_direct

• Dry Bulb Temperature(tdry)
• Dewpoint Temperature(dp)
• Humidity, relative(rh)

• Dry Bulb Temperature(tdry)
• Dewpoint Temperature(dp)
• Humidity, relative(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.

• Humidity, relative(rh)
• Dry Bulb Temperature(tdry)

• Water vapor, total integrated from radiosonde(integ_vap_sonde)

• Dry Bulb Temperature(tdry)
• Dewpoint Temperature(dp)
• Humidity, relative(rh)

• Dry Bulb Temperature(tdry)
• Dewpoint Temperature(dp)
• Humidity, relative(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.

• Humidity, relative(rh)
• Dry Bulb Temperature(tdry)

• Water vapor, total integrated from radiosonde(integ_vap_sonde)

• Dry Bulb Temperature(tdry)
• Dewpoint Temperature(dp)
• Humidity, relative(rh)

• Dry Bulb Temperature(tdry)
• Dewpoint Temperature(dp)
• Humidity, relative(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.

• Humidity, relative(rh)
• Dry Bulb Temperature(tdry)
• alt

• Dewpoint Temperature(dp)
• Dry Bulb Temperature(tdry)
• asc
• alt
• Humidity, relative(rh)

• Dewpoint Temperature(dp)
• Humidity, relative(rh)
• asc
• Dry Bulb Temperature(tdry)
• alt

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.

• Dewpoint Temperature(dp)
• Humidity, relative(rh)

• Dewpoint Temperature(dp)
• Humidity, relative(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.

• Raw data stream - documentation not supported

• Dewpoint Temperature(dp)
• asc
• Pressure, atmospheric, constant value of model level, RUC model output(pres)
• Eastward Wind Component(u_wind)
• Dry Bulb Temperature(tdry)
• lon
• Mean Wind Speed(wspd)
• base_time
• Wind Direction(deg)
• Northward Wind Component(v_wind)
• time_offset
• lat
• alt
• wstat
• Humidity, relative(rh)

• lon
• Dewpoint Temperature(dp)
• Wind Direction(deg)
• wstat
• Humidity, relative(rh)
• Mean Wind Speed(wspd)
• asc
• Northward Wind Component(v_wind)
• alt
• lat
• Eastward Wind Component(u_wind)
• base_time
• time_offset
• Dry Bulb Temperature(tdry)
• 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.

• Raw data stream - documentation not supported

• Dewpoint Temperature(dp)
• asc
• Pressure, atmospheric, constant value of model level, RUC model output(pres)
• Eastward Wind Component(u_wind)
• Dry Bulb Temperature(tdry)
• lon
• Mean Wind Speed(wspd)
• base_time
• Wind Direction(deg)
• Northward Wind Component(v_wind)
• time_offset
• lat
• alt
• wstat
• Humidity, relative(rh)

• lon
• Dewpoint Temperature(dp)
• Wind Direction(deg)
• wstat
• Humidity, relative(rh)
• Mean Wind Speed(wspd)
• asc
• Northward Wind Component(v_wind)
• alt
• lat
• Eastward Wind Component(u_wind)
• base_time
• time_offset
• Dry Bulb Temperature(tdry)
• 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.

• Dewpoint Temperature(dp)
• Humidity, relative(rh)

• Dewpoint Temperature(dp)
• Humidity, relative(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.

• Dewpoint Temperature(dp)
• Humidity, relative(rh)

• Dewpoint Temperature(dp)
• Humidity, relative(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)
• Dewpoint Temperature(dp)
• Humidity, relative(rh)

• Dry Bulb Temperature(tdry)
• Dewpoint Temperature(dp)
• Humidity, relative(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)
• Dewpoint Temperature(dp)
• Humidity, relative(rh)

• Dry Bulb Temperature(tdry)
• Dewpoint Temperature(dp)
• Humidity, relative(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)
• Dewpoint Temperature(dp)
• Humidity, relative(rh)

• Dry Bulb Temperature(tdry)
• Dewpoint Temperature(dp)
• Humidity, relative(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.

• Dewpoint Temperature(dp)
• Humidity, relative(rh)

• Dewpoint Temperature(dp)
• Humidity, relative(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.

• Raw data stream - documentation not supported

• Dewpoint Temperature(dp)
• asc
• Pressure, atmospheric, constant value of model level, RUC model output(pres)
• Eastward Wind Component(u_wind)
• Dry Bulb Temperature(tdry)
• lon
• Mean Wind Speed(wspd)
• base_time
• Wind Direction(deg)
• Northward Wind Component(v_wind)
• time_offset
• lat
• alt
• wstat
• Humidity, relative(rh)

• lon
• Dewpoint Temperature(dp)
• Wind Direction(deg)
• wstat
• Humidity, relative(rh)
• Mean Wind Speed(wspd)
• asc
• Northward Wind Component(v_wind)
• alt
• lat
• Eastward Wind Component(u_wind)
• base_time
• time_offset
• Dry Bulb Temperature(tdry)
• 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)

• 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.

• Humidity, relative(rh)
• lat
• Pressure, atmospheric, constant value of model level, RUC model output(pres)
• Dry Bulb Temperature(tdry)
• alt
• time_offset
• lon
• base_time

• Raw data stream - documentation not supported

• Dewpoint Temperature(dp)
• asc
• Pressure, atmospheric, constant value of model level, RUC model output(pres)
• Eastward Wind Component(u_wind)
• Dry Bulb Temperature(tdry)
• lon
• Mean Wind Speed(wspd)
• base_time
• Wind Direction(deg)
• Northward Wind Component(v_wind)
• time_offset
• lat
• alt
• wstat
• Humidity, relative(rh)

• lon
• Wind Direction(deg)
• Dewpoint Temperature(dp)
• wstat
• Humidity, relative(rh)
• Mean Wind Speed(wspd)
• asc
• Northward Wind Component(v_wind)
• alt
• lat
• base_time
• Eastward Wind Component(u_wind)
• time_offset
• Dry Bulb Temperature(tdry)
• 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)
• Dewpoint Temperature(dp)
• Humidity, relative(rh)

• Dry Bulb Temperature(tdry)
• Dewpoint Temperature(dp)
• Humidity, relative(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)
• Dewpoint Temperature(dp)
• Humidity, relative(rh)

• Dry Bulb Temperature(tdry)
• Dewpoint Temperature(dp)
• Humidity, relative(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)
• Dewpoint Temperature(dp)
• Humidity, relative(rh)

• Dry Bulb Temperature(tdry)
• Dewpoint Temperature(dp)
• Humidity, relative(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)
• Dewpoint Temperature(dp)
• Humidity, relative(rh)

• Dry Bulb Temperature(tdry)
• Dewpoint Temperature(dp)
• Humidity, relative(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.

• Dewpoint Temperature(dp)
• Humidity, relative(rh)

• Dewpoint Temperature(dp)
• Humidity, relative(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)
• Dewpoint Temperature(dp)
• Humidity, relative(rh)

• Dry Bulb Temperature(tdry)
• Dewpoint Temperature(dp)
• Humidity, relative(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)
• Dewpoint Temperature(dp)

• Dry Bulb Temperature(tdry)
• Dewpoint Temperature(dp)

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)
• Dewpoint Temperature(dp)
• Humidity, relative(rh)

SGP/SONDE/C1 - Bad RH Data

The RH values during the first half 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.

• Dewpoint Temperature(dp)
• Humidity, relative(rh)

SGP/SONDE/C1 - Bad RH Data

The RH values during the first part of this sounding oscillate between reasonable values 
and near-zero values.  The oscillation seems to be related to failure of the RH sensor 
heating process.

• Dewpoint Temperature(dp)
• Humidity, relative(rh)

SGP/SONDE/C1 - Surface pressure incorrect

I think the operator inadvdertently transposed to digits when entering the surface 
pressure value.  The value entered is 987.0 hPa but the value shown in the raw data file at 
launch is 978.0.  As a result, the absolute altitudes in this sounding will be slightly 
incorrect as will be the ascent rate during the first 30 seconds of flight.

• alt
• asc

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)
• Dewpoint Temperature(dp)
• Humidity, relative(rh)

SGP/SONDE/C1 - Broken temperature sensor

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

• Dry Bulb Temperature(tdry)
• Dewpoint Temperature(dp)
• Humidity, relative(rh)

SGP/SONDE/C1 - Temperature sensor broke high into the sounding

The temperature sensor on this radiosonde appeared to break 56 minutes and 22 seconds into 
the sounding at an altitude of 16570 m.  All the data below this point are good; only 
the data above this point to the end of the sounding (88 minutes and 14 seconds) are bad.

• Dry Bulb Temperature(tdry)
• Dewpoint Temperature(dp)
• Humidity, relative(rh)

SGP/SONDE/C1 - Incorrect surface temperature

The operator entered a the surface temperature incorrectly on this sounding.  The sonde 
data file shows the temperature as 33.5 degC but the operations log shows it as 3.5 degC.  
The first temperature recorded by the sonde after launch is 3.7 degC, consistent with the 
typical early morning inversion.

• Dry Bulb Temperature(tdry)
• Dewpoint Temperature(dp)
• Humidity, relative(rh)

SGP/SONDE/C1 - Scheduled Soundings Missed

The following scheduled sonde launches were missed due to computer 
system failures:

20040116.2330
20040117.0530
20040117.1130
20040117.1730
20040118.0530
20040121.0530

• Raw data stream - documentation not supported

• Dewpoint Temperature(dp)
• Dry Bulb Temperature(tdry)
• lon
• Mean Wind Speed(wspd)
• base_time
• asc
• Pressure, atmospheric, constant value of model level, RUC model output(pres)
• Wind Direction(deg)
• Northward Wind Component(v_wind)
• lat
• time_offset
• alt
• wstat
• Humidity, relative(rh)
• Eastward Wind Component(u_wind)

SGP/SONDE/C1 - Possibly bad pressure sensor or operator data entry error

There is a discrepency between the surface pressure and temperature data entered by the 
operator and that recorded by the THWAPS.  Review of the raw data from the radiosonde shows 
that the pressure was periodically varying by as much as 12 hPa (~988 to 1000)in the 
time period before launch.  The operator entry of 998.2 is at the high end of this range - 
the concurrent THWAPS reading was about 988.4 at the low end.  The operator entered 
temperature 6.2 degC is considerably higher than the THWAPS value of 1.8.  The pre-flight log 
entry for this sounding is missing from the OMIS database.  If not for the extremely 
unstable pressure reading I would have assumed this was an operator error.  It will take some 
more research to figure out what is going on.

• Dewpoint Temperature(dp)
• Dry Bulb Temperature(tdry)
• lon
• Mean Wind Speed(wspd)
• base_time
• asc
• Pressure, atmospheric, constant value of model level, RUC model output(pres)
• Wind Direction(deg)
• Northward Wind Component(v_wind)
• lat
• time_offset
• alt
• wstat
• Humidity, relative(rh)
• Eastward Wind Component(u_wind)

SGP/SONDE/C1 - Surface pressure incorrect

I think the operator inadvdertently entered an incorrect surface pressure value.  The 
value entered is 988.8 hPa but the value shown in the raw data file at launch is 968.8.  As a 
result, the absolute altitudes in this sounding will be slightly incorrect as will be 
the ascent rate during the first 30 seconds of flight.

• alt
• asc

SGP/SONDE/C1 - Surface pressure bad and other data noisy

I was checking this sounding because the surface pressure entered by the operator was 
considerably higher than that recorded by the TWHAPS and SMOS.  I'm not sure why, but the 
pressure data are very noisy while the sonde is on the ground (which accounts for the 
incorrect surface pressure) and the RH data aloft do not look terrible but do not look great 
either.

• Dewpoint Temperature(dp)
• Dry Bulb Temperature(tdry)
• lon
• Mean Wind Speed(wspd)
• base_time
• asc
• Pressure, atmospheric, constant value of model level, RUC model output(pres)
• Wind Direction(deg)
• Northward Wind Component(v_wind)
• lat
• time_offset
• alt
• wstat
• Humidity, relative(rh)
• Eastward Wind Component(u_wind)

SGP/SONDE/C1 - Surface pressure incorrect

I think the operator inadvdertently typed an 89 instead of a 78 when entering the surface 
pressure value.  The value entered is 989.9 hPa but the value shown in the raw data file 
at launch is 978.9.  As a result, the absolute altitudes in this sounding will be 
slightly incorrect as will be the ascent rate during the first 30 seconds of flight.

• alt
• asc

SGP/SONDE/C1 - Surface pressure incorrect

I think the operator inadvdertently mistyped a digit when entering the surface pressure 
value.  The value entered is 975.6 hPa but the value shown in the raw data file at launch 
is 972.6.  As a result, the absolute altitudes in this sounding will be slightly incorrect 
as will be the ascent rate during the first 30 seconds of flight.

• alt
• asc

SGP/SONDE/C1 - Bad RH Data

The RH values below 6 km are incorrect.  The problem relates to a failure of the GC25 
ground check set used before this particular sounding.  The failure seems to have affected 
the sensor calibration with the effect that one of the two sensors was reading artificially 
high.  Because the internal processing software uses the highest of the two sensor 
readings, the bad sensor value is chosen whenever it is not heated.

• Dewpoint Temperature(dp)
• Humidity, relative(rh)

SGP/SONDE/C1 - Bad T/RH and surface P.

Apparently multiple failures.  The radiosonde temperature sensor broke on launch causing 
an approximate 35 degC negative offset and as a result, the RH is incorrect.  Furthermore, 
it appears that the pressure sensor was off by approximately 4 hPa, though this would 
not affect the altitude calculation, the absolute pressure is wrong.

• Dry Bulb Temperature(tdry)
• Humidity, relative(rh)
• Pressure, atmospheric, constant value of model level, RUC model output(pres)

SGP/SONDE/C1 - Temperature/RH incorrect

The temperature throughout this sounding is too high and as a result the RH values will be 
incorrect as well.  I'm not sure what is wrong here but the operators noted reasonable 
values (18.1 degC, 87%) in the log before launch.  Review of the raw data, however, shows 
the sonde reporting temperatures nearly 20 degC higher.  I suppose it is possible that 
the operator entered into the log the reference temperature from the GC25 ground check set 
rather than the temperature reported by the sonde - I can't think of any other 
explanation - there is no doubt that the temperature sensor on this sonde was bad.

• Humidity, relative(rh)
• Dry Bulb Temperature(tdry)

• Dry Bulb Temperature(tdry)
• Dewpoint Temperature(dp)
• Humidity, relative(rh)

SGP/SONDE/C1 - Bad RH Data

The RH values during this sounding oscillate between reasonable values and near-zero 
values.  The oscillation is due to failure of the RH sensor heating process.

• Dewpoint Temperature(dp)
• Humidity, relative(rh)

SGP/SONDE/C1 - Sonde RH values incorrect

RH values for all sondes launched during this time were incorrect due to a faulty Ground 
Check set which damaged or conditioned the RH sensor improperly.

• Dewpoint Temperature(dp)
• Humidity, relative(rh)

SGP/SONDE/C1 - Mixed use of RS92-SGP and RS92-KL radiosondes

Because of a manufacturer's production problem, we will be using both RS92-SGP (GPS 
windfinding and RS92-KL (Loran windfinding) radiosondes at the SGP/CF starting February 10, 
2006.  The radiosonde type used for the each sounding may be determined by looking the 
metadata variable "launch_status" in the netCDF data files.

• wstat
• lon
• Mean Wind Speed(wspd)
• Wind Direction(deg)
• Northward Wind Component(v_wind)
• lat
• Eastward Wind Component(u_wind)

SGP/SONDE/C1 - Soundings done as part of dual-sonde flights

The following soundings done during the subject time period were flown in dual-sonde mode 
in which the standard ARM RS92 radiosonde was attached to the same balloon with a NASA 
ATR (atmospheric temperature reference) radiosonde.  The radiosondes were separated by a 6' 
styrofoam bar.  To accommodate the additional weight, we used 1200g balloons rather than 
350g balloons.  Accordingly, we want to alert users that these soundings may reach 
higher altitudes than normal for ARM soundings and that the ascent rate may be somewhat 
higher.  The following soundings are affected:

Sequence  Date    UTC launch time
    1     2/22        0530
    2     2/22        1730
    3     2/22        2330 <---- No data: launch failure    
    4     2/23        0230
    5     2/23        0530
    6     2/23        1730    
    7     2/23        2030
    8     2/23        2330
    9     2/24        2330
   10     2/25        0215
   11     2/25        0509    
   12     2/25        1730
   13     2/25        1930
   14     2/25        2300

• Dewpoint Temperature(dp)
• Dry Bulb Temperature(tdry)
• lon
• Mean Wind Speed(wspd)
• base_time
• asc
• Pressure, atmospheric, constant value of model level, RUC model output(pres)
• Wind Direction(deg)
• Northward Wind Component(v_wind)
• lat
• time_offset
• alt
• wstat
• Humidity, relative(rh)
• Eastward Wind Component(u_wind)

SGP/SONDE/C1 - DigiCORAIII failed, replaced with S01/S02 launches

The digiCORA-III failed on Saturday 2004-01-17.  The operators reported that they were 
unable to load the software and conduct normal soundings.	Following procedure, they 
conducted the regular soundings by using the S01/S02 systems as allowed by the AIRS IOP schedule.
The netCDF header fields "input_source" and "facility_id" will mention which of the 
S01/S02 systems was used in these launches.

• Raw data stream - documentation not supported

• alt
• lon
• lat

SGP/SONDE/C1 - No Wind/Lat/Lon Data in Sonde Files

The wind finding hardware failed so that no wind or latitude/longitude data was collected 
on the launches for these days.

• wstat
• lon
• Mean Wind Speed(wspd)
• Northward Wind Component(v_wind)
• lat
• Eastward Wind Component(u_wind)

SGP/SONDE/C1 - RH values offset due to error in ground check

Background: After installation of the latest software update , we began performing formal 
ground checks on RS92 radiosondes.  By comparing the
radiosonde readings with reference values in a controlled environment, the
ground check is intended to ensure that the radiosonde sensors are in
calibration before launch.  The radisonde values during the ground check
process are recorded automatically; the reference values are entered by the
operator.  If the radiosonde readings vary from the reference values, the
system 'corrects' the radiosonde values.  In the case of RH, the correction
is applied as an offset (true RH = indicated RH + correction).

Problem: Some operators misunderstood the ground-check procedure and entered the 
radiosonde values of RH rather than the reference value (assumed 0%RH), thus, some soundings done 
during this period have RH values that are different from what they would be if the 
ground check procedure had been done correctly.

Consequence:  Because the RH corrections generally are small (averaging
about 0.5% RH) and the precision of the reported RH data during this time
period is 1% RH, some values will not be affected at all; others will be off by about 1% 
RH (still within the stated accuracy of the sensor). 
Furthermore, because entering the radiosonde value as the reference value
results in a near zero 'correction,' one may view these soundings as being
done without the ground check correction.  Also note that the dew point
value will be suspect as well.

I am attaching below a listing of the soundings that were affected during the indicated 
time period.  Users can see the magnitude of the problem and choose whether or not to apply 
an offset in RH.  Note that application of the offset to the processed RH data (in the 
netCDF file) will not have the same effect of applying the correction to the absolutely 
raw data (before processing), but the differences should be insignificant.  Also note that 
the corrections for each sounding are included in the netCDF header information.  These 
attributes are named 'humidity_correction' and 'humidity_correction_2'.  The values of RH 
indicated by the radiosonde while it is in the ground check set are in attributes 
'humidity_gc_sonde' and 'humidity_gc_sonde_2.'  There is an RH reading for each of the two RH 
sensors used in the RS92 radiosonde.

Here is the list - RH1 and RH2 are the radiosonde readings in the ground
check set.  Ref is the reference value entered by the operator.  The
correcte reference value should be 0%.  To obtain an approximation to the RH value that 
would have been recorded if the ground check had been done
properly, subtract the Ref value from the indicated RH.

 YYYYMMDD  HHMM  SerialN      RH1     RH2     Ref
 20060827  2332  B2624322    1.00    1.00    1.00
 20060828  1731  B2634078    1.00    1.00    1.00
 20060828  2332  B2624380    3.00    3.00    2.00
 20060909  2331  B2615266    1.00    1.00    1.00
 20060915  1759  B2914012    1.00    1.00    1.00
 20060919  2350  B2825128    1.00    1.00    1.00
 20060920  1800  B2825088    1.00    1.00    1.00
 20060920  2346  B2815633    1.00    1.00    1.00
 20060921  1728  B2834732    1.30    1.30    1.30
 20060921  2330  B2825042    1.50    1.50    1.50
 20060922  0527  B2825043    1.70    1.80    1.70
 20060922  1128  B2825031    1.60    1.50    1.60
 20060922  1729  B2834437    1.50    1.50    1.50
 20060922  2330  B2825040    0.40    0.50    0.50
 20060923  0529  B2834733    0.30    0.30    0.30
 20060923  1128  B2825026    0.40    0.40    0.40
 20060923  1729  B2825064    0.60    0.70    0.60
 20060923  2330  B2825041    0.40    0.50    0.50
 20060924  0529  B2825039    0.30    0.30    0.30
 20060924  1729  B2825025    0.20    0.30    0.20
 20060924  2329  B2825032    0.30    0.40    0.40
 20060925  0529  B2824234    0.20    0.30    0.20

• Dewpoint Temperature(dp)
• Humidity, relative(rh)

SGP/SONDE/C1 - Increased precision for alt, dp, pres, rh, tdry

The output precision of the following variables was increased 20060928

alt  changed from 1m to 0.1m
dp   changed from 0.1degC to 0.01degC
pres changed from 0.1 hPa to 0.01 hPa
RH   changed from 1%RH to 0.01%RH
tdry changed from .1degC to 0.01degC

Note that the increase in precision does not necessarily imply an increase in accuracy.  
Users are cautioned to continue to use their best scientific judgement when using these or 
any other data.

• alt
• Dry Bulb Temperature(tdry)
• Dewpoint Temperature(dp)
• Humidity, relative(rh)
• Pressure, atmospheric, constant value of model level, RUC model output(pres)

SGP/SONDE/C1 - RH Sensor failure

The differences between the two RH sensors on this sonde are unreasonably high (~20%).  As 
a result the reported RH values oscillate by this amount during the times the sensors 
are alternately heated.  After the heating stops, the reported RH comes from the sensor 
reading the higher value.  There is no way of knowing if this is the correct value.

• Dewpoint Temperature(dp)
• Humidity, relative(rh)

SGP/SONDE/C1 - Suspect RH profile from 150-350 m above ground level

Several radiosondes were noticed to have a very stark dry layer between 150 m and 350 m, 
where the RH dropped from approximately 60-80% (which I would take as close to the ambient 
conditions) to less than 2%.  The character of these dropouts look like instrument 
issues, as it only a handful of radiosondes that appear to be affected.  The quicklook images 
from the Raman lidar does not show any very dry layers, thus supporting the hypothesis 
that the RH measurements from these radiosondes (at least in this small ~200 m level) are 
in error.  I should note that the temperature profiles look normal.

• Dewpoint Temperature(dp)
• Humidity, relative(rh)

SGP/SONDE/C1 - Suspect RH values

RH values only are suspect for the duration of this radiosonde flight, exhibiting a 
"sawtooth" pattern.

• Humidity, relative(rh)

SGP/SONDE/C1 - Sensor failure

Temperature sensor failure on sonde.  Data is incorrect, do not use.

• Dewpoint Temperature(dp)
• Dry Bulb Temperature(tdry)
• lon
• Mean Wind Speed(wspd)
• base_time
• asc
• Pressure, atmospheric, constant value of model level, RUC model output(pres)
• Wind Direction(deg)
• Northward Wind Component(v_wind)
• lat
• time_offset
• alt
• wstat
• Humidity, relative(rh)
• Eastward Wind Component(u_wind)