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.

• Relative humidity inside the instrument enclosure(rh)
• Surface dew point temperature(dp)

• Surface dew point temperature(dp)
• Relative humidity inside the instrument enclosure(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)
• Relative humidity inside the instrument enclosure(rh)
• Surface dew point temperature(dp)

• Surface dew point temperature(dp)
• Dry bulb temperature(tdry)
• Relative humidity inside the instrument enclosure(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)
• Relative humidity inside the instrument enclosure(rh)
• Surface dew point temperature(dp)

• Surface dew point temperature(dp)
• Dry bulb temperature(tdry)
• Relative humidity inside the instrument enclosure(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)
• Relative humidity inside the instrument enclosure(rh)
• Surface dew point temperature(dp)

• Surface dew point temperature(dp)
• Dry bulb temperature(tdry)
• Relative humidity inside the instrument enclosure(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.

• Relative humidity inside the instrument enclosure(rh)
• Surface dew point temperature(dp)

• Surface dew point temperature(dp)
• Relative humidity inside the instrument enclosure(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.

• null(Raw data stream - documentation not supported)

• Mean Wind Speed(wspd)
• Dummy altitude for Zeb(alt)
• V-component(v_wind)
• base time(base_time)
• Relative humidity inside the instrument enclosure(rh)
• Ascent Rate(asc)
• Wind Direction(deg)
• Wind Status(wstat)
• U-component(u_wind)
• Surface dew point temperature(dp)
• Dry bulb temperature(tdry)
• Time offset of tweaks from base_time(time_offset)
• lat(lat)
• lon(lon)
• Retrieved pressure profile(pres)

• Mean Wind Speed(wspd)
• U-component(u_wind)
• lat(lat)
• Ascent Rate(asc)
• lon(lon)
• Time offset of tweaks from base_time(time_offset)
• V-component(v_wind)
• Dummy altitude for Zeb(alt)
• Surface dew point temperature(dp)
• base time(base_time)
• Relative humidity inside the instrument enclosure(rh)
• Retrieved pressure profile(pres)
• Wind Direction(deg)
• Wind Status(wstat)
• Dry bulb temperature(tdry)

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.

• Mean Wind Speed(wspd)
• V-component(v_wind)
• Dummy altitude for Zeb(alt)
• base time(base_time)
• Relative humidity inside the instrument enclosure(rh)
• Ascent Rate(asc)
• U-component(u_wind)
• Wind Status(wstat)
• Wind Direction(deg)
• Surface dew point temperature(dp)
• Dry bulb temperature(tdry)
• Time offset of tweaks from base_time(time_offset)
• lat(lat)
• lon(lon)
• Retrieved pressure profile(pres)

• U-component(u_wind)
• Mean Wind Speed(wspd)
• lat(lat)
• Ascent Rate(asc)
• lon(lon)
• Time offset of tweaks from base_time(time_offset)
• V-component(v_wind)
• Dummy altitude for Zeb(alt)
• Surface dew point temperature(dp)
• base time(base_time)
• Relative humidity inside the instrument enclosure(rh)
• Retrieved pressure profile(pres)
• Wind Direction(deg)
• Wind Status(wstat)
• Dry bulb temperature(tdry)

• null(Raw data stream - documentation not supported)

• lon(lon)
• Dummy altitude for Zeb(alt)
• base time(base_time)
• Retrieved pressure profile(pres)
• Relative humidity inside the instrument enclosure(rh)
• Dry bulb temperature(tdry)
• lat(lat)
• Time offset of tweaks from base_time(time_offset)

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)
• Relative humidity inside the instrument enclosure(rh)
• Surface dew point temperature(dp)

• Surface dew point temperature(dp)
• Dry bulb temperature(tdry)
• Relative humidity inside the instrument enclosure(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)
• Relative humidity inside the instrument enclosure(rh)
• Surface dew point temperature(dp)

• Surface dew point temperature(dp)
• Dry bulb temperature(tdry)
• Relative humidity inside the instrument enclosure(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)
• Relative humidity inside the instrument enclosure(rh)
• Surface dew point temperature(dp)

• Surface dew point temperature(dp)
• Dry bulb temperature(tdry)
• Relative humidity inside the instrument enclosure(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)
• Relative humidity inside the instrument enclosure(rh)
• Surface dew point temperature(dp)

• Surface dew point temperature(dp)
• Dry bulb temperature(tdry)
• Relative humidity inside the instrument enclosure(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.

• Relative humidity inside the instrument enclosure(rh)
• Surface dew point temperature(dp)

• Surface dew point temperature(dp)
• Relative humidity inside the instrument enclosure(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)
• Relative humidity inside the instrument enclosure(rh)
• Surface dew point temperature(dp)

• Surface dew point temperature(dp)
• Dry bulb temperature(tdry)
• Relative humidity inside the instrument enclosure(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)
• Surface dew point temperature(dp)

• Surface dew point temperature(dp)
• Dry bulb temperature(tdry)

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.

• Surface dew point temperature(dp)
• Dry bulb temperature(tdry)
• Relative humidity inside the instrument enclosure(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.

• Surface dew point temperature(dp)
• Relative humidity inside the instrument enclosure(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.

• Surface dew point temperature(dp)
• Relative humidity inside the instrument enclosure(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.

• Ascent Rate(asc)
• Dummy altitude for Zeb(alt)

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.

• Surface dew point temperature(dp)
• Dry bulb temperature(tdry)
• Relative humidity inside the instrument enclosure(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.

• Surface dew point temperature(dp)
• Dry bulb temperature(tdry)
• Relative humidity inside the instrument enclosure(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.

• Surface dew point temperature(dp)
• Dry bulb temperature(tdry)
• Relative humidity inside the instrument enclosure(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.

• Surface dew point temperature(dp)
• Dry bulb temperature(tdry)
• Relative humidity inside the instrument enclosure(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

• Surface dew point temperature(dp)
• base time(base_time)
• Mean Wind Speed(wspd)
• U-component(u_wind)
• Relative humidity inside the instrument enclosure(rh)
• lat(lat)
• Ascent Rate(asc)
• Retrieved pressure profile(pres)
• Wind Direction(deg)
• Wind Status(wstat)
• lon(lon)
• Dry bulb temperature(tdry)
• Time offset of tweaks from base_time(time_offset)
• V-component(v_wind)
• Dummy altitude for Zeb(alt)

• null(Raw data stream - documentation not supported)

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.

• Surface dew point temperature(dp)
• base time(base_time)
• Mean Wind Speed(wspd)
• U-component(u_wind)
• Relative humidity inside the instrument enclosure(rh)
• lat(lat)
• Ascent Rate(asc)
• Retrieved pressure profile(pres)
• Wind Direction(deg)
• Wind Status(wstat)
• lon(lon)
• Dry bulb temperature(tdry)
• Time offset of tweaks from base_time(time_offset)
• V-component(v_wind)
• Dummy altitude for Zeb(alt)

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.

• Ascent Rate(asc)
• Dummy altitude for Zeb(alt)

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.

• Surface dew point temperature(dp)
• base time(base_time)
• Mean Wind Speed(wspd)
• U-component(u_wind)
• Relative humidity inside the instrument enclosure(rh)
• lat(lat)
• Ascent Rate(asc)
• Retrieved pressure profile(pres)
• Wind Direction(deg)
• Wind Status(wstat)
• lon(lon)
• Dry bulb temperature(tdry)
• Time offset of tweaks from base_time(time_offset)
• V-component(v_wind)
• Dummy altitude for Zeb(alt)

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.

• Ascent Rate(asc)
• Dummy altitude for Zeb(alt)

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.

• Ascent Rate(asc)
• Dummy altitude for Zeb(alt)

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.

• Surface dew point temperature(dp)
• Relative humidity inside the instrument enclosure(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)
• Relative humidity inside the instrument enclosure(rh)
• Retrieved pressure profile(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.

• Surface dew point temperature(dp)
• Dry bulb temperature(tdry)
• Relative humidity inside the instrument enclosure(rh)

• Relative humidity inside the instrument enclosure(rh)
• Dry bulb temperature(tdry)

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.

• Surface dew point temperature(dp)
• Relative humidity inside the instrument enclosure(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.

• Surface dew point temperature(dp)
• Relative humidity inside the instrument enclosure(rh)

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.

• lon(lon)
• lat(lat)
• Dummy altitude for Zeb(alt)

• null(Raw data stream - documentation not supported)

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.

• Surface dew point temperature(dp)
• Dry bulb temperature(tdry)
• Relative humidity inside the instrument enclosure(rh)
• Retrieved pressure profile(pres)
• Dummy altitude for Zeb(alt)