TWP/C2/Sonde Missing Data

There were no sondes launced during this period because there was
no helium on site and the hydrogen generator was not working.  The
hydrogen generator was repaired and launches resumed.

• Raw data stream - documentation not supported

• Raw data stream - documentation not supported

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

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

TWP/SONDE/C2 - Missing Winds

About half of the soundings in November-December exhibited drop-outs
in the winds.  These dropouts were typically over a depth of 1-2 km.
Sometimes the dropout occurred at the surface, sometimes at the top of
the sounding and sometimes in the middle.  These gaps occurred on:

19981126
19981129
19981206
19981209
19981210
19981211
19981212
19981221
19981222

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

• Mean Wind Speed(wspd)

TWP/C2/Balloon Soundings: Missing Flights

No sondes were launched during this period for reasons unknown.

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

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

TWP/C1 - Incorrect elevation reported in Manus Data

(From Bill Clements) We have been using 6m MSL as the station
elevation of Momote (Manus).  This was based on information
posted near the station barometer in the Momote Weather Service
Office.  It turns out that the official WMO station elevation
for Momote is 4m MSL and the upper air elevation is 5m MSL.

All Manus instruments except the sonde station are at 4m MSL.
The sonde launching station is at 5m MSL.

• alt

TWP/C1/Balloon Soundings Maximum Altitude

Only surface data included in this data file.

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

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

TWP/C1/Balloon Soundings Maximum Altitude

Only surface data included in this data file.

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

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

TWP/C1/Balloon Soundings Maximum Altitude

Only surface data included in this data file.

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

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

TWP/C1/Balloon Soundings Maximum Altitude

Only surface data included in this data file.

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

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

TWP/C1/Balloon Soundings Maximum Altitude

This sonde only reached a height of 0.3 km.

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

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

TWP/C1 - Generator Problem

On November 18 the generator was turned off due to a fault in the oil
pressure sensor. It had been having trouble for at least a day prior
to the manual shut-down. ADaM, the MPL, and the WSI were also shut
down to prevent an unscheduled power cycle. As a result, there is a block 
of missing data from November 20-27 for all of the instruments except 
those connected to the Zeno loggers (SKYRAD, GNDRAD, SMET).

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

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

• laser_temperature
• lon
• Backscatter(backscatter)
• measurement_parameters
• base_time
• Vertical visibility(vertical_visibility)
• alt_highest_signal
• alt
• lat
• Second lowest cloud base height(second_cbh)
• Lowest cloud base height detected.(first_cbh)
• receiver_sensitivity
• Third cloud base height(third_cbh)
• range
• detection_status
• time_offset
• background_light
• sum_backscatter
• status_flag
• window_contamination
• tilt_angle
• laser_pulse_energy
• filename
• status_string

• laser_pulse_energy
• Second lowest cloud base height(second_cbh)
• time_offset
• receiver_sensitivity
• Vertical visibility(vertical_visibility)
• filename
• measurement_parameters
• status_string
• background_light
• sum_backscatter
• lon
• status_flag
• detection_status
• range
• laser_temperature
• Third cloud base height(third_cbh)
• Lowest cloud base height detected.(first_cbh)
• alt
• alt_highest_signal
• tilt_angle
• Backscatter(backscatter)
• window_contamination
• lat
• base_time

• logger_volt
• lon
• alt
• diffuse_hemisp_broadband
• base_time
• cosine_solar_zenith_angle
• lat
• Direct Normal Broadband Irradiance(direct_norm_broadband)
• time_offset
• callang_flags
• hemisp_narrowband
• diffuse_hemisp_narrowband
• total_hemisp_broadband
• mfrsr_temp
• Direct Normal Irradiance, NIMFR(direct_norm_narrowband)

• lat
• dif6
• dif5
• dif7
• dif2
• dif1
• dif4
• dif3
• supply_voltage
• base_time
• detector_temp
• alt
• time_offset
• tot3
• tot4
• lon
• tot1
• tot2
• tot7
• tot5
• tot6
• dirn4
• dirn3
• dirn2
• dirn1
• dirn7
• dirn6
• dirn5

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

TWP/C2  Installation

The Nauru ARCS was installed during the period September-November
1998.  Data were being collected by the end of October, but for the
first several weeks of November, the site was undergoing considerable
change, so data from that period should be used with caution.  The
official site dedication occured on November 20.  Most on-site
activity ended following the dedication so we will consider November
20 to be the beginning of the Nauru operations.  The last members of
the installation team left Nauru on November 24.

• Raw data stream - documentation not supported

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

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

TWP/C1 - Incorrect elevation reported in Manus Data

(From Bill Clements) We have been using 6m MSL as the station
elevation of Momote (Manus).  This was based on information
posted near the station barometer in the Momote Weather Service
Office.  It turns out that the official WMO station elevation
for Momote is 4m MSL and the upper air elevation is 5m MSL.

All Manus instruments except the sonde station are at 4m MSL.
The sonde launching station is at 5m MSL.

• alt

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
• 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 - 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
• 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 - 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)

TWP/SONDE/C2  - Broken Temperature Sensor

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

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

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

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

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

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
• 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 - 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
• Dewpoint Temperature(dp)
• Wind Direction(deg)
• 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)

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.

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

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

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)

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(rh)
• Dewpoint Temperature(dp)

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

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

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)

NSA/SONDE/C1 - Broken temperature sensor

It appears that the temperature sensor on this radiosonde broke after launch.  There is a 
sudden drop of 12 degC in 2 seconds and the remaining tdry values seem to be about 30 
degC low.

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

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

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

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.

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

• Humidity, relative(rh)
• 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)

• 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)

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.

• Raw data stream - documentation not supported

• Raw data stream - documentation not supported

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

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

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(rh)
• Dewpoint Temperature(dp)

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)

TWP/SONDE/C2 - Broken temperature sensors

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

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

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

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(rh)
• 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)

TWP/SONDE/C1 - Broken temperature sensor

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

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

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)

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(rh)
• Dewpoint Temperature(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(rh)
• Dewpoint Temperature(dp)

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

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

NSA/SONDE/C1 - This is a test sounding done using an RS80H radiosonde

This was a sounding done using an RS80H radiosonde to test a special operational 
procedure.  There is nothing wrong with the data, though users should be aware that the sounding 
was not done using the current ARM standard RS90 radiosonde.

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

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(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(rh)
• Dewpoint Temperature(dp)

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)

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(rh)
• Dewpoint Temperature(dp)

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)
• time_offset
• lat
• alt
• wstat
• Humidity, relative(rh)
• Eastward Wind Component(u_wind)

NSA/SONDE/C1 - Test sounding using RS80H

This is a test sounding done using an old RS80H radiosonde rather than the production RS90 
version.  Although the sonde functioned normally, the RH data may be subject to a dry 
bias caused by the age of the sensor and possible contamination.

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

NSA/SONDE/C1 - Incorrect surface altitude

The value of the station altitude (relative to mean sea level) is
incorrect in all NSA radiosonde files prior to 2/14/2004.  The correct
value is 8 m.  The incorrect value can be different.  Prior to 4/24/2002
(in platform nsaisssonde...) it was given as 12 m.  From 4/24/2002 to
2/13/2004 (in platform nsasondewnpn...) it is almost always given as
27 m (sometimes [rarely] 17 m).

• alt

• Raw data stream - documentation not supported

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(rh)
• Dewpoint Temperature(dp)

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)
• time_offset
• lat
• alt
• wstat
• Humidity, relative(rh)
• Eastward Wind Component(u_wind)

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(rh)
• Dewpoint Temperature(dp)

NSA/SONDE/C1 - Bad temperature

Because of strong winds, the radiosonde hit the ground after launch and the temperature 
sensor broke.  The RH and pressure data also should be considered suspect.

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

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)
• time_offset
• lat
• 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)

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(rh)
• Dewpoint Temperature(dp)

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)

TWP/SONDE/C2 - Broken temperature sensor

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

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

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)
• time_offset
• lat
• 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

TWP/SONDE/C2  - Broken temperature sensor

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

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

TWP/SONDE/C2  - Bad RH in lower 8km

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(rh)
• Dewpoint Temperature(dp)

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)

NSA/SONDE/C1 - Noisy/Unstable RH and dew point data

The RH readings during the first 8 minutes of this sounding include three apparently 
incorrect oscillations to near-zero values.  After checking the absolutely raw data, it seems 
as though this period was excessively noisy, resulting in many missing values.  The noise 
abatted and the remaining sounding values are valid.

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

NSA/SONDE/C1 - Bad surface RH and temperature values

This is a subtle problem that might escape notice.  For the identified sonde launches, the 
ground station lost its signal between the time it was removed from the ground check set 
and the time it was launched.  As a result, the software, which automatically determines 
the launch time and surface conditions at time of launch mistakenly used values of 
temperature and RH representative of the ground check set and the GW rather than of the 
ambient conditions before launch.  The bad values influenced only the first few samples and the 
remainder of the sounding values are correct.  

A procedural problem was identified and corrected.

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

NSA/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  SerialNo     RH1     RH2     Ref
 20060713  0532  B1924431    0.30    0.20    0.30
 20060713  1751  B1854963    0.20    0.30    0.30
 20060714  0521  B1924425    0.40    0.40    0.40
 20060714  1739  B1854206    0.30    0.30    0.30
 20060715  0522  B1715127    1.20    1.20    1.20
 20060715  1737  B1854966    0.60    0.60    0.60
 20060716  0508  B1715126    0.40    0.40    0.40
 20060716  1732  B1844098    0.50    0.50    0.50
 20060717  0517  B1914170    0.40    0.40    0.40
 20060718  0516  B1914173    0.70    0.70    0.70
 20060720  0523  B1854149    0.40    0.40    0.40
 20060721  0517  B1914153    0.40    0.40    0.40
 20060722  0521  B1844097    1.00    1.10    1.10
 20060722  1730  B1914174    0.60    0.70    0.70
 20060723  0537  B1714439    0.40    0.40    0.40
 20060723  1734  B1734155    0.50    0.50    0.50
 20060724  0529  B1134336    0.50    0.50    0.50
 20060725  0525  B1754099    0.60    0.70    0.70
 20060726  0541  B1844108    1.80    1.80    1.80
 20060727  0520  B1714382    0.70    0.80    0.70
 20060728  0531  B1854116    0.80    0.80    0.80
 20060729  0527  B1724027    1.00    1.00    1.00
 20060729  1726  B1714392    0.70    0.80    0.80
 20060730  0522  B1854100    0.70    0.80    0.80
 20060730  1724  B1854764    0.90    1.00    1.00
 20060731  0515  B1664086    0.90    0.80    0.90
 20060801  0520  B1724758    1.50    1.50    1.50
 20060801  1729  B1754116    1.10    1.10    1.10
 20060802  0518  B1724516    0.80    0.80    0.80
 20060803  0523  B1674148    0.80    0.80    0.80
 20060804  0532  B1754092    0.90    0.90    0.90
 20060804  1727  B1844117    3.50    3.50    3.50
 20060805  0531  B1714741    0.30    0.30    0.30
 20060805  1728  B1754098    0.30    0.30    0.30
 20060806  0528  B1844115    0.40    0.40    0.40
 20060806  1728  B1914161    0.20    0.20    0.20
 20060807  0530  B1714549    0.30    0.30    0.30
 20060808  0517  B1844107    0.50    0.50    0.50
 20060808  1744  B1914166    0.20    0.20    0.20
 20060809  0527  B1914164    0.30    0.40    0.40
 20060809  1736  B1914163    0.30    0.30    0.30
 20060810  0521  B1914160    0.40    0.50    0.50
 20060810  1745  B1744671    0.40    0.40    0.40
 20060811  0525  B1854965    0.50    0.50    0.50
 20060811  1753  B1724131    0.10    0.10    0.10
 20060812  0527  B1754104    0.50    0.50    0.50
 20060812  1740  B1854256    0.30    0.40    0.40
 20060813  0522  B1854240    0.30    0.40    0.40
 20060814  0525  B1714106    0.20    0.20    0.20
 20060814  1742  B1854106    0.40    0.40    0.40
 20060815  0534  B1914169    0.50    0.60    0.60
 20060815  1734  B1854233    0.60    0.70    0.70
 20060816  0539  B1724791    0.20    0.20    0.20
 20060816  1732  B1914171    0.10    0.20    0.20
 20060817  0535  B1354283    0.10    0.10    0.10
 20060817  1740  B1354574    0.40    0.40    0.40
 20060818  0516  B1354633    0.50    0.40    0.50
 20060818  1744  B1364673    0.20    0.20    0.20
 20060819  0538  B1364126    0.20    0.30    0.30
 20060819  1745  B1354598    0.50    0.60    0.60
 20060820  0532  B1354290    1.10    1.10    1.10
 20060820  1729  B1354317    0.40    0.40    0.40
 20060821  0530  B1354545    0.60    0.70    0.70
 20060821  1728  B1354516    0.70    0.70    0.70
 20060822  0524  B1354619    0.50    0.60    0.60
 20060822  1728  B1364377    0.40    0.40    0.40
 20060823  0533  B1354309    0.30    0.30    0.30
 20060823  1730  B1354527    0.70    0.70    0.70
 20060824  0533  B1354230    0.60    0.60    0.60
 20060824  1812  B1354587    0.70    0.70    0.70
 20060825  0517  B1354614    0.70    0.70    0.70
 20060825  1730  B1354630    0.60    0.60    0.60
 20060826  0537  B1334114    0.90    0.90    0.90
 20060826  1734  B1354246    0.70    0.70    0.70
 20060827  0508  B1354534    0.70    0.70    0.70
 20060827  1729  B1354618    0.60    0.60    0.60
 20060828  0517  B1354115    0.40    0.40    0.40
 20060828  1738  B1354206    0.50    0.60    0.60
 20060829  0516  B1354617    0.50    0.60    0.60
 20060829  1717  B1354622    0.50    0.60    0.60
 20060830  0511  B1354314    0.40    0.50    0.50
 20060830  1732  B1354537    0.60    0.70    0.70
 20060831  1802  B1354239    0.60    0.80    0.80
 20060905  1724  B1354626    0.60    0.60    0.60
 20060906  0522  B1354525    0.60    0.80    0.80
 20060906  1734  B1354107    0.50    0.50    0.50
 20060907  0537  B1354543    0.70    0.70    0.70
 20060907  1803  B1354586    0.80    0.80    0.80
 20060908  0531  B1354519    0.60    0.60    0.60
 20060908  1728  B1354224    0.60    0.60    0.60
 20060909  0534  B1354532    0.70    0.80    0.80
 20060909  1732  B1354513    0.80    0.90    0.90
 20060910  0516  B1354125    0.60    0.70    0.60
 20060910  1727  B1354110    0.40    0.50    0.50
 20060911  0528  B1354235    0.90    0.90    0.90
 20060911  1849  B1354514    0.70    0.70    0.70
 20060912  0525  B1354124    0.60    0.70    0.70
 20060913  0534  B1344478    0.50    0.50    0.50
 20060914  0520  B1354226    0.70    0.70    0.70
 20060915  0529  B1344459    0.40    0.50    0.50
 20060916  0532  B1344469    0.50    0.40    0.50
 20060916  1732  B1354106    0.50    0.60    0.60
 20060917  0527  B1354210    0.70    0.70    0.70
 20060918  0533  B1354087    0.60    0.60    0.60
 20060919  0526  B1354097    0.70    0.50    0.60
 20060920  0516  B1344462    0.50    0.40    0.50
 20060920  1810  B1354536    0.70    0.70    0.70
 20060921  0534  B1354112    0.50    0.60    0.60
 20060921  1800  B1344502    0.40    0.40    0.40
 20060922  0525  B1354531    0.70    0.80    0.80
 20060922  1736  B1354541    0.70    0.70    0.70
 20060923  0519  B1354101    0.50    0.60    0.60
 20060923  1738  B1354576    0.70    0.50    0.70
 20060924  0536  B1354095    0.60    0.60    0.60
 20060925  0536  B1354098    0.60    0.60    0.60
 20060925  1755  B1354100    0.50    0.50    0.50
 20060926  0531  B1334691    0.70    0.70    0.70
 20060926  1742  B1354108    0.40    0.50    0.50

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

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)

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

The output precision of the following variables was increased 20060929:

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

NSA/SONDE/C1 - Incorrect surface values of T and RH

The radiosonde was launched too quickly after being removed from the ground check set.  As 
a result, the system did not equilibrate with the local ground conditions and the 
automatically entered surface values are incorrect.

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

NSA/SONDE/C1 - RH sensor failure

It appears that one of the two RH sensors on this radiosonde was affected by ice after 
emerging from a low cold cloud.  As a result the reported RH values oscillate by about 10 
percent until the alternate heating cycle stops.  I suspect the lower value is more close 
to correct, but can't be absolutely sure.

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

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)

NSA/SONDE/C1 - Incorrect surface RH value

For an unknown reason the surface RH was reported a 0%.  Becuase these values are entered 
automatically by the system, this is NOT likely an operator error.  Examination of the 
raw data shows that the surface RH at launch time was approximately 81.2 %RH.

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

NSA/SONDE/C1 - Temperature sensor broke at launch

The temperature sensor on this sonde broke at launch.  As a result all the thermodynamic 
data are incorrect.  The wind data are OK, though there will be some uncertainty in the 
altitude values.  This sounding was done at a non-standard time and it isn't clear whether 
it was delayed for some reason or a RHUBC sounding.  In either case, there is no fix.

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

TWP/SONDE/C2 - Surface Temperature Incorrect

The first two temperature values in the datafile are incorrect.  It appears that the 
observer mis-typed the surface temperature as -27 instead of +27.  The next value was 8 which 
is also incorrect and was caused by the system interpolating from the incorrect surface 
value and what the sonde temperature sensor was reading.

• Dry Bulb Temperature(tdry)

TWP/SONDE/C2 - Surface RH value incorrect

The surface RH value was incorrect.  It appears the observer mis-typed 70 instead of 80.  
This error also caused the dew point temperature to be incorrect.

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