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.

• null(Raw data stream - documentation not supported)

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

• null(Raw data stream - documentation not supported)

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

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)

• U-component(u_wind)
• Mean Wind Speed(wspd)
• V-component(v_wind)

TWP/C2/Balloon Soundings: Missing Flights

No sondes were launched during this period for reasons unknown.

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

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

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.

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

• null(Raw data stream - documentation not supported)

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

TWP/MWR/C3 - Elevated Skybrightness Temperatures

For an unknown reason, the MWR began to exhibit elevated sky brightness 
temperatures. This problem was corrected when the instrument was power-cycled.

• MWR column precipitable water vapor(vap)
• Averaged total liquid water along LOS path(liq)
• Sky brightness temperature at 31.4 GHz(tbsky31)
• Sky brightness temperature at 23.8 GHz(tbsky23)

• MWR column precipitable water vapor(vap)
• Averaged total liquid water along LOS path(liq)
• Sky brightness temperature at 31.4 GHz(tbsky31)
• Sky brightness temperature at 23.8 GHz(tbsky23)

TWP/MWR/C3 - Wet Window Flag not correct

The moisture sensor threshold voltage in the MWR configuration file was 
set to the wrong value for the new heater/blower assembly. This caused the 
wet window flag to not be set high during times of rain.

• Water on Teflon window (1=WET, 0=DRY)(wet_window)

• Water on Teflon window (1=WET, 0=DRY)(wet_window)

• Water on Teflon window (1=WET, 0=DRY)(wet_window)

TWP/SONDE/C2  - Broken Temperature Sensor

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

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

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

TWP/MWR/C3 - Intermittent Negative Sky Brightness Temperatures

Several related and recurring problems with the MWRs have been reported
dating back to 1999.  These problems were due to the occurrence of
blackbody signals (in counts) that were half of those expected. The
symptoms included noisy data, spikes in the data, negative brightness
temperatures, and apparent loss of serial communication between the
computer and the radiometer, which results in a self-termination of the
MWR program.

Because these all initially appeared to be hardware-related problems,
the instrument mentor and SGP site operations personnel (1) repeatedly
cleaned and replaced the fiber optic comm. components, (2) swapped
radiometers, (3) sent radiometers back to Radiometrics for evaluation
(which did not revealed any instrument problems), and (4) reconfigured
the computer's operating system.  Despite several attempts to isolate
and correct it, the problem persisted.

It became apparent that some component of the Windows98 configuration
conflicted with the DOS-based MWR program or affected the serial port
or the contents of the serial port buffer. This problem was finally
corrected by upgrading the MWR software with a new Windows-compatible
program.

• MWR column precipitable water vapor(vap)
• Averaged total liquid water along LOS path(liq)
• Sky brightness temperature at 31.4 GHz(tbsky31)
• Sky brightness temperature at 23.8 GHz(tbsky23)

• MWR column precipitable water vapor(vap)
• Averaged total liquid water along LOS path(liq)
• Sky brightness temperature at 31.4 GHz(tbsky31)
• Sky brightness temperature at 23.8 GHz(tbsky23)

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.

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

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

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.

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

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

TWP/MWR/C3 - min/max/delta values incorrect

The values of valid_min, valid_max, and valid_delta for fields tkxc and tknd were 
incorrect. They should be 303, 333, and 0.5 K, respectively.

• Mixer kinetic (physical) temperature(tkxc)
• (tknd)

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.

• null(Raw data stream - documentation not supported)

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

• null(Raw data stream - documentation not supported)

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.

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

TWP/SONDE/C2 - Broken temperature sensors

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

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

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.

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

TWP/SONDE/C2  - Bad RH sensor

It appears that the RH sensor heating circuit failed during this sounding.  The RH 
oscillates rapidly between low (~0 %RH) and not so low (ambient %RH) and the oscillation seems 
to stop when the temperature is below ~35 degC.  According to Vaisala these are symptoms 
of failure in the ASIC (application specific integrated circuit) that controls the heating.

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

TWP/SONDE/C2 - Bad RH values aloft

It appears that the RH sensor heating circuit on this sonde failed about 24 minutes into 
the flight.  The RH values look reasonable, though somewhat noisy, from the surface to 
approximately 6.9 km (439 hPa) at which point they begin to oscillate between 0 and 100 %.  
This behavior stops when the sonde reaches approximately 11.5km (232 hPa) when the air 
temperature drops below -40 degC.  The oscillation stops at that point, though the RH 
remains higher than might be expected even under supersaturated conditions.

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

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

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

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.

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

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

TWP/MWR/C3 - Reprocess - Revised Retrieval Coefficients

IN THE BEGINNING (June 1992), the retrieval coefficients used to derive 
the precipitable water vapor (PWV) and liquid water path (LWP) from the 
MWR brightness temperatures were based on the Liebe and Layton (1987) 
water vapor and oxygen absorption model and the Grant (1957) liquid 
water absorption model.

Following the SHEBA experience, revised retrievals based on the more 
recent Rosenkranz (1998) water vapor and oxygen absorption models and 
the Liebe (1991) liquid waer absorption model were developed.  The 
Rosenkranz water vapor absorption model resulted a 2 percent increase 
in PWV relative to the earlier Liebe and Layton model.  The Liebe 
liquid water absorption model decreased the LWP by 10% relative to the 
Grant model.  However, the increased oxygen absorption caused a 
0.02-0.03 mm (20-30 g/m2) reduction in LWP, which was particularly 
significant for low LWP conditions (i.e. thin clouds encountered at 
SHEBA).

Recently, it has been shown (Liljegren, Boukabara, Cady-Pereira, and 
Clough, TGARS v. 43, pp 1102-1108, 2005) that the half-width of the 
22 GHz water vapor line from the HITRAN compilation, which is 5 percent 
smaller than the Liebe and Dillon (1969) half-width used in Rosenkranz 
(1998), provided a better fit to the microwave brightness temperature 
measurements at 5 frequencies in the range 22-30 GHz, and yielded more 
accurate retrievals. Accordingly, revised MWR retrieval coefficients 
have been developed using MONORTM, which utilizes the HITRAN compilation 
for its spectroscopic parameters.  These new retrievals provide 3 
percent less PWV and 2.6 percent greater LWP than the previous 
retrievals based on Rosenkranz (1998).

Although the MWR data will be reprocessed to apply the new monortm-based 
retrievals, for most purposes it will be sufficient to correct the data 
using the following factors:

PWV_MONORTM = 0.9695 * PWV_ROSENKRANZ
LWP_MONORTM = 1.026  * LWP_ROSENKRANZ

The Rosenkranz-based retrieval coefficients was active at TWP.C3 from
inception of the data, 20020227.0151.  The MONORTM-based retrieval
coefficients became active at TWP.C3 20050630.2100.

Note: a reprocessing effort is already underway to apply the 
Rosenkranz-based retrieval coefficients to all MWR prior to April 
2002.  An additional reprocessing task will be undertaken to apply 
the MONORTM retrieval to all MWR data when the first is completed. 
Read reprocessing comments in the netcdf file header carefully to 
ensure you are aware which retrieval is in play.

• MWR column precipitable water vapor(vap)
• Averaged total liquid water along LOS path(liq)

• MWR column precipitable water vapor(vap)
• Averaged total liquid water along LOS path(liq)

• Total water vapor along zenith path using tip-derived brightness temperatures(vaptip)
• Total liquid water along zenith path using tip-derived brightness temperatures(liqtip)

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.

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

TWP/MWR/C3 - New software version (4.15) installed

A problem began with the installation of MWR.EXE version 4.12 in October 2002. The 
software had been upgraded from a "DOS" to a "Windows"-compiled program to address an earlier 
problem.  The software upgrade corrected the earlier problem but introduced a new one that 
caused line-of-sight observing cycles to be skipped, a 15% reduction in the number of tip 
curves, and saturation of CPU usage.  Software versions 4.13 and 4.14 also produced 
these problems.

The new MWR software version (4.15) was installed on 9/20/2005. As a consequence of this 
upgrade, the tip curve frequency increased. The tip cycle time decreased from ~60s to ~50s.

• Sky brightness temperature at 31.4 GHz(tbsky31)
• 23.8 GHz blackbody+noise injection signal(bbn23)
• Noise injection temp at nominal temperature at 23.8 GHz(tnd_nom23)
• 31.4 GHz blac2body+noise injection signal(bbn31)
• Temperature correction coefficient at 23.8 GHz(tc23)
• 23.8 GHz Blackbody signal(bb23)
• MWR column precipitable water vapor(vap)
• Averaged total liquid water along LOS path(liq)
• 31.4 GHz blackbody(bb31)
• 31.4 GHz sky signal(sky31)
• 23.8 GHz sky signal(sky23)
• Sky brightness temperature at 23.8 GHz(tbsky23)
• Noise injection temp at nominal temperature at 31.4 GHz(tnd_nom31)
• Temperature correction coefficient at 31.4 GHz(tc31)
• Noise injection temp at 31.4 GHz adjusted to tkbb(tnd31)
• Sky Infra-Red Temperature(sky_ir_temp)
• Blackbody kinetic temperature(tkbb)
• Mixer kinetic (physical) temperature(tkxc)
• (tknd)
• Ambient temperature(tkair)
• Noise injection temp at 23.8 GHz adjusted to tkbb(tnd23)

• Ambient temperature(tkair)
• Blackbody kinetic temperature(tkbb)
• (tknd)
• Temperature correction coefficient at 31.4 GHz(tc31)
• Noise injection temp at nominal temperature at 31.4 GHz(tnd_nom31)
• 23.8 GHz sky brightness temperature derived from tip curve(tbskytip23)
• Noise injection temp at nominal temperature at 23.8 GHz(tnd_nom23)
• Total water vapor along zenith path using tip-derived brightness temperatures(vaptip)
• Noise injection temp at 31.4 GHz derived from this tip(tnd31I)
• Temperature correction coefficient at 23.8 GHz(tc23)
• 23.8 GHz sky signal(tipsky23)
• Noise injection temp at 31.4 GHz adjusted to tkbb(tnd31)
• 31.4 GHz blackbody(bb31)
• 31.4 GHz goodness-of-fit coefficient(r31)
• 31.8 GHz sky brightness temperature derived from tip curve(tbskytip31)
• 23.8 GHz blackbody+noise injection signal(bbn23)
• Total liquid water along zenith path using tip-derived brightness temperatures(liqtip)
• Mixer kinetic (physical) temperature(tkxc)
• 31.4 GHz blac2body+noise injection signal(bbn31)
• Noise injection temp at 23.8 GHz derived from this tip(tnd23I)
• 31.4 GHz sky signal(tipsky31)
• 23.8 GHz goodness-of-fit coefficient(r23)
• Noise injection temp at 23.8 GHz adjusted to tkbb(tnd23)
• 23.8 GHz Blackbody signal(bb23)

TWP/MWR/C3 - Instrument failure, Power outage

A lightning strike sent the MWR offline. The radiometer suffered extensive damage, was 
removed from the site and sent to the vendor for repair. A spare radiometer was sent to the 
TWP/C3 site and was installed on 12/07. However, some hardaware communication issues 
prevented data collection until 12/10.

• Noise injection temp at nominal temperature at 23.8 GHz(tnd_nom23)
• MWR column precipitable water vapor(vap)
• 23.8 GHz Blackbody signal(bb23)
• Sky brightness temperature at 31.4 GHz(tbsky31)
• Noise injection temp at 31.4 GHz adjusted to tkbb(tnd31)
• Temperature correction coefficient at 31.4 GHz(tc31)
• Water on Teflon window (1=WET, 0=DRY)(wet_window)
• base time(base_time)
• Noise injection temp at 23.8 GHz adjusted to tkbb(tnd23)
• 23.8 GHz blackbody+noise injection signal(bbn23)
• Mixer kinetic (physical) temperature(tkxc)
• Temperature correction coefficient at 23.8 GHz(tc23)
• (tknd)
• Averaged total liquid water along LOS path(liq)
• Dummy altitude for Zeb(alt)
• 31.4 GHz blackbody(bb31)
• lon(lon)
• Ambient temperature(tkair)
• Sky Infra-Red Temperature(sky_ir_temp)
• 23.8 GHz sky signal(sky23)
• Noise injection temp at nominal temperature at 31.4 GHz(tnd_nom31)
• lat(lat)
• Time offset of tweaks from base_time(time_offset)
• Sky brightness temperature at 23.8 GHz(tbsky23)
• Blackbody kinetic temperature(tkbb)
• 31.4 GHz blac2body+noise injection signal(bbn31)
• 31.4 GHz sky signal(sky31)

• 23.8 GHz blackbody+noise injection signal(bbn23)
• lon(lon)
• 31.4 GHz blac2body+noise injection signal(bbn31)
• Temperature correction coefficient at 23.8 GHz(tc23)
• Time offset of tweaks from base_time(time_offset)
• MWR column precipitable water vapor(vap)
• Noise injection temp at nominal temperature at 31.4 GHz(tnd_nom31)
• Noise injection temp at 31.4 GHz adjusted to tkbb(tnd31)
• Water on Teflon window (1=WET, 0=DRY)(wet_window)
• (tknd)
• Ambient temperature(tkair)
• Sky brightness temperature at 31.4 GHz(tbsky31)
• base time(base_time)
• Noise injection temp at nominal temperature at 23.8 GHz(tnd_nom23)
• Dummy altitude for Zeb(alt)
• 23.8 GHz Blackbody signal(bb23)
• Averaged total liquid water along LOS path(liq)
• 31.4 GHz blackbody(bb31)
• 31.4 GHz sky signal(sky31)
• 23.8 GHz sky signal(sky23)
• Sky brightness temperature at 23.8 GHz(tbsky23)
• Temperature correction coefficient at 31.4 GHz(tc31)
• lat(lat)
• Sky Infra-Red Temperature(sky_ir_temp)
• Blackbody kinetic temperature(tkbb)
• Mixer kinetic (physical) temperature(tkxc)
• Noise injection temp at 23.8 GHz adjusted to tkbb(tnd23)

• Ambient temperature(tkair)
• Noise injection temp at nominal temperature at 31.4 GHz(tnd_nom31)
• Water on Teflon window (1=WET, 0=DRY)(wet_window)
• 23.8 GHz sky brightness temperature derived from tip curve(tbskytip23)
• Total water vapor along zenith path using tip-derived brightness temperatures(vaptip)
• Noise injection temp at 31.4 GHz derived from this tip(tnd31I)
• Temperature correction coefficient at 23.8 GHz(tc23)
• 23.8 GHz sky signal(tipsky23)
• 31.4 GHz blackbody(bb31)
• Time offset of tweaks from base_time(time_offset)
• 23.8 GHz blackbody+noise injection signal(bbn23)
• Total liquid water along zenith path using tip-derived brightness temperatures(liqtip)
• 31.4 GHz blac2body+noise injection signal(bbn31)
• base time(base_time)
• Noise injection temp at 23.8 GHz adjusted to tkbb(tnd23)
• 23.8 GHz Blackbody signal(bb23)
• Blackbody kinetic temperature(tkbb)
• (tknd)
• Temperature correction coefficient at 31.4 GHz(tc31)
• Noise injection temp at nominal temperature at 23.8 GHz(tnd_nom23)
• Noise injection temp at 31.4 GHz adjusted to tkbb(tnd31)
• 31.4 GHz goodness-of-fit coefficient(r31)
• 31.8 GHz sky brightness temperature derived from tip curve(tbskytip31)
• lon(lon)
• Mixer kinetic (physical) temperature(tkxc)
• Noise injection temp at 23.8 GHz derived from this tip(tnd23I)
• 31.4 GHz sky signal(tipsky31)
• 23.8 GHz goodness-of-fit coefficient(r23)
• Dummy altitude for Zeb(alt)
• lat(lat)
• Actual elevation angle(actel)
• Actual Azimuth(actaz)

• null(Raw data stream - documentation not supported)

TWP/SONDE/C2 - Broken temperature sensor

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

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

TWP/MWR/C3 - REPROCESS- Updated retrieval coefficients

The statistical retrieval coefficients currently in use at the Darwin (TWP/C3) site were 
developed using radiosonde RS80 launched from Manus Island during the TOGA-COARE 
experiment.
Data from Manus Island have minimal seasonality, therefore a single, annual set of 
coefficients was used at all three sites. Retrievals using these coefficients are sufficiently 
accurate especially during the local summer months (December-January). However, the Darwin 
site displays a summer/winter seasonality resulting in larger differences during the 
southern winter (May-
June).
Since we now have enough radiosonde soundings (RS80 and RS90) available at the Darwin 
site, the Darwin coefficients were modified to better reflect the local seasonality.

• MWR column precipitable water vapor(vap)
• Averaged total liquid water along LOS path(liq)

• Total water vapor along zenith path using tip-derived brightness temperatures(vaptip)
• Total liquid water along zenith path using tip-derived brightness temperatures(liqtip)

TWP/SONDE/C2  - Broken temperature sensor

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

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

TWP/SONDE/C2  - Broken temperature sensor

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

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

TWP/SONDE/C2  - Broken temperature sensor

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

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

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.

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

TWP/MWR/C3 - Site shutdown

On 4/24, the site was shutdown in preparation for a cyclone. Instruments were back up on 
4/25 at 22:59

• Noise injection temp at nominal temperature at 23.8 GHz(tnd_nom23)
• MWR column precipitable water vapor(vap)
• 23.8 GHz Blackbody signal(bb23)
• Sky brightness temperature at 31.4 GHz(tbsky31)
• Noise injection temp at 31.4 GHz adjusted to tkbb(tnd31)
• Temperature correction coefficient at 31.4 GHz(tc31)
• Water on Teflon window (1=WET, 0=DRY)(wet_window)
• base time(base_time)
• Noise injection temp at 23.8 GHz adjusted to tkbb(tnd23)
• 23.8 GHz blackbody+noise injection signal(bbn23)
• Mixer kinetic (physical) temperature(tkxc)
• Temperature correction coefficient at 23.8 GHz(tc23)
• (tknd)
• Averaged total liquid water along LOS path(liq)
• Dummy altitude for Zeb(alt)
• 31.4 GHz blackbody(bb31)
• lon(lon)
• Ambient temperature(tkair)
• Sky Infra-Red Temperature(sky_ir_temp)
• 23.8 GHz sky signal(sky23)
• Noise injection temp at nominal temperature at 31.4 GHz(tnd_nom31)
• lat(lat)
• Time offset of tweaks from base_time(time_offset)
• Sky brightness temperature at 23.8 GHz(tbsky23)
• Blackbody kinetic temperature(tkbb)
• 31.4 GHz blac2body+noise injection signal(bbn31)
• 31.4 GHz sky signal(sky31)

• 23.8 GHz blackbody+noise injection signal(bbn23)
• lon(lon)
• 31.4 GHz blac2body+noise injection signal(bbn31)
• Temperature correction coefficient at 23.8 GHz(tc23)
• Time offset of tweaks from base_time(time_offset)
• MWR column precipitable water vapor(vap)
• Noise injection temp at nominal temperature at 31.4 GHz(tnd_nom31)
• Noise injection temp at 31.4 GHz adjusted to tkbb(tnd31)
• Water on Teflon window (1=WET, 0=DRY)(wet_window)
• (tknd)
• Ambient temperature(tkair)
• Sky brightness temperature at 31.4 GHz(tbsky31)
• base time(base_time)
• Noise injection temp at nominal temperature at 23.8 GHz(tnd_nom23)
• Dummy altitude for Zeb(alt)
• 23.8 GHz Blackbody signal(bb23)
• Averaged total liquid water along LOS path(liq)
• 31.4 GHz blackbody(bb31)
• 31.4 GHz sky signal(sky31)
• 23.8 GHz sky signal(sky23)
• Sky brightness temperature at 23.8 GHz(tbsky23)
• Temperature correction coefficient at 31.4 GHz(tc31)
• lat(lat)
• Sky Infra-Red Temperature(sky_ir_temp)
• Blackbody kinetic temperature(tkbb)
• Mixer kinetic (physical) temperature(tkxc)
• Noise injection temp at 23.8 GHz adjusted to tkbb(tnd23)

• Ambient temperature(tkair)
• Noise injection temp at nominal temperature at 31.4 GHz(tnd_nom31)
• Water on Teflon window (1=WET, 0=DRY)(wet_window)
• 23.8 GHz sky brightness temperature derived from tip curve(tbskytip23)
• Total water vapor along zenith path using tip-derived brightness temperatures(vaptip)
• Noise injection temp at 31.4 GHz derived from this tip(tnd31I)
• Temperature correction coefficient at 23.8 GHz(tc23)
• 23.8 GHz sky signal(tipsky23)
• 31.4 GHz blackbody(bb31)
• Time offset of tweaks from base_time(time_offset)
• 23.8 GHz blackbody+noise injection signal(bbn23)
• Total liquid water along zenith path using tip-derived brightness temperatures(liqtip)
• 31.4 GHz blac2body+noise injection signal(bbn31)
• base time(base_time)
• Noise injection temp at 23.8 GHz adjusted to tkbb(tnd23)
• 23.8 GHz Blackbody signal(bb23)
• Blackbody kinetic temperature(tkbb)
• (tknd)
• Temperature correction coefficient at 31.4 GHz(tc31)
• Noise injection temp at nominal temperature at 23.8 GHz(tnd_nom23)
• Noise injection temp at 31.4 GHz adjusted to tkbb(tnd31)
• 31.4 GHz goodness-of-fit coefficient(r31)
• 31.8 GHz sky brightness temperature derived from tip curve(tbskytip31)
• lon(lon)
• Mixer kinetic (physical) temperature(tkxc)
• Noise injection temp at 23.8 GHz derived from this tip(tnd23I)
• 31.4 GHz sky signal(tipsky31)
• 23.8 GHz goodness-of-fit coefficient(r23)
• Dummy altitude for Zeb(alt)
• lat(lat)
• Actual elevation angle(actel)
• Actual Azimuth(actaz)

• null(Raw data stream - documentation not supported)

TWP/MWR/C3 - Sun in field of view of radiometer

Each day from 9/20 and 10/9 around local noon, there is an increase in the brightness 
temperature due to the sun being in the field of view of the radiometer.

• MWR column precipitable water vapor(vap)
• Averaged total liquid water along LOS path(liq)
• Sky brightness temperature at 31.4 GHz(tbsky31)
• Sky brightness temperature at 23.8 GHz(tbsky23)

• 31.8 GHz sky brightness temperature derived from tip curve(tbskytip31)
• Total water vapor along zenith path using tip-derived brightness temperatures(vaptip)
• Total liquid water along zenith path using tip-derived brightness temperatures(liqtip)
• 23.8 GHz sky signal(tipsky23)
• 31.4 GHz sky signal(tipsky31)
• 23.8 GHz sky brightness temperature derived from tip curve(tbskytip23)

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.

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

TWP/SONDE/C2 - Surface RH value incorrect

The surface RH was reproted as 78%.  The value should have been in the low 50's.  It 
appears the observer did not allow the sonde to equilibrate to ambient conditions before 
taking the reading.  This error also caused an incorrect dew point.

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

TWP/SONDE/C2 - Surface RH Value incorrect

The surface value entered by the observers for RH (96%) is incorrect.  At the ascent time 
listed in the .ptu file the readings by the Sonde were around 65%.  This low RH value is 
supported by the nearby SMET tower RH reading of 71.8%.  This also caused the surface dew 
point to be incorrect.

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

TWP/SONDE/C2 - Surface RH too high

The surface Rh was entered as 94%.  The ascent time has 72% and this value is supported by 
RH values from the nearby SMET system.  This error also will affect the dew point.

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

TWP/SONDE/C2 - Broken temperature sensor at launch

Temperature sensor broken at launch.  All thermodynamic values are incorrect.

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

TWP/SONDE/C2 - Broken temperature sensor at launch

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

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

TWP/SONDE/C2 - Failure of RH sensor

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

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