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)

• Time offset from base_time(base_time)
• east longitude for all the input platforms.(lon)
• Wind Direction(deg)
• Ascent Rate(asc)
• surface wind speed(wspd)
• Relative humidity scaled, by total column amount from MWR(rh)
• Dry-Bulb Temperature(tdry)
• Surface dew point temperature(dp)
• Wind Status(wstat)
• altitude above sea levelaltunits(alt)
• north latitude for all the input platforms.(lat)
• pressure at constant pressure surface(pres)
• Time offset of tweaks from base_time(time_offset)

• Raw data stream - documentation not supported(Raw data stream - documentation not supported)

• Dry-Bulb Temperature(tdry)
• Time offset of tweaks from base_time(time_offset)
• model zonal wind velocity(u_wind)
• east longitude for all the input platforms.(lon)
• north latitude for all the input platforms.(lat)
• Relative humidity scaled, by total column amount from MWR(rh)
• pressure at constant pressure surface(pres)
• Ascent Rate(asc)
• Wind Direction(deg)
• Surface dew point temperature(dp)
• altitude above sea levelaltunits(alt)
• Wind Status(wstat)
• Time offset from base_time(base_time)
• surface wind speed(wspd)
• model meridional wind velocity(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

• surface wind speed(wspd)

• model zonal wind velocity(u_wind)
• surface wind speed(wspd)
• model meridional wind velocity(v_wind)

TWP/C2/Balloon Soundings: Missing Flights

No sondes were launched during this period for reasons unknown.

• Time offset from base_time(base_time)
• east longitude for all the input platforms.(lon)
• Wind Direction(deg)
• Ascent Rate(asc)
• surface wind speed(wspd)
• Relative humidity scaled, by total column amount from MWR(rh)
• Dry-Bulb Temperature(tdry)
• Surface dew point temperature(dp)
• Wind Status(wstat)
• altitude above sea levelaltunits(alt)
• north latitude for all the input platforms.(lat)
• pressure at constant pressure surface(pres)
• Time offset of tweaks from base_time(time_offset)

• Dry-Bulb Temperature(tdry)
• Time offset of tweaks from base_time(time_offset)
• model zonal wind velocity(u_wind)
• east longitude for all the input platforms.(lon)
• north latitude for all the input platforms.(lat)
• Relative humidity scaled, by total column amount from MWR(rh)
• pressure at constant pressure surface(pres)
• Ascent Rate(asc)
• Wind Direction(deg)
• Surface dew point temperature(dp)
• altitude above sea levelaltunits(alt)
• Wind Status(wstat)
• Time offset from base_time(base_time)
• surface wind speed(wspd)
• model meridional wind velocity(v_wind)

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.

• altitude above sea levelaltunits(alt)

TWP/C1/Balloon Soundings Maximum Altitude

Only surface data included in this data file.

• surface wind speed(wspd)
• altitude above sea levelaltunits(alt)
• Dry-Bulb Temperature(tdry)
• pressure at constant pressure surface(pres)
• Ascent Rate(asc)
• north latitude for all the input platforms.(lat)
• Time offset from base_time(base_time)
• Wind Status(wstat)
• Relative humidity scaled, by total column amount from MWR(rh)
• east longitude for all the input platforms.(lon)
• Surface dew point temperature(dp)
• Time offset of tweaks from base_time(time_offset)
• Wind Direction(deg)

• Time offset of tweaks from base_time(time_offset)
• Surface dew point temperature(dp)
• east longitude for all the input platforms.(lon)
• north latitude for all the input platforms.(lat)
• pressure at constant pressure surface(pres)
• Relative humidity scaled, by total column amount from MWR(rh)
• Wind Status(wstat)
• Ascent Rate(asc)
• model meridional wind velocity(v_wind)
• altitude above sea levelaltunits(alt)
• Time offset from base_time(base_time)
• model zonal wind velocity(u_wind)
• surface wind speed(wspd)
• Dry-Bulb Temperature(tdry)
• Wind Direction(deg)

TWP/C1/Balloon Soundings Maximum Altitude

Only surface data included in this data file.

• surface wind speed(wspd)
• altitude above sea levelaltunits(alt)
• Dry-Bulb Temperature(tdry)
• pressure at constant pressure surface(pres)
• Ascent Rate(asc)
• north latitude for all the input platforms.(lat)
• Time offset from base_time(base_time)
• Wind Status(wstat)
• Relative humidity scaled, by total column amount from MWR(rh)
• east longitude for all the input platforms.(lon)
• Surface dew point temperature(dp)
• Time offset of tweaks from base_time(time_offset)
• Wind Direction(deg)

• Time offset of tweaks from base_time(time_offset)
• Surface dew point temperature(dp)
• east longitude for all the input platforms.(lon)
• north latitude for all the input platforms.(lat)
• pressure at constant pressure surface(pres)
• Relative humidity scaled, by total column amount from MWR(rh)
• Wind Status(wstat)
• Ascent Rate(asc)
• model meridional wind velocity(v_wind)
• altitude above sea levelaltunits(alt)
• Time offset from base_time(base_time)
• model zonal wind velocity(u_wind)
• surface wind speed(wspd)
• Dry-Bulb Temperature(tdry)
• Wind Direction(deg)

TWP/C1/Balloon Soundings Maximum Altitude

Only surface data included in this data file.

• surface wind speed(wspd)
• altitude above sea levelaltunits(alt)
• Dry-Bulb Temperature(tdry)
• pressure at constant pressure surface(pres)
• Ascent Rate(asc)
• north latitude for all the input platforms.(lat)
• Time offset from base_time(base_time)
• Wind Status(wstat)
• Relative humidity scaled, by total column amount from MWR(rh)
• east longitude for all the input platforms.(lon)
• Surface dew point temperature(dp)
• Time offset of tweaks from base_time(time_offset)
• Wind Direction(deg)

• Time offset of tweaks from base_time(time_offset)
• Surface dew point temperature(dp)
• east longitude for all the input platforms.(lon)
• north latitude for all the input platforms.(lat)
• pressure at constant pressure surface(pres)
• Relative humidity scaled, by total column amount from MWR(rh)
• Wind Status(wstat)
• Ascent Rate(asc)
• model meridional wind velocity(v_wind)
• altitude above sea levelaltunits(alt)
• Time offset from base_time(base_time)
• model zonal wind velocity(u_wind)
• surface wind speed(wspd)
• Dry-Bulb Temperature(tdry)
• Wind Direction(deg)

TWP/C1/Balloon Soundings Maximum Altitude

Only surface data included in this data file.

• surface wind speed(wspd)
• altitude above sea levelaltunits(alt)
• Dry-Bulb Temperature(tdry)
• pressure at constant pressure surface(pres)
• Ascent Rate(asc)
• north latitude for all the input platforms.(lat)
• Time offset from base_time(base_time)
• Wind Status(wstat)
• Relative humidity scaled, by total column amount from MWR(rh)
• east longitude for all the input platforms.(lon)
• Surface dew point temperature(dp)
• Time offset of tweaks from base_time(time_offset)
• Wind Direction(deg)

• Time offset of tweaks from base_time(time_offset)
• Surface dew point temperature(dp)
• east longitude for all the input platforms.(lon)
• north latitude for all the input platforms.(lat)
• pressure at constant pressure surface(pres)
• Relative humidity scaled, by total column amount from MWR(rh)
• Wind Status(wstat)
• Ascent Rate(asc)
• model meridional wind velocity(v_wind)
• altitude above sea levelaltunits(alt)
• Time offset from base_time(base_time)
• model zonal wind velocity(u_wind)
• surface wind speed(wspd)
• Dry-Bulb Temperature(tdry)
• Wind Direction(deg)

TWP/C1/Balloon Soundings Maximum Altitude

This sonde only reached a height of 0.3 km.

• surface wind speed(wspd)
• altitude above sea levelaltunits(alt)
• Dry-Bulb Temperature(tdry)
• pressure at constant pressure surface(pres)
• Ascent Rate(asc)
• north latitude for all the input platforms.(lat)
• Time offset from base_time(base_time)
• Wind Status(wstat)
• Relative humidity scaled, by total column amount from MWR(rh)
• east longitude for all the input platforms.(lon)
• Surface dew point temperature(dp)
• Time offset of tweaks from base_time(time_offset)
• Wind Direction(deg)

• Time offset of tweaks from base_time(time_offset)
• Surface dew point temperature(dp)
• east longitude for all the input platforms.(lon)
• north latitude for all the input platforms.(lat)
• pressure at constant pressure surface(pres)
• Relative humidity scaled, by total column amount from MWR(rh)
• Wind Status(wstat)
• Ascent Rate(asc)
• model meridional wind velocity(v_wind)
• altitude above sea levelaltunits(alt)
• Time offset from base_time(base_time)
• model zonal wind velocity(u_wind)
• surface wind speed(wspd)
• Dry-Bulb Temperature(tdry)
• Wind Direction(deg)

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).

• Background signal(background_signal)
• Detector temperature(detector_temp)
• altitude above sea levelaltunits(alt)
• GPS raw data filename(filename)
• east longitude for all the input platforms.(lon)
• Voltage level which operates the thermistor(voltage_10)
• Average cloud base height used in the retrieval(cbh)
• Repetition rate, or Trigger Frequency of the laser(pulse_rep)
• Voltage level which operates the energy monitor(voltage_15)
• north latitude for all the input platforms.(lat)
• Laser temperature(laser_temp)
• Filter temperature(filter_temp)
• Number of laser pulses summed during measurement interval(shots_summed)
• Instrument temperature(instrument_temp)
• Time offset from base_time(base_time)
• Aerosol volume backscattering coefficient at 355 nm(backscatter)
• Time offset of tweaks from base_time(time_offset)
• Voltage level which operates the A_D card and the detector(voltage_5)
• Energy output per pulse of transmitted laser beam at 523 nm (Doubled Nd-YLF)(energy_monitor)

• surface wind speed(wspd)
• Dry-Bulb Temperature(tdry)
• Time offset from base_time(base_time)
• Surface dew point temperature(dp)
• north latitude for all the input platforms.(lat)
• east longitude for all the input platforms.(lon)
• Wind Direction(deg)
• pressure at constant pressure surface(pres)
• Ascent Rate(asc)
• altitude above sea levelaltunits(alt)
• Wind Status(wstat)
• Relative humidity scaled, by total column amount from MWR(rh)
• Time offset of tweaks from base_time(time_offset)

• north latitude for all the input platforms.(lat)
• Diffuse Hemispheric Broadband Irradiance, offset subtracted, cosine corrected,
  broadband scale applied(diffuse_hemisp_broadband)
• Direct Normal Irradiance, NIMFR(direct_norm_narrowband)
• altitude above sea levelaltunits(alt)
• east longitude for all the input platforms.(lon)
• Diffuse Hemispheric Irradiance, MFRSR(diffuse_hemisp_narrowband)
• Cosine of Apparent Solar Zenith Angle(cosine_solar_zenith_angle)
• Hemispheric Irradiance, MFRSR(hemisp_narrowband)
• Hemispheric Broadband Irradiance, offset and cosine corrected, broadband scale
  factor applied(hemisp_broadband)
• Fields flagged by callang: 0 = no flag\n,(callang_flags)
• MFRSR Detector Temperature(mfrsr_temp)
• Time offset of tweaks from base_time(time_offset)
• Direct Normal Irradiance, Uncalibrated Silicon Detector, NIMFR(direct_norm_broadband)
• Time offset from base_time(base_time)
• Data Logger Supply Voltage(logger_volt)

• distance to center of range bin after correcting for offset in sync(range)
• Degrees from vertical (-15 to +90)(tilt_angle)
• east longitude for all the input platforms.(lon)
• Time offset of tweaks from base_time(time_offset)
• Third cloud base height(third_cbh)
• Aerosol volume backscattering coefficient at 355 nm(backscatter)
• Time offset from base_time(base_time)
• Percentage of nominal factory setting (0 to 999%)(laser_pulse_energy)
• Flag indicating aeri retrieval status(status_flag)
• Warning and alarm status bits(status_string)
• north latitude for all the input platforms.(lat)
• altitude above sea levelaltunits(alt)
• Lowest cloud base height detected.(first_cbh)
• Percentage of nominal factory setting (0 to 999%)(receiver_sensitivity)
• Laser temperature(laser_temperature)
• Millivolts at internal ADC input(window_contamination)
• SUM of detected and normalized backscatter(sum_backscatter)
• Vertical visibility(vertical_visibility)
• GPS raw data filename(filename)
• Detection status. See details(detection_status)
• Altitude of highest signal(alt_highest_signal)
• 6 character string describing instrument measurement parameters(measurement_parameters)
• Millivolts at internal ADC input (0 to 2500)(background_light)
• Second lowest cloud base height(second_cbh)

• Hemispheric Broadband Irradiance (Approximate), MFRSR(total_hemisp_broadband)
• MFRSR Detector Temperature(mfrsr_temp)
• Data Logger Supply Voltage(logger_volt)
• Fields flagged by callang: 0 = no flag\n,(callang_flags)
• north latitude for all the input platforms.(lat)
• Hemispheric Irradiance, MFRSR(hemisp_narrowband)
• Diffuse Hemispheric Irradiance, MFRSR(diffuse_hemisp_narrowband)
• altitude above sea levelaltunits(alt)
• Diffuse Hemispheric Broadband Irradiance, offset subtracted, cosine corrected,
  broadband scale applied(diffuse_hemisp_broadband)
• Cosine of Apparent Solar Zenith Angle(cosine_solar_zenith_angle)
• Time offset from base_time(base_time)
• Direct Normal Irradiance, NIMFR(direct_norm_narrowband)
• Time offset of tweaks from base_time(time_offset)
• east longitude for all the input platforms.(lon)
• Direct Normal Irradiance, Uncalibrated Silicon Detector, NIMFR(direct_norm_broadband)

• north latitude for all the input platforms.(lat)
• Diffuse Horizontal Irradiance, 610 nm(dif4)
• Total Horizontal Irradiance, 500 nm(tot3)
• Direct-normal Irradiance, 665 nm(dirn5)
• Diffuse Horizontal Irradiance, 665 nm(dif5)
• Total Horizontal Irradiance, 610 nm(tot4)
• Direct-normal Irradiance, 610 nm(dirn4)
• Diffuse Horizontal Irradiance, 500 nm(dif3)
• Total Horizontal Irradiance, 940 nm(tot7)
• Diffuse Horizontal Irradiance, 415 nm(dif2)
• altitude above sea levelaltunits(alt)
• Direct-normal Irradiance, Broadband Solar(dirn1)
• Direct-normal Irradiance, 415 nm(dirn2)
• Time offset of tweaks from base_time(time_offset)
• Total Horizontal Irradiance, 862 nm(tot6)
• Total Horizontal Irradiance, 665 nm(tot5)
• Direct-normal Irradiance, 500 nm(dirn3)
• Datalogger supply voltage(supply_voltage)
• Detector temperature(detector_temp)
• Diffuse Horizontal Irradiance, 940 nm(dif7)
• Diffuse Horizontal Irradiance, 862 nm(dif6)
• east longitude for all the input platforms.(lon)
• Time offset from base_time(base_time)
• Diffuse Horizontal Irradiance, Broadband Solar(dif1)
• Total Horizontal Irradiance, 415 nm(tot2)
• Direct-normal Irradiance, 862 nm(dirn6)
• Total Horizontal Irradiance, Broadband Solar(tot1)
• Direct-normal Irradiance, 940 nm(dirn7)

• Raw data stream - documentation not supported(Raw data stream - documentation not supported)

• east longitude for all the input platforms.(lon)
• Time offset from base_time(base_time)
• Time offset of tweaks from base_time(time_offset)
• Ascent Rate(asc)
• model meridional wind velocity(v_wind)
• Surface dew point temperature(dp)
• Relative humidity scaled, by total column amount from MWR(rh)
• Wind Status(wstat)
• model zonal wind velocity(u_wind)
• surface wind speed(wspd)
• Dry-Bulb Temperature(tdry)
• north latitude for all the input platforms.(lat)
• pressure at constant pressure surface(pres)
• altitude above sea levelaltunits(alt)
• Wind Direction(deg)

• Aerosol volume backscattering coefficient at 355 nm(backscatter)
• Lowest cloud base height detected.(first_cbh)
• Millivolts at internal ADC input(window_contamination)
• SUM of detected and normalized backscatter(sum_backscatter)
• GPS raw data filename(filename)
• altitude above sea levelaltunits(alt)
• 6 character string describing instrument measurement parameters(measurement_parameters)
• Altitude of highest signal(alt_highest_signal)
• Warning and alarm status bits(status_string)
• north latitude for all the input platforms.(lat)
• Laser temperature(laser_temperature)
• Second lowest cloud base height(second_cbh)
• distance to center of range bin after correcting for offset in sync(range)
• Time offset of tweaks from base_time(time_offset)
• Percentage of nominal factory setting (0 to 999%)(receiver_sensitivity)
• Detection status. See details(detection_status)
• Percentage of nominal factory setting (0 to 999%)(laser_pulse_energy)
• Vertical visibility(vertical_visibility)
• Degrees from vertical (-15 to +90)(tilt_angle)
• Time offset from base_time(base_time)
• Millivolts at internal ADC input (0 to 2500)(background_light)
• Flag indicating aeri retrieval status(status_flag)
• Third cloud base height(third_cbh)
• east longitude for all the input platforms.(lon)

SGP/SONDE/B1 - Incorrect surface temperature

The operator entered 8.1 degC as the surface temperature for this sounding instead of -8.1 
degC.  This is the only value affected.

• Raw data stream - documentation not supported(Raw data stream - documentation not supported)

• Dry-Bulb Temperature(tdry)

• Dry-Bulb Temperature(tdry)

SGP/SONDE/B1 - Bad sounding data (incorrect calibration?)

I'm not sure what happened here but the temperature data for this sounding
clearly are wrong.  Along with the missing humidity data and the problems
the operator reported with his previous sounding it looks as if all the data
in this file are bad.  It may be that the sensor was damaged at launch (it
was very windy).

• Raw data stream - documentation not supported(Raw data stream - documentation not supported)

• east longitude for all the input platforms.(lon)
• Ascent Rate(asc)
• Time offset of tweaks from base_time(time_offset)
• Dry-Bulb Temperature(tdry)
• Surface dew point temperature(dp)
• north latitude for all the input platforms.(lat)
• altitude above sea levelaltunits(alt)
• surface wind speed(wspd)
• Relative humidity scaled, by total column amount from MWR(rh)
• Wind Status(wstat)
• pressure at constant pressure surface(pres)
• Time offset from base_time(base_time)
• Wind Direction(deg)

• Surface dew point temperature(dp)
• Wind Status(wstat)
• east longitude for all the input platforms.(lon)
• pressure at constant pressure surface(pres)
• model meridional wind velocity(v_wind)
• Time offset of tweaks from base_time(time_offset)
• Relative humidity scaled, by total column amount from MWR(rh)
• altitude above sea levelaltunits(alt)
• surface wind speed(wspd)
• Dry-Bulb Temperature(tdry)
• Time offset from base_time(base_time)
• north latitude for all the input platforms.(lat)
• Wind Direction(deg)
• Ascent Rate(asc)
• model zonal wind velocity(u_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.

• Time offset from base_time(base_time)
• east longitude for all the input platforms.(lon)
• Wind Direction(deg)
• Ascent Rate(asc)
• surface wind speed(wspd)
• Relative humidity scaled, by total column amount from MWR(rh)
• Dry-Bulb Temperature(tdry)
• Surface dew point temperature(dp)
• Wind Status(wstat)
• altitude above sea levelaltunits(alt)
• north latitude for all the input platforms.(lat)
• pressure at constant pressure surface(pres)
• Time offset of tweaks from base_time(time_offset)

• Raw data stream - documentation not supported(Raw data stream - documentation not supported)

• Dry-Bulb Temperature(tdry)
• Time offset of tweaks from base_time(time_offset)
• model zonal wind velocity(u_wind)
• east longitude for all the input platforms.(lon)
• north latitude for all the input platforms.(lat)
• Relative humidity scaled, by total column amount from MWR(rh)
• pressure at constant pressure surface(pres)
• Ascent Rate(asc)
• Wind Direction(deg)
• Surface dew point temperature(dp)
• altitude above sea levelaltunits(alt)
• Wind Status(wstat)
• Time offset from base_time(base_time)
• surface wind speed(wspd)
• model meridional wind velocity(v_wind)

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.

• altitude above sea levelaltunits(alt)

SGP/SONDE/B4 - Soundings contaminated by interference

These five soundings, done in succession on 11/07/2002 as part of the SCM/IOP are 
contaminated by interference.  I can't tell whether the problem has to do with improper tuning of 
the radiosondes, inadequate frequency separation among radiosondes launched from 
different locations, or some other operator problem.  I suspect that there is an operator 
component to the difficulty because the surface pressure is given as an unreasonably low 896.6 
hPa on the 1730 sounding and 886.1 hPa on the 2331 sounding.  This may indicate that the 
ground station was locked another station's radiosonde rather than on the B4 radiosonde.

• Relative humidity scaled, by total column amount from MWR(rh)
• east longitude for all the input platforms.(lon)
• pressure at constant pressure surface(pres)
• north latitude for all the input platforms.(lat)
• Dry-Bulb Temperature(tdry)
• altitude above sea levelaltunits(alt)

• maximum height attained by the balloon in pressure units(max_height_sonde)
• MWR IPM output for 23.8 GHz sky brightness temperature using sonde T,P,RH(model_tbsky23)
• Integrated vapor column from sonde using MWR Instrument Performance Model (IPM)(integ_vap_sonde)
• MWR IPM output for atmospheric mean radiating temp using sonde T,P,RH(model_tmr31)
• MWR IPM output for 31.4 GHz sky brightness temperature using sonde T,P,RH(model_tbsky31)
• MWR IPM output for atmospheric mean radiating temp using sonde T,P,RH(model_tmr23)

• surface wind speed(wspd)
• Surface dew point temperature(dp)
• east longitude for all the input platforms.(lon)
• north latitude for all the input platforms.(lat)
• model meridional wind velocity(v_wind)
• Dry-Bulb Temperature(tdry)
• model zonal wind velocity(u_wind)
• Relative humidity scaled, by total column amount from MWR(rh)
• pressure at constant pressure surface(pres)
• Ascent Rate(asc)
• altitude above sea levelaltunits(alt)
• Wind Direction(deg)

• altitude above sea levelaltunits(alt)
• north latitude for all the input platforms.(lat)
• Wind Direction(deg)
• pressure at constant pressure surface(pres)
• surface wind speed(wspd)
• Dry-Bulb Temperature(tdry)
• Surface dew point temperature(dp)
• model meridional wind velocity(v_wind)
• east longitude for all the input platforms.(lon)
• Ascent Rate(asc)
• Relative humidity scaled, by total column amount from MWR(rh)
• model zonal wind velocity(u_wind)

SGP/SONDE/B4 - Possible interference in B4 sounding 20021110.1729

There is a strange inversion aloft in the subject sounding.  The
temperature goes from -56.3 degC to -51.5 degC in less than two
minutes (approximately .72 km).  This is somewhat below the estimated
tropopause height.  I suspect this may be an interference problem,
but note that both the recorded pressure and RH values are reasonably
continuous.  More accurate assessment would require analysis of the
absolutely raw binary data; something that would require effort beyond
the limits of my IM funding.

• Raw data stream - documentation not supported(Raw data stream - documentation not supported)

• surface wind speed(wspd)
• Surface dew point temperature(dp)
• east longitude for all the input platforms.(lon)
• Wind Status(wstat)
• north latitude for all the input platforms.(lat)
• model meridional wind velocity(v_wind)
• Dry-Bulb Temperature(tdry)
• model zonal wind velocity(u_wind)
• Relative humidity scaled, by total column amount from MWR(rh)
• pressure at constant pressure surface(pres)
• Ascent Rate(asc)
• Time offset from base_time(base_time)
• Time offset of tweaks from base_time(time_offset)
• Wind Direction(deg)
• altitude above sea levelaltunits(alt)

• Time offset from base_time(base_time)
• altitude above sea levelaltunits(alt)
• north latitude for all the input platforms.(lat)
• Wind Direction(deg)
• pressure at constant pressure surface(pres)
• surface wind speed(wspd)
• Dry-Bulb Temperature(tdry)
• Time offset of tweaks from base_time(time_offset)
• Surface dew point temperature(dp)
• model meridional wind velocity(v_wind)
• east longitude for all the input platforms.(lon)
• Ascent Rate(asc)
• Relative humidity scaled, by total column amount from MWR(rh)
• model zonal wind velocity(u_wind)
• Wind Status(wstat)

SGP/SONDE/B4 - B4 sounding contaminated by interference

Much of this sounding is contaminated, apparently by interference from another sonde 
signal.  It is still no clear why this seems to happen more frequently at B4 than the other 
sites, especially since the wind seems to have been from the west and B4 should be the most 
upwind station.

• Raw data stream - documentation not supported(Raw data stream - documentation not supported)

• surface wind speed(wspd)
• Surface dew point temperature(dp)
• east longitude for all the input platforms.(lon)
• Wind Status(wstat)
• north latitude for all the input platforms.(lat)
• model meridional wind velocity(v_wind)
• Dry-Bulb Temperature(tdry)
• model zonal wind velocity(u_wind)
• Relative humidity scaled, by total column amount from MWR(rh)
• pressure at constant pressure surface(pres)
• Ascent Rate(asc)
• Time offset from base_time(base_time)
• Time offset of tweaks from base_time(time_offset)
• Wind Direction(deg)
• altitude above sea levelaltunits(alt)

• Time offset from base_time(base_time)
• altitude above sea levelaltunits(alt)
• north latitude for all the input platforms.(lat)
• Wind Direction(deg)
• pressure at constant pressure surface(pres)
• surface wind speed(wspd)
• Dry-Bulb Temperature(tdry)
• Time offset of tweaks from base_time(time_offset)
• Surface dew point temperature(dp)
• model meridional wind velocity(v_wind)
• east longitude for all the input platforms.(lon)
• Ascent Rate(asc)
• Relative humidity scaled, by total column amount from MWR(rh)
• model zonal wind velocity(u_wind)
• Wind Status(wstat)

SGP/SONDE/B1 - Temperature sensor failed

It appears that the temperature sensor on this sonde broke shortly after launch with the 
effect that the temperatures read approximately 30 degC too low.  Other measurements that 
do not rely on the temperature, for example pressure and wind velocity, should be OK.

• Relative humidity scaled, by total column amount from MWR(rh)
• Dry-Bulb Temperature(tdry)
• Surface dew point temperature(dp)

• Surface dew point temperature(dp)
• Dry-Bulb Temperature(tdry)
• Relative humidity scaled, by total column amount from MWR(rh)

TWP/SONDE/C2  - Broken Temperature Sensor

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

• Relative humidity scaled, by total column amount from MWR(rh)
• Dry-Bulb Temperature(tdry)
• Surface dew point temperature(dp)

• Surface dew point temperature(dp)
• Dry-Bulb Temperature(tdry)
• Relative humidity scaled, by total column amount from MWR(rh)

TWP/SONDE/C1  - Broken Temperature Sensor

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

• Surface dew point temperature(dp)
• Relative humidity scaled, by total column amount from MWR(rh)
• Dry-Bulb Temperature(tdry)

• Relative humidity scaled, by total column amount from MWR(rh)
• Dry-Bulb Temperature(tdry)
• Surface dew point temperature(dp)

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.

• Surface dew point temperature(dp)
• Relative humidity scaled, by total column amount from MWR(rh)

• Relative humidity scaled, by total column amount from MWR(rh)
• Surface dew point temperature(dp)

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 scaled, by total column amount from MWR(rh)
• Surface dew point temperature(dp)

• Surface dew point temperature(dp)
• Relative humidity scaled, by total column amount from MWR(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.

• Surface dew point temperature(dp)
• Relative humidity scaled, by total column amount from MWR(rh)

• Relative humidity scaled, by total column amount from MWR(rh)
• Surface dew point 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.

• Surface dew point temperature(dp)
• Relative humidity scaled, by total column amount from MWR(rh)

• Relative humidity scaled, by total column amount from MWR(rh)
• Surface dew point temperature(dp)

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.

• Relative humidity scaled, by total column amount from MWR(rh)
• Dry-Bulb Temperature(tdry)
• Surface dew point temperature(dp)

• Surface dew point temperature(dp)
• Relative humidity scaled, by total column amount from MWR(rh)
• Dry-Bulb Temperature(tdry)

TWP/SONDE/C1 - Broken temperature sensor

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

• Surface dew point temperature(dp)
• Relative humidity scaled, by total column amount from MWR(rh)
• Dry-Bulb Temperature(tdry)

• Relative humidity scaled, by total column amount from MWR(rh)
• Dry-Bulb Temperature(tdry)
• Surface dew point temperature(dp)

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 scaled, by total column amount from MWR(rh)
• Surface dew point temperature(dp)

• Surface dew point temperature(dp)
• Relative humidity scaled, by total column amount from MWR(rh)

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)

• Dry-Bulb Temperature(tdry)
• Ascent Rate(asc)
• east longitude for all the input platforms.(lon)
• north latitude for all the input platforms.(lat)
• Wind Status(wstat)
• surface wind speed(wspd)
• model meridional wind velocity(v_wind)
• pressure at constant pressure surface(pres)
• Time offset of tweaks from base_time(time_offset)
• Relative humidity scaled, by total column amount from MWR(rh)
• Surface dew point temperature(dp)
• Time offset from base_time(base_time)
• model zonal wind velocity(u_wind)
• Wind Direction(deg)
• altitude above sea levelaltunits(alt)

• Raw data stream - documentation not supported(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 scaled, by total column amount from MWR(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 scaled, by total column amount from MWR(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 scaled, by total column amount from MWR(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 scaled, by total column amount from MWR(rh)
• Surface dew point temperature(dp)

TWP/SONDE/C1 - Broken temperature sensor

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

• Surface dew point temperature(dp)
• Relative humidity scaled, by total column amount from MWR(rh)
• 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.

• Surface dew point temperature(dp)
• Relative humidity scaled, by total column amount from MWR(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.

• Relative humidity scaled, by total column amount from MWR(rh)
• Surface dew point 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.

• Surface dew point temperature(dp)
• Relative humidity scaled, by total column amount from MWR(rh)

• Relative humidity scaled, by total column amount from MWR(rh)
• Surface dew point 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.

• Surface dew point temperature(dp)
• Relative humidity scaled, by total column amount from MWR(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 (~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.

• Surface dew point temperature(dp)
• Relative humidity scaled, by total column amount from MWR(rh)

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.

• Surface dew point temperature(dp)
• Relative humidity scaled, by total column amount from MWR(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 (~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.

• Surface dew point temperature(dp)
• Relative humidity scaled, by total column amount from MWR(rh)

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 scaled, by total column amount from MWR(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)
• east longitude for all the input platforms.(lon)
• north latitude for all the input platforms.(lat)
• Wind Status(wstat)
• surface wind speed(wspd)
• model meridional wind velocity(v_wind)
• pressure at constant pressure surface(pres)
• Time offset of tweaks from base_time(time_offset)
• Relative humidity scaled, by total column amount from MWR(rh)
• Surface dew point temperature(dp)
• Time offset from base_time(base_time)
• model zonal wind velocity(u_wind)
• Wind Direction(deg)
• altitude above sea levelaltunits(alt)

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.

• surface wind speed(wspd)
• Wind Direction(deg)
• Ascent Rate(asc)
• Dry-Bulb Temperature(tdry)
• model meridional wind velocity(v_wind)
• Time offset from base_time(base_time)
• pressure at constant pressure surface(pres)
• north latitude for all the input platforms.(lat)
• model zonal wind velocity(u_wind)
• east longitude for all the input platforms.(lon)
• Surface dew point temperature(dp)
• Wind Status(wstat)
• Time offset of tweaks from base_time(time_offset)
• Relative humidity scaled, by total column amount from MWR(rh)
• altitude above sea levelaltunits(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 scaled, by total column amount from MWR(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 scaled, by total column amount from MWR(rh)
• Surface dew point 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 (~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.

• Surface dew point temperature(dp)
• Relative humidity scaled, by total column amount from MWR(rh)

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.

• Relative humidity scaled, by total column amount from MWR(rh)
• Surface dew point temperature(dp)

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).

• altitude above sea levelaltunits(alt)

• Raw data stream - documentation not supported(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.

• Surface dew point temperature(dp)
• Relative humidity scaled, by total column amount from MWR(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 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.

• Surface dew point temperature(dp)
• Relative humidity scaled, by total column amount from MWR(rh)

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.

• surface wind speed(wspd)
• Wind Direction(deg)
• Ascent Rate(asc)
• Dry-Bulb Temperature(tdry)
• model meridional wind velocity(v_wind)
• Time offset from base_time(base_time)
• pressure at constant pressure surface(pres)
• north latitude for all the input platforms.(lat)
• model zonal wind velocity(u_wind)
• east longitude for all the input platforms.(lon)
• Surface dew point temperature(dp)
• Wind Status(wstat)
• Time offset of tweaks from base_time(time_offset)
• Relative humidity scaled, by total column amount from MWR(rh)
• altitude above sea levelaltunits(alt)

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 scaled, by total column amount from MWR(rh)
• 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 scaled, by total column amount from MWR(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 scaled, by total column amount from MWR(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 scaled, by total column amount from MWR(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 scaled, by total column amount from MWR(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 scaled, by total column amount from MWR(rh)
• Surface dew point temperature(dp)

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.

• Relative humidity scaled, by total column amount from MWR(rh)
• Surface dew point temperature(dp)

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.

• Relative humidity scaled, by total column amount from MWR(rh)
• Dry-Bulb Temperature(tdry)
• Surface dew point temperature(dp)

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

• Relative humidity scaled, by total column amount from MWR(rh)
• Surface dew point temperature(dp)

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.

• Relative humidity scaled, by total column amount from MWR(rh)
• Dry-Bulb Temperature(tdry)
• altitude above sea levelaltunits(alt)
• pressure at constant pressure surface(pres)
• Surface dew point temperature(dp)

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.

• Relative humidity scaled, by total column amount from MWR(rh)
• Dry-Bulb Temperature(tdry)
• Surface dew point temperature(dp)

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.

• Relative humidity scaled, by total column amount from MWR(rh)
• Surface dew point temperature(dp)

SGP/SONDE - Dry bias in sonde RH

Vaisala has confirmed ARM findings of an apparent dry bias in the
relative humidity measured by RS-80H radiosondes.  The cause of
the dry bias is thought to be contamination of the humidity sensor
by volatile organic substances originating from some plastic parts
of the radiosonde.  The amount of contamination is a function of
the time between the date of sonde manufacture and its use.  All
RS-80H sondes manufactured before week 34 of 1998 will show this
bias.  After week 34 of 1998 Vaisala changed its packaging to
reduce, but not eliminate the contamination problem.

Starting with RS-80 radiosonde manufactured in late June 2000 Vaisala
enclosed the sensor boom in an inert plastic shield, thereby eliminating
the contamination that caused the dry bias.

Starting in May 2001 at the SGP, May 2002 at the TWP, and later 2002
at the NSA, ARM has moved to using RS-90 radiosondes.  These sondes
are not subject to the contaminatino that caused the dry bias.

Vaisala is in the process of developing an algorithm that can be 
used to estimate the correct RH from knowledge of the sonde age.
All of the ARM sounding data have sufficient metadata available
to apply the correction.

Additionally, ARM has funded a Science Team effort (Milosevich) to
develop a 'best' correction algorithm for the RS-80 radiosonde humidity
data.  When completed this algorithm will allow us to reprocess the
accumulated RS-80 data and produce a new data platform with what we
hope will be more accurate data.

• Raw data stream - documentation not supported(Raw data stream - documentation not supported)

• (Development raw data stream - documentation not supported)

• Raw data stream - documentation not supported(Raw data stream - documentation not supported)

• Relative humidity scaled, by total column amount from MWR(rh)
• Surface dew point temperature(dp)

• (Development raw data stream - documentation not supported)

• (Development data stream - documentation not supported)

• Surface dew point temperature(dp)
• Relative humidity scaled, by total column amount from MWR(rh)

• (Development raw data stream - documentation not supported)

• Surface dew point temperature(dp)
• Relative humidity scaled, by total column amount from MWR(rh)

• (Development data stream - documentation not supported)

• (Development data stream - documentation not supported)

• Relative humidity scaled, by total column amount from MWR(rh)
• Surface dew point temperature(dp)

• Raw data stream - documentation not supported(Raw data stream - documentation not supported)

• Raw data stream - documentation not supported(Raw data stream - documentation not supported)

• (Development raw data stream - documentation not supported)

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• Relative humidity scaled, by total column amount from MWR(rh)
• Surface dew point temperature(dp)

• Surface dew point temperature(dp)
• Relative humidity scaled, by total column amount from MWR(rh)

• Raw data stream - documentation not supported(Raw data stream - documentation not supported)

• Relative humidity scaled, by total column amount from MWR(rh)
• Surface dew point temperature(dp)

• Relative humidity scaled, by total column amount from MWR(rh)
• Surface dew point temperature(dp)

• Surface dew point temperature(dp)
• Relative humidity scaled, by total column amount from MWR(rh)

• Raw data stream - documentation not supported(Raw data stream - documentation not supported)

• (Development raw data stream - documentation not supported)

• Surface dew point temperature(dp)
• Relative humidity scaled, by total column amount from MWR(rh)

• Raw data stream - documentation not supported(Raw data stream - documentation not supported)

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• Raw data stream - documentation not supported(Raw data stream - documentation not supported)

• Surface dew point temperature(dp)
• Relative humidity scaled, by total column amount from MWR(rh)

• Raw data stream - documentation not supported(Raw data stream - documentation not supported)

• Surface dew point temperature(dp)
• Relative humidity scaled, by total column amount from MWR(rh)

• (Development data stream - documentation not supported)

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• (Development raw data stream - documentation not supported)

• Relative humidity scaled, by total column amount from MWR(rh)
• Surface dew point temperature(dp)

• Relative humidity scaled, by total column amount from MWR(rh)
• Surface dew point temperature(dp)

• Raw data stream - documentation not supported(Raw data stream - documentation not supported)

• Surface dew point temperature(dp)
• Relative humidity scaled, by total column amount from MWR(rh)

• Relative humidity scaled, by total column amount from MWR(rh)
• Surface dew point temperature(dp)

• Relative humidity scaled, by total column amount from MWR(rh)
• Surface dew point temperature(dp)

• Surface dew point temperature(dp)
• Relative humidity scaled, by total column amount from MWR(rh)

• Surface dew point temperature(dp)
• Relative humidity scaled, by total column amount from MWR(rh)

• (Development raw data stream - documentation not supported)

• Surface dew point temperature(dp)
• Relative humidity scaled, by total column amount from MWR(rh)

• Surface dew point temperature(dp)
• Relative humidity scaled, by total column amount from MWR(rh)

• (Development data stream - documentation not supported)

• Surface dew point temperature(dp)
• Relative humidity scaled, by total column amount from MWR(rh)

• Relative humidity scaled, by total column amount from MWR(rh)
• Surface dew point temperature(dp)

• (Development data stream - documentation not supported)

• (Development data stream - documentation not supported)

• Relative humidity scaled, by total column amount from MWR(rh)
• Surface dew point temperature(dp)

• Raw data stream - documentation not supported(Raw data stream - documentation not supported)

• (Development data stream - documentation not supported)

• (Development data stream - documentation not supported)

• (Development data stream - documentation not supported)

• Relative humidity scaled, by total column amount from MWR(rh)
• Surface dew point temperature(dp)

• Relative humidity scaled, by total column amount from MWR(rh)
• Surface dew point temperature(dp)

• Surface dew point temperature(dp)
• Relative humidity scaled, by total column amount from MWR(rh)

• Surface dew point temperature(dp)
• Relative humidity scaled, by total column amount from MWR(rh)

• (Development raw data stream - documentation not supported)

• Raw data stream - documentation not supported(Raw data stream - documentation not supported)

• Surface dew point temperature(dp)
• Relative humidity scaled, by total column amount from MWR(rh)

• Relative humidity scaled, by total column amount from MWR(rh)
• Surface dew point temperature(dp)

• Surface dew point temperature(dp)
• Relative humidity scaled, by total column amount from MWR(rh)

• Relative humidity scaled, by total column amount from MWR(rh)
• Surface dew point temperature(dp)

• Raw data stream - documentation not supported(Raw data stream - documentation not supported)

• (Development data stream - documentation not supported)

• Surface dew point temperature(dp)
• Relative humidity scaled, by total column amount from MWR(rh)

• Relative humidity scaled, by total column amount from MWR(rh)
• Surface dew point temperature(dp)

• (Development raw data stream - documentation not supported)

• Relative humidity scaled, by total column amount from MWR(rh)
• Surface dew point temperature(dp)

• Surface dew point temperature(dp)
• Relative humidity scaled, by total column amount from MWR(rh)

• Surface dew point temperature(dp)
• Relative humidity scaled, by total column amount from MWR(rh)

• Relative humidity scaled, by total column amount from MWR(rh)
• Surface dew point temperature(dp)

• (Development data stream - documentation not supported)

• (Development data stream - documentation not supported)

• Raw data stream - documentation not supported(Raw data stream - documentation not supported)

• (Development data stream - documentation not supported)