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/SMET/C2 - Wind Sensor failure

Wind sensor #2 (lower one) failed.  Wind direction showed little or
no variation, unlike the colocated sensor #1.  This caused lower
wind speed values as the sensor was not rotating properly to orient
itself parallel to the wind stream.  The sensor was replaced.

• Wind #2 speed maximum(wind2_spd_max)
• Wind #2 speed vector average(wind2_spd_vec_avg)
• Wind #2 direction standard deviation(wind2_dir_sd)
• Wind #2 speed maximum gust(wind2_spd_max_gust)
• Wind #2 direction vector average(wind2_dir_vec_avg)
• Wind #2 speed standard deviation(wind2_spd_sd)
• Wind #2 speed arithmetic average(wind2_spd_arith_avg)
• Wind #2 speed minimum(wind2_spd_min)

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/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/SMET/C2 - All data missing due to logger change

All data are missing at this site during this time period due to collection system, logger 
and enclosure change.  Data resumed after change.

• Relative humidity mean(relh_mean)
• Wind #1 direction standard deviation(wind1_dir_sd)
• Mean Air Temperature or Hardware Error(temp_mean)
• Wind #1 speed maximum(wind1_spd_max)
• Wind #2 speed maximum gust(wind2_spd_max_gust)
• Wind #1 speed standard deviation(wind1_spd_sd)
• Time offset from base_time(base_time)
• Max Temperature at lowest Model Level- 1 hr(temp_max)
• east longitude for all the input platforms.(lon)
• Wind #2 speed vector average(wind2_spd_vec_avg)
• Internal Logger Temperature(logger_temp)
• Bit data. See details.(bit_data)
• Time offset of tweaks from base_time(time_offset)
• Wind #2 direction standard deviation(wind2_dir_sd)
• Wind #1 speed arithmetic average(wind1_spd_arith_avg)
• Wind #1 speed vector average(wind1_spd_vec_avg)
• precipitation minimum(precip_min)
• Wind #2 speed minimum(wind2_spd_min)
• Vapor pressure mean(vappress_mean)
• Internal voltage(internal_voltage)
• Std Dev of Relative Humidity or Hardware Error Code(relh_sd)
• Wind #2 speed maximum(wind2_spd_max)
• Wind #1 speed minimum(wind1_spd_min)
• GPS raw data filename(filename)
• Temperature standard deviation(temp_sd)
• Min Temperature at lowest Model Level- 1 hr(temp_min)
• Atmospheric pressure(atmos_pressure)
• altitude above sea levelaltunits(alt)
• Relative humidity minimum(relh_min)
• Wind #2 speed standard deviation(wind2_spd_sd)
• Wind #2 speed arithmetic average(wind2_spd_arith_avg)
• Vapor pressure standard deviation(vappress_sd)
• north latitude for all the input platforms.(lat)
• Relative humidity maximum(relh_max)
• Precipitation maximum(precip_max)
• Wind #1 direction vector average(wind1_dir_vec_avg)
• External voltage(external_voltage)
• Wind #2 direction vector average(wind2_dir_vec_avg)
• Wind #1 speed maximum gust(wind1_spd_max_gust)
• Precipitation mean(precip_mean)
• Precipitation standard deviation(precip_sd)

TWP/SMET/C2 - connection and timing issues with new logger

Atmospheric pressure data are intermittent during this time period due to connection 
problems and program timing issues with new logger installation.  Data resumed normal 
operations after this time period.

• Atmospheric pressure(atmos_pressure)

TWP/SMET/C2 - Negative rainfall rates

Due to limitations of the Zeno dataloggers all voltage measurements
from the optical rain gauge (ORG) were converted to rainfall rates. 
This resulted in negative values for rain rates.  Any value below
0.10 mm/hr should be considered to be 0 mm/hr.  New dataloggers 
alleviated this problem.

• Precipitation maximum(precip_max)
• Precipitation mean(precip_mean)
• precipitation minimum(precip_min)
• Precipitation standard deviation(precip_sd)

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)

TWP/SMET/C2 - Incorrect rainrate equation used.

There are two different Optical Raingages in use at the TWP sites.  The incorrect equation 
was used at this site.  The incorrect equation is (25*(V^1.87)) - 0.15.
The correct equation is (20*(V^2)) - 0.05.  The correct equation was installed.

• Precipitation maximum(precip_max)
• Precipitation mean(precip_mean)
• precipitation minimum(precip_min)
• Precipitation standard deviation(precip_sd)

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/SMET/C2 - Instrument failure

Upper wind sensor failed. Wind direction was reported at a near constant value of 69 
degrees and was significantly different than the lower wind sensor's direction values. Sensor 
replaced.

• Wind #1 direction standard deviation(wind1_dir_sd)
• Wind #1 direction vector average(wind1_dir_vec_avg)

TWP/SMET/C2 - Upper wind sensor failure

After replacement on 03/03/2005 the upper wind sensor began reporting erroneous values 
again on 03/09/2005 becoming very apparent after 03/17/2005.  Wind speed data appears 
reasonable but the wind direction data do not agree well with the lower wind sensor.

• Wind #1 direction standard deviation(wind1_dir_sd)
• Wind #1 direction vector average(wind1_dir_vec_avg)

TWP/SMET/C2 - Reprocess: Incorrect Units Listed for Vapor Pressure

The netcdf header file incorrectly listed the units of Vapor Pressure as hPa when in fact 
they were kPa.

• Vapor pressure standard deviation(vappress_sd)
• Vapor pressure mean(vappress_mean)

TWP/SMET/C2 - RH failure

The RH values were frequently over MAX value of 104% starting on 7/10/2005 through end of 
period.  Sensor was replaced.

• Relative humidity mean(relh_mean)
• Relative humidity maximum(relh_max)
• Std Dev of Relative Humidity or Hardware Error Code(relh_sd)
• Relative humidity minimum(relh_min)

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/SMET/C2 - Instrument maintenance

Instrument calibration and testing were taking place for brief periods.

• Relative humidity mean(relh_mean)
• Wind #1 direction standard deviation(wind1_dir_sd)
• Mean Air Temperature or Hardware Error(temp_mean)
• Wind #1 speed maximum(wind1_spd_max)
• Wind #2 speed maximum gust(wind2_spd_max_gust)
• Wind #1 speed standard deviation(wind1_spd_sd)
• Max Temperature at lowest Model Level- 1 hr(temp_max)
• Wind #2 speed vector average(wind2_spd_vec_avg)
• Wind #2 direction standard deviation(wind2_dir_sd)
• Wind #1 speed vector average(wind1_spd_vec_avg)
• Wind #1 speed arithmetic average(wind1_spd_arith_avg)
• Vapor pressure mean(vappress_mean)
• Wind #2 speed minimum(wind2_spd_min)
• Std Dev of Relative Humidity or Hardware Error Code(relh_sd)
• Wind #1 speed minimum(wind1_spd_min)
• Wind #2 speed maximum(wind2_spd_max)
• Temperature standard deviation(temp_sd)
• Min Temperature at lowest Model Level- 1 hr(temp_min)
• Wind #2 speed standard deviation(wind2_spd_sd)
• Relative humidity minimum(relh_min)
• Wind #2 speed arithmetic average(wind2_spd_arith_avg)
• Vapor pressure standard deviation(vappress_sd)
• Relative humidity maximum(relh_max)
• Wind #1 direction vector average(wind1_dir_vec_avg)
• Wind #2 direction vector average(wind2_dir_vec_avg)
• Wind #1 speed maximum gust(wind1_spd_max_gust)

TWP/SMET/C2 - ORG data incorrect

Data from the ORG was incorrect due to heavy condensation on the lens.

• Precipitation maximum(precip_max)
• Precipitation mean(precip_mean)
• precipitation minimum(precip_min)
• Precipitation standard deviation(precip_sd)

TWP/SMET/C2 - Tower down for calibration activities

Tower lowered, wind vanes spun at different frequencies, and ORG tested with electronic 
rain.

• Relative humidity mean(relh_mean)
• Wind #1 direction standard deviation(wind1_dir_sd)
• Mean Air Temperature or Hardware Error(temp_mean)
• Wind #1 speed maximum(wind1_spd_max)
• Wind #2 speed maximum gust(wind2_spd_max_gust)
• Wind #1 speed standard deviation(wind1_spd_sd)
• Max Temperature at lowest Model Level- 1 hr(temp_max)
• Wind #2 speed vector average(wind2_spd_vec_avg)
• Wind #2 direction standard deviation(wind2_dir_sd)
• Wind #1 speed arithmetic average(wind1_spd_arith_avg)
• Wind #1 speed vector average(wind1_spd_vec_avg)
• precipitation minimum(precip_min)
• Vapor pressure mean(vappress_mean)
• Wind #2 speed minimum(wind2_spd_min)
• Std Dev of Relative Humidity or Hardware Error Code(relh_sd)
• Wind #1 speed minimum(wind1_spd_min)
• Wind #2 speed maximum(wind2_spd_max)
• Temperature standard deviation(temp_sd)
• Min Temperature at lowest Model Level- 1 hr(temp_min)
• Relative humidity minimum(relh_min)
• Wind #2 speed standard deviation(wind2_spd_sd)
• Wind #2 speed arithmetic average(wind2_spd_arith_avg)
• Vapor pressure standard deviation(vappress_sd)
• Precipitation maximum(precip_max)
• Relative humidity maximum(relh_max)
• Wind #1 direction vector average(wind1_dir_vec_avg)
• Wind #2 direction vector average(wind2_dir_vec_avg)
• Wind #1 speed maximum gust(wind1_spd_max_gust)
• Precipitation mean(precip_mean)
• Precipitation standard deviation(precip_sd)

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)