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/MWR/C2 - thermal instability

The MWR required an unusually long time to reach thermal stability after a 4-day outage 
due to a power failure that damaged the blower/heater assembly. Also during this period, 
the heater, which had been replaced, appears to have been on continously, causing the data 
to be inappropriately flagged.

• 31.4 GHz sky signal(sky31)
• Noise injection temp at nominal temperature at 31.4 GHz(tnd_nom31)
• Noise injection temp at nominal temperature at 23.8 GHz(tnd_nom23)
• Water on Teflon window (1=WET, 0=DRY)(wet_window)
• Temperature correction coefficient at 31.4 GHz(tc31)
• Temperature correction coefficient at 23.8 GHz(tc23)
• Sky brightness temperature at 23.8 GHz(tbsky23)
• MWR column precipitable water vapor(vap)
• 23.8 GHz sky signal(sky23)
• Sky brightness temperature at 31.4 GHz(tbsky31)
• Averaged total liquid water along LOS path(liq)

• 31.4 GHz sky signal(tipsky31)
• Temperature correction coefficient at 23.8 GHz(tc23)
• Noise injection temp at nominal temperature at 31.4 GHz(tnd_nom31)
• 23.8 GHz sky signal(tipsky23)
• Water on Teflon window (1=WET, 0=DRY)(wet_window)
• Noise injection temp at nominal temperature at 23.8 GHz(tnd_nom23)
• Temperature correction coefficient at 31.4 GHz(tc31)

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/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 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/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.

• Mean Relative Humidity(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)
• base time(base_time)
• Temperature maximum(temp_max)
• lon(lon)
• Wind #2 speed vector average(wind2_spd_vec_avg)
• Logger panel 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)
• Battery 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)
• Std Dev of Air Temperature(temp_sd)
• Temperature minimum(temp_min)
• Barometric Pressure(atmos_pressure)
• Dummy altitude for Zeb(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)
• lat(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.

• Barometric 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)
• 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/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/MWR/C2 - Data collection problem

Large, frequent data gaps occurred due to a failing laptop computer. The problem was 
corrected when a new computer was installed.

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

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

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

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/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/MWR/C2 - Heater problem

When the wiring of the air temperature sensor was checked the heater apparently began 
activating too often.

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

• Fraction of data in averaging interval with water on Teflon window(water_flag_fraction)

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

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/MWR/C2 - mixer temperature

When the wiring of the air temperature sensor was checked the mixer temperature 
unexpectedly decreased 4 degrees. It increased to its normal value when the dielectric window was 
replaced. The problem was probably caused by a loose and/or corroded connection.

• Mixer kinetic (physical) temperature(tkxc)

• Mixer kinetic (physical) temperature(tkxc)

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.

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

TWP/MWR/C2 - Reprocessed: 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).

The Rosenkranz-based retrieval coefficients became active at TWP.C2 20020427.0600.  The 
MONORTM-based retrieval coefficients became active at TWP.C2 20050630.2100.

Note: The TWP.C2 data for 19981028-20050630 have been reprocessed to apply the 
MONORTM-based retrievals for all time.  The reprocessed data were archived 20061003.

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

• Ensemble average for MWR liquid in window centered about balloon release(mean_liq_mwr)
• Ensemble average for MWR vapor in window centered about balloon release(mean_vap_mwr)

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

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/SMET/C2 - Instrument maintenance

Instrument calibration and testing were taking place for brief periods.

• Mean Relative Humidity(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)
• Temperature maximum(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)
• Std Dev of Air Temperature(temp_sd)
• Temperature minimum(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/MWR/C2 - New software version (4.15) installed

A problem began with the installation of MWR.EXE version 4.12 in November 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 9/15/2005. As a consequence of this 
upgrade, the tip curve frequency increased. The tip cycle time decreased from ~60s to ~50s.

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

• 31.4 GHz sky signal(tipsky31)
• (tknd)
• Blackbody kinetic temperature(tkbb)
• Noise injection temp at 31.4 GHz derived from this tip(tnd31I)
• Noise injection temp at 31.4 GHz adjusted to tkbb(tnd31)
• Noise injection temp at 23.8 GHz adjusted to tkbb(tnd23)
• 31.4 GHz goodness-of-fit coefficient(r31)
• 23.8 GHz goodness-of-fit coefficient(r23)
• Temperature correction coefficient at 23.8 GHz(tc23)
• Noise injection temp at nominal temperature at 31.4 GHz(tnd_nom31)
• 23.8 GHz sky signal(tipsky23)
• 31.4 GHz blac2body+noise injection signal(bbn31)
• 31.4 GHz blackbody(bb31)
• Noise injection temp at 23.8 GHz derived from this tip(tnd23I)
• Noise injection temp at nominal temperature at 23.8 GHz(tnd_nom23)
• 23.8 GHz blackbody+noise injection signal(bbn23)
• Temperature correction coefficient at 31.4 GHz(tc31)
• Mixer kinetic (physical) temperature(tkxc)
• Ambient temperature(tkair)

TWP/SMET/C2 - Tower down for calibration activities

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

• Mean Relative Humidity(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)
• Temperature maximum(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)
• Std Dev of Air Temperature(temp_sd)
• Temperature minimum(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 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/SMET/C2 - Reprocess: Barometric Data Changed from hPa to kPa

Barometric pressure data was converted from hPa to kPa in order to standardize the 
measurement units among ARM sites and to conform to accepted standard units determined by the 
scientific community.

• Barometric Pressure(atmos_pressure)

TWP/SMET/C2 - Reprocess: Tipping bucket rain gauge added

A tipping bucket rain gauge was added to the TWP.C2 SMET suite of instruments on 20061129. 
Effective 20060926, two new variables (count and rain amount) were added to the end of 
the twpsmet60sC2.b1 datastream.  Between 9/26 and 11/29, the data for these two variables 
are filled with zeros.  Users should not use the data during this period as the zeros are 
not representative of the rain fall at the site.  When reprocessing of this datastream 
occurs these variables will be added for the 19981021-20060926 and data from 
19981021-20061129 will be filled with -9999 (missing).

• base time(base_time)

TWP/MWR/C2 - Missing Data

Data are missing and unrecoverable.

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