TWP/SMET/C3 - Rain blocked pressure port

Atmospheric pressure values were suspect due to anomolous readings during heavy rain 
events.  Suspect blockage of port due to rainfall.  New logger and enclosure corrected problem.

• Barometric Pressure(atmos_pressure)

TWP/SMET/C3 - Data missing due to Logger Change

All Data from this site are missing during this time period due to a change of the 
collection system, logger and enclosure.  Data resumed after change.

• External voltage(external_voltage)
• lat(lat)
• Time offset of tweaks from base_time(time_offset)
• Precipitation maximum(precip_max)
• Wind #2 speed arithmetic average(wind2_spd_arith_avg)
• Battery Voltage(internal_voltage)
• Wind #1 speed minimum(wind1_spd_min)
• Logger panel temperature(logger_temp)
• Wind #2 speed maximum(wind2_spd_max)
• precipitation minimum(precip_min)
• Wind #1 direction standard deviation(wind1_dir_sd)
• Wind #2 speed minimum(wind2_spd_min)
• Wind #1 speed maximum(wind1_spd_max)
• Mean Air Temperature or Hardware Error(temp_mean)
• Temperature maximum(temp_max)
• Vapor pressure mean(vappress_mean)
• Barometric Pressure(atmos_pressure)
• Vapor pressure standard deviation(vappress_sd)
• Mean Relative Humidity(relh_mean)
• Relative humidity maximum(relh_max)
• Wind #1 direction vector average(wind1_dir_vec_avg)
• Wind #1 speed standard deviation(wind1_spd_sd)
• Wind #1 speed vector average(wind1_spd_vec_avg)
• Wind #2 direction vector average(wind2_dir_vec_avg)
• Std Dev of Relative Humidity or Hardware Error Code(relh_sd)
• Relative humidity minimum(relh_min)
• Bit data. See details.(bit_data)
• Precipitation mean(precip_mean)
• Wind #2 speed vector average(wind2_spd_vec_avg)
• base time(base_time)
• Temperature minimum(temp_min)
• Dummy altitude for Zeb(alt)
• Wind #2 speed maximum gust(wind2_spd_max_gust)
• Precipitation standard deviation(precip_sd)
• Wind #1 speed maximum gust(wind1_spd_max_gust)
• Wind #1 speed arithmetic average(wind1_spd_arith_avg)
• lon(lon)
• Wind #2 direction standard deviation(wind2_dir_sd)
• Wind #2 speed standard deviation(wind2_spd_sd)
• Std Dev of Air Temperature(temp_sd)

TWP/SMET/C3 - 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 mean(precip_mean)
• Precipitation maximum(precip_max)
• Precipitation standard deviation(precip_sd)
• precipitation minimum(precip_min)

TWP/SMET/C3 - Data non-representative

Tower mast was lowered for inspection.  Data during this time is non-representative.

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

TWP/SMET/C3 - Instrument logger problem, Sensor failure

The wind_lower direction sensor failed on 4/14 and disagrees significantly with the 
wind_upper direction.  The wind_lower sensor reports a constant value around 0-15 degrees since 
it failed.  Testing showed that excitation channel two on the logger was the problem.  
Logger was replaced by spare.

• Wind #2 direction standard deviation(wind2_dir_sd)
• Wind #2 direction vector average(wind2_dir_vec_avg)

TWP/MWR/C3 - Reprocess - Revised Retrieval Coefficients

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

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

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

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

PWV_MONORTM = 0.9695 * PWV_ROSENKRANZ
LWP_MONORTM = 1.026  * LWP_ROSENKRANZ

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

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

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

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

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

TWP/SMET/C3 - Data not representative

Tower was lowered for radiometer change and characterization.  Wind, temp and RH data not 
representative of local conditions.

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

TWP/SMET/C3 - Towrr lowered for sensor comparisons, data not representative

The tower was lowered for radiometer change and comparisons.  During the time period the 
data listed was not representative.

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

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

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

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

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

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

TWP/MWR/C3 - Instrument failure, Power outage

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

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

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

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

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

TWP/SMET/C3 - Upper wind sensor failure

A lightning strike destroyed the upper (#1) wind sensor.

• Wind #1 direction vector average(wind1_dir_vec_avg)
• Wind #1 speed minimum(wind1_spd_min)
• Wind #1 speed maximum(wind1_spd_max)
• Wind #1 speed standard deviation(wind1_spd_sd)
• Wind #1 speed maximum gust(wind1_spd_max_gust)
• Wind #1 speed arithmetic average(wind1_spd_arith_avg)
• Wind #1 speed vector average(wind1_spd_vec_avg)
• Wind #1 direction standard deviation(wind1_dir_sd)

TWP/SMET/C3 - RH Values Artificially High

Lightning strike caused RH readings to be higher than reasonable (130%).

• Vapor pressure standard deviation(vappress_sd)
• Mean Relative Humidity(relh_mean)
• Relative humidity maximum(relh_max)
• Vapor pressure mean(vappress_mean)
• Std Dev of Relative Humidity or Hardware Error Code(relh_sd)
• Relative humidity minimum(relh_min)

TWP/SMET/C3 - Instrument failure

A lightning strike caused a failure in the ORG.  Rainfall was being continually recorded.

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

TWP/MWR/C3 - REPROCESS- Updated retrieval coefficients

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

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

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

TWP/SMET/C3 - ORG data noisy due to degraded ground

SMET Rain Data began to be noisy during December 2005 and the problem slowly became worse 
over time so that in February 2006 the ORG was reporting with a constant background value 
of around 0.10 mm/hr rain rate.  ORG voltage showed a near constant value above the 85mV 
threshold.  The ground for the ORG had become degraded and was lost due to corrosion.

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

TWP/SMET/C3 - 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/C3 - Reprocess: Tipping bucket rain gauge added

A tipping bucket rain gauge was added to the SMET suite of instruments effective 20060926. 
 Two new variables (count and rain amount) were added at the end of the twpsmet60sC1.b1 
datastream.  When reprocessing of this datastream occurs these variables will be added 
with -9999 (missing) as the value for dates prior to gauge installation.

• base time(base_time)