TWP/MWR/C2 - Uncertainty in clock time

At ARCS2, the MWR computer clock was not being updated because no NTP time service 
software was installed on the computer. During Nauru99, on 6/24/99, the clock was found to be 3 
minutes and 17 seconds fast. 

Assuming that the time was properly set at installation on 10/26/98 (which is not 
indicated in the installation report) and never reset until 6/24/99, the rate of time drift on 
the computer was about +0.8 seconds per day. However, if the time was not reset since 
integration at AIS on 1/14/98 (which is recorded in my integration notes), then the rate of 
drift is about +0.4 seconds per day.

The computer was replaced and time service started on 7/30/99.

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

• 31.4 GHz sky signal(tipsky31)
• 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 blackbody+noise injection signal(bbn31)
• 31.4 GHz Blackbody signal(bb31)
• Noise injection temp at nominal temperature at 23.8 GHz(tnd_nom23)
• Ambient temperature(tkair)
• Noise diode mount temperature(tknd)
• Time offset from 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)
• Actual elevation angle(actel)
• Temperature correction coefficient at 23.8 GHz(tc23)
• 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)
• 23.8 GHz blackbody+noise injection signal(bbn23)
• Mixer kinetic (physical) temperature(tkxc)
• Temperature correction coefficient at 31.4 GHz(tc31)

TWP/C2/SMET Wind Speeds

Beginning on December 24, Anemometer #1 (there are two anemometers on
the SMET stand) occasionally reported wind speed values that were low
relative to the other sensor.  It is clear from the data that the low
reading here is the anomalous one.

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

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

TWP/C2/SMET Wind Speeds

Beginning on December 24, Anemometer #1 (there are two anemometers on
the SMET stand) occasionally reported wind speed values that were low
relative to the other sensor.  It is clear from the data that the low
reading here is the anomalous one.

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

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

TWP/C2/SMET Winds Speeds

Beginning on December 24, Anemometer #1 (there are two anemometers on
the SMET stand) occasionally reported wind speed values that were low
relative to the other sensor.  It is clear from the data that the low
reading here is the anomalous one.

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

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

TWP/C2/SMET Temperature spike

There was a brief -4 C spike in the temperature at approximately
21.5 Z on December 3.  This spike also showed up in the vapor pressure
which is calculated from the temperature and relative humidity.

• Mean Air Temperature or Hardware Error(temp_mean)
• Temperature standard deviation(temp_sd)
• Min Temperature at lowest Model Level- 1 hr(temp_min)
• Vapor pressure standard deviation(vappress_sd)
• Max Temperature at lowest Model Level- 1 hr(temp_max)
• Vapor pressure mean(vappress_mean)

• Max Temperature at lowest Model Level- 1 hr(temp_max)
• Vapor pressure standard deviation(vappress_sd)
• Vapor pressure mean(vappress_mean)
• Mean Air Temperature or Hardware Error(temp_mean)
• Temperature standard deviation(temp_sd)
• Min Temperature at lowest Model Level- 1 hr(temp_min)

TWP/MWR/C2 - Excessive wet_window flags

The wet_window flag is set high more than expected from the measured value of liquid water 
path. This may be caused by dew or, if the heater sensivity is slightly misadjusted, by 
the diurnal variation in ambient temperature.

The "wet_window" flag is an indicator of moisture on the MWR window which invalidates the 
measurements of precipitable water vapor and liquid water path. Sometimes this flag can 
be incorrectly set high or low if the heater sensivity is slightly misadjusted. The heater 
adjustment is a resistive device that is dependent on ambient temperature. Another 
indicator of moisture on the window is unreasonably high ( > 3*liquid_retrieval_rms_accuracy ) 
values of "liq".

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

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

TWP/SMET/C2 - RH Sensor bad at Nauru

RH sensor bad from 16 Dec 2001 03 GMT to 3 Jan 2002

• 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)

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

TWP - Switch to new Data Header Formats not timely

On April 1, 2001 at 00:00:00 new data header with consistent variable naming
conventions, etc were to be used for all sites, all data streams.  At the TWP
sites the time of the movement to the new convention did not occur precisely at 00:00:00.  
The following data files contain between 40 seconds and 20 minutes of data from 4/1/02 
in the old format.  The delayed format change did not affect data quality in any way.

twpgndrad60sC2.a1.20010401.000000.cdf
twpgndrad60sC2.b1.20010401.000000.cdf
twpmfrsrC2.a0.20010401.000000.cdf
twpmfrsrC2.b1.20010401.000000.cdf
twpskyrad20sC2.a1.20010401.000001.cdf
twpsmet60sC1.a1.20010401.000001.cdf
twpsmet60sC1.b1.20010401.000001.cdf
twpsmet60sC2.a1.20010401.000000.cdf
twpsmet60sC2.b1.20010401.000000.cdf

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

• north latitude for all the input platforms.(lat)
• Instantaneous Downwelling Pyrgeometer Dome Thermistor Resistance, Shaded
  Pyrgeometer(inst_down_long_shaded_dome_resist)
• Instantaneous Downwelling Pyrgeometer Thermopile Voltage, Shaded Pyrgeometer(inst_down_long_hemisp_shaded_tp)
• altitude above sea levelaltunits(alt)
• Instantaneous PIR1 dome thermistor(pir1_dome_therm)
• Instantaneous PIR2 case thermistor(pir2_case_therm)
• Instantaneous Downwelling Ultraviolet Biometer Temperature(inst_down_uvb_temp)
• Instantaneous UVB temperature(uvb_temp)
• Instantaneous Downwelling Pyrgeometer Case Thermistor Resistance, Shaded
  Pyrgeometer(inst_down_long_shaded_case_resist)
• Instantaneous PIR1 uncorrected irradiance(pir1_uncorr_irradiance)
• Instantaneous PIR1 case thermistor(pir1_case_therm)
• Instantaneous PIR2 dome thermistor(pir2_dome_therm)
• Instantaneous UVB uncorrected irradiance(uvb_uncorr_irradiance)
• Instantaneous Downwelling Pyrgeometer Dome Thermistor Resistance, Unshaded
  Pyrgeometer(inst_down_long_unshaded_dome_resist)
• Instantaneous Downwelling Pyrgeometer Case Thermistor Resistance, Unshaded
  Pyrgeometer(inst_down_long_unshaded_case_resist)
• Time offset from base_time(base_time)
• east longitude for all the input platforms.(lon)
• Time offset of tweaks from base_time(time_offset)
• Instantaneous PIR2 uncorrected irradiance(pir2_uncorr_irradiance)
• GPS raw data filename(filename)
• Instantaneous Uncorrected Downwelling Ultraviolet Irradiance, UV Biometer(inst_down_uvb_irradiance)
• Instantaneous Downwelling Pyrgeometer Thermopile, Unshaded Pyrgeometer(inst_down_long_hemisp_unshaded_tp)

• altitude above sea levelaltunits(alt)
• Upwelling (10 meter) Longwave Hemispheric Irradiance, Ventilated Pyrgeometer,
  Maxima(up_long_hemisp_max)
• IRT1 standard deviation(irt1_sd)
• Bit data. See details.(bit_data)
• Upwelling (10 meter) Longwave Hemispheric Irradiance, Ventilated Pyrgeometer(up_long_hemisp)
• Internal Logger Temperature(logger_temp)
• Net Radiation, Maxima(net_max)
• GPS raw data filename(filename)
• Effective Surface (Skin) Temperature(sfc_ir_temp)
• Upwelling (10 meter) Longwave Hemispheric Irradiance, Ventilated Pyrgeometer,
  Minima(up_long_hemisp_min)
• Net Radiation, Minima(net_min)
• PSP1 unshaded mean(psp1_mean)
• east longitude for all the input platforms.(lon)
• Net Radiation(net)
• External voltage(external_voltage)
• PIR1 unshaded minimum(pir1_min)
• PSP1 unshaded minimum(psp1_min)
• Surface Infra-Red Temperature Maxima(sfc_ir_temp_max)
• IRT1 maximum(irt1_max)
• IRT1 minimum(irt1_min)
• Surface Infra-Red Temperature, Standard Deviation(sfc_ir_temp_std)
• PIR1 unshaded mean(pir1_mean)
• Time offset of tweaks from base_time(time_offset)
• north latitude for all the input platforms.(lat)
• Upwelling (10 meter) Shortwave Hemispheric Irradiance, Ventilated Pyranometer,
  Maxima(up_short_hemisp_max)
• Net Radiation, Standard Deviation(net_std)
• Time offset from base_time(base_time)
• PIR1 unshaded maximum(pir1_max)
• PIR1 unshaded standard deviation(pir1_sd)
• Upwelling (10 meter) Shortwave Hemispheric Irradiance, Ventilated Pyranometer,
  Minima(up_short_hemisp_min)
• PSP1 unshaded standard deviation(psp1_sd)
• Upwelling (10 meter) Shortwave Hemispheric Irradiance, Ventilated Pyranometer,
  Standard Deviation(up_short_hemisp_std)
• Internal voltage(internal_voltage)
• PSP1 unshaded maximum(psp1_max)
• Surface Infra-Red Temperature Minima(sfc_ir_temp_min)
• Upwelling (10 meter) Shortwave Hemispheric Irradiance, Ventilated Pyranometer(up_short_hemisp)
• NET standard deviation(net_sd)
• IRT1 mean(irt1_mean)
• Upwelling (10 meter) Longwave Hemispheric Irradiance, Ventilated Pyrgeometer,
  Standard Deviation(up_long_hemisp_std)
• NET mean(net_mean)

• Narrowband Hemispheric Irradiance, Filter 1, offset and cosine corrected(hemisp_narrowband_filter1)
• Narrowband Diffuse Hemispheric Irradiance, Filter 6, offset and cosine corrected(diffuse_hemisp_narrowband_filter6)
• Narrowband Hemispheric Irradiance, Filter 3, offset and cosine corrected(hemisp_narrowband_filter3)
• Time offset from base_time(base_time)
• Direct Normal Broadband Irradiance, cosine corrected, broadband scale applied(direct_normal_broadband)
• Narrowband Diffuse Hemispheric Irradiance, Filter 4, offset and cosine corrected(diffuse_hemisp_narrowband_filter4)
• Narrowband Hemispheric Irradiance, Filter 5, offset and cosine corrected(hemisp_narrowband_filter5)
• Hemispheric Broadband Irradiance, offset and cosine corrected, broadband scale
  factor applied(hemisp_broadband)
• Narrowband Diffuse Hemispheric Irradiance, Filter 3, offset and cosine corrected(diffuse_hemisp_narrowband_filter3)
• Fields flagged by callang: 0 = no flag\n,(callang_flags)
• Narrowband Direct Normal Irradiance, Filter 6, cosine corrected(direct_normal_narrowband_filter6)
• Narrowband Direct Normal Irradiance, Filter 4, cosine corrected(direct_normal_narrowband_filter4)
• Narrowband Direct Normal Irradiance, Filter 2, cosine corrected(direct_normal_narrowband_filter2)
• Detector Temperature(head_temp)
• Data Logger Supply Voltage(logger_volt)
• MFRSR Detector Temperature(mfrsr_temp)
• Diffuse Hemispheric Irradiance, MFRSR(diffuse_hemisp_narrowband)
• Hemispheric Irradiance, MFRSR(hemisp_narrowband)
• east longitude for all the input platforms.(lon)
• Narrowband Direct Normal Irradiance, Filter 1, cosine corrected(direct_normal_narrowband_filter1)
• Narrowband Hemispheric Irradiance, Filter 2, offset and cosine corrected(hemisp_narrowband_filter2)
• north latitude for all the input platforms.(lat)
• Narrowband Direct Normal Irradiance, Filter 3, cosine corrected(direct_normal_narrowband_filter3)
• Time offset of tweaks from base_time(time_offset)
• Direct Normal Irradiance, Uncalibrated Silicon Detector, NIMFR(direct_norm_broadband)
• Narrowband Hemispheric Irradiance, Filter 4, offset and cosine corrected(hemisp_narrowband_filter4)
• Narrowband Hemispheric Irradiance, Filter 6, offset and cosine corrected(hemisp_narrowband_filter6)
• Narrowband Diffuse Hemispheric Irradiance, Filter 2, offset and cosine corrected(diffuse_hemisp_narrowband_filter2)
• Narrowband Diffuse Hemispheric Irradiance, Filter 5, offset and cosine corrected(diffuse_hemisp_narrowband_filter5)
• Narrowband Direct Normal Irradiance, Filter 5, cosine corrected(direct_normal_narrowband_filter5)
• Narrowband Diffuse Hemispheric Irradiance, Filter 1, offset and cosine corrected(diffuse_hemisp_narrowband_filter1)
• altitude above sea levelaltunits(alt)
• Cosine of Apparent Solar Zenith Angle(cosine_solar_zenith_angle)
• Direct Normal Irradiance, NIMFR(direct_norm_narrowband)
• Diffuse Hemispheric Broadband Irradiance, offset subtracted, cosine corrected,
  broadband scale applied(diffuse_hemisp_broadband)

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

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

• Narrowband Direct Normal Irradiance, Filter 1, cosine corrected(direct_normal_narrowband_filter1)
• Narrowband Hemispheric Irradiance, Filter 6, offset and cosine corrected(hemisp_narrowband_filter6)
• Direct Normal Broadband Irradiance, cosine corrected, broadband scale applied(direct_normal_broadband)
• Narrowband Hemispheric Irradiance, Filter 3, offset and cosine corrected(hemisp_narrowband_filter3)
• Direct Normal Irradiance, NIMFR(direct_norm_narrowband)
• Narrowband Hemispheric Irradiance, Filter 1, offset and cosine corrected(hemisp_narrowband_filter1)
• MFRSR Detector Temperature(mfrsr_temp)
• Fields flagged by callang: 0 = no flag\n,(callang_flags)
• Narrowband Hemispheric Irradiance, Filter 5, offset and cosine corrected(hemisp_narrowband_filter5)
• Direct Normal Irradiance, Uncalibrated Silicon Detector, NIMFR(direct_norm_broadband)
• Hemispheric Broadband Irradiance (Approximate), MFRSR(total_hemisp_broadband)
• Narrowband Direct Normal Irradiance, Filter 6, cosine corrected(direct_normal_narrowband_filter6)
• Narrowband Diffuse Hemispheric Irradiance, Filter 2, offset and cosine corrected(diffuse_hemisp_narrowband_filter2)
• Narrowband Diffuse Hemispheric Irradiance, Filter 5, offset and cosine corrected(diffuse_hemisp_narrowband_filter5)
• Narrowband Direct Normal Irradiance, Filter 4, cosine corrected(direct_normal_narrowband_filter4)
• Narrowband Diffuse Hemispheric Irradiance, Filter 4, offset and cosine corrected(diffuse_hemisp_narrowband_filter4)
• Diffuse Hemispheric Broadband Irradiance, offset subtracted, cosine corrected,
  broadband scale applied(diffuse_hemisp_broadband)
• Narrowband Direct Normal Irradiance, Filter 2, cosine corrected(direct_normal_narrowband_filter2)
• altitude above sea levelaltunits(alt)
• Time offset from base_time(base_time)
• Hemispheric Irradiance, MFRSR(hemisp_narrowband)
• Narrowband Hemispheric Irradiance, Filter 2, offset and cosine corrected(hemisp_narrowband_filter2)
• Cosine of Apparent Solar Zenith Angle(cosine_solar_zenith_angle)
• east longitude for all the input platforms.(lon)
• Diffuse Hemispheric Irradiance, MFRSR(diffuse_hemisp_narrowband)
• Hemispheric Broadband Irradiance, offset and cosine corrected, broadband scale
  factor applied(hemisp_broadband)
• north latitude for all the input platforms.(lat)
• Narrowband Hemispheric Irradiance, Filter 4, offset and cosine corrected(hemisp_narrowband_filter4)
• Detector Temperature(head_temp)
• Narrowband Direct Normal Irradiance, Filter 5, cosine corrected(direct_normal_narrowband_filter5)
• Narrowband Diffuse Hemispheric Irradiance, Filter 1, offset and cosine corrected(diffuse_hemisp_narrowband_filter1)
• Time offset of tweaks from base_time(time_offset)
• Narrowband Direct Normal Irradiance, Filter 3, cosine corrected(direct_normal_narrowband_filter3)
• Narrowband Diffuse Hemispheric Irradiance, Filter 3, offset and cosine corrected(diffuse_hemisp_narrowband_filter3)
• Narrowband Diffuse Hemispheric Irradiance, Filter 6, offset and cosine corrected(diffuse_hemisp_narrowband_filter6)
• Data Logger Supply Voltage(logger_volt)

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

• Internal Logger Temperature(logger_temp)
• PIR1 unshaded minimum(pir1_min)
• east longitude for all the input platforms.(lon)
• Upwelling (10 meter) Longwave Hemispheric Irradiance, Ventilated Pyrgeometer,
  Standard Deviation(up_long_hemisp_std)
• north latitude for all the input platforms.(lat)
• NET mean(net_mean)
• Net Radiation, Standard Deviation(net_std)
• IRT1 maximum(irt1_max)
• Surface Infra-Red Temperature Maxima(sfc_ir_temp_max)
• PSP1 unshaded maximum(psp1_max)
• PSP1 unshaded standard deviation(psp1_sd)
• Upwelling (10 meter) Shortwave Hemispheric Irradiance, Ventilated Pyranometer(up_short_hemisp)
• IRT1 minimum(irt1_min)
• Time offset of tweaks from base_time(time_offset)
• Bit data. See details.(bit_data)
• Time offset from base_time(base_time)
• Upwelling (10 meter) Shortwave Hemispheric Irradiance, Ventilated Pyranometer,
  Maxima(up_short_hemisp_max)
• Internal voltage(internal_voltage)
• PSP1 unshaded minimum(psp1_min)
• altitude above sea levelaltunits(alt)
• Effective Surface (Skin) Temperature(sfc_ir_temp)
• Upwelling (10 meter) Longwave Hemispheric Irradiance, Ventilated Pyrgeometer(up_long_hemisp)
• PIR1 unshaded maximum(pir1_max)
• PIR1 unshaded mean(pir1_mean)
• Net Radiation(net)
• IRT1 mean(irt1_mean)
• Upwelling (10 meter) Shortwave Hemispheric Irradiance, Ventilated Pyranometer,
  Standard Deviation(up_short_hemisp_std)
• NET standard deviation(net_sd)
• External voltage(external_voltage)
• Net Radiation, Minima(net_min)
• Net Radiation, Maxima(net_max)
• PIR1 unshaded standard deviation(pir1_sd)
• GPS raw data filename(filename)
• Upwelling (10 meter) Shortwave Hemispheric Irradiance, Ventilated Pyranometer,
  Minima(up_short_hemisp_min)
• Upwelling (10 meter) Longwave Hemispheric Irradiance, Ventilated Pyrgeometer,
  Maxima(up_long_hemisp_max)
• Surface Infra-Red Temperature, Standard Deviation(sfc_ir_temp_std)
• Surface Infra-Red Temperature Minima(sfc_ir_temp_min)
• IRT1 standard deviation(irt1_sd)
• Upwelling (10 meter) Longwave Hemispheric Irradiance, Ventilated Pyrgeometer,
  Minima(up_long_hemisp_min)
• PSP1 unshaded mean(psp1_mean)

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

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

• Total Horizontal Irradiance, 862 nm(tot6)
• Hemispheric Broadband Irradiance, offset and cosine corrected, broadband scale
  factor applied(hemisp_broadband)
• Diffuse Horizontal Irradiance, Broadband Solar(dif1)
• Data Logger Supply Voltage(logger_volt)
• Time offset of tweaks from base_time(time_offset)
• Diffuse Horizontal Irradiance, 500 nm(dif3)
• Detector Temperature(head_temp)
• Direct-normal Irradiance, 610 nm(dirn4)
• Direct-normal Irradiance, 862 nm(dirn6)
• Narrowband Direct Normal Irradiance, Filter 2, cosine corrected(direct_normal_narrowband_filter2)
• altitude above sea levelaltunits(alt)
• Diffuse Hemispheric Broadband Irradiance, offset subtracted, cosine corrected,
  broadband scale applied(diffuse_hemisp_broadband)
• Fields flagged by callang: 0 = no flag\n,(callang_flags)
• Narrowband Hemispheric Irradiance, Filter 4, offset and cosine corrected(hemisp_narrowband_filter4)
• Narrowband Diffuse Hemispheric Irradiance, Filter 3, offset and cosine corrected(diffuse_hemisp_narrowband_filter3)
• Narrowband Diffuse Hemispheric Irradiance, Filter 1, offset and cosine corrected(diffuse_hemisp_narrowband_filter1)
• Narrowband Direct Normal Irradiance, Filter 5, cosine corrected(direct_normal_narrowband_filter5)
• Narrowband Hemispheric Irradiance, Filter 2, offset and cosine corrected(hemisp_narrowband_filter2)
• Total Horizontal Irradiance, Broadband Solar(tot1)
• Diffuse Horizontal Irradiance, 415 nm(dif2)
• Narrowband Hemispheric Irradiance, Filter 6, offset and cosine corrected(hemisp_narrowband_filter6)
• Narrowband Diffuse Hemispheric Irradiance, Filter 6, offset and cosine corrected(diffuse_hemisp_narrowband_filter6)
• Diffuse Horizontal Irradiance, 862 nm(dif6)
• Total Horizontal Irradiance, 500 nm(tot3)
• Direct-normal Irradiance, 500 nm(dirn3)
• Total Horizontal Irradiance, 665 nm(tot5)
• Direct Normal Broadband Irradiance, cosine corrected, broadband scale applied(direct_normal_broadband)
• Narrowband Direct Normal Irradiance, Filter 1, cosine corrected(direct_normal_narrowband_filter1)
• Diffuse Horizontal Irradiance, 610 nm(dif4)
• Direct-normal Irradiance, 665 nm(dirn5)
• Datalogger supply voltage(supply_voltage)
• Narrowband Direct Normal Irradiance, Filter 3, cosine corrected(direct_normal_narrowband_filter3)
• Detector temperature(detector_temp)
• Time offset from base_time(base_time)
• Direct-normal Irradiance, 940 nm(dirn7)
• Total Horizontal Irradiance, 940 nm(tot7)
• Narrowband Diffuse Hemispheric Irradiance, Filter 2, offset and cosine corrected(diffuse_hemisp_narrowband_filter2)
• Narrowband Hemispheric Irradiance, Filter 5, offset and cosine corrected(hemisp_narrowband_filter5)
• Narrowband Diffuse Hemispheric Irradiance, Filter 4, offset and cosine corrected(diffuse_hemisp_narrowband_filter4)
• Narrowband Diffuse Hemispheric Irradiance, Filter 5, offset and cosine corrected(diffuse_hemisp_narrowband_filter5)
• Narrowband Hemispheric Irradiance, Filter 1, offset and cosine corrected(hemisp_narrowband_filter1)
• east longitude for all the input platforms.(lon)
• Diffuse Horizontal Irradiance, 665 nm(dif5)
• Narrowband Direct Normal Irradiance, Filter 4, cosine corrected(direct_normal_narrowband_filter4)
• Narrowband Direct Normal Irradiance, Filter 6, cosine corrected(direct_normal_narrowband_filter6)
• Narrowband Hemispheric Irradiance, Filter 3, offset and cosine corrected(hemisp_narrowband_filter3)
• Direct-normal Irradiance, 415 nm(dirn2)
• north latitude for all the input platforms.(lat)
• Diffuse Horizontal Irradiance, 940 nm(dif7)
• Total Horizontal Irradiance, 610 nm(tot4)
• Direct-normal Irradiance, Broadband Solar(dirn1)
• Total Horizontal Irradiance, 415 nm(tot2)

TWP/VCEIL/C2 - Nauru Vceil data suspect

During this period the ceilometer began producing a cross-talk warning. Since it is a 
warning, some of the data are OK. However, the instrument began to be limited to detecting 
clouds only about 2 km above the ground.

• Aerosol volume backscattering coefficient at 355 nm(backscatter)
• Flag indicating aeri retrieval status(status_flag)
• Third cloud base height(third_cbh)
• Lowest cloud base height detected.(first_cbh)
• Warning and alarm status bits(status_string)
• distance to center of range bin after correcting for offset in sync(range)
• Percentage of nominal factory setting (0 to 999%)(receiver_sensitivity)
• Vertical visibility(vertical_visibility)
• Altitude of highest signal(alt_highest_signal)
• Second lowest cloud base height(second_cbh)
• SUM of detected and normalized backscatter(sum_backscatter)

• Altitude of highest signal(alt_highest_signal)
• Flag indicating aeri retrieval status(status_flag)
• SUM of detected and normalized backscatter(sum_backscatter)
• distance to center of range bin after correcting for offset in sync(range)
• Warning and alarm status bits(status_string)
• Percentage of nominal factory setting (0 to 999%)(receiver_sensitivity)
• Vertical visibility(vertical_visibility)
• Detection status. See details(detection_status)
• Third cloud base height(third_cbh)
• Aerosol volume backscattering coefficient at 355 nm(backscatter)
• Second lowest cloud base height(second_cbh)

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/SMET/C2 - Temperature Sensor Failed, Data Missing

The T/RH sensor on Nauru failed and was replaced (only the temperature sensor failed).

• Mean Air Temperature or Hardware Error(temp_mean)
• Temperature standard deviation(temp_sd)
• Min Temperature at lowest Model Level- 1 hr(temp_min)
• Max Temperature at lowest Model Level- 1 hr(temp_max)

• Max Temperature at lowest Model Level- 1 hr(temp_max)
• Mean Air Temperature or Hardware Error(temp_mean)
• Temperature standard deviation(temp_sd)
• Min Temperature at lowest Model Level- 1 hr(temp_min)

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/SMET/C2 -  WIND SENSOR #1 (HIGHER) INOPERATIVE

Wind speed sensor #1 (higher sensor) failed.  Wind speeds were reported as 0 m/s and wind 
direction data was not in agreement with wind sensor #2. Anemometer was replaced.

• Wind #1 direction standard deviation(wind1_dir_sd)
• Wind #1 speed minimum(wind1_spd_min)
• Wind #1 speed maximum(wind1_spd_max)
• Wind #1 direction vector average(wind1_dir_vec_avg)
• 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)

TWP/VCEIL/C2 - Power outage in I-Van resulted in Missing Data

I forgot to put in the daily report that we took the I van down yesterday to replace the 
fans in the Clary UPS. This was from 2300z on 24May03 to 0010z on 25May03. Instruments 
affected :

MPL
Ceilometer
MWR
WSI
TSI

Rex

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

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

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

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/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/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.

• Mean total water vapor amount along LOS path(vap)
• Mean total liquid water amount 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)

• Mean total liquid water amount along LOS path(liq)
• Mean total water vapor amount along LOS path(vap)

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)
• Mean 23.8 GHz sky brightness temperature(tbsky23)
• 31.4 GHz Blackbody signal(bb31)
• Mean total water vapor amount along LOS path(vap)
• 23.8 GHz sky signal(sky23)
• Noise diode mount temperature(tknd)
• Ambient temperature(tkair)
• Mean IR brightness temperature(ir_temp)
• Noise injection temp at nominal temperature at 23.8 GHz(tnd_nom23)
• 31.4 GHz blackbody+noise injection signal(bbn31)
• Sky/Cloud 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)
• Mean 31.4 GHz sky brightness temperature(tbsky31)
• Mean total liquid water amount along LOS path(liq)

• 31.4 GHz sky signal(tipsky31)
• Noise diode mount temperature(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 blackbody+noise injection signal(bbn31)
• 31.4 GHz Blackbody signal(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/MWR/C2 - software upgrade (version 3.29)

The MWR operating program was upgraded to version 3.29 on 30 July 1999. This version 
included a beam width correction as well as provided the capability to automatically level the 
elevation mirror (that is, to automatically detect and correct offsets in the elevation 
angle stepper motor position.)
   
The improvement in the quality of the tip curves resulting from the auto-leveling has been 
dramatic: differences in the brightness temperatures at 3 airmasses (19.5 and 160.5 
degrees) have been reduced from +/- 5 K to +/- 0.5 K. In order to take full advantage of this 
improvement to detect and reject cloudy tip curves, the minimum value of the 
goodness-of-fit coefficient for a valid tip curve has been increased from 0.995 to 0.998.

The data prior to July 30 1999 do not include beam-width and mirror-leveling corrections.

• Mean 23.8 GHz sky brightness temperature(tbsky23)
• Mean total water vapor amount along LOS path(vap)
• Mean 31.4 GHz sky brightness temperature(tbsky31)
• Mean total liquid water amount along LOS path(liq)

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.

• Atmospheric 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).

• Time offset from 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)
• north latitude for all the input platforms.(lat)
• Water on Teflon window (1=WET, 0=DRY)(wet_window)
• east longitude for all the input platforms.(lon)
• 23.8 GHz Blackbody signal(bb23)
• Temperature correction coefficient at 23.8 GHz(tc23)
• Mean 23.8 GHz sky brightness temperature(tbsky23)
• 31.4 GHz Blackbody signal(bb31)
• Mean total water vapor amount along LOS path(vap)
• 23.8 GHz sky signal(sky23)
• Noise diode mount temperature(tknd)
• Actual Azimuth(actaz)
• Ambient temperature(tkair)
• Mean IR brightness temperature(ir_temp)
• Time offset of tweaks from base_time(time_offset)
• Actual elevation angle(actel)
• Time offset from base_time(base_time)
• altitude above sea levelaltunits(alt)
• Noise injection temp at nominal temperature at 23.8 GHz(tnd_nom23)
• 31.4 GHz blackbody+noise injection signal(bbn31)
• Sky/Cloud 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)
• Mean 31.4 GHz sky brightness temperature(tbsky31)
• Mean total liquid water amount along LOS path(liq)

Calibration interruption at TWP Nauru

The ceilometer was tipped horizontal for a calibration check

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

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

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