TWP/SKYRAD/C3 - NIP instrument failure

The NIP (Short Direct Normal) was replaced after it displayed symptoms of failure 
associated with either unknown precipitation related issues or a possible lightning strike.

NIP data are not recoverable.  Direct normal data can be reconstructed from global 
hemispheric and global diffuse data using the following relationship:
   global hemispheric = direct*cos(sza) + diffuse hemispheric

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

• Shortwave Direct Normal Irradiance, Pyrgeometer, Minima(short_direct_normal_min)
• Shortwave Direct Normal Irradiance, Pyrgeometer(short_direct_normal)
• Shortwave Direct Normal Irradiance, Pyrgeometer, Maxima(short_direct_normal_max)
• Shortwave Direct Normal Irradiance, Pyrgeometer, Standard Deviation(short_direct_normal_std)

• Instantaneous Direct Normal Shortwave Irradiance, Pyheliometer Thermopile
  Voltage(inst_direct_normal)

TWP/GNDRAD/C2 - IRT signal

When the other GNDRAD radiometers were replaced on 12/3/2006, the quality of the IRT 
signal began to degrade until 12/26 when it became unusable. The instrument was replaced on 
2/4/2007.

• Surface Infra-Red Temperature Minima(sfc_ir_temp_min)
• Surface Infra-Red Temperature, Standard Deviation(sfc_ir_temp_std)
• Surface Infra-Red Temperature Maxima(sfc_ir_temp_max)
• Effective Surface (Skin) Temperature(sfc_ir_temp)

TWP/SKYRAD/C2 - Short direct normal

The short_direct_normal (NIP) data are missing or incorrect due to instrument cable 
failure.  The cable was replaced.

The short_direct_normal can be calculated using the following relationship for shortwave 
radiometers:
global hemispheric = diffuse hemispheric + direct normal *cos (zenith angle)

• Shortwave Direct Normal Irradiance, Pyrgeometer, Standard Deviation(short_direct_normal_std)
• Shortwave Direct Normal Irradiance, Pyrgeometer, Maxima(short_direct_normal_max)
• Shortwave Direct Normal Irradiance, Pyrgeometer, Minima(short_direct_normal_min)
• Shortwave Direct Normal Irradiance, Pyrgeometer(short_direct_normal)

• Instantaneous Direct Normal Shortwave Irradiance, Pyheliometer Thermopile
  Voltage(inst_direct_normal)

TWP/SMET/C3 - Barometer Data Incorrect

The barometer data was incorrect or missing due to water intrusion.

• Barometric Pressure(atmos_pressure)

TWP/SMET/C3 - Data Incorrect Due to Water Intrusion

Data became erratic and unreasonable after water intrusion into the enclosure.

• Vapor pressure standard deviation(vappress_sd)
• Precipitation maximum(precip_max)
• Relative humidity maximum(relh_max)
• Mean Relative Humidity(relh_mean)
• Std Dev of Relative Humidity or Hardware Error Code(relh_sd)
• Relative humidity minimum(relh_min)
• precipitation minimum(precip_min)
• Precipitation mean(precip_mean)
• Temperature minimum(temp_min)
• Mean Air Temperature or Hardware Error(temp_mean)
• Temperature maximum(temp_max)
• Precipitation standard deviation(precip_sd)
• Vapor pressure mean(vappress_mean)
• Std Dev of Air Temperature(temp_sd)

TWP/SKYRAD/C2 - IRT calibration

The IRT was not properly calibrated and was not able to measure sky temperatures below 
273.2 K. (This instrument was the same one damaged by lightning in November 2005 in Darwin. 
It was returned for repair and received a new lens but was calibrated only down to 0 deg 
C, so the problem was neither detected nor repaired.) The IRT was replaced on 2/22/2007.

• Sky Infra Red Temperature Minima(sky_ir_temp_min)
• Sky Infra Red Temperature Maxima(sky_ir_temp_max)
• Sky Infra-Red Temperature(sky_ir_temp)
• Standard Deviation of Sky Infra Red Temperature(sky_ir_temp_std)

TWP/GNDRAD/C2 - Reprocess: IRT calibration

The configuration of the IRT was set to that used at TWP/C3. This caused the calibration 
of the data to be wrong. It was corrected by reconfiguring the IRT to match the datalogger 
program.
   
These data can be reprocessed and corrected by adding 10K, i.e. sfc_ir_temp(new) = 
sfc_ir_temp(old) + 10K.

• Surface Infra-Red Temperature Minima(sfc_ir_temp_min)
• Surface Infra-Red Temperature Maxima(sfc_ir_temp_max)
• Effective Surface (Skin) Temperature(sfc_ir_temp)

TWP/SMET/C2 - Lower windspeed sensor questionable

Lower wind speed sensor had degraded bearings.  This sensor was reporting as much as 0.4 
m/s lower values than the upper sensors when the winds were 2 m/s or below.  The sensor 
was replaced.

• Wind #2 speed maximum(wind2_spd_max)
• Wind #2 speed vector average(wind2_spd_vec_avg)
• Wind #2 speed maximum gust(wind2_spd_max_gust)
• 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/GNDRAD/C3 - Maintenance activities affected GNDRAD

While maintenance was performed on the SMET anenometer, the GNDRAD instruments were 
inverted. Disregard GNDRAD data during this time.

• Time offset of tweaks from base_time(time_offset)
• Instantaneous Upwelling Pyrgeometer Case Thermistor Resistance Pyrgeometer(inst_up_long_case_resist)
• Instantaneous Surface Infra-Red Signal(inst_sfc_ir_signal)
• Instantaneous Upwelling Shortwave Hemispheric Irradiance, Pyranometer(inst_up_short_hemisp)
• time(time)
• base time(base_time)
• Dummy altitude for Zeb(alt)
• Instantaneous Upwelling Pygeometer Thermopile Voltage(inst_up_long_hemisp_tp)
• lat(lat)
• lon(lon)
• Instantaneous Upwelling Pyrgeometer Dome Thermistor Resistance Pyrgeometer(inst_up_long_dome_resist)

• Upwelling (10 meter) Shortwave Hemispheric Irradiance, Pyranometer, Standard
  Deviation(up_short_hemisp_std)
• Upwelling (10 meter) Shortwave Hemispheric Irradiance, Pyranometer(up_short_hemisp)
• Net Radiation, Standard Deviation(net_std)
• Net Radiation, Maxima(net_max)
• Surface Infra-Red Temperature Minima(sfc_ir_temp_min)
• lat(lat)
• Surface Infra-Red Temperature Maxima(sfc_ir_temp_max)
• Surface Infra-Red Temperature, Standard Deviation(sfc_ir_temp_std)
• External voltage(external_voltage)
• Effective Surface (Skin) Temperature(sfc_ir_temp)
• Upwelling (10 meter) Longwave Hemispheric Irradiance, Pyrgeometer, Minima(up_long_hemisp_min)
• Upwelling (10 meter) Shortwave Hemispheric Irradiance, Pyranometer, Maxima(up_short_hemisp_max)
• Logger panel temperature(logger_temp)
• Upwelling (10 meter) Shortwave Hemispheric Irradiance, Pyranometer, Minima(up_short_hemisp_min)
• Upwelling (10 meter) Longwave Hemispheric Irradiance, Pyrgeometer, Maxima(up_long_hemisp_max)
• Net Radiation, Minima(net_min)
• lon(lon)
• Upwelling (10 meter) Longwave Hemispheric Irradiance, Pyrgeometer, Standard
  Deviation(up_long_hemisp_std)
• base time(base_time)
• Upwelling (10 meter) Longwave Hemispheric Irradiance, Pyrgeometer(up_long_hemisp)
• Time offset of tweaks from base_time(time_offset)
• Battery Voltage(internal_voltage)
• Bit data. See details.(bit_data)
• Net Radiation(net)
• Dummy altitude for Zeb(alt)