TWP/MWR/C3 - Sun in field of view of radiometer

Each day from approximately 9/15 to 10/9 around local noon, there is an increase in the 
brightness temperature due to the sun being in the field of view of the radiometer.

• MWR column precipitable water vapor(vap)
• Averaged total liquid water along LOS path(liq)
• Sky brightness temperature at 31.4 GHz(tbsky31)
• Sky brightness temperature at 23.8 GHz(tbsky23)

• 31.8 GHz sky brightness temperature derived from tip curve(tbskytip31)
• Total water vapor along zenith path using tip-derived brightness temperatures(vaptip)
• Total liquid water along zenith path using tip-derived brightness temperatures(liqtip)
• 23.8 GHz sky signal(tipsky23)
• 31.4 GHz sky signal(tipsky31)
• 23.8 GHz sky brightness temperature derived from tip curve(tbskytip23)

TWP/MWR/C1/C2 - Sun in the field of view

Every day between around noon local time (usually between 1 and 2 AM UTC time) there is an 
increase in the brightness temperatures due to the sun in the field of vie of the 
radiometer.

• 31.4 GHz sky signal(sky31)
• 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)

• MWR column precipitable water vapor(vap)
• 31.4 GHz sky signal(sky31)
• Sky brightness temperature at 23.8 GHz(tbsky23)
• Sky brightness temperature at 31.4 GHz(tbsky31)
• Averaged total liquid water along LOS path(liq)
• 23.8 GHz sky signal(sky23)

• 23.8 GHz sky brightness temperature derived from tip curve(tbskytip23)
• 31.8 GHz sky brightness temperature derived from tip curve(tbskytip31)
• Total liquid water along zenith path using tip-derived brightness temperatures(liqtip)
• Total water vapor along zenith path using tip-derived brightness temperatures(vaptip)

• 31.4 GHz sky signal(tipsky31)
• 23.8 GHz sky signal(tipsky23)

TWP/SKYRAD/C1 - IRT measurement error

The IRT 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 in 
April 2006 and again in April 2007 and both times calibrated only down to 0 deg C, so the 
problem was neither detected nor repaired.) The problem was corrected by replacing the IRT.

• 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/C1 - IRT power connector

The power connector of the IRT broke due to corrosion. The instrument was replaced.

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

TWP/MWR/C2 - Incorrect ambient temperature during rain

The ambient temperature was approximately 15 degree higher than what it should be when it 
was raining and the heater came. On Jan 9 2009 the dewblower was replaced which solved 
the problem.

The increased ambient temperature (tkair) was happening during times of rain and users 
should always disregard MWR data during rain events.  Therefore this DQR is colored 
transparent.

• Ambient temperature(tkair)

• Ambient temperature(tkair)

TWP/SKYRAD/C3 - Direct normal instrument failure

The NIP instrument (short_direct_normal data stream) failed giving bad data during this 
time period.  The failure start time coincides with a reported DC power failure but no 
connection between the reported power failure and the failure of this instrument could be 
determined. 

Ops also reported the tracker clock running 2.9 minutes slow during maintenance on 12/22 
0300GMT (see CS-2008-0714).  Again, the slow clock is not suspect and did not appear to 
affect alignment.

Ops replaced the NIP instrument on 12/30 and short_direct_normal data resumed normal 
operation.

Disregard the short_direct_normal (NIP) data during this time period or calculate using 
the global and diffuse instruments and the following relationship:
short_direct_normal = ((down_short_hemisp - down_short_diffuse_hemisp))/cos(zenith angle)

• 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/SKYRAD/C2 - Tracker failure

Tracker failed to wake up on 12/17.  Ops reset tracker on 12/21.  

The affected instruments are the 8-48 (down_short_diffuse) and NIP (direct_normal) 
shortwave instruments.

• Shortwave Direct Normal Irradiance, Pyrgeometer, Standard Deviation(short_direct_normal_std)
• Shortwave Direct Normal Irradiance, Pyrgeometer, Maxima(short_direct_normal_max)
• Downwelling Shortwave Diffuse Hemispheric Irradiance, Ventilated Pyranometer(down_short_diffuse_hemisp)
• Downwelling Shortwave Diffuse Hemispheric Irradiance, Ventilated Pyranometer,
  Maxima(down_short_diffuse_hemisp_max)
• Downwelling Shortwave Hemispheric Irradiance, Pyranometer, Standard Deviation(down_short_diffuse_hemisp_std)
• Shortwave Direct Normal Irradiance, Pyrgeometer, Minima(short_direct_normal_min)
• Downwelling Shortwave Diffuse Hemispheric Irradiance, Ventilated Pyranometer,
  Minima(down_short_diffuse_hemisp_min)
• Shortwave Direct Normal Irradiance, Pyrgeometer(short_direct_normal)

• Instantaneous Direct Normal Shortwave Irradiance, Pyheliometer Thermopile
  Voltage(inst_direct_normal)
• Instantaneous Uncorrected Downwelling Shortwave Diffuse, Shaded Pyranometer
  Thermopile Voltage(inst_diffuse)

TWP/MWR/C1 - Ambient temperature data missing

The ambient temperature readings (tkair) suddenly failed. The sensor was replaced on Feb 
6.

• Ambient temperature(tkair)

• Ambient temperature(tkair)