TWP/GNDRAD/C3 - Gndrad shutdown for tropical cylone

On Jan 3rd approximately 1000GMT the effects of a tropical cyclone started affecting the 
installed radiometer measurements at ARM/TWP/C3(Darwin) - both Skyrad and Gndrad.  On Jan 
4th 0740 GMT the Gndrad station was shutdown to avoid damage due to the close passing of 
this storm.  Station was restarted Jan 7th 0515GMT.

• time_offset
• alt
• lat
• inst_up_long_case_resist
• inst_up_long_hemisp_tp
• lon
• base_time
• inst_up_long_dome_resist

• inst_sfc_ir_signal
• inst_up_short_hemisp
• lat
• lon
• base_time
• time
• alt
• inst_up_long_hemisp_tp
• time_offset

• up_long_hemisp_std
• time_offset
• lat
• Radiation, longwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_long_hemisp)
• lon
• Effective Surface (Skin) Temperature(sfc_ir_temp)
• logger_temp
• base_time
• sfc_ir_temp_std
• alt
• Surface Infra-Red Temperature Maxima(sfc_ir_temp_max)
• Upwelling Longwave Hemispheric Irradiance, Unventilated Pyrgeometer, Maxima(up_long_hemisp_max)
• up_short_hemisp_std
• Upwelling Shortwave Hemispheric Irradiance, Unventilated Pyranometer, Maxima(up_short_hemisp_max)
• Upwelling Shortwave Hemispheric Irradiance, Unventilated Pyranometer, Minima(up_short_hemisp_min)
• Upwelling Longwave Hemispheric Irradiance, Unventilated Pyrgeometer, Minima(up_long_hemisp_min)
• Surface Infra-Red Temperature Minima(sfc_ir_temp_min)
• Radiation, shortwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_short_hemisp)

• Raw data stream - documentation not supported

TWP/SKYRAD/C3 - IRT power supply

The 12-to-24V DC converter the provides power to the IRT had shut down and was restarted 
by power-cycling.

• sky_ir_temp_min
• sky_ir_temp_max
• IR Brightness Temperature(sky_ir_temp)
• sky_ir_temp_std

TWP/SKYRAD/C3 - Contamination

The IRT exhibited a positive bias compared to AERI. The problem was corrected when the 
lens and mirror were cleaned.

• sky_ir_temp_min
• sky_ir_temp_max
• IR Brightness Temperature(sky_ir_temp)
• sky_ir_temp_std

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, Pyrheliometer, Minima(short_direct_normal_min)
• Radiation, shortwave, direct normal irradiance, 1-min avg(short_direct_normal)
• Shortwave Direct Normal Irradiance, Pyrheliometer, Maxima(short_direct_normal_max)
• short_direct_normal_std

• inst_direct_normal