NSA/SKYRAD/C1 - PIR data suspect

PIR shaded and PIR unshaded show unusual differences during this time period, frosting or 
icing is the most probable explanation but we don't know for sure.

• pir1_mean
• pir1_max
• pir1_sd
• pir1_min

• pir1_sd
• pir1_max
• pir1_min
• pir1_mean

NSA/SKYRAD/C1 - Shaded PIR data unreasonable

Scientificly unreasonable data values, the problem disappeared after the datalogger was 
exchanged with the spare. The data logger was exchanged on 11/7 at 20:10 GMT.

• pirs_sd
• pirs_min
• pirs_mean
• pirs_max

• pirs_min
• pirs_mean
• pirs_max
• pirs_sd

NSA/SKYRAD/C1 - PIR data suspect

PIR shaded and PIR unshaded show unusual differences during this time period, frosting or 
icing is one possible explanation but we don't know.

• pirs_mean
• pir1_min
• pir1_mean
• pir1_max
• pirs_sd
• pir1_sd
• pirs_min
• pirs_max

• pir1_max
• pir1_min
• pirs_mean
• pir1_sd
• pirs_min
• pirs_sd
• pirs_max
• pir1_mean

NSA/SKYRAD/C1 - Unshaded PIR maintenance

Unreasonable data from 3/15 23:45 until 3/16 0:45 due to exchange of PIR instrument to the 
PIR spare (32054F3). This was done so the PIR could go to NOAA/CMDL in Boulder for 
calibration as part of the IPARSC II IOP and be included in this work.

• pir1_mean
• pir1_max
• pir1_sd
• pir1_min

• pir1_sd
• pir1_max
• pir1_min
• pir1_mean

NSA/SKYRAD/C1 - Miscalibrated Unshaded PIR data

Calibration coefficient for PIR spare (32054F3) was updated on 3/25 2:35 GMT. The old PIR 
cal coefficient was used during this period. The PIR spare (32054F3) was calibrated by 
NOAA/CMDL in Boulder prior to the IOP and replacement on 3/16 when the original station PIR 
was shipped to Boulder for a post IOP calibration.

• pir1_mean
• pir1_max
• pir1_sd
• pir1_min

• pir1_sd
• pir1_max
• pir1_min
• pir1_mean

NSA/SKYRAD/C1 - Noise in Unshaded PIR data

Noise increased and an offset from shaded PIR became apparent during this period.

• pir1_mean
• pir1_max
• pir1_sd
• pir1_min

• pir1_sd
• pir1_max
• pir1_min
• pir1_mean

NSA/GNDRAD/C1 - Instrument Maintenance

Tip tower was lowered for instrument maintenance.  Data taken 
              during this period are corrupt.

• psp1_min
• psp1_max
• psp1_mean
• psp1_sd

• psp1_mean
• psp1_sd
• psp1_min
• psp1_max

NSA/GNDRAD/C1 - PSP erroneously replaced by B&W

The PSP was erroneously replaced with a B&W on 6/13 and then 
              changed back to the PSP on 6/21. Data should still be good since
              appropriate calibration factors were applied.

• psp1_min
• psp1_max
• psp1_mean
• psp1_sd

• psp1_mean
• psp1_sd
• psp1_min
• psp1_max

NSA/GNDRAD/C1 - Instrument maintenance

The tip tower was lowered for instrument maintenance.  Data
              recorded are garbage.

• psp1_min
• psp1_max
• psp1_mean
• psp1_sd

• psp1_mean
• psp1_sd
• psp1_min
• psp1_max

NSA/GNDRAD/C1 - Bad calibrations applied

Bad data due to erroneous calibration constant in configuration 
              file

• pir1_mean
• psp1_sd
• pir1_sd
• psp1_min
• psp1_max
• psp1_mean
• pir1_max
• pir1_min

• psp1_mean
• psp1_sd
• psp1_min
• psp1_max
• pir1_sd
• pir1_max
• pir1_min
• pir1_mean

NSA/GNDRAD/C1 - PSP Data corrupted by brief spike

Large unreasonable narrow spike in PSP data; cause not known.

• psp1_min
• psp1_max
• psp1_mean
• psp1_sd

• psp1_mean
• psp1_sd
• psp1_min
• psp1_max

NSA/SKYRAD/C1 - NIP shaded by skyrad stand around local midnight

Around local midnight 9:30-10:30 GMT during summer clear sky the normal incidence 
pyranometer is shaded by the instrument stand.This causes the reading to be 0 W/m2. If cosine 
correction is applied for irradiance calulations this effect is negligible due to the low 
solar angle.

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

• nip_max
• nip_sd
• nip_min
• nip_mean

NSA/SKYRAD/C1 - PSP shaded by MFRSR after local midnight

Just past local midnight (11:00-11:40 GMT during summer clear sky) the global 
hemispherical pyranometer is shaded by the MFRSR instrument for about 40 minutes. This causes the 
reading to be 0 W/m2. This effect would be negligible in a daily average due to the low 
solar angle.

• Radiation, shortwave, downwelling total hemispheric irradiance, 1-min avg(down_short_hemisp)
• down_short_hemisp_std
• Downwelling Shortwave Hemispheric Irradiance, Ventilated Pyranometer, Maxima(down_short_hemisp_max)
• Downwelling Shortwave Hemispheric Irradiance, Ventilated Pyranometer, Minima(down_short_hemisp_min)

• psp1_sd
• psp1_mean
• psp1_min
• psp1_max

NSA/SKYRAD/C1 - IRT incorrect min/max value

The values of valid_min and valid_max for field sky_ir_temp were incorrectly assigned to 
-49.7 and +50.0 C, respectively. The actual values should be -60 and +40 C.

• sky_ir_temp_min
• sky_ir_temp_max
• Temperature, Sky Infra-Red(sky_ir_temp)

NSA/SKYRAD/C1 - IRT measurements during precipitation events

The IRT measurement of sky/cloud temperature was in question during
precipitation events because rain or snow could accumulate in the
upward-pointed lens barrel. This was corrected by reorienting the
IRT to measure the sky temperature as reflected by a gold mirror.

• sky_ir_temp_min
• sky_ir_temp_std
• sky_ir_temp_max
• Temperature, Sky Infra-Red(sky_ir_temp)

NSA/SKYRAD/C1 - NSA B&W nighttime offset in Barrow too large

This problem only became apparent as NSA C1 nights became long enough for full darkness. 
The shaded global diffuse instrument (Eppley 8-48) showed a negative nighttime offset 
larger than the expected 0 to -4 W/m2. Typically -5 to -8 W/m2. This size of offset is not 
uncommon with Eppley PSPs but not observed with Eppley 8-48s.  The problem was corrected 
with replacement of mounting screws which were creating a ground loop.

• Raw data stream - documentation not supported

• psps_sd
• Radiation, shortwave, downwelling diffuse hemispheric irradiance, 1-min avg(down_short_diffuse_hemisp)
• psps_mean
• psps_min
• Downwelling Shortwave Diffuse Hemisp. Irrad., Ventilated Pyranometer, Maxima(down_short_diffuse_hemisp_max)
• down_short_diffuse_hemisp_std
• Downwelling Shortwave Diffuse Hemisp. Irrad., Ventilated Pyranometer, Minima(down_short_diffuse_hemisp_min)
• psps_max

• psps_max
• down_short_diffuse_hemisp_std
• Downwelling Shortwave Diffuse Hemisp. Irrad., Ventilated Pyranometer, Maxima(down_short_diffuse_hemisp_max)
• Downwelling Shortwave Diffuse Hemisp. Irrad., Ventilated Pyranometer, Minima(down_short_diffuse_hemisp_min)
• Radiation, shortwave, downwelling diffuse hemispheric irradiance, 1-min avg(down_short_diffuse_hemisp)
• psps_sd
• psps_mean
• psps_min

NSA/SKYRAD/C1 - Summer solstice shading of radiometers

On and around the summer solstice, the NIP (Direct Normal shortwave measurement) and PSP 
(global hemispheic shortwave measurement) radiometers are shaded by other instruments or 
support structures.  Shading azimuths have been determined for this site.  The radiometer 
mentor suggests not using the data from the NIP and PSP radiometers when the sun is 
within the following azimuth bounds (typically from May 8th to August 5th of each year):
Instrmt Obstruction     AzStart     AzEnd     
NIP     rad table       346         358
NIP     met tower       13          15
PSP     mfrsr           6           16

• psps_sd
• psp1_sd
• Radiation, shortwave, downwelling total hemispheric irradiance, 1-min avg(down_short_hemisp)
• psps_mean
• psps_min
• Downwelling Shortwave Hemispheric Irradiance, Ventilated Pyranometer, Maxima(down_short_hemisp_max)
• nip_sd
• Downwelling Shortwave Hemispheric Irradiance, Ventilated Pyranometer, Minima(down_short_hemisp_min)
• psp1_min
• psp1_max
• Shortwave Direct Normal Irradiance, Pyrheliometer, Minima(short_direct_normal_min)
• nip_mean
• Radiation, shortwave, direct normal irradiance, 1-min avg(short_direct_normal)
• nip_min
• psps_max
• nip_max
• psp1_mean
• down_short_hemisp_std
• short_direct_normal_std
• Shortwave Direct Normal Irradiance, Pyrheliometer, Maxima(short_direct_normal_max)

NSA/GNDRAD/C1 - Net radiometer removed

The net radiometer was removed from the NSA.C1 GNDRAD instrument suite on Feb 3, 2000.  
Net rad variables were filled with garbage data until Sept 23, 2000 and with missing values 
(-9999) until 20041103.  The net rad variables were removed from the netcdf files after 
20041103.

A reprocessing task (RID-526) has been submitted to the queue to address the need to add 
metadata to the NSA.C1 GNDRAD netcdf files documenting the missing data as well as to move 
toward a consistent datastream format throughout time.

• base_time

• net_mean
• net_std
• net_max
• net_min
• net
• net_sd