SGP/SIRS/C1 - Missing data due to Ice storm and clock problems

Data are missing due to power failures caused by an ice storm
and resulting system/instrument clock problems.

• gswfluxdn_cloudeffect
• Altitude above mean sea level(alt)
• sswfluxdn_cloudeffect
• time_offset_LST
• difswfluxdn_cloudeffect
• Fractional Sky Cover(cloudfraction)
• difratiodn_measured_stdev
• guvbdn_measured
• nsamples_clearsky_detection
• sswfluxdn_measured
• nsamples_sswfluxdn_measured
• site
• nsamples_gswfluxdn_clearskyfit
• difratiodn_measured
• difratiodn_clearskyfit
• East longitude(lon)
• base_time_LST
• guvbdn_clearskyfit
• North latitude(lat)
• Clear-sky Fit Estimated Downwelling Global Shortwave Irradiance (cgsw)(gswfluxdn_clearskyfit)
• solar_cos_z
• Measured Downwelling Global Shortwave Irradiance (gsw)(gswfluxdn_measured)
• sun_earth_distance
• sswfluxdn_clearskyfit
• time_offset
• difcloudeffect_normalized
• Clear-sky Fit Estimated Downwelling Diffuse Field Shortwave Irradiance (cdif)(difswfluxdn_clearskyfit)
• nsamples_cloudfraction
• base_time
• Irradiance, shortwave, downwelling, diffuse, measured(difswfluxdn_measured)
• Measured Downwelling Direct Shortwave Irradiance (dir)(dirfluxdn_measured)
• Measured Surface Albedo from Shortwave Irradiance Measurements (alb)(albedosw_measured)
• Clear-sky Fit Estimated Sfc. Albedo from Shortwave Irrad. Measurements (calb)(albedosw_clearskyfit)
• Clear-sky Fit Estimated Downwelling Direct Shortwave Irradiance (cdir)(dirfluxdn_clearskyfit)

SGP/SIRS/C1 - Reprocess: Adjust Direct Normal Irradiance

Direct normal broadband shortwave irradiance measured by NIP s/n 30722E6 was found to have 
a 0.62%% negative bias when compared in-situ with absolute cavity radiometer 
measurements taken on August 21, 2000.  The estimated measurement uncertainty of the calibration of 
NIP s/n 30722E6 on July 18, 2000 was -2.6% to +4.8%.  

Data from NIP s/n 30722E6 can be adjusted according to the in-situ comparisons to reduce 
the apparent measurement bias.

• Measured Downwelling Direct Shortwave Irradiance (dir)(dirfluxdn_measured)

SGP/SIRS/C1 - SWFANAL Data description error

The long name attribute for the cloud effect fields incorrectly
defines the cloud effect to be the difference between the 
clearskyfit and measured values:

"Difference: ***fluxdn_clearskyfit - ***fluxdn_measured (***fcg)" ;

The cloud effects are correctly calculated by subtracting the 
irradiance calculated in the clear sky fit from the measured 
irradiance.

"Difference: ***fluxdn_measured - ***fluxdn_clearskyfit (***fcg)" ;

NOTE: this is just a documentation error.  The data are correctly
calculated.

• gswfluxdn_cloudeffect
• sswfluxdn_cloudeffect
• difswfluxdn_cloudeffect