VAP : Correction of Diffuse Shortwave Measurements (DIFFCOR)

Instrument Categories
Derived Quantities and Models

The DIFFCORR1DUTT VAP uses two techniques to correct shortwave (SW) data during daytime hours, using information from a collocated pyrgeometer. First, the detector-only correction technique uses data in the form of irradiance loss from the pyrgeometer detector. Second, the full-correction technique uses information from collocated pyrgeometer detector data, plus the difference between the case and dome temperatures. Both techniques collect nighttime data with corresponding pyranometer infrared-loss data. The fitting routine for detection and correction consists of two modes: dry and moist. Each mode is detected separately in the nighttime data and applied separately during the daytime. The correction to the SW daylight data is applied only if the data pass quality analysis checks. The DiffCorr1Dutt VAP output files contain a best estimate of the downwelling SW, and a best estimate of the diffuse SW. In addition, the output files contain other useful values, such as an estimate of the clear-sky Rayleigh diffuse SW amount, and standard surface meteorological measurements.

For more details, see Improved Correction of IR Loss in Diffuse Shortwave Measurements: An ARM Value-Added Product technical report.

Output Products

  • siros1dutt : Solar and Infrared Radiation Observing Station (SIROS): 1-min data with Dutton correction
  • sirs1dutt : SIRS: derived, correction of downwelling shortwave diffuse hemispheric measurements using Dutton and full algorithm

Primary Measurements

The following measurements are those considered scientifically relevant.


North Slope Alaska
NSAC1 Browse DataCentral Facility, Barrow AK retired
NSAC2 Browse DataCentral Facility, Atqasuk AK retired
Southern Great Plains
SGPC1 Browse DataCentral Facility, Lamont, OK retired
SGPE1 Browse DataLarned, KS (Extended) retired
SGPE2 Browse DataHillsboro, KS (Extended) retired
SGPE3 Browse DataLeRoy, KS (Extended) retired
SGPE4 Browse DataPlevna, KS (Extended) retired
SGPE5 Browse DataHalstead, KS (Extended) retired
SGPE6 Browse DataTowanda, KS (Extended) retired
SGPE7 Browse DataElk Falls, KS (Extended) retired
SGPE8 Browse DataColdwater, KS (Extended) retired
SGPE9 Browse DataAshton, KS (Extended) retired
SGPE10 Browse DataTyro, KS (Extended) retired
SGPE11 Browse DataByron, OK (Extended) retired
SGPE12 Browse DataPawhuska, OK (Extended) retired
SGPE13 Browse DataLamont, OK (Extended) retired
SGPE15 Browse DataRingwood, OK (Extended) retired
SGPE16 Browse DataVici, OK (Extended) retired
SGPE18 Browse DataMorris, OK (Extended) retired
SGPE19 Browse DataEl Reno, OK (Extended) retired
SGPE20 Browse DataMeeker, OK (Extended) retired
SGPE21 Browse DataOkmulgee, OK (Extended) retired
SGPE22 Browse DataCordell, OK (Extended) retired
SGPE24 Browse DataCyril, OK (Extended) retired
SGPE25 Browse DataSeminole, OK (Extended) retired
Tropical Western Pacific
TWPC1 Browse DataCentral Facility, Manus I., PNG retired
TWPC2 Browse DataCentral Facility, Nauru Island retired
 retired = Originating instrument has been retired at this location


Laura Riihimaki
Pacific Northwest National Laboratory
(509) 375-6406