Start Date | Start Time | End Date | End Time | Data Quality Metric |
---|---|---|---|---|
09/17/1997 | 0000 | 10/03/1997 | 2359 | Suspect |
Subject: | Reference Broadband Shortwave Data at SGP Central Cluster during Fall IOP '97 |
DataStreams: | sgpbsrnC1.00, sgpbsrnC1.a0, sgpsirosE13.00, sgpsirosE13.a1, sgpbsrnC1.a1, sgpsirsE13.a1, sgpsirsE13.a0 |
Description: | This is a recommendation for the best available broadband shortwave data from the SGP Central Cluster (Lamont, OK) during the Combined Fall IOP, 15 Sept - 5 Oct 1997. Data available from the SGP Radiometer Calibration Facility (RCF) has lower measurement uncertainties than similar measurements from the C1, E-13, and BSRN/BRS platforms. The RCF data were collected using the same Broadband Outdoor Radiometer CALibration (BORCAL) system used for routine calibration of pyranometers and pyrheliometers at the RCF. The data are available for 30-second interval. Direct normal irradiance measurements from a windowed RCF Absolute Cavity Radiometer during the IOP is considered more accurate (+/- 0.5%) than the Normal Incidence Pyrheliometers (NIP) at the Central Cluster (+/- 2%). The Automated Hickey-Frieden cavity radiometer is electrically self-calibrating and provides reference standard data suitable for the calibration of the NIPs used at all the CART sites. Diffuse horizontal irradiance is available as the average of two Eppley Precision Spectral Pyranometers and is considered slightly more accurate than the downwelling diffuse (DD) data from the Central Cluster instruments. The RCF data will have periodic gaps during the electrical calibration intervals (about 6-10 minutes, 4 or 5 times per day). The reference global horizontal (or Downwelling Shortwave - DS) has been computed from the measured direct normal and diffuse components: DS = NIP x Cos(Z) + DD, where, Z = solar zenith angle. All RCF data collected during the IOP are on the ARM IOP Web page (iop.archive.arm.gov/arm-iop). with other data from the Fall97 shortwave IOP. Additional corrections to the diffuse data may be possible after researching PSP nighttime offsets. Data from C1, E-13, and BSRN/BRS platforms during the SW-IOP '97 are still being investigated. |
Suggestions: | Use the RCF/BORCAL data files available during the Fall SW-IOP in place of the SIRS data from C1 and E-13 and the BSRN data for NIP, DD, and DS values. This data set has been archived as sgprcfbbswiop97C1.00 |
Measurements: | sgpsirsE13.a1: more
sgpsirosE13.a1: more sgpsirosE13.00: more sgpsirsE13.a0: more sgpbsrnC1.a0: more sgpbsrnC1.a1: more sgpbsrnC1.00: more |