VAP : Shortwave Flux Analysis (SWFLUXANAL)
The SW (shortwave) Flux Analysis VAP applies a clear-sky detection and fitting technique (Long and Ackerman 2000) to data from broadband SW radiometers located at the Southern Great Plains site. This technique uses hemispheric, broadband total- and diffuse-shortwave irradiance measurements to identify clear-sky periods using the known characteristics of typical clear-sky irradiance time series. These clear-sky estimates are then used to infer the effect of cloudiness on the measured downwelling SW at 1-minute resolution for daylight hours. The 1-minute resolution analysis also includes data quality assessment that goes beyond standard min/max/delta and component comparison testing. The SW Flux Analysis VAP also uses a technique (Long et al. 1999) to infer average fractional sky cover at 15-minute resolution for solar elevation angles 10° or greater.
For more details, see The Shortwave (SW) Clear-Sky Detection and Fitting Algorithm: Algorithm Operational Details and Explanations technical report.
- 15swfanalbrs1long : Short Wave Flux Analysis: 15-min resolution on BRS data, Long algorithm
- 15swfanalsiros1long : Short Wave Flux Analysis: 15-min resolution on SIROS data, Long algorithm
- 15swfanalsirs1long : Short Wave Flux Analysis: 15-min resolution on SIRS data, Long algorithm
- 15swfanalskyrad1long : Short Wave Flux Analysis: 15-min resolution on SKYRAD data, Long algorithm
- 15swfcldfac1long : Fractional cloud cover, clear-sky and all-sky shortwave flux for each of 25 individual SGP facilities.
- 1swfanalbrs1long : Short Wave Flux Analysis: 1-min resolution on BRS data, Long algorithm
- 1swfanalsiros1long : Short Wave Flux Analysis: 1-min resolution on SIROS data, Long algorithm
- 1swfanalsirs1long : Short Wave Flux Analysis: 1-min resolution on SIRS data, Long algorithm
- 1swfanalskyrad1long : Short Wave Flux Analysis: 1-min resolution on SKYAD data, Long algorithm
The following measurements are those considered scientifically relevant.
- Cloud fraction
- Shortwave broadband diffuse downwelling irradiance
- Shortwave broadband direct downwelling irradiance
- Shortwave broadband total downwelling irradiance
- Surface albedo