SeaWiFS Surface Solar Irradiance Data Set (NASA/GISS)

[Source: NASA/GISS, https://data.giss.nasa.gov/seawifs/ ]

Surface solar irradiance and related products were obtained through the implementation of three generations of an algorithm (Bishop and Rossow 1991). The information was produced for the SeaWiFS project. The second generation (version 2) datasets (spanning eight years) are now archived at NCAR, and a year of the third generation (version 3) datasets from July 1983 to June 1984 is presently available (see below). Applications of the Bishop and Rossow datasets are found in papers by Mitchell et al. (1991, Linmol & Ocean. 36, 1662-1667), Liu et al. (1994, JGR 99, 12623-12637), and Seager and Blumenthal (1994, J. Climate 7, 1943-1957). The algorithm uses C1 data from the International Satellite Cloud Climatology Project (ISCCP), which combines data from multiple geostationary and polar orbiting meteorological satellites to provide a global view of the occurrence and optical properties of clouds. A high resolution (30-km) dataset obtained from ISCCP DX data is in production and five test days of data are currently available.

Atmospheric, cloud, and surface data from ISCCP are used as input with a fast scheme for computing clear-sky irradiance from the solar zenith angle, air properties, and surface reflectance. The scheme then uses simple cloud properties (cloud fraction, cloud optical thickness, and diffuse albedo) to produce total and photosynthetically active solar irradiance fields (Bishop and Rossow 1991; ISCCP Documentation of Cloud Data; Frouin et al. 1989).

Input and output data fields are given in a 2.5 latitude and longitude grid.

The input data fields are ISCCP data:

* Solar zenith angle (every 3hr)
* Ozone, total precipitable water, surface pressure (daily)
* Surface reflectance (every 3hr)
* Cloud cover and optical thickness (every 3hr)
* Land-water fraction
* Snow and ice cover (every 5 days)

The output data fields are:
* Clear sky irradiance
* Total irradiance including clouds
* Photosynthetically active solar irradiance fields

The output fields are available every three hours, and as daily and monthly averages. Daily and monthly averages of the input fields are also produced when adequate.

This data set may also be obtained from the National Center for Atmospheric Research (NCAR).