Solar Fluxes

TOA solar fluxes used in Streamer, given below, are compiled from MODTRAN3, where fluxes for all wavenumbers (cm-1) are summed over the Streamer bands. The total flux in the shortwave spectrum (0.28 - 4.0 um) is 1354.2 W m-2. These are based on the mean Earth-Sun distance, which is adjusted for actual Earth-Sun distance based on the day of the year.


Flux (W m-2)
Band

+0

+1

+2

+3

+4

106:

6.79596

11.25329

22.57683

19.13139

72.08298

111:

28.28439

89.91177

40.46196

52.22254

64.40662

116:

114.96570

93.06992

34.41000

84.12315

76.00535

121:

122.59850

94.00961

76.16579

79.38628

67.82777

126:

44.14775

28.95610

22.63300

8.78925


Note: The solar constant in Streamer calculations that is equal to that calculated for the mean Earth-Sun distance occurs on approximately April 2 and October 4.

The total solar flux of 1354.2 W m-2 differs from the typical "solar constant" value of approximately 1370 W m-2 (at a mean Earth-Sun distance) because of the difference in the width of the solar spectrum. In Streamer the shortwave spectrum covers the wavelengths 0.28 - 4.0 mm. If Streamer's spectrum ranged from 0.2 to 5.0 mm, the total solar flux would be approximately 1367 W m-2.