(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

Compute the solar irradiance in the near IR range (0.7 - 1.5 microns) at the top of the atmosphere over Denver at noon on August 23rd, and assume that 37 per cent of the solar spectrum is in this range.

2. Relevant equations

Equations? I=ScosZ where Z is the azimuth angle over Denver at this time, S is 1360Wm-2. Also, there is an equation that's supposed to give actual amount striking surface:

I = I(0) exp(-u secZ), where u is the optical depth.

3. The attempt at a solution

Failed miserably because my computed azimuth angle is 254.8 degrees which results in a negative value for the first equation. I tried the second equation anyway, and the secant of 254.8 is undefined. I spent a lot of time trying to figure out the azimuth angle and could only come up with 254.8 degrees. For that equation (azimuth) I used:

A = 180 deg. + sin-1(cos(11.5)sin(99.8) / sin(90))

Here, 11.5 is the declination angle, which was found from the analemma; 99.8 is the solar hour angle; and 90 is the sun's zenith angle at noon.

Please help. Thanks.

1. The problem statement, all variables and given/known data

2. Relevant equations

3. The attempt at a solution

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# Homework Help: How to find solar insolation in the IR spectrum

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