clarified things a bit

Author: aaronjridley

day_8/radiative_transfer.md

@@ -49,17 +49,21 @@ Here are steps on the road to producing a radiative transfer model of Earth's up
 
 6. Make a function that takes the altitude, temperature, scale-height, and bottom density and returns the density as a function of altitude. Run this for O and make sure if looks as expected. (Use n(O, 100 km) = 5.0e17/m3.)
 
-7. Make a function that takes SZA, n(O, z), H(O, z), sigma(O, wavelength) and returns Tau as a function of altitude. For a first pass, I would concentrate only on one wavelength (e.g., 50 - 100 Angstrom bin) and SZA = 0.  Plot out the single Tau as a function of wavelength.  Tau should pass through 1 somewhere between 120 - 150 km altitude.  Once this works, you can make the Tau for all of the 37 wavelength bins. Tau will then be a function of wavelength and altitude.  You can then implement SZA and limit it to < 75 degrees.
+7. Make a function that takes SZA, n(O, z), H(O, z), sigma(O, wavelength) and returns Tau as a function of altitude. For a first pass, I would concentrate only on one wavelength (e.g., 50 - 100 Angstrom bin) and SZA = 0.  Plot out the single Tau as a function of wavelength.  Tau should pass through 1 somewhere between 120 - 150 km altitude.  Once this works, you can make the Tau for all of the 37 wavelength bins. Tau will then be a function of wavelength and altitude. 
+
+(If you make it here, you are doing really, really well).
 
 8. Create a function that calculates the energy as a function of wavelength bin. It should take the wavelength and return energy.
 
 9. Create a function that calculates dT/dt. Again, test the code out with just one wavelength to make sure that it works ok.  Then expand it to other wavelengths.
 
 10. Expand all relevant functions that use n(O, z) to use n(O2, z) and n(N2, z) also. 
 
+11. You can then implement SZA in the Tau calculation. Limit it to < 75 degrees, and have Tau be very large (say 10 or so) if SZA < 75 degrees.
+
 11. Set a dt (less than 5 minutes), and then update T given dT/dt. Recalculate n(O, z), n(O2, z), and n(N2, z) using your functions.
 
-12. Update the SZA given the time.
+12. Update the SZA given the time of day.
 
 13. Repeat for 24 hours.