Posted by Krysten on .
At a spot in the ocean , the surface irradiance is 7.8*10^16 photons cm^2 s^1, and k=0.14 m^1. At what depth does the euphotic zone end? (Find definition for euphotic zone and solve for z)

Physics 
Damon,
Same idea as the last question but e^(.14 z)
and Io = 7.8*10^16
and you have to look up the irradiance for light to die out enough.
Once you do that, take the ln of both sides to solve it. 
Physics 
Damon,
From wikipedia:
"It extends from the atmospherewater interface downwards to a depth where light intensity falls to 1 percent of that at the surface (also called euphotic depth), "
so where I = .01 Io
or
I/Io = .01 = e^.14z
ln .01 = .14 z
4.6 = .14 z
solve for z