| We computed the ratio of direct to total horizontal irradiance as a function of SZA and column ozone amount. |
| Depletion of the Earth's ozone layer is considered responsible for an increase in the solar ultraviolet irradiance reaching the surface. |
| An additional advantage of this method is that UV-B irradiance can be determined at any depth within a leaf. |
| This irradiance and the radiance in the opposite direction were then inserted into equation to calculate the ideal reflectance. |
| From these values the integrated irradiance values are obtained for the desired time interval. |
| Although the solar simulator provides a higher spectral irradiance throughout the UV, its spectrum differs from natural sunlight. |
