| タイトル | Low cloud investigations for project FIRE: Island studies of cloud properties, surface radiation, and boundary layer dynamics. A simulation of the reflectivity over a stratocumulus cloud deck by the Monte Carlo method |
| 本文（外部サイト） | http://hdl.handle.net/2060/19930008812 |
| 著者（英） | Ackerman, Thomas P.; Lin, Ruei-Fong |
| 著者所属（英） | Pennsylvania State Univ. |
| 発行日 | 1993-02-01 |
| 言語 | eng |
| 内容記述 | The radiation field over a broken stratocumulus cloud deck is simulated by the Monte Carlo method. We conducted four experiments to investigate the main factor for the observed shortwave reflectively over the FIRE flight 2 leg 5, in which reflectivity decreases almost linearly from the cloud center to cloud edge while the cloud top height and the brightness temperature remain almost constant through out the clouds. From our results, the geometry effect, however, did not contribute significantly to what has been observed. We found that the variation of the volume extinction coefficient as a function of its relative position in the cloud affects the reflectivity efficiently. Additional check of the brightness temperature of each experiment also confirms this conclusion. The cloud microphysical data showed some interesting features. We found that the cloud droplet spectrum is nearly log-normal distributed when the clouds were solid. However, whether the shift of cloud droplet spectrum toward the larger end is not certain. The decrease of number density from cloud center to cloud edges seems to have more significant effects on the optical properties. |
| NASA分類 | METEOROLOGY AND CLIMATOLOGY |
| レポートNO | 93N18001
NASA-CR-192083
NAS 1.26:192083 |
| 権利 | No Copyright |
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