| dc.contributor.author | Wong, Jeff. | en_US |
| dc.date.accessioned | 2014-10-21T12:38:17Z | |
| dc.date.available | 1998 | |
| dc.date.issued | 1998 | en_US |
| dc.identifier.other | AAINQ36594 | en_US |
| dc.identifier.uri | http://hdl.handle.net/10222/55607 | |
| dc.description | The effect of aerosols and clouds on Earth's shortwave radiation budget is studied in this thesis. | en_US |
| dc.description | An expression for the global annual mean radiative forcing due to sulfate aerosols is extended for absorbing aerosols using a two-stream approximation. This expression depends on the backscattering fraction of the aerosol which varies with the effective radius of the aerosol size distribution. This variation leads to a factor of 2.0 variation in the radiative forcing of slightly absorbing aerosols. | en_US |
| dc.description | Water vapor condenses onto hygroscopic aerosols which results in a change in size and a change in the concentration of the chemical components of the aerosol. The original Kohler equation accurately describes the equilibrium size of a hygroscopic aerosol. Use of the modified Kohler equation leads to errors due to its thermodynamically inconsistent nature. On a global annual average, the direct radiative forcing of hygroscopic sulfate aerosol is --0.69 W m--2. Over highly polluted regions, the local radiative forcing can be as high as --7 W m--2 which is comparable to the forcing due to increased greenhouse gas concentrations. | en_US |
| dc.description | Using a plane-parallel model, an analytical expression is derived for the cloud radiative forcing ratio which is used as a measure of enhanced shortwave radiation absorption of clouds. With this model, high values of this ratio can be achieved by thick clouds with absorptances of approximately 0.3. High values of the ratio can also be obtained with low level clouds if the transmittance of the atmosphere above the cloud is reduced to approximately 0.8. This can be achieved by a high concentration of strongly absorbing aerosols. | en_US |
| dc.description | Thesis (Ph.D.)--Dalhousie University (Canada), 1998. | en_US |
| dc.language | eng | en_US |
| dc.publisher | Dalhousie University | en_US |
| dc.publisher | | en_US |
| dc.subject | Physics, Atmospheric Science. | en_US |
| dc.subject | Environmental Sciences. | en_US |
| dc.title | Radiative impact of atmospheric aerosols and clouds. | en_US |
| dc.type | text | en_US |
| dc.contributor.degree | Ph.D. | en_US |
