| タイトル | Investigating Type I Polar Stratospheric Cloud Formation Mechanisms with POAM Satellite Observations |
| 著者（英） | Fromm, M.; Strawa, Anthony W.; Gore, Warren J.; Browell, E.; Dempsey, D.; Drdla, K.; Hoppel, K.; Hamill, P. |
| 著者所属（英） | NASA Ames Research Center |
| 発行日 | 2001-11-02 |
| 言語 | eng |
| 内容記述 | Type Ia PSCs are believed to be composed of nitric acid hydrate particles. Recent results from the SOLVE/THESEO 2000 campaign showed evidence that this type of PSC was composed of a small number of very large particles capable of sedimentary denitrification of regions of the stratosphere. It is unknown whether homogeneous or heterogeneous nucleation is responsible for the formation of these PSCs. Arctic winters are tending to be colder in response to global tropospheric warming. The degree to which this influences ozone depletion will depend on the freezing mechanism of nitric acid hydrate particles. If nucleation is homogeneous it implies that the freezing process is an inherent property of the particle, while heterogeneous freezing means that the extent of PSCs will depend in part on the number of nuclei available. The Polar Ozone and Aerosol Measurement (POAM)II and III satellites have been making observations of stratospheric aerosols and Polar Stratospheric Clouds (PSCs) since 1994. Recently, we have developed a technique that can discriminate between Type Ia and Ib PSCs using these observations. A statistical approach is employed to demonstrate the robustness of this approach and results are compared with lidar measurements. The technique is used to analyze observations from POAM II and II during Northern Hemisphere winters where significant PSC formation occurred with the objective of exploring Type I PSC formation mechanisms. The different PSCs identified using this method exhibit different growth curve as expressed as extinction versus temperature. |
| NASA分類 | Geophysics |
| 権利 | No Copyright |
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