Record Details
Field | Value |
---|---|
Title | Penetrative elements at the top of the atmospheric mixed layer |
Names |
Paumier, James
(creator) Mahrt, Larry J. (advisor) |
Date Issued | 1981-03-05 (iso8601) |
Note | Graduation date: 1981 |
Abstract | High resolution data of moisture, temperature and wind velocity collected by aircraft during the 1975 Air Mass Transformation Experiment (ANTEX '75) provide information for detailed investigations of the phenomena occurring at the top of a cloud-topped mixed layer. Joint frequency diagrams of humidity and temperature reveal that for parts of the record the coldest temperatures occur in air near saturation while drier air or air with substantial liquid water is warmer. This suggests the possible occurrence of cloud-top entrainment instability (Deardorff, 1980). Using humidity as an indicator, the flight record is systematically searched for penetrative mixed layer elements and pockets of dry air penetrating into cloudy air (wisps). The separate phenomena are then composited to produce an "average" wisp and penetrating element. The composites show evidence of net cooling due to evaporation downstream from the penetrating element and upstream from the wisps. Sinking motion is associated with the cold temperatures. These results suggest the interaction of shear, penetrating elements and wisps, and the existence of cloud-top entrainment instability. |
Genre | Thesis/Dissertation |
Topic | Planetary boundary layer |
Identifier | http://hdl.handle.net/1957/29287 |