Cirrus clouds cover between 20% - 50% of the globe and are an essential
component in the climate. The improved understanding of ice cloud
microphysical properties is contingent on acquiring and analyzing in-situ and
remote sensing data from cirrus clouds. In ??u observations of microphysical
properties of ice and mixed-phase clouds using the mini-Video Ice Particle Sizer
(mini-VIPS) aboard robotic unmanned aerial vehicles (UAVs) provide a promising
and powerful platform for obtaining valuable data in a cost-effective, safe, and
long-term manner.
The purpose of this study is to better understand cirrus microphysical
properties by analyzing the effectiveness of the mini-VIPS/UAV in-situ platform.
The specific goals include:
(1) To validate the mini-VIPS performance by comparing the mini-VIPS data
retrieved during an Artic UAV mission with data retrieved from the millimeterwavelength
cloud radar (MMCR) at the Barrow ARM/CART site.
(2) To analyze mini-VIPS data to survey the properties of high latitude mixedphase
clouds
The intercomparison between in-situ and remote sensing measurements
was carried out by comparing reflectivity values calculated from in-situ
measurements with observations from the MMCR facility. Good agreement
between observations and measurements is obtained during the time frame
where the sampled volume was saturated with respect to ice. We also have
1 2
shown that the degree of closure between calculated and observed reflectivity
strongly correlates with the assumption of ice crystal geometry observed in the
mini-VIPS images. The good correlation increases the confidence in mini-VIPS
and MMCR measurements. Finally, the size distribution and ice crystal geometry
obtained from the data analysis is consistent with published literature for similar
conditions of temperature and ice supersaturation.
| Identifer | oai:union.ndltd.org:GATECH/oai:smartech.gatech.edu:1853/7252 |
| Date | 21 July 2005 |
| Creators | Williams, Robyn D. |
| Publisher | Georgia Institute of Technology |
| Source Sets | Georgia Tech Electronic Thesis and Dissertation Archive |
| Language | en_US |
| Detected Language | English |
| Type | Thesis |
| Format | 1328421 bytes, application/pdf |
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