Greg Lee Sova

Date of Award

January 2021

Document Type

Thesis

Degree Name

Master of Science (MS)

Department

Atmospheric Sciences

First Advisor

David Delene

Abstract

The Rosemount Icing Detector (RICE Probe) is a vibrating cylinder icing probe that measures the supercooled liquid water in the atmosphere that contributes to aircraft icing conditions. The frequency of the RICE Probe vibration decreases with increasing ice accretion. The RICE Probe was mounted on the fuselage of the NASA P-3 Orion aircraft for the IMPACTS 2020 field campaign. During the project, flight scientists had real-time frequency data for qualitative assessment of the presence of supercooled liquid water. For quantitative measurements of the liquid water, flight scientists used the King Liquid Water Sensor (King Probe) and the Cloud Droplet Probe (CDP). While the King Probe and CDP perform well in certain conditions, both probes are subject to measurement uncertainties that are dependent on cloud environment.A supercooled liquid water content (SLWC) product is derived for the model 0871ND4 RICE Probe by comparing the change in output frequency to a known liquid water content measurement in supercooled water-only conditions. The k constant relating RICE Probe frequency, true air speed, and the probe dimensions to the SLWC is empirically found to be 4.752 ⨯ 10-4 g Hz-1. The SLWC product is then evaluated for different environments to test the effectiveness of the product under a variety of conditions. Temperature is found to be the most important effect, with conditions warmer than -3 ℃ being unsuitable for use. While mounted on the NASA P-3 Orion, pitch angles greater than 3° are found to be unsuitable as well. At temperatures between -5 ℃ and -3 ℃, slower air speeds improved the RICE Probe’s effectiveness at sampling SLWC.

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