Freezing drizzle production in warm frontal overunning cloud layers: an observational study
| dc.contributor.author | McDonough, Frank, author | |
| dc.contributor.author | Cotton, William R., advisor | |
| dc.contributor.author | Kreidenweis, Sonia M., committee member | |
| dc.contributor.author | Mielke, Paul W., Jr., committee member | |
| dc.date.accessioned | 2022-07-01T00:08:24Z | |
| dc.date.available | 2022-07-01T00:08:24Z | |
| dc.date.issued | 2010 | |
| dc.description.abstract | National Weather Service operational and research aircraft data were used to analyze the large and small-scale structure of warm-frontal overrunning cloud layers forming freezing drizzle. Two detailed case studies, one from a maritime region (Juneau, AK), and one from a continental region (Green Bay, WI) are presented. The synoptic scale situation for both cases showed descending motion aloft, drying at the mid-levels and warming cloud top temperatures. The warming cloud top temperatures shut down the production of the ice phase and allowed supercooled liquid water to dominate the cloud microstructure. The cloud layers were formed by both isentropic lift and convective instability, although the convective layers had higher liquid water contents. In addition to helping form the clouds the warm air advection created thin warm layers aloft which allowed discrete cloud layers to form. Each of the layers had distinct thermodynamic and microphysical properties. Freezing drizzle (FZDZ) was observed in all the cloud layers but the initial formation of FZDZ was in layers detached from the boundary layer with low droplet concentrations. Radiational cooling at the highest cloud top was likely present in both cases and may have formed FZDZ, but its presence was not a necessary condition. Isobaric mixing at cloud top was observed in the maritime case and was likely present at cloud top in both cases. | |
| dc.format.medium | masters theses | |
| dc.identifier.uri | https://hdl.handle.net/10217/235401 | |
| dc.language | English | |
| dc.language.iso | eng | |
| dc.publisher | Colorado State University. Libraries | |
| dc.relation | Catalog record number (MMS ID): 991014242989703361 | |
| dc.relation | QC921.5.M446 2010 | |
| dc.relation.ispartof | 2000-2019 | |
| dc.rights | Copyright and other restrictions may apply. User is responsible for compliance with all applicable laws. For information about copyright law, please see https://libguides.colostate.edu/copyright. | |
| dc.subject | Cloud physics | |
| dc.subject | Freezing rain | |
| dc.title | Freezing drizzle production in warm frontal overunning cloud layers: an observational study | |
| dc.type | Text | |
| dcterms.rights.dpla | This Item is protected by copyright and/or related rights (https://rightsstatements.org/vocab/InC/1.0/). You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s). | |
| thesis.degree.discipline | Atmospheric Science | |
| thesis.degree.grantor | Colorado State University | |
| thesis.degree.level | Masters | |
| thesis.degree.name | Master of Science (M.S.) |