Field experiment observations of a dryline and the associated clouds and precipitation

• Author / Creator

  Daniel, Brown

• The UNderstanding Severe Thunderstorms and Alberta Boundary Layer Experiment (UNSTABLE) in July 2008 was a field project to investigate the initiation of thunderstorms in southern Alberta. Special field observations included an enhanced surface network augmented with instrumented vehicles. Upper air observations were taken from four sites every two hours.

  This thesis focuses on the case study day of 17 July 2008 when a dryline formed parallel to the Rocky Mountains at 1030 MDT and persisted for up to nine hours. The vapour mixing ratio changed from 4.5 to 8.5 g/kg over 5 km. We documented the spatial and temporal distribution of cloud and precipitation relative to the dryline. Initially, extensive cloud formed over the dry air to the west of the dryline, while the capping inversion at 800 mb inhibited cloud formation in the moist air. In the afternoon, convection was triggered along the dryline and severe thunderstorms were observed.

• Subjects / Keywords

  • Field experiments
  • Dryline
  • Meteorology
  • Thunderstorm
  • Humidity

• Graduation date

  Spring 2010

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/R3JD4G

• License

  This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.