Date of Award
2023
Document Type
Dissertation
Degree Name
Doctor of Philosophy (PhD)
Department
Atmospheric and Earth Science
Committee Chair
Lawrence Carey
Committee Member
Patrick Gatlin
Committee Member
Phillip Bitzer
Committee Member
John Mecikalski
Subject(s)
Hurricanes--Development--Remote sensing, Cyclones--Development--Tropics--Remote sensing, Convection (Meteorology), Lightning, Precipitation (Meteorology)
Abstract
This study creates a new and unique merged satellite dataset, with data sources including matched Geostationary Lightning Mapper (GLM) and low-earth orbiting Global Precipitation Measurement (GPM) Mission observations. Crafting and iterative analysis of the dataset resulted in a reprocessing of the GPM precipitation feature (PF) database, significant due to use by a broad segment of the science community. The new dataset is used to examine characteristics of mid-/high latitude deep convection as compared to the tropics, and significantly, provide new integrated observations of convective evolution throughout the tropical cyclone (TC) lifecycle to include post-tropical cyclone (PTC) phases. The combined datasets are analyzed in the context of their background meteorological environments to investigate relationships between lightning flash rate and GPM radar-based reflectivity profiles and passive microwave characteristics of convective PFs (cPFs). Analysis results indicate that mid-latitude cPFs with detectable lightning are characterized by colder temperatures of the maximum 30 dBz echo top height and a narrower range of microwave brightness temperatures (TBs) when compared with tropical cPFs. Electrically-active cPFs TB characteristics are highly correlated to radar-diagnosed ice mass; this relationship dominates lightning sensitivities to synoptic-scale thermodynamic proxies used for describing convective strength and organization. When the new dataset is applied to TC convective evolution, more lightning flashes are observed during the PTC phase than during tropical phases. Total lightning maxima are found in the forward right (downshear) quadrant relative to storm motion (shear) vectors. Additionally, a unimodal radial distribution is observed regardless of TC phase as well as for TS and PTC phases. Vertical profiles of radar reflectivity show that super electrically-active cPFs (>100 flashes) within the PTC phase have deeper mixed phase depths and higher reflectivity at -10°C than other phases, indicating more intense convection. Overall, a balance between the frequency of lightning producing cells and storm-relative intensity differences between those cells drives convective behavior between TC phases relative to lightning production. The breadth of analysis possible with this new GLM and PF integrated dataset is substantial. Future research approaches using the database will undoubtedly reveal much more about the physics and coupling of deep convection dynamics, microphysics, and lightning.
Recommended Citation
Heuscher, Lena V., "Identification of satellite observed lightning and precipitation markers throughout tropical cyclone evolution" (2023). Dissertations. 276.
https://louis.uah.edu/uah-dissertations/276