The Influence of Protective Pouches on the Development and Intensification of Hurricane ETA (2020)
Abstract
This thesis investigates the development of Hurricane Eta (2020) and its rapid intensification in the Western Caribbean during the late hurricane season. This study aims to show that the different stages of development of the system are supported by the marsupial paradigm. This paradigm requires, for tropical cyclogenesis, the existence of a protective pouch defined by a dividing streamline with a recirculating flow in a comoving frame of reference, which in the Atlantic is often associated with a westward-tracking African easterly wave. Global Model Analyses were examined in a comoving frame and indeed the precursor to Hurricane Eta was determined to have originated over Africa and then tracked westward over the Atlantic. Moreover, thorough examination of the model analyses allowed for a careful study of the interaction of multiple vortices within the pouch. Specifically, as the pouch crossed the central Atlantic, the separation distance between the two vortices within the pouch increased and then subsequently decreased as they merged and came into vertical alignment soon before formation as a tropical depression. The rapid intensification phase of Hurricane Eta immediately before landfall in Nicaragua is described also by examining moisture, relative vorticity, and vertical wind shear.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 2023
- Accession Number
- AD1213171
Entities
People
- Nicohl M. Corretjer
Organizations
- Naval Postgraduate School