Date of Award
1-1-2019
Language
English
Document Type
Dissertation
Degree Name
Doctor of Philosophy (PhD)
College/School/Department
Department of Atmospheric and Environmental Sciences
Content Description
1 online resource (ix, 157 pages) : color illustrations, color maps.
Dissertation/Thesis Chair
Paul E. Roundy
Committee Members
Christopher D. Thorncroft, Andrea Lang, Katherine Straub
Keywords
Intraseasonal Variability, Madden-Julian Oscillation, Tropical-Extratropical Interactions, Madden-Julian oscillation, Convection (Meteorology), Cyclones, Ocean-atmosphere interaction
Subject Categories
Atmospheric Sciences
Abstract
Madden-Julian Oscillation (MJO) deep convection often initially forms over the western Indian Ocean and is frequently preceded by upper tropospheric circulation precursors. These precursors include subtropical cyclonic Rossby gyres near eastern Africa and Southwest Asia, coherent extratropically circumnavigating Rossby wave trains extending back across the Atlantic, and tropically circumnavigating easterlies. Easterly acceleration associated with the circulation precursors may help to reduce large-scale subsidence over the tropical Indian Ocean prior to convective onset; when intraseasonal easterly acceleration reaches the western extent of a region of intraseasonal upper level westerlies, it produces upper-tropospheric divergence, providing a forcing for upward motion.
Recommended Citation
Gahtan, Jennifer Anne, "Extratropical precursors to the onset of Madden-Julian Oscillation deep convection over the Western Indian Ocean" (2019). Legacy Theses & Dissertations (2009 - 2024). 2285.
https://scholarsarchive.library.albany.edu/legacy-etd/2285