September 3rd (Thursday), 2020 1:00 PM
https://us02web.zoom.us/j/87116840863?pwd=Z1V1a0VycDhyREY2N1FaMm1aMEhGQT09
THESIS COMMITTEE MEMBERS
Dr. Emanuele Di Lorenzo (Academic Advisor)
School of Earth & Atmospheric Sciences
Georgia Institute of Technology
311 Ferst Drive Atlanta, GA, 30332-0340, USA
Email: edl@eas.gatech.edu
Dr. Taka Ito
School of Earth & Atmospheric Sciences
Georgia Institute of Technology
311 Ferst Drive Atlanta, GA, 30332-0340, USA
Email: taka.ito@eas.gatech.edu
Dr. Jie He
School of Earth & Atmospheric Sciences
Georgia Institute of Technology
311 Ferst Drive Atlanta, GA, 30332-0340, USA
Email: jie.he@eas.gatech.edu
Dr. Antonietta Capotondi (External, from NOAA)
NOAA/ESRL/PSD, and CIRES Climate Diagnostics Center
325 Broadway Boulder, CO, 80305
E-mail: Antonietta.Capotondi@noaa.gov
Dr. Benjamin Kirtman (External, from UM)
Rosenstiel School for Marine and Atmospheric Science
University of Miami
4600 Rickenbacker Causeway Miami, Fl 33149
Email: bkirtman@rsmas.miami.edu
PHD THEIS DISSERTATION
TITLE
PACIFIC TELECONNECTIONS DYNAMICS IN A CHANGING CLIMATE: THEORIES, OBSERVATIONS, AND MODELS
ABSTRACT
Pacific climate and weather extreme events such as heatwaves, drought, and hydrological extremes, which drive economically significant changes along the US, are dynamically linked to not only the local coupling of ocean-atmosphere but also large-scale climate variability (e.g., North Pacific decadal variability and El Niño Southern Oscillation). This work aims at improving the theories of climate coupling within the North Pacific and across to the central tropical Pacific system and investigating their changes and response to anthropogenic forcing. Using multiple observational reanalyses and global climate model ensembles, we find that the multi-year persistence of marine heatwaves of the North Pacific is associated with the dominant modes of North Pacific decadal variability through the El Niño Southern Oscillation (ENSO) atmospheric teleconnections. The results suggest that the marine heatwaves in the North Pacific will be not only becoming stronger in amplitude with a larger area but also more persistent in a warming climate under anthropogenic forcing. Next, we provide observational evidence revealing that a preferred decadal timescale (~10yrs) in the Kuroshio Extension (KE) region may arise from interactions with the central tropical Pacific variability (e.g., Central Pacific ENSO, CP-ENSO). Applying satellite data with several observation reanalysis products, we suggest that the KE dynamic states can drive persistent downstream atmospheric response (e.g., wins stress curl anomalies) over the subtropical Pacific and project on atmospheric forcing of North Pacific Meridional Modes (PMM) and CP-ENSO. Finally, we diagnose the decadal KE dynamics and conclude that the decadal KE dynamics and its linkages to the tropics have not been stationary. We find that the extratropical-tropical KE coupled system has enhanced by showing a significant difference in the decadal KE statistics (e.g., timescale), especially after mid-1980. We suggest that an increase in this coupling might be associated with the stronger wind stress response of KE (e.g., atmospheric forcing of Pacific Meridional Modes) with driving the ENSO-favorable conditions. These results imply that the higher amplitude quasi-decadal fluctuations of KE/CP-ENSO may lead to a stronger basis for decadal predictions of the Pacific region, especially for societally relevant biogeochemical quantities (e.g., salinity, oxygen, and chlorophyll-A) and fisheries.
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