Thesis (Ph. D.)--University of Hawaii, 2001. / Includes bibliographical references (leaves 176-184).

Thesis (Ph. D.)--Ohio State University, 2005. / Title from first page of PDF file. Includes bibliographical references (p. 152-162).

Thesis (Ph. D.)--Florida State University, 2006. / Advisors: Kevin Speer, Martin Wegkamp, Florida State University, College of Arts and Sciences, Dept. of Statistics. Title and description from dissertation home page (viewed Sept. 20, 2006). Document formatted into pages; contains x, 48 pages. Includes bibliographical references.

Thesis (M. Sc.)--University of Canterbury, 2007. / Typescript (photocopy). Includes bibliographical references (leaves 60-64). Also available via the World Wide Web.

L'objectif de cette thèse est d'étudier l'influence sur l'atmosphère de la variabilité des fronts océaniques associés aux extensions du Kuroshio (KE) et de l'Oyashio (OE), et de la différencier de l'influence des modes de variabilité grande échelle de la SST du Pacifique Nord, en particulier l'oscillation décennale du Pacifique (PDO). Nous utilisons pour cela la réanalyse atmosphérique ERA-Interim à partir de 1979, et des index déjà disponibles décrivant la variabilité des courants. Dans une première partie, nous nous focalisons sur l'influence du KE, en utilisant une méthode statistique de régression partielle avec décalage temporel, avec filtrage en amont du signal lié aux téléconnexions ENSO. Nous montrons que la phase positive du KE induit une réponse atmosphérique significative équivalente barotrope pendant la saison d'octobre à janvier, avec une anomalie positive de pression au centre du Pacifique Nord et sur l'ouest des Etats-Unis, et un renforcement du vortex polaire. Dans une deuxième partie, nous utilisons une méthode statistique multivariable permettant d'analyser en parallèle les réponses atmosphériques aux différents forçages océaniques pouvant être corrélés entre eux. Cette méthode permet d'inclure, outre les indices décrivant la variabilité du KE et de l'OE, les principaux modes de variabilité grande échelle de la SST tels que la PDO qui est très corrélée à l'OE, les modes tropicaux tels qu'ENSO, mais également la variabilité de la glace de mer. La réponse atmosphérique étant très dépendante de l'état moyen de l'atmosphère, nous distinguons trois saisons : le début d'hiver (OND), l'hiver (DJF), et la fin d'hiver (FMA). / The aim of this work is to study the influence on the atmosphere of the variability of the oceanic fronts associated with the Kuroshio and Oyashio Extensions (KE and OE), and to differentiate it from the influence of the main SST mode of the North Pacific, in particular the Pacific Decadal Oscillation (PDO). We use the atmospheric reanalysis ERA-Interim starting from 1979, and indices that describe the variability of the KE and OE that are already available. In the first part of this work, we focus on the KE influence, using lag partial regression analysis with the ENSO signal removed. We show that in October to January the positive phase of the KE leads to a downstream barotropic high response in the central North Pacific and over western United States, and an enhanced polar vortex. We try to understand the mechanisms behind this atmospheric response analyzing the KE influence on the synoptic activity. In the second part, we use a multivariate statistical method that allows us to analyze in parallel the atmospheric response to different oceanic forcings that may be correlated to each other. In addition to the KE and OE indices, we include in the analysis the main modes of SST variability of the tropical and northern hemisphere oceans, such as the PDO in the North Pacific and ENSO in the tropical Pacific. We also include sea ice variability in the Arctic. The atmospheric response being very dependent on the mean background flow, we distinguish between three seasons: early winter (OND), winter (DJF) and late winter (FMA).

Droughts that achieve extreme spatial extent over the contiguous United States pose unique challenges because of their potential to strain multiple water resources simultaneously. Two such spatially coherent, reoccurring droughts are (i) those that span the majority of the US (herein pan-CONUS droughts) and (ii) those that span the US Pacific coast (herein pan-coastal droughts). These droughts can have drastic impacts on US agriculture, water resources, and wildfire risk, thus posing serious risks to our food security, infrastructure, and economy. Such events are difficult to characterize due to the relatively short instrumental record and the rarity of observed widespread drought. The combined availability of observations, ensembles of climate model simulations, and high-resolution paleoclimate reconstructions, however, have recently increased the sampling and length of the hydroclimate record. This wealth of climate data makes the time ripe to investigate the causes and dynamics of spatially widespread droughts, with implications for their impacts in the future under a changing climate. Previous studies have established the sensitivity of North American drought variability to large-scale atmosphere-ocean modes. In particular, the El Niño Southern Oscillation (ENSO) and Atlantic Multidecadal Oscillation (AMO) have been linked with widespread drying over the United States. While neither mode alone is likely to cause either pan-CONUS or pan-coastal droughts, the canonical understanding of oceanic influences on North American hydroclimate nevertheless suggest that (i) pan-CONUS droughts are forced by a contemporaneous cold tropical Pacific Ocean and a warm tropical Atlantic Ocean and (ii) pan-coastal droughts are forced by cold tropical and north Pacific conditions. By examining how pan-CONUS and pan-coastal droughts are represented in climate model simulations and comparing them against observation and paleoclimate reconstructions, the work in this dissertation tests the above-mentioned canonical understanding. For pan-CONUS droughts, SST forcing is shown to originate almost entirely from La Niña conditions, with little contribution from the tropical Atlantic. Furthermore, internal atmospheric variability influences pan-CONUS drought occurrence by as much or more than ocean forcing and can alone cause pan-CONUS droughts. Internal atmospheric variability is shown to play an even larger, predominant role in driving pan-coastal droughts, accounting for upwards of 80% of the severity of the events; cold Pacific conditions, while playing a clearly detectable role, are only secondary in their influence relative to internal atmospheric variability. These results are then compared to the observational and/or paleoclimate record, which supports the model-inferred conclusions. Collectively, the work outlined in this dissertation holds important implications regarding (i) mechanistic understandings of North American hydroclimate, (ii) predictability, or lack thereof, of pan-CONUS and pan-coastal droughts, and (iii) how pan-CONUS and pan-costal droughts may change in the future due to increases in greenhouse gas emissions. The research contained herein furthermore demonstrates the precise extent to which large-scale ocean-atmosphere and internal atmospheric variability interact. In so doing, this dissertation contributes to a fundamental understanding of the importance of large-scale ocean-atmosphere modes relative to internal atmospheric variability in North American hydroclimate dynamics.

Thesis (Sc.D.)--Massachusetts Institute of Technology, Dept. of Meteorology, 1980. / Microfiche copy available in Archives and Science. / Vita. / Bibliography: leaves 315-325. / by John Merrill Toole. / Sc.D.

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Meteorology, 1979. / Microfiche copy available in Archives and Science. / Bibliography : leaves 45-48. / by Clare Bertram Billing, Jr. / M.S.

Thesis. 1976. M.S.--Massachusetts Institute of Technology. Dept. of Meteorology. / Microfiche copy available in Archives and Science. / Bibliography: leaves 119-122. / by Angel G. Cornejo Garrido. / M.S.

Thesis. 1978. Ph.D.--Massachusetts Institute of Technology. Dept. of Meteorology. / Microfiche copy available in Archives and Science. / Bibliography: p. 239-241. / Ph.D.