Thesis (Ph. D.)--University of Washington, 2002. / Vita. Includes bibliographical references (p. 219-228).

Graduation date: 1988

Thesis (M.S.)--Florida State University, 1996. / Abstract. Includes bibliographical references (leaves 85-87).

Thesis (M. Sc.)--University of Hong Kong, 1999. / Includes bibliographical references (leaves 48-65).

Thesis (Ph. D.)--Florida State University, 2006. / Advisor: Fei-Fei Jin, Florida State University, College of Arts and Sciences, Geophysical Fluid Dynamics Institute. Title and description from dissertation home page (viewed Sept. 19, 2006). Document formatted into pages; contains xiii, 118 pages. Includes bibliographical references.

Thesis (M.S.)--Florida State University, 2006. / Advisor: James J. O'Brien, Florida State University, College of Arts and Sciences, Dept. of Meteorology. Title and description from dissertation home page (viewed Sept. 19, 2006). Document formatted into pages; contains ix, 43 pages. Includes bibliographical references.

Thesis (Ph. D.)--University of Hawaii at Manoa, 2001. / Includes bibliographical references (leaves 176-184). Also available on microfiche.

PhD. (Environmental Management) / This research investigates associations between El Niño Southern Oscillation (ENSO) phases and the occurrence of an unusual atmospheric transport patterns over southern Africa, observed during the SAFARI 2000 field campaign. This transport pattern manifested itself as a smoke and hazeladen flow, originating from the sub-equatorial tropical regions over northern Angola and western Zambia, and traversing the subcontinent with exit off the south-east coast over southern Mozambique and northern KwaZulu-Natal into the Indian Ocean. This pattern has been dubbed The River of Smoke. This pattern is distinctly different from the continental re-circulation pattern associated with continental high-pressure systems over the subtropical sub-region, which is the prevalent system according to current literature. The period during which the SAFARI 2000 campaign was conducted happened to be at the height of the strong 1999/2000 La Niña episode, associated with excessively wet conditions over the sub-continent. In contrast, during an earlier field campaign, SAFARI’92, the continental re-circulation transport mode, termed the gyre, was observed to prevail over the subtropical sub-region. SAFARI’92 coincided with the 1991/1992 El Niño episode that resulted in drought conditions over much of southern Africa. These observations triggered the current investigation of the causal associations and frequencies of the River of Smoke flow with phases of the ENSO. This study has employed conventional and modeled methods of meteorological analysis to investigate the influence of ENSO on atmospheric transport and synoptic coupling mechanisms, Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) forward trajectory computations supported by an enhanced method of cluster analysis were used to determine and characterize the mean atmospheric transport modes over the subcontinent. Trajectories were calculated originating at two source points, representative of the tropical and subtropical subregions respectively (Mongu, Zambia; and Tshane, Botswana). Three study years were selected, corresponding to three distinct phases of ENSO: an El Niño episode during 1991/1992, a neutral ENSO episode during 1996/1997, and a La Niña episode during 1999/2000. The National Center for Environmental Prediction (NCEP)/ National Center for Atmospheric Research (NCAR) Reanalysis model is employed to reproduce mean composite synoptic circulation fields over southern Africa during the three periods. Findings show that for airflows originating over tropical southern Africa, the Indian Ocean fast exit pathway is unique to the neutral ENSO phase, while the continental re-circulation transport mode exhibits zero occurrences during the neutral phase. A continental re-circulation transport mode in the lower troposphere was observed during the El Niño and La Niña extremes, but with low annual frequencies (less than 30%). The direct Atlantic Ocean, the north-west and the Indian Ocean slow exit pathways are common to all three ENSO phases. For airflows originating over the subtropical sub-region, the continental re-circulation transport mode has the highest vi frequencies during all three ENSO phases, more especially during the El Niño episode, with more than 50% annual frequency, as observed during SAFARI’92. The north-west, Indian Ocean slow and Indian Ocean fast pathways are observed during all the three ENSO phases, with lower overall frequencies. The anticyclonic circulation flows are driven by the strengthened high-pressure systems over southern Africa: the semi-permanent subtropical high-pressure systems over the adjacent oceans (Atlantic Ocean High and Indian Ocean High) and the transient cut-off continental high-pressure systems. Airflows exiting toward the Indian Ocean have been described previously. In this work, a novel distinction is made between the Indian Ocean fast and the Indian Ocean slow exit pathways. The Indian Ocean slow corresponds to the conventional off-coast flow, such as observed during SAFARI’92. The Indian Ocean fast exit pathway is a newly described transport mode, which results from strong coupling between the subtropical circulation systems and the mid-latitude westerly flows. This strong-coupling induced transport mechanism provides favourable conditions for transport of mass fluxes, such as fire emissions originating from the tropical sub-region, towards the Indian Ocean. The Indian Ocean fast exit transport mode is characterized by higher speeds while exiting off the south-east coast, and extends further into the temperate latitudes towards Australia. When coupled with tropical sub-region, this flow mode is responsible for the occurrence of the River of Smoke phenomenon identified during SAFARI 2000. This Indian Ocean fast transport mode is intermittent in nature, and couples to the tropical sub-region only during the neutral ENSO episode, during which it exhibits low monthly frequencies, mainly during the dry season July through October. The intermittent nature, dependent on ENSO phases, and the associated low frequencies, may explain why it was observed in SAFARI 2000, but escaped observation and comment during previous studies, such as SAFARI’92.

This study aims for knowledge about the most important climate features that affect the temperature and precipitation in the continental area of Central America. Systems such as The Caribbean Low Level Jet (CLLJ), The Intertropical Convergence Zone (ITCZ) and The Western Hemisphere Warm Pool (WHWP) components are major contributors to regional climate that strongly interact with the topographical features dividing the Pacific and Caribbean slopes of Central America. Daily data within a 35 year long (1981-2015) time-series of precipitation and temperature for 9 different meteorological stations along both slopes have been investigated to identify their relationship with El Niño Southern Oscillation (ENSO) phases. Missing data were filled in using rellenaf, a routine function developed at the Center for Geophysical Research of the University of Costa Rica. The function estimates data values with principal components and autoregressive methods. Data show that the Pacific slope is mainly characterized by a remarkable contrast between the dry season and the rainy season. The seasonal variations in precipitation are less important for the Caribbean slope. The annual cycle of temperature (for all of the stations) has small differences in amplitude and is rather stable throughout the year, except at the northernmost stations, Belize and Puerto Barrios, where relatively low temperatures dominate the winter months due to cold air intrusions. The low frequency atmospheric mode ENSO, impacts the regional climate and interacts with the earlier mentioned CLLJ, ITCZ and WHWP. Strong ENSO episodes of El Niño and La Niña were compared with anomalies in temperature, precipitation and winds at 925 hPa (mainly focusing on CLLJ). A contribution of negative (positive) anomalies in precipitation was observed during El Niño (La Niña) events for the Pacific slope. This relationship was not present for the Caribbean slope. No connection between the temperature and ENSO could be revealed. It was also shown that CLLJ is stronger (weaker) in February for La Niña (El Niño) and stronger (weaker) in July for El Niño (La Niña) events. / I syftet att utöka individuell kunskap om de viktigaste klimatsystemen som påverkar temperatur och nederbörd över den tropiska kontinenten Centralamerika, gjordes en studie. Komponenter såsom den karibiska lågaltituds-jeten (CLLJ The Caribbean Low Level Jet), den intertropiska konvergenszonen (ITCZ The Intertropical Convergence Zone) och västra halvklotets varmvattenspool (WHWP The Western Hemisphere Warm Pool) är huvudsakliga system som påverkar det regionala klimatet och dessa interagerar med topografin. I sin tur delar den upp Centralamerika i Stilla havssidan samt Karibiska sidan, två skiljda regioner ur ett meteorologiskt perspektiv. Dygnsdata, för temperatur och nederbörd inom en tidsperiod av 35 år (1981-2015) för 9 olika meteorologiska stationer, har undersökts för att identifiera mönster kopplat till den södra El Niño-oscillationen (ENSO The El Niño Southern Oscillation). Avsaknad data beräknades med rutinfunktionen rellenaf, som har utvecklats av universitetet i Costa Rica - Centret för geofysisk forskning. Funktionen estimerar datavärden utifrån principiella komponenter -och autoregressiv metod. Från den kompletta datan kunde det identifieras att Stilla havssidan är huvudsakligen kännetecknat av en torrperiod och en regnperiod, medan säsongsvariationerna i nederbörd för Karibiska sidan är mindre. Den årliga temperaturcykeln för hela regionen erhåller små skillnader i amplitud, med andra ord är temperaturen mer eller mindre konstant genom årets gång. Med undantag för de mer nordliga stationerna Belize och Puerto Barrios där lägre temperaturer förekommer under norra halvklotets vintermånader som är orsakat av kallfronter. ENSO är ett lågfrekvent atmosfäriskt system som har påverkan på det regionala klimatet genom att interagera med de tidigare nämna CLLJ, ITCZ and WHWP. De starka faserna El Niño och La Niña observerades och jämfördes med anomalier för temperatur, nederbörd och vindfält på 925 hPa nivå (huvudsakligen fokus på CLLJ). En majoritet av negativa (positiva) anomalier för nederbörd kunde observeras under El Niño (La Niña) fenomen för Stilla havssidan. Dock fanns inte denna relation för den Karibiska sidan. Det fanns heller ingen koppling mellan temperatur och ENSO. Det kunde även ses att CLLJ är starkare (svagare) i februari för la niña (el niño) och starkare (svagare) i juli för el niño (la niña).

by Yeung Wai Lung. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references (leaves 120-122). / Text in English; abstracts in English and Chinese. / by Yeung Wai Lung. / Abstract --- p.i / Abstract (Chinese version) --- p.ii / Acknowledgements --- p.iii / Contents --- p.iv / List of figures --- p.vii / List of tables --- p.xi / Chapter 1 --- Introduction --- p.1 / Chapter 2 --- The El Nino ´ؤ Southern Oscillation Phenomenon --- p.3 / Chapter 2.1 --- Introduction to El Nino - Southern Oscillation --- p.3 / Chapter 2.2 --- The mean conditions of the Tropical Ocean --- p.4 / Chapter 2.3 --- Life Cycle of ENSO --- p.8 / Chapter 2.4 --- Understanding ENSO --- p.12 / Chapter 3 --- ENSO prediction schemes --- p.18 / Chapter 3.1 --- Introduction --- p.18 / Chapter 3.2 --- Statistical prediction models --- p.19 / Chapter 3.2.1 --- Introduction --- p.19 / Chapter 3.2.2 --- Atmospheric models --- p.19 / Chapter 3.2.3 --- Oceanic models --- p.22 / Chapter 3.3 --- Coupled ocean-atmosphere models --- p.24 / Chapter 3.3.1 --- Introduction --- p.24 / Chapter 3.3.2 --- Intermediate coupled models --- p.25 / Chapter 3.3.3 --- Hybrid coupled models --- p.28 / Chapter 3.3.4 --- Coupled general circulation models --- p.30 / Chapter 3.4 --- Skill sensitivities --- p.36 / Chapter 3.4.1 --- Introduction --- p.36 / Chapter 3.4.2 --- Dependence of skill on season --- p.36 / Chapter 3.4.3 --- Dependence of skill on decade --- p.37 / Chapter 3.4.4 --- Dependence of skill on the Phase of the ENSO cycle --- p.38 / Chapter 4 --- The ENSO model --- p.40 / Chapter 4.1 --- Introduction --- p.40 / Chapter 4.2 --- Models formalism --- p.40 / Chapter 4.2.1 --- Oceanic model --- p.40 / Chapter 4.2.2 --- Atmospheric model --- p.43 / Chapter 4.2.3 --- Coupling of atmospheric and oceanic models --- p.44 / Chapter 4.3 --- Numerical implementation --- p.45 / Chapter 4.3.1 --- Oceanic model --- p.45 / Chapter 4.3.2 --- Atmospheric model --- p.49 / Chapter 4.3.3 --- Averaging and interpolation during coupling --- p.52 / Chapter 4.4 --- Standard response of the model --- p.54 / Chapter 4.5 --- Limitation of the model --- p.57 / Chapter 5 --- Behavior of the ENSO model --- p.59 / Chapter 5.1 --- Introduction --- p.59 / Chapter 5.2 --- Numerical results of the model --- p.60 / Chapter 5.3 --- Effects of the parameters --- p.62 / Chapter 5.3.1 --- Introduction --- p.62 / Chapter 5.3.2 --- Coupling constant parameters --- p.62 / Chapter 5.3.3 --- Rayleigh friction --- p.66 / Chapter 5.3.4 --- The oceanic Kelvin wave speed --- p.69 / Chapter 5.3.5 --- The ocean basin length --- p.69 / Chapter 5.3.6 --- Reflections at the western boundary --- p.74 / Chapter 5.4 --- Modification of the model background state --- p.76 / Chapter 5.4.1 --- Introduction --- p.76 / Chapter 5.4.2 --- The results of the modified model --- p.77 / Chapter 5.4.3 --- Sensitivity of the western boundary of the modified model --- p.81 / Chapter 5.4.4 --- Parameters sensitivities of the modified model --- p.83 / Chapter 5.5 --- Conclusion and discussion --- p.87 / Appendix A --- p.91 / Appendix B --- p.112 / Bibliography --- p.120