1992, Seoul N ation al U niversity M .S. Ju ne 1996, Seoul N ation al University A D issertation S u b m itted to th e Faculty of O ld D om inion U niversity in Partial Fulfillm ent of th e R equirem ent for th e D This study presents results from models that are designed to simulate the underwater light field, to simulate phytoplankton primary production, and to estim ate the fate of phytoplankton carbon in continental shelf waters of the west Antarctic Peninsula (W AP) and Ross Sea.

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... of the underwater light field required derivation of new coefficient sets for power function-type cloud cover correction algorithms, which were found to be influenced by multiple reflections between the bottom of clouds and the surface. The coefficient sets indicate that the spectral effect of clouds on the properties of the surface irradiance was spectrally-neutral for wavelengths greater than 330 nm. The regional dependency of the newly-derived coefficient sets provide an approach for developing general cloud cover correction algorithms for Antarctic coastal waters. Next, a bio-optical production model that was forced with the sim ulated surface irradiance fields, corrected for cloud conditions, and the simulated underwater light field was used to estim ate primary production and subsequent car bon flux at several sites along the western Antarctic Peninsula and in the Ross Sea. T he parameterizations used in the bio-optical production model included depthdependent photosynthesis-irradiance relationships that involved different patterns of diel variation. Sensitivity studies showed simulated primary production estim ates were increased by up to 130% when photosynthetic parameters w ith a diel period icity were used in the production model. Inclusion of spectrally-resolved quantum yields increased primary production estim ates by as much as 300%, relative to a reference simulation that used constant parameters. T he fate of newly-produced phytoplankton carbon obtained from simulations for the WAP and Ross Sea was in vestigated using budget calculations that included the effects of grazing, advection, and sinking. For the western Antarctic Peninsula region, horizontal (across-shelf Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. component) advection is the dominant process controlling primary production car bon in the outer-shelf areas in all seasons. Depending on season, advection can remove up to 40% of the phytoplankton carbon in the shelf waters. Grazing, how ever, is as important as across-shelf advection during the summer and can be an order of magnitude greater in inner shelf waters than in mid-and outer-shelf waters. Sinking is also a dominant process that can remove up to 6% of primary produc tion carbon, except in the austral winter season. Similar calculations for the Ross Sea show that zonal advection is the dominant process controlling phytoplankton primary production carbon (up to 57%) in the outer-shelf regions in all seasons. Grazing is an important removal process in the summer in the inner-and mid-shelf areas of Ross Sea continental shelf waters, but was found to be less of a control relative to advective removal. Sinking is also an important process for removing phytoplankton carbon, with 20% and 220% of the daily primary production being removed by this process in the summer and winter, respectively. The results of car bon budgets show that advective processes provide a dominant control on the fate of primary production, which suggests that primary production estim ates for Antarctic coastal waters should be based on observational studies or models that incorporate circulation as well as biological processes. Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. To my father, Kim, Kyung-Eun, a pure soul. v Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. ACKNOWLEDGMENTS First of all, I would like to thank Dr. Eileen E. Hofmann from the bottom of my heart. She was the advisor who led me to a whole new world of modeling study with kindness, patience and enthusiasm. She not only helped broaden the scope of my view in science but also supported me to attend scientific meetings and conferences. She also gave me a chance to join one of the Southern Ocean Global Ocean Ecosystems Dynamics (GLOBEC) cruises to the western Antarctic Peninsula during the austral winter of 2001. This life-time experience added one more unforgettable memory to my personal research experiences. I also give heartfelt thanks to my com m ittee members, Drs. Grosch and Klinck provided ample amounts of help on statistics, mathematics and physics issues when I worked on data processing. Drs. Prezelin and Smith kindly and generously offered me their invaluable data sets, and also willingly provided helpful comments and suggestions on biological processes. I appreciate the mentorship Dr. Suam Kim has given to me. He is the first person who introduced me to this interdisciplinary field of oceanography in Korea. Many thanks should be given to Michael Dinniman for his kindness and generosity and for providing to me the valuable ROMS simulation results he created. Julie Mor gan, for her administrative assistance on considerable paperwork and Joe Ruettgers, for his technical support in computing facilities, are also much appreciated. I also appreciate the moral support my fellow graduate students and Spanish speaking fellows have given me. I am grateful to Nandita, Isaac, Junho and Sebastian who willingly offered me food and a place to stay while I was homeless in Norfolk. T he moral support and love that my wife, Eun-Kyung, and my lovely daughter, Hanni, showed have always been appreciated. My brothers, sister and in-laws are also among those who I must thank. I do not know how I can fully appreciate the unselfish love my mother and father have given.