Li, Jing, 2005, Investigation of mixed layer depths along Line P and throughout the Gulf of Alaska using historical data and Argo floats: Edmonton, Alberta, Canada, University of Alberta, M.S. thesis, 40 p.
Mixed layer depths are computed, based on a new method proposed by Kara et al. (2000) for historical measurements along Line P, in the Gulf of Alaska. Forty-six years of data are used for the monthly climatological calculations. To examine variability, the data are divided into two periods, based around the changes that occurred in the 1970s, except at Station P, where a sufficient abundance of data permits the examination of monthly mixed layer changes over 5-year pentads. These results are also compared with the main modes of climate variability in the Pacific, such as PNA (Pacific/North American) and WP (West Pacific) to see which of those climate modes is driving the Station P MLD (mixed layer depth) variability in a given season. Mixed layer depths are also computed from Argo floats and mapped onto the Line P stations using an objective analysis method. Argo data from 2001, 2002, and 2003 are used. Using the historical measurements for validation, the mixed layer depths estimated from the Argo floats agree well with the shipboard observations. The 2003 data show reduced mixed-layer depths that occurred in winter 03/04. Furthermore, the objective analysis scheme is used to map the Argo mixed layer depths throughout the Gulf of Alaska. Finally, the correlation coeffcients between monthly average MLD in the Gulf of Alaska and Ekman pumping are calculated. The extreme r value is -0.64, which shows the Ekman pumping is a key contributor to MLD variability in the Gulf of Alaska.
Theses and Dissertations
