Abstract
We analyzed the hydrographic variability of La Paz Bay, the largest coastal water body in the Gulf of California, and its relationship with Pacific large-scale phenomena, including the El Ni?o-Southern Oscillation (ENSO), Pacific Decadal Oscillation (PDO), Pacific-North America pattern (PNA), and North Pacific pattern (NP). We used several indices related to these phenomena and the hydrographic variability data of La Paz Bay, consisting of the annual sea surface temperature patterns from satellite imagery from 2000 to 2010 and the mixed layer depths measured with in situ data from 1994 to 2009. The results indicate the sea surface temperature fluctuated during the study period, with 2007 as the coldest year and 2009 as the warmest. Two periods were identified in the annual thermal cycle of the bay, one period of warmth from June to November, and one of cold from December to May. The sea surface temperature is primarily influenced by the ENSO. The mixed layer depth analysis showed its absence during August-September, while the deepest ones were in November-March. The unusual 100 m mixed layer depth noted during February 2002 and its absence in March 1996 and 2009 were related to uncommon atmospheric conditions in the annual patterns of the ENSO, PNA, and NP. The variability of the mixed layer depth is primarily related to the variability of the NP. We concluded that the hydrographic conditions of La Paz Bay are most influenced by the NP during the cold phase of its annual cycle, and by the ENSO during the warm phase.
Highlights
Many large-scale phenomena occur in the Pacific Ocean that act on varied time-scales, from the El Niño-How to cite this paper: Guevara-Guillén, C., Shirasago-Germán, B. and Pérez-Lezama, E.L. (2015) The Influence of LargeScale Phenomena on La Paz Bay Hydrographic Variability
Two periods were clearly distinguished in the annual cycle of the sea surface temperature in La Paz Bay (Figure 3), a cold period with an average temperature range of 20.5 ̊C - 26.0 ̊C during December-May and a warm period of 26.0 ̊C - 31.0 ̊C during June-November
The annual variability of the La Paz Bay sea surface temperature showed that, the bay is a semi-enclosed body of water, it has interannual variability and abrupt changes, such as occurred during the 2007 and 2009 years. This indicates La Paz Bay is highly dynamic and influenced by the North Pacific, which agrees with reports by [24] [41] [42] [45] [48], who described the seasonal changes of this bay and emphasized the influence of the ocean-atmospheric processes that determine its hydrographic conditions
Summary
Many large-scale phenomena occur in the Pacific Ocean that act on varied time-scales, from the El Niño-How to cite this paper: Guevara-Guillén, C., Shirasago-Germán, B. and Pérez-Lezama, E.L. (2015) The Influence of LargeScale Phenomena on La Paz Bay Hydrographic Variability. Southern Oscillation (ENSO) with month-year cycles to decadal-to-multidecadal frequency events such as the Pacific Decadal Oscillation (PDO) Their effects are detectable in global to local ecosystems, and their aggregate contributions establish climatic shifts that have shown fluctuations in the atmospheric and oceanic conditions such as sea temperature [1], wind fields associated with atmospheric pressure variations [2], ocean currents [3], coastal upwellings [4], and mixed layer depths [5]. Climate variability due to large-scale influences in the North Pacific receives considerable attention due to its impact on tropical and extra-tropical climate [7] and the weather over North America [8]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
