title: Macro-Scale Patterns in Upwelling/Downwelling Activity at North American West Coast.
abstract: The seasonal and interannual variability of vertical transport (upwelling/downwelling) has been relatively well studied, mainly for the California Current System, including low-frequency changes and latitudinal heterogeneity. The aim of this work was to identify potentially predictable patterns in upwelling/downwelling activity along the North American west coast and discuss their plausible mechanisms. To this purpose we applied the min/max Autocorrelation Factor technique and time series analysis. We found that spatial co-variation of seawater vertical movements present three dominant low-frequency signals in the range of 33, 19 and 11 years, resembling periodicities of: atmospheric circulation, nodal moon tides and solar activity. Those periodicities might be related to the variability of vertical transport through their influence on dominant wind patterns, the position/intensity of pressure centers and the strength of atmospheric circulation cells (wind stress). The low-frequency signals identified in upwelling/downwelling are coherent with temporal patterns previously reported at the study region: sea surface temperature along the Pacific coast of North America, catch fluctuations of anchovy Engraulis mordax and sardine Sardinops sagax, the Pacific Decadal Oscillation, changes in abundance and distribution of salmon populations, and variations in the position and intensity of the Aleutian low. Since the vertical transport is an oceanographic process with strong biological relevance, the recognition of their spatio-temporal patterns might allow for some reasonable forecasting capacity, potentially useful for marine resources management of the region.
authors.affiliation: Instituto Politécnico Nacional, Centro Interdisciplinario de Ciencias Marinas (CICIMAR), La Paz, Baja California Sur, México.|Centro de Investigaciones Biológicas del Noroeste, La Paz, Baja California Sur, México.
authors.forename: Romeo
authors.initials: R
authors.lastname: Saldívar-Lucio
authors.affiliation: School of Earth & Atmospheric Sciences, Georgia Institute of Technology, Atlanta, Georgia, United States of America.
authors.forename: Emanuele
authors.initials: E
authors.lastname: Di Lorenzo
authors.affiliation: Área de Probabilidad y Estadística, Centro de Investigación en Matemáticas AC, Guanajuato, México.
authors.forename: Miguel
authors.initials: M
authors.lastname: Nakamura
authors.affiliation: Instituto Politécnico Nacional, Centro Interdisciplinario de Ciencias Marinas (CICIMAR), La Paz, Baja California Sur, México.
authors.forename: Héctor
authors.initials: H
authors.lastname: Villalobos
authors.affiliation: Centro de Investigaciones Biológicas del Noroeste, La Paz, Baja California Sur, México.
authors.forename: Daniel
authors.initials: D
authors.lastname: Lluch-Cota
authors.affiliation: Instituto Politécnico Nacional, Centro Interdisciplinario de Ciencias Marinas (CICIMAR), La Paz, Baja California Sur, México.
authors.forename: Pablo
authors.initials: P
authors.lastname: Del Monte-Luna
mesh_terms: D017753:Ecosystem; D009656:North America; D012621:Seasons; D012623:Seawater / Q000737:chemistry*; D013696:Temperature; D014872:Water Movements