Coastal Upwelling Front Detection off Central Chile (36.5–37°S) and Spatio-Temporal Variability of Frontal Characteristics

Abstract

Abstract:In Eastern Boundary Upwelling Systems, cold coastal waters are separated from offshore by a strong cross-shore Sea Surface Temperature (SST) gradient zone. This upwelling front plays a major role for the coastal ecosystem. This paper proposes a method to automatically identify the front and define its main characteristics (position, width, and intensity) from high resolution data. The spatio-temporal variability of the front characteristics is then analyzed in a region off Central Chile (37 • S), from 2003 to 2016. The front is defined on daily 1 km-resolution SST maps by isotherm T 0 with T 0 computed from mean SST with respect to the distance from the coast. The probability of detecting a front, as well as the front width and intensity are driven by coastal wind conditions and increased over the 2007-2016 period compared to the 2003-2006 period. The front position, highly variable, is related to the coastal jet configuration and does not depend on the atmospheric forcing. This study shows an increase by 14% in the probability of detecting a front and also an intensification by 17% of the cross-front SST difference over the last 14 years. No trend was found in the front position.

Influence of the El Niño‐Southern Oscillation on SST Fronts Along the West Coasts of North and South America

“…SST fronts in EBCS have received a great deal of attention over the past two decades (e.g., Castelao et al., 2006 ; Mauzole et al., 2020 ; Meunier et al., 2012 ; Nieto et al., 2012 ; Oerder et al., 2018 ; Santos et al., 2012 ; Vazquez‐Cuervo et al., 2013 ; Veitch & Penven, 2017 ; Wang et al., 2015 , 2021 ). In the two EBCS in the Pacific Ocean, located along the west coasts of the United States and Mexico and along Peru and Chile, fronts have been shown to exhibit latitudinal and seasonal variability, largely due to the seasonality of upwelling (Castelao & Wang, 2014 ; Kahru et al., 2012 ; Strub et al., 1998 ; Vazquez‐Cuervo et al., 2013 ; Wang et al., 2015 , 2021 ), and mesoscale dynamics (Kahru et al., 2012 ; Vazquez‐Cuervo et al., 2013 ; Yuan & Castelao, 2017 ) in these regions.…”

Skew-Reflected-Gompertz Information Quantifiers with Application to Sea Surface Temperature Records

“…The results show that the proposed methodology serves to compare two sets of samples, Skew-Reflected-Gompertz distributed. The proposed asymptotic test is therefore useful to detect anomalies in sea surface temperature, linked to extreme events influenced by environmental conditions [11,24,25]. We encourage researchers to consider the proposed methodology for further investigations related to environmental datasets [1].…”

“…In addition, SST is strongly correlated with atmospheric pressure at sea level and thus climatic time scales. Therefore, changes in SST overlap with ecosystem changes [25]. However, SST influence on ecosystems is not clear because other physical processes such as superficial warming, horizontal advection of currents, upwelling, etc.…”

Molecular evidence for a new endemic species of Acartia (Copepoda, Calanoida) from the Southeast Pacific coast

“…Table S2 ), lineages A and D were not found. The environmental variability in Concepcion appears to be influenced by seasonal upwelling, the input of fresh water and organic matter from rivers 72 , 73 , a wide continental shelf and the presence of frontal structures acting as plankton retention and accumulation zone 74 . These environmental factors may exert selective pressures that favors the dominance of the most common lineage within the Intermediate Area (lineage B, Fig.…”