The influence of El Niño–Southern Oscillation (ENSO) on productivity at upwelling systems has been extensively studied. However, in recent decades, ENSO diversity has been documented; there are more frequent events with anomalies in the central Pacific (CP) causing ecological impacts that are different from the canonical events centered in the eastern Pacific (EP). We hypothesize that ENSO effects on upwelling intensity and its biological response are highly dependent on ENSO diversity. Wavelet coherence was computed for monthly standardized anomalies of Ekman transport and sea surface Chlorophyll-a (Chl-a) concentration from eight upwelling centers located along the west coast of the Baja California peninsula (1993–2022). Ekman transport (ET) showed a non-linear association with ENSO at interannual periodicities between 1.2 and 7 years, as well as semiannual scale variability. Coherence between ENSO and ET showed a reduction in upwelling intensity during CP ENSO events and an increased upwelling intensity after EP El Niño events with regional differences. Our results reveal an influence of northern Pacific circulation that subsequently influences ENSO events during its development and its peak. We detected an influence of SST and wind anomalies on the ENSO–Ekman transport connection associated with the northern Pacific Meridional Mode pattern. The CP shows an important role in sea surface Chl-a concentration anomalies (1998–2022). We highlight the conceptual relevance of distinguishing ENSO diversity, with influential ecological effects associated with CP ENSO events.

To explore the impacts of El Niño-Southern Oscillation (ENSO) on the North Atlantic Oscillation (NAO), the linear correlation among the indices of each oscillation was investigated. The indices Niño 1+2, Niño 3, Niño 3.4, Niño 4, ONI, SOI, BEST, TNI and MEI were used to represent the ENSO, besides the NAO index. The analysis considers the ENSO diversity in its spatial structure. The results show that when years with Eastern Pacific (EP) La Niña events were omitted, the linear correlation increased concerning other scenarios. This means that NAO responses for the Central Pacific (CP) ENSO tend to be linear, but seemingly they are not so for EP ENSO, which explains why the ENSO/NAO relationship has been difficult to identify and predict. The TNI-NAO relationship had the highest correlation values, followed by NAO-El Niño 4, whilst NAO/El Niño 1+2 and NAO/El Niño 3 showed the lowest coefficients. The results also confirmed that the atmospheric dynamics over the North Atlantic have a more linear teleconnection to the West and Central Pacific than to the Eastern Pacific. Changes in deep convection, atmospheric circulation, and vorticity are discussed like possible mechanisms that trigger the changes in impacts over the North Atlantic and other locations. The composite anomalies map also showed the contrast in the effects of both events and the importance of considering those differences when modeling ocean dynamics.

El incremento progresivo que ha presentado la temperatura del aire en las últimas décadas requiere de acciones y estrategias que permitan planes de gestión que conlleven a la mitigación y adaptabilidad de comunidades, ecosistemas y especies. El presente capítulo aborda la urgente necesidad de desarrollar e implementar estrategias efectivas para enfrentar los desafíos que plantea el cambio climático en las zonas costeras del continente americano. Por esto, mediante las secciones del capítulo, se presenta un contexto histórico de la temperatura del aire a diferentes escalas temporales haciendo énfasis en los cambios y tendencias temporales que ha tenido la temperatura del aire dentro del periodo 1950 a 2024. El contexto actual presenta los cambios en las últimas tres décadas, encontrando tres temporadas: fría (1995-2004), intermedia (2005-2014) y cálida (2015-2024), respecto al periodo base 1991-2020. Aunado a esto, se pudo determinar que para el periodo 1950-2024 las regiones polares se vieron más afectadas por los incrementos de temperatura (0.0363 °C/año), en comparación con el Ecuador y los trópicos. Al analizar los cambios mensuales que tuvo la temperatura del aire en el 2024 respecto al periodo base (1991-2020), pudimos determinar que los meses de septiembre y octubre son los más cálidos, con predominio de anomalías positivas en todo el continente e incrementos hasta de 9.6 °C. Estos incrementos en la temperatura del aire permitieron proponer estrategias de adaptabilidad que involucran desde el sector económico hasta la salud pública en las comunidades costeras, donde la densidad de poblaciónes significativamente alta.