This paper presents a compilation of atmospheric radiocarbon for the period 1950–2019, derived from atmospheric CO2 sampling and tree rings from clean-air sites. Following the approach taken by Hua et al. (2013), our revised and extended compilation consists of zonal, hemispheric and global radiocarbon (14C) data sets, with monthly data sets for 5 zones (Northern Hemisphere zones 1, 2, and 3, and Southern Hemisphere zones 3 and 1–2). Our new compilation includes smooth curves for zonal data sets that are more suitable for dating applications than the previous approach based on simple averaging. Our new radiocarbon dataset is intended to help facilitate the use of atmospheric bomb 14C in carbon cycle studies and to accommodate increasing demand for accurate dating of recent (post-1950) terrestrial samples.

ABSTRACT. The Southeast Pacific Subtropical Anticyclone (SPSA) extends over the entire South Pacific Basin and it is the dominant forcing of the Humboldt Current System. The SPSA has seasonal, interannual, and decadal (interdecadal) variability. The latter variability has been associated with the Pacific Decadal Oscillation (PDO), recognized as a Pan-Pacific mode. However, most of the ocean-atmosphere studies on interdecadal scales have been conducted in the Northern Hemisphere, and very few in the Southern Hemisphere. Thus, through reanalysis model outputs and satellite data, this research mainly establishes the relationship between SPSA and PDO in the period 1949-2012 and its impact on sea surface temperature along the north-central coast of Chile between 2000 and 2012. For this purpose we first analyzed the seasonal and interannual variability of the SPSA. An analysis of correlation between air pressure at sea level and the PDO and Southern Annular Mode (SAM) indices established that, at the interdecadal scale, these oscillations explained 49% and 40% of the variance, respectively; however, SAM had a time lag of six years to explain this variance. The PDO, in the air pressure field, produced similar changes to El Niño-Southern Oscillation. Over the past 13 years, the SPSA has intensified and shifted toward the southwest, increasing the offshore Ekman transport and Ekman suction, which would explain much of the observed coastal cooling south of 33º S (central Chile).Key words: Southeast Pacific Subtropical Anticyclone, coastal jet, ENSO-like variability, Antarctic oscillation, upwelling. RESUMEN.El Anticiclón Subtropical del Pacífico Sudeste (ASPS) se extiende sobre toda la cuenca oceánica del Pacífico Sur y es el forzamiento dominante del Sistema de la Corriente de Humboldt. El ASPS presenta variabilidades estacionales, interanuales y decadales (interdecadales). Esta última variabilidad se ha asociado a la Oscilación Decadal del Pacífico (ODP), reconocida como un modo de la cuenca del Pacífico. Sin embargo, la mayoría de los estudios sobre la relación entre el océano y la atmósfera a escala interdecadal han sido conducidos en el hemisferio norte, y muy pocos en el hemisferio sur. Así, a través de información de salida de modelos de reanálisis y datos satelitales, esta investigación establece principalmente la relación entre el ASPS y la ODP en el periodo 1949-2012 y su repercusión en la temperatura superficial del mar a lo largo de la costa centro-norte de Chile entre 2000 y 2012. Para esto, primero se analizó la variabilidad estacional e interanual del ASPS. Mediante un análisis de correlación entre el campo de presión del aire a nivel de mar y los índices de la ODP y el Modo Anular del Sur (MAS), se estableció que a escala interdecadal éstas oscilaciones explicaron el 49% y 40% de la varianza, respectivamente; sin embargo, el MAS presentó un desfase de seis años para explicar esa varianza. La ODP, en el campo de la presión del aire, produjo cambios parecidos a los de El Niño-Oscilación del Sur. En los últim...

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