Time series pCO2 at a coastal mooring: Internal consistency, seasonal cycles, and interannual variability

Multidecadal fCO2 Increase Along the United States Southeast Coastal Margin

“…We then applied a secondary quality assessment to determine data points potentially influenced by biofouling and other contamination, random outliers, and gap‐filling (using linear interpolation) for gaps no longer than 2 days (using the daily mean time series). Extensive validation of this time series is presented in Reimer et al (). We present observations through 15 October 2015, which provide just less than a decade of observations.…”

<i>p</i>CO<sub>2</sub> variability in the surface waters of the eastern Gulf of Cádiz (SW Iberian Peninsula)

“…To determine the relative importance of the thermal and nonthermal effects on the changes in pCO 2 in seawater (e.g. Landschützer et al, 2015;Reimer et al, 2017), we follow the method described by Takahashi et al (2002). To remove the thermal effect from the observed pCO 2 , the data were normalized to a constant temperature (the mean in situ SST depending on the focus considered) according to Eq.…”

“…the Guadalquivir, Rio Tinto, Odiel and Guadiana. Various studies have been conducted in this area to evaluate the variability in the sea surface partial pressure of CO 2 (pCO 2 ), although they cover smaller areas and a shorter duration of time than this work (González-Dávila et al, 2003;Aït-Ameur and Goyet, 2006;Huertas et al, 2006;Ribas-Ribas et al, 2011) or only a specific area like the Strait of Gibraltar (Dafner et al, 2001;Santana-Casiano et al, 2002;de la Paz et al, 2009). All of these studies, however, have determined that this zone behaves as a sink of CO 2 with seasonal variations induced mainly by the combination of the fluctuations of biomass concentration and temperature.…”

“…It has also been possible to estimate the influence that various sea surface currents have on pCO 2 variability since this study considers deeper areas than previous works. Therefore, we can analyse the change that has occurred in relation to the CO 2 uptake capacity in the Gulf of Cádiz in the last 10 years in comparison with other studies that analyse the seasonal variation underway by pCO 2 in this area (Ribas-Ribas et al, 2011). In this work we have analysed a surface measurement database of > 26 000 values of pCO 2 obtained during cruises made between 2014 and 2016 and covering an area of 0.8 • × 1.3 • of the Gulf of Cádiz.…”

Reply to review by Niki Gruber

“…South of Cape Hatteras, seasonal phytoplankton blooms do not occur regularly and biologically driven CO 2 uptake is less pronounced than that further north ( Fig. 3e; Reimer et al, 2017;Wang et al, 2013), although sporadic phytoplankton blooms do occur because of intrusions of high-nutrient subsurface Gulf Stream water (Wang et al, 2005. The influence of riverine inputs is small and localized in the SAB (Cai and Wang, 1998;Wang and Cai, 2004;Wang et al, 2005;L.…”