Variability and trends in surface seawater pCO₂ and CO₂ flux in the Pacific Ocean

Abstract

Variability and change in the ocean sink of anthropogenic carbon dioxide (CO2) have implications for future climate and ocean acidification. Measurements of surface seawater CO2 partial pressure (pCO2) and wind speed from moored platforms are used to calculate high‐resolution CO2 flux time series. Here we use the moored CO2 fluxes to examine variability and its drivers over a range of time scales at four locations in the Pacific Ocean. There are significant surface seawater pCO2, salinity, and wind speed trends in the North Pacific subtropical gyre, especially during winter and spring, which reduce CO2 uptake over the 10 year record of this study. Starting in late 2013, elevated seawater pCO2 values driven by warm anomalies cause this region to be a net annual CO2 source for the first time in the observational record, demonstrating how climate forcing can influence the timing of an ocean region shift from CO2 sink to source.

Revisiting the Estimate of the North Sea Air‐Sea Flux of CO2 in 2001/2002: The Dominant Role of Different Wind Data Products

“…Wind speed is corrected to a height of 10 m above the sea surface using equation (1) of Sutton et al (). where U 10 is wind speed in m/s at 10 m, z is the height (m) of the wind sensor, U z is wind speed in m/s recorded by the sensor, Cd 10 is the drag coefficient (0.0011), and 0.4 is von Karman constant.…”

“…Wind speed is corrected to a height of 10 m above the sea surface using equation (1) of Sutton et al (2017).…”

Warm Events Induce Loss of Resilience in Organic Carbon Production in the Northeast Pacific Ocean

“…Still, in 2015, there was a decline in zooplankton stocks off the coast of Mexico and a shift in the vertical distribution of fish larvae in response (Sánchez-Velasco et al, 2017). For the first time on record, the northeast Pacific Ocean was a pCO 2 source (Sutton et al, 2017) at the same time that net organic carbon production declined in 2015 (Figure 5a). Although the zooplankton stocks gradually recovered in 2015 (McKibben et al, 2017;McKinstry & Campbell, 2018), the consequences to fisheries came later.…”

“…The development of the Arc pattern along the west coast of United States between 2014 and 2015 altered the local phytoplankton community structure (Du & Peterson, 2018), with elevated SSTs stimulating harmful algae blooms in the northern California Current (McKibben et al, 2017;Zhu et al, 2017). For the first time on record, the northeast Pacific Ocean was a pCO 2 source (Sutton et al, 2017) at the same time that net organic carbon production declined in 2015 ( Figure 5a). For the first time on record, the northeast Pacific Ocean was a pCO 2 source (Sutton et al, 2017) at the same time that net organic carbon production declined in 2015 ( Figure 5a).…”

Observing Changes in Ocean Carbonate Chemistry: Our Autonomous Future

“…For example, long-term observations in a tropical coral reef system demonstrated the importance of various processes that influence air-sea CO 2 flux including rainfall, nutrient delivery, winds, and local biological communities [37,38]. Sustained mooring observations in the Tropical Pacific revealed that climate forcings such as El Niño/La Niña cycles [35,39] and anomalous warming events in the Pacific [40] are dominant drivers for interannual variability of pCO 2 . Furthermore, these surface observations of pCO 2 are compiled along with shipboard observations into the Surface Ocean CO 2 Atlas (SOCAT) [24], providing crucial information about the seasonal cycle for calculating global air-sea CO 2 fluxes (e.g., [41,42]).…”