Seasonal and interannual variability of CO2 in the equatorial Pacific

摘要: Abstract As part of the JGOFS field program, extensive CO2 partial-pressure measurements were made in atmosphere and surface waters equatorial Pacific from 1992 to 1999. For first time, we are able determine how processes occurring western portion impact sea–air fluxes central eastern regions. These 8 years data compared with decade 1980s. Over this period, surface-water pCO2 indicate significant seasonal interannual variations. The largest decreases associated 1991–94 1997–98 El Nino events. lower during these two periods result combined effects interconnected large-scale locally forced physical processes: (1) development a low-salinity cap as formation warm pool Pacific, (2) deepening thermocline by propagating Kelvin waves (3) weakening winds half basin. serve reduce values towards near-equilibrium at height phase ENSO. In there is small but increase seawater strong events (i.e., 1982–83 1997–98) little or no change weak (1991–94). net effect variations lower-than-normal flux Nino. annual average that Ninos release 0.2–0.4 Pg C yr−1 0.8–1.0 Pg C yr−1 non-El years.