Temporal variations in the partial pressure and flux of CO₂ at ocean station P in the subarctic northeast Pacific Ocean

Abstract

The temporal variations in the partial pressure and air-sea flux of CO₂ in surface seawater at Ocean Station P (50°N 145°W) between August, 1973, and July, 1978, were investigated. In the summer months of 1973—1977, the evasion of CO₂ from the ocean to the atmosphere was less than 1 mM m^-2 d^-1 except for July of 1975 with a higher net flux of 1—2 mM m^-2 d^-1. In the other seasons and also in the summer of 1978, a net sea-to-air CO₂ flux of about - 3 mM m^-2 d^-1 occurred. The eastern subarctic waters around Station P was probably a small sink for CO₂ during the 5-year observational period with an average net sea-to-air flux of about — 0.7 M m^-2 yr^-1. The CO₂ exchange coefficient (K) was about 0.05 M m^-2μatm^-1 yr^-1 and the unidirectional CO₂ exchange rate was about 17 M m^-2 yr^-1.