Export production and its regulating factors in the West Antarctica Peninsula region of the Southern Ocean

In connection with the Palmer LTER program, mixed layer water samples were collected during the cruise of the L. M. Gould in Jan., 2008 at 49 stations on a 20 x 100 km grid in the West Antarctica Peninsula (WAP) region of the Southern Ocean. In this study, {[}O-2]/{[}Ar] ratios and the triple isotope composition of dissolved O-2 were measured, and were used to estimate net community O-2 production (NCP) and gross primary O-2 production (GPP), respectively. These estimates are further converted to carbon export production, primary production and the f-ratio. Our measurements give NCP ranging from -3 to 76 mmol O-2 m(-2) day(-1) (-25 to 650 mg C m(-2) day(-1)), and GPP from 40 to 220 mmol O-2 m(-2) day(-1) (180 to 1010 mg C m(-2) day(-1)). The O-2 NCP/GPP ratios range from -0.04 to 0.43, corresponding to f-ratios of -0.08 to 0.83. NCP and the NCP/GPP ratio are highest in the northern coastal areas, and decrease to lower values toward the southern coastal area and the open ocean. The inshore-offshore gradient appears to be regulated primarily by iron availability, as supported by the positive correlation between NCP and F-v/F-m ratios (r(2) = 0.22, p

Duke Scholars

Author Nicolas Cassar Earth and Climate Sciences