Premium
Quantifying subtropical North Pacific gyre mixed layer primary productivity from Seaglider observations of diel oxygen cycles
Author(s) -
Nicholson David P.,
Wilson Samuel T.,
Doney Scott C.,
Karl David M.
Publication year - 2015
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/2015gl063065
Subject(s) - diel vertical migration , ocean gyre , environmental science , subtropics , mixed layer , oceanography , productivity , primary production , chlorophyll a , atmospheric sciences , geology , ecosystem , ecology , biology , botany , macroeconomics , economics
Using autonomous underwater gliders, we quantified diurnal periodicity in dissolved oxygen, chlorophyll, and temperature in the subtropical North Pacific near the Hawaii Ocean Time‐series (HOT) Station ALOHA during summer 2012. Oxygen optodes provided sufficient stability and precision to quantify diel cycles of average amplitude of 0.6 µmol kg −1 . A theoretical diel curve was fit to daily observations to infer an average mixed layer gross primary productivity (GPP) of 1.8 mmol O 2 m −3 d −1 . Cumulative net community production (NCP) over 110 days was 500 mmol O 2 m −2 for the mixed layer, which averaged 57 m in depth. Both GPP and NCP estimates indicated a significant period of below‐average productivity at Station ALOHA in 2012, an observation confirmed by 14 C productivity incubations and O 2 /Ar ratios. Given our success in an oligotrophic gyre where biological signals are small, our diel GPP approach holds promise for remote characterization of productivity across the spectrum of marine environments.