Skip to main content

Free Content Observations of the influence of diurnal convection on upper ocean dissolved gas measurements

Download Article:
(PDF 1041.6875 kb)


An important example of the interaction between biological productivity and near-surface oceanography is the role of nocturnal convection and diurnal restratification in modifying the environment in which photosynthetic activity takes place. In situ time series measurements of dissolved oxygen reveal the effects of photosynthetic activity, respiration and redistribution by mixing. Moored thermistor time series and frequent CTD casts show that restratification during the day is confined to a warmer shallow surface layer where most of the biological production is expected to occur. The depth and rate of mixing is measured with neutrally buoyant floats which track the vertical excursions of convecting water parcels. Early in the evening, at the onset of night time convection, this warm oxygenated water is mixed down and diluted by deeper less oxygenated water. The interpretation of oxygen time series at specified depths (here 21 m and 30 m) requires knowledge of this mixing process. Use is made of in situ dissolved nitrogen time series to infer that gas transfer at the surface is of secondary importance in determining the diurnal dissolved oxygen budget. A qualitative coupled biological/oceanographic model of the data is presented and discussed. It is concluded that a serious overestimate of daily oxygen production can result from excluding diurnal convection from the interpretation of oxygen time series.

Document Type: Research Article


Publication date: 1995-01-01

More about this publication?
  • The Journal of Marine Research publishes peer-reviewed research articles covering a broad array of topics in physical, biological and chemical oceanography. Articles that deal with processes, as well as those that report significant observations, are welcome. In the area of biology, studies involving coupling between ecological and physical processes are preferred over those that report systematics. Authors benefit from thorough reviews of their manuscripts, where an attempt is made to maximize clarity. The time between submission and publication is kept to a minimum; there is no page charge.
  • Editorial Board
  • Information for Authors
  • Subscribe to this Title
  • Ingenta Connect is not responsible for the content or availability of external websites
  • Access Key
  • Free content
  • Partial Free content
  • New content
  • Open access content
  • Partial Open access content
  • Subscribed content
  • Partial Subscribed content
  • Free trial content
Cookie Policy
Cookie Policy
Ingenta Connect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more