Methane and hydrogen in seawater (Atlantic Ocean)
Abstract
Measurements of dissolved methane and hydrogen from the Atlantic Ocean, between 50°N and 35°S, showed the surface water to be supersaturated, while the deep ocean water was in equilibrium or slightly undersaturated with respect to atmospheric CH 4 and H 2. Dissolved H 2 was highest in surface water and decreased within the upper 100 m of the water column, whereas dissolved CH 4 remained high within the entire euphotic water layer. There is evience for a diurnal variation of dissolved H 2, with higher amplitudes at the water surface compared to 20m depth. Dissolved CH 4 at 4 m depth also was measured using a continuously working equilibration technique which procided information on short-term fluctuations. The dissolved CH 4 showed no diurnal variations and was independent of wind speed. Highest CH 4 concentrations were observed in areas with high nutrient input, e.g. in the upwelling areas off West Africa, and correlated well with the observed chorophyll a concentrations. Based on an average CH 4 saturation factor of about 1.1, the total source strength for atmospheric CH 4 is calculated to about 1.5 Tg y -1.
- Publication:
-
Deep Sea Research A
- Pub Date:
- December 1988
- DOI:
- 10.1016/0198-0149(88)90116-1
- Bibcode:
- 1988DSRA...35.1903C