Loading...
Please wait, while we are loading the content...
Similar Documents
Importance of N2 fixation vs. nitrate eddy diffusion along a latitudinal transect in the Atlantic Ocean
| Content Provider | Semantic Scholar |
|---|---|
| Author | Mouriño-Carballido, Beatriz Grana, R. Fernández, Ana Belén Méndez Bode, Antonio Varela, Manuel F. Domínguez, J. Ferreirós Escánez, José Armas, Demetrio De Marañón, Emilio |
| Copyright Year | 2011 |
| Abstract | We present ocean, basin-scale simultaneous measurements of N 2 -fixation, nitrate diffusion, and primary production along a south-north transect in the Atlantic Ocean crossing three biogeographic provinces: the south subtropical Atlantic (SSA; ∼ 31°S―12°S), the equatorial Atlantic (EA; ∼ 12°S―16°N), and the north subtropical Atlantic (NSA, ∼ 16°N―9°N) in April-May 2008. N 2 -fixation and primary production were measured as 15 N 2 and 14 C uptake, respectively. Dissipation rates of turbulent kinetic energy (e) were measured with a microstructure profiler. The vertical input of nitrate through eddy diffusion was calculated from the product of diffusivity, derived from e, and the gradient of nanomolar nitrate concentration across the base of the euphotic zone. The mean N 2 -fixation rate in EA was 56 ± 49 μmol N m ―2 d ―1 , whereas SSA and NSA had much lower values (∼ 10 μmol N m ―2 d ―1 ). Because of the large spatial variability in nitrate diffusion (34 ± 50, 405 ± 888, and 844 ± 1258 μmol N m ―2 d ―1 in SSA, EA, and NSA, respectively), the contribution of N 2 -fixation to new production in the SSA, EA, and NSA was 44% ± 30%, 22% ± 19%, and 2% ± 2%, respectively. The differences between SSA and NSA in the contribution of N 2 fixation were partly due to the contrasting seasonal forcing in each hemisphere, which likely affected both N 2 fixation rates and vertical nitrate diffusion. The variability in the nitrogen budget of the Atlantic subtropical gyres was unexpectedly high and largely uncoupled from relatively constant phytoplankton standing stocks and primary production rates. |
| Starting Page | 999 |
| Ending Page | 1007 |
| Page Count | 9 |
| File Format | PDF HTM / HTML |
| DOI | 10.4319/lo.2011.56.3.0999 |
| Volume Number | 56 |
| Alternate Webpage(s) | http://bmourino.webs.uvigo.es/mourino_etal_2011_lo.pdf |
| Alternate Webpage(s) | https://doi.org/10.4319/lo.2011.56.3.0999 |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
