|
|
|
|
|
| Fry, Claudia H.; Tyrrell, Toby; Hain, Mathis P.; Bates, Nicholas R.; Achterberg, Eric P.. |
| The export of calcium carbonate (CaCO3) from the surface ocean is poorly constrained. A better understanding of the magnitude and spatial distribution of this flux would improve our knowledge of the ocean carbon cycle and marine biogeochemistry. Here, we investigate controls over the spatial distribution of total alkalinity in the surface global ocean and produce a tracer for CaCO3 cycling. We took surface ocean bottle data for total alkalinity from global databases (GLODAP, CARINA, PACIFICA) and subtracted the effects of several processes: evaporation and precipitation, river discharge, and nutrient uptake and remineralization. The remaining variation in alkalinity exhibits a robust and coherent pattern including features of large amplitude and spatial... |
| Tipo: Text |
Palavras-chave: Alkalinity; Calcium carbonate; Biogeochemical cycles; Tracers. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00292/40367/83011.pdf |
| |
|
|
| Jiang, Zong-pei; Tyrrell, Toby; Hydes, David J.; Dai, Minhan; Hartman, Susan E.. |
| The variability of total alkalinity (TA) and its relationship with salinity in the tropical and subtropical surface ocean were examined using data collected in various marine environments from a ship of opportunity. In the open ocean regions of the Atlantic, Pacific, and Indian Oceans, sea surface TA variability was observed to be mainly controlled by the simple dilution or concentration (SDC) effect of precipitation and evaporation, and the measured concentrations of TA agreed well with those predicted from salinity and temperature. Non-SDC changes in alkalinity in ocean margins and inland seas were examined by comparing the salinity-normalized alkalinity with that of the open ocean end-member. Non-SDC alkalinity additions to the western North Atlantic... |
| Tipo: Text |
|
| Ano: 2014 |
URL: https://archimer.ifremer.fr/doc/00292/40349/38934.pdf |
| |
|
|
| Wu, Yingxu; Hain, Mathis P.; Humphreys, Matthew P.; Hartman, Sue; Tyrrell, Toby. |
| Previous work has not led to a clear understanding of the causes of spatial pattern in global surface ocean dissolved inorganic carbon (DIC), which generally increases polewards. Here, we revisit this question by investigating the drivers of observed latitudinal gradients in surface salinity-normalized DIC (nDIC) using the Global Ocean Data Analysis Project version 2 (GLODAPv2) database. We used the database to test three different hypotheses for the driver producing the observed increase in surface nDIC from low to high latitudes. These are (1) sea surface temperature, through its effect on the CO2 system equilibrium constants, (2) salinity-related total alkalinity (TA), and (3) high-latitude upwelling of DIC- and TA-rich deep waters. We find that... |
| Tipo: Text |
|
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00675/78726/80988.pdf |
| |
|
|
| Demuynck, Pieter; Tyrrell, Toby; Garabato, Alberto Naveira; Moore, Mark Christopher; Martin, Adrian Peter. |
| The nutrient composition (high in nitrate but low in silicate) of Subantarctic Mode Water (SAMW) forces diatom scarcity across much of the global surface ocean. This is because diatoms cannot grow without silicate. After formation and downwelling at the Southern Ocean's northern edge, SAMW re-emerges into the surface layers of the mid- and low-latitude oceans, providing a major nutrient source to primary producers in those regions. The distinctive nutrient composition of SAMW originates in the surface waters of the Southern Ocean, from which SAMW is formed. These waters are observed to transition from being rich in both silicate and nitrate in high-latitude areas of the Southern Ocean to being nitrate-rich but silicate-depleted at SAMW formation sites... |
| Tipo: Text |
|
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00676/78840/81147.pdf |
| |
|
|
|
