Equatorial Pacific bulk 𝛿15N supports a secular increase in subantarctic zone nitrate utilization after the mid-Pleistocene Transition
Abstract
Pacific-wide measurements of nitrate and its isotopic composition have furthered our understanding of modern subsurface circulation and have revealed basin-scale connections between oceanographic and nitrogen cycle processes. From the Eastern Tropical Pacific (ETP), the isotopic signature of denitrification is spread zonally and meridionally via subsurface currents. From the Pacific sector of the Southern Ocean, Subantarctic Mode Water (SAMW) penetrates to the low latitudes, delivering nitrate (and likely its isotopic signature) to equatorial surface waters via upwelling. These two regional processes combine to inform much of the thermocline nitrogen dynamics of the Pacific. Here, we compare a new 1.4-Myr bulk sediment
- Publication:
-
EGU General Assembly Conference Abstracts
- Pub Date:
- April 2021
- DOI:
- 10.5194/egusphere-egu21-12463
- Bibcode:
- 2021EGUGA..2312463L