A5005379708- Marine and coastal ecosystems
- Oceanographic and Atmospheric Processes
- Ocean Acidification Effects and Responses
- Marine Biology and Ecology Research
- Groundwater and Isotope Geochemistry
- Marine Bivalve and Aquaculture Studies
- Isotope Analysis in Ecology
- Arctic and Antarctic ice dynamics
- Marine and fisheries research
University of Cape Town
2020-2022
Abstract. The production and removal of ammonium (NH4+) are essential upper-ocean nitrogen cycle pathways, yet in the Southern Ocean where NH4+ has been observed to accumulate surface waters, its mixed-layer cycling remains poorly understood. For seawater samples collected between Cape Town Marginal Ice Zone winter 2017, we found that concentrations were 5-fold higher than is typical for summer lower north south Subantarctic Front (0.01–0.26 µM versus 0.19–0.70 µM). Our observations confirm...
Abstract The well‐established importance of Agulhas Current “leakage” for Indian‐Atlantic Ocean exchange heat and salt raises the question relevance eddies carbon nitrogen cycling. We measured net primary production (NPP), nitrate ammonium uptake, nitrification along a transect Cape Basin (CB) in winter 2017, including across an anticyclonic eddy sampled at high‐resolution. Euphotic zone‐integrated rates NPP uptake were more than three‐fold lower center its edges, with intermediate outside...
Abstract. The production and consumption of ammonium (NH4+) are essential upper-ocean nitrogen cycle pathways, yet in the Southern Ocean where NH4+ has been observed to accumulate surface waters, its mixed-layer cycling remains poorly understood. For samples collected between Cape Town marginal ice zone (MIZ) winter 2017, we found that concentrations were five-fold higher than is typical for summer, lower north south Subantarctic Front (SAF; 0.01–0.26 µM versus 0.19–0.70 µM). Our...