This dataset includes measurements of the dissolved isotope radium-226 in the South Pacific and Southern Ocean. Samples were collected on the US GEOTRACES GP17-OCE cruise (Papeete, Tahiti to Punta Arenas, Chile) on R/V Roger Revelle from December 2022 to January 2023. Radium-223, radium-224, and radium-228 data will be made available in the future.
more »
« less
Dissolved barium (Ba) concentrations in seawater samples collected on the US GEOTRACES GP17-OCE cruise on R/V Roger Revelle (RR2214) in the South Pacific and Southern Oceans from December 2022 to January 2023
This dataset includes measurements of dissolved barium (Ba) concentrations in the South Pacific and Southern Ocean from the US GEOTRACES GP17 section (GP17-OCE, Papeete, Tahiti to Punta Arenas, Chile) on R/V Roger Revelle from December 2022 to January 2023.
more »
« less
- Award ID(s):
- 2048604
- PAR ID:
- 10640003
- Publisher / Repository:
- Biological and Chemical Oceanography Data Management Office (BCO-DMO)
- Date Published:
- Edition / Version:
- 1
- Subject(s) / Keyword(s):
- barium South Pacific Southern Ocean GEOTRACES
- Format(s):
- Medium: X
- Location:
- Woods Hole, MA
- Institution:
- Woods Hole Oceanographic Institution
- Sponsoring Org:
- National Science Foundation
More Like this
-
-
These data comprise the concentrations of dissolved iron and manganese determined in water-column and near-surface seawater samples, collected using a trace-metal clean CTD rosette or underway towfish sampler, respectively, during U.S. GEOTRACES cruise GP17-OCE (R/V Roger Revelle cruise RR2214). The dissolved iron data include shipboard measurements made using flow-injection analysis, and post-cruise measurements made using inductively-coupled plasma mass spectrometry, whereas the dissolved manganese data include only post-cruise measurements made using inductively-coupled plasma mass spectrometry.more » « less
-
This dataset includes the concentrations of iron (Fe) bound to humic-like substances and total iron-binding capacity of humic-like substances from discrete depth profile and towfish samples collected on the GP17-ANT cruise NBP24-01 on the R/V IB Nathaniel B. Palmer in the Amundsen Sea from 29 November 2023 to 28 January 2024. This project investigates the impact of Fe-binding humic-like substances on Fe biogeochemistry in the Amundsen Sea. The project used a combination of depth profile and surface towfish samples to characterize the contributions of humic-like substances to Fe biogeochemistry across gradients in primary production, water masses, and bathymetric features in the Amundsen Sea. Understanding the distributions of Fe-binding humic-like substances provides insight into the impact of compositional changes of the Fe-binding ligand pool on Fe biogeochemistry and may help elucidate specific sources of these ligands.more » « less
-
Abstract We present measurements of silicon isotopes in silicic acid, δ30Si, from GEOTRACES GP17OCEbetween 20°S and 60°S along 152°W. The section sampled key water masses, allowing assessment of controls on large‐scale δ30Si features. Observational data paralleled results of a data‐constrained Si isotope model and are consistent with nutrient trapping and partial nutrient consumption in polar surface waters leading to the accumulation of light silicon isotopes in the deep Southern Ocean (SO) and transport of the residually heavy fraction northward within Sub‐Antarctic Mode Water (SAMW) and Antarctic Intermediate Water (AAIW). Deep‐water δ30Si values were nearly constant along isopycnals in the South Pacific, with vertical gradients driven by an increasing fractional contribution of isotopically light regenerated silicic acid with depth. Isotope values in deep waters from the SO to Tahiti exhibited a greater range than previously observed in the South Pacific or predicted by models, with δ30Si falling between 1.19‰ and 1.45‰. SAMW and AAIW exhibited relatively heavy, uniform δ30Si. Model results suggest that these mode waters are composed of preformed silicic acid subducted in the outcropping region and regenerated silicic acid sourced in roughly equal measure from polar waters and northern distal sources. Distal input is mainly through entrainment of underlying Upper Circumpolar Deep Water into AAIW.more » « less
-
Beryllium-7, a radioactive isotope with a half-life of 53.3 days, is formed in the atmosphere, attaches to aerosol particles, and is deposited on the earth’s surface through wet and dry processes. In this project, we measured Be-7 concentrations in aerosol particles and in seawater samples (depths < 200 meters) collected on the GEOTRACES GP17-OCE cruise aboard R/V Roger Revelle. The cruise originated in Papeete, Tahiti, French Polynesia on 1 December 2022 and concluded on 25 January 2023 in Punta Arenas, Chile. Sixteen aerosol samples and seawater from twelve stations in the South Pacific and Southern Oceans were collected. The dataset will be used to study the deposition of trace elements and isotopes (TEIs) and upper ocean mixing processes. Aerosol deposition is an important source of TE micronutrients to open ocean areas that are far removed from riverine sources. But, while the collection aerosol of samples for TEI analysis is straightforward, estimating the deposition flux also requires an appropriate deposition velocity (i.e. deposition flux is the product of the aerosol concentration and deposition velocity). Because Be-7 is supplied to the open ocean exclusively through aerosol deposition and it is removed through radioactive decay, the water column inventory and aerosol concentration of Be-7 can be used to derive the deposition velocity applicable to aerosol TEIs. The penetration of dissolved Be-7 below the ocean mixed layer is limited by the isotope's half-life and the rate of vertical diffusive mixing. Through modeling, the shape of the Be-7 profile below the mixed layer provides an estimate for the vertical diffusivity coefficient (Kz), which can be used to calculate fluxes of chemical species (e.g. oxygen) and physical properties (e.g. heat).more » « less
An official website of the United States government
