Transient tracers, water mass ages and mixing time scales in the Arctic Ocean

Smith and colleagues determined iodine-129 (129I), chlorofluorocarbons (CFC-11) and sulfur hexafluoride (SF6), in the Arctic Ocean in samples collected during two U.S. and one German GEOTRACES cruises that occurred in 2015 (cruises GN01 and GN04). The resulting large, quasi-synoptic tracer data sets provide an opportunity to use these transient tracers to determine water mass mean ages and mixing rates in a highly stratified, arctic, marine system. Their calculated mean age sections are conform to historical ideas of tracer ages while the mixing time is nearly constant in upper intermediate water, which reflects the influence of strong advective flow. The high mixing values found in the upper halocline are congruent with the nutrient maximum indicating that both are governed by winter shelf mixing processes.

Figure: Left panels: Tracer sections across Canada Basin and Eurasian Basin for; (a) CFC-11; (b) SF6 and (c) 129I. Right panels: Tracer sections across Makarov and Eurasian Basin for; (d) CFC-11; (e) SF6 and (f) 129I. Maps of respective tracer sections are illustrated in top panels.


Smith, J. N., Smethie Jr., W. M., & Casacuberta, N. (2022). Synoptic 129 I and CFC–SF 6 Transit Time Distribution (TTD) Sections Across the Central Arctic Ocean From the 2015 GEOTRACES Cruises. Journal of Geophysical Research: Oceans, 127(9). Access the paper: 10.1029/2021jc018120

Latest highlights

A thorough estimate of the hydrothermal plumes on neodymium concentration and isotope oceanic cycles

Basak and coworkers investigated the influence of particulate matter on neodymium distributions in the Southern East Pacific Rise Hydrothermal Plume.

What are the drivers of the distributions of cadmium, nickel, zinc, copper and cobalt, manganese and aluminium in the Atlantic Ocean? Two papers are tackling this issue

The authors reveal that the distributions of dissolved tracers at depth in the South Atlantic are predominantly controlled by the mixing of North Atlantic Deep Water and waters of Antarctic origin…

Disentangling the sources and transport of iron in the Southern Ocean using a water mass mixing model analysis

Traill and co-workers used an extended optimum multiparameter analysis water‐mass mixing model…

A detailed investigation of iron complexation by organic ligands in the Western Tropical South Pacific Ocean

Léo Mahieu and his co-workers present the conditional concentration and binding-strength of iron-binding ligands during the GEOTRACES TONGA cruise.