- 1Universität Bremen, Institute of Environmental Physics, Bremen, Germany (rsteinf@physik.uni-bremen.de)
- 2Federal Maritime and Hydrographic Agency (BSH)
Transient tracer observations from GLODAPv2 and more recent data are used to
compute transit time distributions (TTDs) for Labrador Sea Water. These TTDs are then integrated
basin wide over the subpolar, subtropical and tropical Atlantic. This allows to infer ventilation,
export and formation rates of LSW. We further devide the LSW density range into an upper (ULSW) and a
deeper part (DLSW). The results reflect the known variability of LSW formation, with high formation rates
of DLSW in the 1990s and after 2015, and periods with increased ULSW formation in between.
Astonishingly, the DLSW formation rate is always significantly larger than zero,
even in years without direct DLSW ventilation.
We also compare the formation rates derived from the TTDs with those calculated
from CFC/SF6 inventories. This shows, that the formation rates inferred from tracer inventories
depend more strongly on the integration regions (subpolar North Atlantic only
or including subtropics (and tropics)) than the TTD derived formation rates.
How to cite: Steinfeldt, R., Rhein, M., and Kieke, D.: Decadal variability of Labrador Sea Water formation , EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-16176, https://doi.org/10.5194/egusphere-egu25-16176, 2025.
