Abstract
The thermohaline intrusion of the warm and saline Atlantic Water (AW)
into the Arctic Ocean, referred to as “Arctic Atlantification”, has
significant implications and feedback to the dynamics and thermodynamics
of the Arctic Ocean. The AW enters the Arctic Ocean through two
gateways: Fram Strait and the Barents Sea Opening (BSO). The relative
strength of these two AW branches dominates the oceanic heat
contribution to the Arctic Ocean. In conjunction with the measurements
in key hydrographic sections, numerical ocean modelling provides us with
a useful tool to characterize and corroborate the temporal and spatial
variability of the AW branches. Simulations are conducted using the
regional configuration Arctic and North Hemispheric Atlantic (ANHA) of
the ocean/sea-ice model NEMO running at 1/4° and 1/12° resolution.
Online passive tracers from the model configuration are used to trace
the pathways of the AW inflow in the Arctic Ocean. With the AW becoming
more important to the dynamics of the Arctic Ocean, this study aims to
examine its variability, transformation, impacts, and ultimately track
how it evolves. While the heat in the Fram Strait Branch Water (FSBW)
dissipates in a slower process through the mixing with the ambient cold
water below sea surface, the vast majority of the heat loss of the
Barents Sea Branch Water (BSBW) takes place in Barents Sea due to the
sea surface cooling, leading to Cold Atlantic Water (CAW) production
during 2013 and 2014. The CAW pulses result in a significant heat
content reduction in the eastern Arctic.