Abstract
Every austral spring when Antarctic sea ice melts, favorable growing
conditions lead to an intense phytoplankton bloom, which supports much
of the local marine ecosystem. Recent studies have found that Antarctic
sea ice is predictable several years in advance, suggesting that the
spring bloom might exhibit similar predictability. Using a suite of
perfect model predictability experiments, we find that November net
primary production (NPP) is potentially predictable seven to ten years
in advance in many Southern Ocean regions. Sea ice extent predictability
peaks in late winter, followed by absorbed shortwave radiation and NPP
with a two to three months lag. This seasonal progression of
predictability supports our hypothesis that sea ice and light limitation
control the inherent predictability of the spring bloom. Our results
suggest skillful interannual predictions of NPP may be achievable, with
implications for managing fisheries and the marine ecosystem, and
guiding conservation policy in the Southern Ocean.