Pulses of Cold Atlantic Water in the Arctic Ocean From an Ocean Model Simulation

Abstract

AbstractThe intrusion of the warm and saline Atlantic Water (AW) has significant implications and feedback on the dynamics and thermodynamics of the Arctic Ocean. The AW enters the Arctic Ocean through two gateways: Fram Strait (FS) and the Barents Sea Opening (BSO). The AW is the dominant source of oceanic heat to the Arctic Ocean. In conjunction with the measurements in key hydrographic sections, numerical ocean modeling 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 Nucleus for Modeling of the Ocean 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. While studying the variability of the AW through FS and the BSO, a cold mode of AW (Cold Atlantic Water [CAW]) with a temperature below 0℃ is detected along the rim of the eastern Eurasian Basin. It is formed primarily due to the intense sea surface cooling of the AW in the Barents and Kara Seas. The CAW exhibits the cascading process as it propagates downstream through the St. Anna Trough, leading to a considerable mixing with the ambient water. The CAW pulses eventually result in a significant heat content reduction in the eastern Arctic. This study provides insight into the changing AW property and its potential impact on the Arctic Basin.