[22-Feb-2024] Schmidgall, C., Gaube, P., Thompson, L., and Thomson, J.
Presented at the 2024 Ocean Sciences MeetingThe Beaufort Gyre is salinity stratified, allowing warm, salty layers at depth to be capped by cold, fresh layers near the surface. Vertical gradients in salinity therefore set the stability of the water column, and the tendency for subsurface heat to be mixed upward towards the surface. In the spring and summer, cool and fresh meltwater input from sea ice enhances salinity stratification. The degree to which these freshwater anomalies persist and precondition the ocean for sea ice formation is an open question with ramifications for the dynamics of the Beaufort Gyre, the Arctic cryosphere, and the global climate system. The September 2022 NASA Salinity and Stratification at the Sea Ice Edge (SASSIE) field campaign surveyed the Beaufort Gyre during the transition from summer ice melt to autumn ice advance. Here we present results and analysis from measurements collected via the Continuous Underway Multisensor Profiler, which recorded over 2,000 km of temperature and salinity profiles in high vertical (10 cm) and horizontal (1-2 km) resolution in the upper 100 m of the water column. Repeated transects, taken over roughly four days, show the influence of sea ice meltwater in the mixed layer and evolution of pockets of warm Pacific Summer Water beneath the halocline. These observations reveal a high degree of mesoscale and submesoscale variability, indicating the importance of small-scale processes in shaping overall patterns of salinity stratification and sea surface temperature.