Optical measurements of light transmittance of the upper water column, United States Coast Guard Cutter (USCGC) Healy, Chukchi Sea to Central Arctic Ocean (2022)

The Central Arctic Ocean remains profoundly understudied, particularly with respect to carbon cycling, ecosystem alteration, and associated changes in atmospheric, ice and ocean physics that drive those biological and biogeochemical systems. The region is expected to experience continued marked changes over the coming decades, driven by ongoing climate warming. Yet, because of relatively limited understanding of fundamental characteristics and processes in the region, predicting these changes and their Pan-Arctic linkages remains difficult. The Synoptic Arctic Survey (SAS) is organized around three major research areas: (1) physical drivers of importance to the ecosystem and carbon cycle; (2) the ecosystem response and (3) the carbon cycle. The overarching questions are: “What is the present state, and what are the major ongoing transformations of the Arctic marine system?” The overall objective of this expedition was to quantify the present states of the physical, biological, and biogeochemical systems of the Pacific Arctic (here defined as the Chukchi Sea, Beaufort shelf/slope, Chukchi Borderlands) and Canadian Basin (i.e., the Makarov and Canada basins) during summer 2022." - Cruise Report United States Coast Guard Cutter (USCGC) Healy HLY2202/AWS2022 [Prepared by Carin Ashjian ([e-mail]) and the HLY2202 Science Team]. This dataset presents open-ocean (i.e. without the presence of sea ice) upper ocean (~50 meter [m]) optical profiles collected using a Biospherical Compact Optical Profiling System (C-OPS). Eighteen channels (320–780 nanometer [nm]) were measured by upward and downward facing radiometers alongside an upward viewing radiometer at the surface. In addition to the eighteen transmittance channels, subsurface chlorophyll fluorescence and photosynthetic active radiation are provided.