CPP-10. A Spring Bloom in the Arctic Ocean

Abstract
In May, 2019, we measured optical properties of a spring bloom in the Chukchi Sea in the Arctic Ocean northwest of Alaska. The airborne lidar provided profiles of the optical attenuation and backscattering of the water column at the laser wavelength of 532 nm. Both attenuation and backscattering were highest in open water and decreased with increasing ice cover, although the relationship was not strong. High values of both optical properties were observed in the pack ice up to ice fractions of 90%. Where there was complete ice cover, the lidar was not able to penetrate between floes to make the measurement. Attenuation is most closely associated with chlorophyll concentration, while backscatter is most closely associated with the concentration of particulate organic carbon, so we get two different estimates of parameters of the spring phytoplankton bloom. With the additional information from depolarization of the lidar return, we were able to determine that there were several distinct types of scattering particles in the lidar data, although we were not able to identify these particles.