Bias and sensitivity of boundary layer clouds and surface radiative fluxes in MERRA-2 and airborne observations over the Beaufort Sea during the ARISE campaign

Abstract

The research focuses on airborne measurement conducted over the Beaufort Sea during September 2014. We compare our airborne measurement to predicted fields by reanalysis model and use both to reconstruct the surface radiative fluxes and compare them. We find that the reanalysis overestimates near-surface temperatures over open water areas and also over sea ice-covered areas. However, it underestimates relative humidity and clouds close to the surface. Comparing the simulated surface fluxes, we found that the reanalysis shows higher (more positive) surface fluxes in compare with measurements. It also underestimates the amount of ice water content in the low-level Arctic clouds during this time of the year, which results in an overestimation of the predicted fluxes by the model in comparison with those from observations. Overall, we found that cloud vertical structure and water content are the main difference sources (explain more than 70% of the differences) between observation and the modeled fields, with cloud phase and atmospheric parameters second (explain ~20% of the differences).

Samuel LeBlanc

Research Scientist

Atmospheric Scientist studying colors of clouds and aerosol to better measure and understand climate