Remote sensing of aerosols in the Arctic for an evaluation of global climate model simulations

• Published in: Journal of Geophysical Research: Atmospheres
• Main Authors: Glantz, Paul, Bourassa, Adam, Herber, Andreas, Iversen, Trond, Karlsson, Johannes, Kirkevåg, Alf, Maturilli, Marion, Seland, Øyvind, Stebel, Kerstin, Struthers, Hamish, Tesche, Matthias, Thomason, Larry
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Wiley 2014
• Subjects: Arctic; Subarctic; Svalbard
• Online Access: https://epic.awi.de/id/eprint/35814/; https://epic.awi.de/id/eprint/35814/1/Glantz_et_al_JGR2014.pdf; https://hdl.handle.net/10013/epic.43974; https://hdl.handle.net/10013/epic.43974.d001

In this study MODerate resolution Imaging Spectroradiometer (MODIS) Aqua retrievals of aerosol optical thickness (AOT) at 555 nm are compared to sun-photometer measurements from Svalbard for a period of 9 years. For the 642 daily coincident measurements that were obtained, MODIS AOT generally varies within the predicted uncertainty of the retrieval over ocean (ΔAOT = ±0.03 ± 0.05 · AOT). The results from the remote sensing have been used to examine the accuracy in estimates of aerosol optical properties in the Arctic, generated by global climate models and from in-situ measurements at the Zeppelin station, Svalbard. AOT simulated with the Norwegian Earth System Model (NorESM1-M)/ CAM4-Oslo global climate model does not reproduce the observed seasonal variability of the Arctic aerosol. The model overestimates clear-sky AOT by nearly a factor of 2 for the background summer season, while tending to underestimate the values in the spring season. Furthermore, large differences in all-sky AOT of up to one order of magnitude are found for the Coupled Model Intercomparison Project (CMIP5) model ensemble for the spring and summer seasons. Large differences between satellite/ground-based remote sensing of AOT and AOT estimated from dry and humidified scattering coefficients are found for the subarctic marine boundary layer in summer.