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

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...

Full description

Bibliographic Details
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:
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
Description
Summary: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.