Variability in the mass absorption cross-section of black carbon (BC) aerosols is driven by BC internal mixing state at a central European background site (Melpitz, Germany) in winter - Yuan, J.; Modini, R. L.; Zanatta, M.; Herber, A. B.; Müller, T.; Wehner, B.; Poulain, L.; Tuch, T.; Baltensperger, U.; Gysel-Beer, M. (Atmos. Chem. Phys. Discuss., 2020)