The free troposphere as a potential source of arctic boundary layer aerosol particles. Issue 13 (7th July 2017)

• Record Type: Journal Article
• Authors: Igel, Adele L.; Ekman, Annica M. L.; Leck, Caroline; Tjernström, Michael; Savre, Julien; Sedlar, Joseph
• Is Part Of: Geophysical research letters. Volume 44:Issue 13(2017)
• Page Start: 7053
• Page End: 7060
• Publication Date: 2017-07-07
• Subjects: Arctic aerosols -- mixed‐phase clouds -- boundary layer; Geophysics -- Periodicals; Planets -- Periodicals; Lunar geology -- Periodicals; 550
• DOI: 10.1002/2017GL073808
• Languages: English
• ISSNs: 0094-8276

Abstract

Abstract: This study investigates aerosol particle transport from the free troposphere to the boundary layer in the summertime high Arctic. Observations from the Arctic Summer Cloud Ocean Study field campaign show several occurrences of high aerosol particle concentrations above the boundary layer top. Large‐eddy simulations suggest that when these enhanced aerosol concentrations are present, they can be an important source of aerosol particles for the boundary layer. Most particles are transported to the boundary layer by entrainment. However, it is found that mixed‐phase stratocumulus clouds, which often extend into the inversion layer, also can mediate the transport of particles into the boundary layer by activation at cloud top and evaporation below cloud base. Finally, the simulations also suggest that aerosol properties at the surface sometimes may not be good indicators of aerosol properties in the cloud layer. Key Points: High aerosol concentrations were sometimes observed to be in contact with the boundary layer top in the summertime Arctic during ASCOS Free tropospheric aerosol can be transported to the boundary layer by direct entrainment or by cloud‐mediated activation and regeneration Aerosol properties measured at the surface may not be a good indicator of aerosol properties in the cloud layer