Global-scale seasonally resolved black carbon vertical profiles over the Pacific.
[1] Black carbon (BC) aerosol loadings were measured during the High-performance Instrumented Airborne Platform for Environmental Research Pole-to-Pole Observations (HIPPO) campaign above the remote Pacific from 85°N to 67°S. Over 700 vertical profiles extending from near the surface to max ∼14 km altitude were obtained with a single-particle soot photometer between early 2009 and mid-2011. The data provides a climatology of BC in the remote regions that reveals gradients of BC concentration reflecting global-scale transport and removal of pollution. BC is identified as a sensitive tracer of extratropical mixing into the lower tropical tropopause layer and trends toward surprisingly uniform loadings in the lower stratosphere of ∼1 ng/kg. The climatology is compared to predictions from the AeroCom global model intercomparison initiative. The AeroCom model suite overestimates loads in the upper troposphere/lower stratosphere (∼10×) more severely than at lower altitudes (∼3×), with bias roughly independent of season or geographic location; these results indicate that it overestimates BC lifetime.
['Schwarz|J P|JP|', 'Samset|B H|BH|', 'Perring|A E|AE|', 'Spackman|J R|JR|', 'Gao|R S|RS|', 'Stier|P|P|', 'Schulz|M|M|', 'Moore|F L|FL|', 'Ray|Eric A|EA|', 'Fahey|D W|DW|']
black carbon aerosol HIPPO remote tropical tropopause layer AeroCom