ABCLP

One of the major issues confronting aerosol climate simulations of the Arctic and Antarctic Cryospheres is the lack of detailed data on the vertical and spatial distribution of aerosols with which to test these models. This is due, in part, to the inherent difficulty of conducting such measurements in extreme environments. However, given the pronounced sensitivity of the polar regions to radiative balance perturbations, it is incumbent upon our community to better understand and quantify these perturbations, and their unique feedbacks, so that robust model predictions of this region can be realized. One class of under-measured radiative forcing agents in the polar region is absorbing aerosols C black carbon and brown carbon. Black carbon (BC; also referred to as light absorbing carbon [LAC], refractory black carbon [rBC], and soot) is second only to CO2 as a positive forcing agent. Roughly 60% of BC emissions can be attributed to anthropogenic sources (fossil fuel combustion and open-pit cooking) with the remaining fraction being due to biomass burning. Brown carbon (BrC), a major component of biomass burning, collectively refers to non-BC carbonaceous aerosols that typically possess minimal light absorption at visible wavelengths but exhibit pronounced light absorption in the near UV. Both species can be sourced locally or be remotely transported to the Arctic and are expected to perturb the radiative balance. This work addressed one of the more glaring deficiencies currently limiting improved quantification of the impact of BC radiative forcing in the Cryosphere: the paucity of data on the vertical and spatial distributions of BC. By expanding the G-1 payload for the ARM-sponsored ACME-V campaign to include the SP2 (Single Particle Soot Photometer) and leveraging this campaign's deployment within the Arctic Circle during summer 2015 (Deadhorse, Alaska [70° 12' 20" N, 148° 30' 42" W]), a unique opportunity presented itself to acquire profile data on BC loading at little additional cost. Since the SP2 is a particle-resolved measurement, the resulting data set provided refractory black carbon (rBC) mass loadings, size and mass distributions, and a rBC-containing particle mixing state, all of which are expected to readily find value in the modeling community. As part of the ACME-V (http://www.arm.gov/campaigns/aaf2014armacmev) campaign CO, CO2 and CH4 were also measured, providing the unique opportunity for carbon closure. We will also worked closely with modelers who require such data and expect this collaboration will lead directly to a better understanding of the climate impacts of BC in the Arctic. The primary measurement objective was to:

• Acquire airborne data on the vertical and spatial distributions of refractory black carbon (rBC) loading, size and mass distribution, and particle mixing state.

The primary scientific objective was to:

• Provide a targeted dataset of rBC particle distributions to better understand and constrain the impact of black carbon radiative forcing in the Cryosphere.

Timeline

Campaign Data Sets