Aerosol Research at the Arctic Facility for Atmospheric Remote Sensing (AFARS): In Search of Indirect Cloud Effects
| Sassen, Kenneth | University of Alaska Fairbanks |
| Tiruchirapalli, Ramaswamy | Atmospheric Science Group, University of Alaska Fairbanks |
| Daneva, Diana | University of Alaska, Fairbanks |
| Khovorostyanov, Vitaly | Moscow Aerological Observatory |
At high latitudes, local sources of aerosols are generally absent during most seasons. (A notable exception is smoke from local summer boreal fires, as was exceptionally illustrated in the interior of Alaska last year.) Thus, the presence of elevated aerosol layers often indicates aerosol injection from midlatitude sources, which is controlled by large-scale weather patterns. This is especially true in the high Arctic at sites like Barrow, Alaska, which can remain isolated from air mass exchanges for long periods. The seasonality of the corresponding atmospheric circulations has important implications for both the direct and indirect effects of aerosols on Arctic climate.
In our study we are combining the following elements to improve our understanding of aerosols and Arctic climate:
- Extended polarization lidar measurement campaigns from AFARS at Fairbanks and Barrow (during M-PACE) to detect aerosols and possible cloud interactions.
- Climatological studies of Arctic clouds and aerosols over the Barrow ARM site, using a 3+ year record of micropulse lidar (MPL) observations and extensive back-trajectory analyses.
- An improved lidar-only algorithm for characterizing the properties of mixed-phase supercooled water clouds with and without ice virga.
- Mixed-phase cloud model simulations to predict the microphysical changes caused by aerosol effects, and the corresponding remote sensing signatures.
So far, we have observed many aerosol/cloud interactions involving Alaskan and Russian forest fire smoke (at AFARS and M-PACE), and ice cloud formation at unusually warm temperatures and low ice supersaturations (via deposition nucleation) involving transported Asian dust layers (as will be reported in Nature).
This poster will be displayed at the ARM Science Team Meeting.