Observations of New Particle Formation in the Remote Atmosphere from NASA's Atmospheric Tomography Mission
Abstract
Cloud modifications due to aerosol are still the largest uncertainty on total anthropogenic radiative forcing in global climate models. A large part of this uncertainty is related to the number and spatial distribution of cloud condensation nuclei (CCN) in the global atmosphere. Aerosol from new particle formation (NPF) may account for more than 50% of CCN in global low-level clouds, yet the processes that form, grow and remove these particles in the atmosphere are under-constrained. This is particularly true in remote regions, where aerosol from NPF are more likely to influence cloud properties and thus global radiative balance. Global-scale measurements are necessary to understand the dominant factors controlling NPF. In-situ measurements are necessary because it is not possible to retrieve information from satellites about particles small enough to indicate the occurrence of NPF.
We recently flew a substantial aerosol payload on the NASA Atmospheric Tomography Mission (ATom), which consisted of four sets of research flights over the remote Pacific and Atlantic oceans. The flights were conducted once in each of the four seasons, between 86° S and 83° N, constant profiling between 0.2 and 12 km altitude. We measured aerosol size distributions between 3 nm to 930 mm diameter, single particle and bulk aerosol composition. We present analysis of the global distribution of NPF, including seasonal trends and the influence of anthropogenic emissions in remote regions. In areas where our measurements show a clear link between NPF and production of CCN, we compare our observations to global chemistry-climate models to assess model skill in representing these aerosol and their effect on global radiative balance.- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFM.A31W2722W
- Keywords:
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- 0305 Aerosols and particles;
- ATMOSPHERIC COMPOSITION AND STRUCTURE;
- 0365 Troposphere: composition and chemistry;
- ATMOSPHERIC COMPOSITION AND STRUCTURE;
- 0368 Troposphere: constituent transport and chemistry;
- ATMOSPHERIC COMPOSITION AND STRUCTURE