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Soot superaggregates from flaming wildfires and their direct radiative forcing
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Beres, Nicholas D. Liu, Li Mishchenko, Michael I. Mazzoleni, Claudio China, Swarup Dubey, Manvendra K. Chakrabarty, Rajan K. Moosmuller,Hans |
| Copyright Year | 2014 |
| Description | Wildfires contribute significantly to global soot emissions, yet their aerosol formation mechanisms and resulting particle properties are poorly understood and parameterized in climate models. The conventional view holds that soot is formed via the cluster-dilute aggregation mechanism in wildfires and emitted as aggregates with fractal dimension D(sub f) approximately equals 1.8 mobility diameter D(sub m) (is) less than or equal to 1 micron, and aerodynamic diameter D(sub a) (is) less than or equal to 300 nm. Here we report the ubiquitous presence of soot superaggregates (SAs) in the outflow from a major wildfire in India. SAs are porous, low-density aggregates of cluster-dilute aggregates with characteristic D(sub f) approximately equals 2.6,D(sub m) (is) greater than 1 micron, and D(sub a) is less than or equal to 300 nm that form via the cluster-dense aggregation mechanism.We present additional observations of soot SAs in wildfire smoke-laden air masses over Northern California, New Mexico, and Mexico City. We estimate that SAs contribute, per unit optical depth, up to 35% less atmospheric warming than freshly-emitted (D(sub f) approximately equals 1.8) aggregates, and approximately equals 90% more warming than the volume-equivalent spherical soot particles simulated in climate models.|||||||| |
| File Size | 462904 |
| Page Count | 8 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_20140017420 |
| Archival Resource Key | ark:/13960/t3pw1h227 |
| Language | English |
| Publisher Date | 2014-07-01 |
| Access Restriction | Open |
| Subject Keyword | Sas Climate Models Soot Deuterium Fluorides Aggregates Aerosols Air Masses California Smoke Electron Microscopy Particles Forest Fires India Emittance Optical Properties Global Warming Radiative Forcing Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Article |
