Morphology and mixing state of aged soot particles at a remote marine free troposphere site: Implications for optical properties
Loading...
Authors
China, Swarup
Scarnato, Barbara
Owen, Robert C.
Zhang, Bo
Ampadu, Marian T.
Kumar, Sumit
Dzepina, Katja
Dziobak, Michael P.
Fialho, Paulo
Perlinger, Judith A.
Subjects
Long-range transported soot in the
free troposphere is very compact
Soot compaction increases single scattering albedo and reduces direct forcing
Mie model might provide a reasonable approximation in remote marine atmosphere
Soot compaction increases single scattering albedo and reduces direct forcing
Mie model might provide a reasonable approximation in remote marine atmosphere
Advisors
Date of Issue
2015-02-18
Date
Publisher
American Geophysical Union (AGU)
Language
Abstract
The radiative properties of soot particles depend on their morphology and mixing state, but
their evolution during transport is still elusive. Here we report observations from an electron microscopy
analysis of individual particles transported in the free troposphere over long distances to the remote Pico
Mountain Observatory in the Azores in the North Atlantic. Approximately 70% of the soot particles were
highly compact and of those 26% were thinly coated. Discrete dipole approximation simulations indicate
that this compaction results in an increase in soot single scattering albedo by a factor of ≤2.17. The top of
the atmosphere direct radiative forcing is typically smaller for highly compact than mass-equivalent lacy
soot. The forcing estimated using Mie theory is within 12% of the forcing estimated using the discrete
dipole approximation for a high surface albedo, implying that Mie calculations may provide a reasonable
approximation for compact soot above remote marine clouds.
Type
Article
Description
The article of record as published may be found at http://dx.doi.org/10.1002/2014GL062404
The data for this paper are available upon request from the authors.
The data for this paper are available upon request from the authors.
Series/Report No
Department
Meteorology
Organization
Naval Postgraduate School (U.S.)
Identifiers
NPS Report Number
Sponsors
U.S. Department of Energy’s Atmospheric System Research
National Science Foundation
NASA’s Earth and Space Science Graduate Fellowship
Earth Planetary and Space Sciences Institute
National Science Foundation
NASA’s Earth and Space Science Graduate Fellowship
Earth Planetary and Space Sciences Institute
Funding
U.S. Department of Energy’s Atmospheric System Research grant DE-SC0006941
National Science Foundation grant AGS-1110059
NASA’s Earth and Space Science Graduate Fellowship grant NNX13AN68H
National Science Foundation grant AGS-1110059
NASA’s Earth and Space Science Graduate Fellowship grant NNX13AN68H
Format
8 p.
Citation
China, S., et al. (2015), Morphology and
mixing state of aged soot particles at a
remote marine free troposphere site:
Implications for optical properties,
Geophys. Res. Lett., 42, 1243–1250.
Distribution Statement
Rights
This publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. Copyright protection is not available for this work in the United States.
This publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. Copyright protection is not available for this work in the United States.
This publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. Copyright protection is not available for this work in the United States.