Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published June 16, 2014 | Supplemental Material + Published
Journal Article Open

Observations of continental biogenic impacts on marine aerosol and clouds off the coast of California


During the 2011 Eastern Pacific Emitted Aerosol Cloud Experiment (E-PEACE) and 2013 Nucleation in California Experiment (NiCE) field campaigns, a predominantly organic aerosol (> 85% by mass) was observed in the free troposphere over marine stratocumulus off the coast of California. These particles originated from a densely forested region in the Northwestern United States. The organic mass spectrum resolved by positive matrix factorization is consistent with the mass spectra of previously measured biogenic organic aerosol. Particulate organic mass exhibits a latitudinal gradient that corresponds to the geographical distribution of vegetation density and composition, with the highest concentration over regions impacted by densely populated monoterpene sources. Due to meteorological conditions during summer months, cloud-clearing events transport aerosol from the Northwestern United States into the free troposphere above marine stratocumulus. Based on the variation of meteorological variables with altitude, dry air containing enhanced biogenic organic aerosol is shown to entrain into the marine boundary layer. Fresh impacts on cloud water composition are observed north of San Francisco, CA which is consistent with fresh continental impacts on the marine atmosphere at higher latitudes. Continental aerosol size distributions are bimodal. Particles in the 100 nm mode are impacted by biogenic sources, while particles in the ∼ 30 nm mode may originate from fresh biogenic emissions. Continental aerosol in the 100 nm mode is cloud condensation nuclei active and may play a role in modulating marine stratocumulus microphysics.

Additional Information

© 2014 American Geophysical Union. Received 21 November 2013; Accepted 16 May 2014; Accepted article online 21 May 2014; Published online 11 June 2014. This work was funded by ONR grants N00014-11-1-0783, N00014-14-1-0097, and N00014-10-1-0811, and NSF grants AGS-1008848 and AGS-1013381. A.N. acknowledges support from an NSF CAREER award. J.J.L. acknowledges support from a Georgia Tech President's fellowship and a NASA Graduate Student Researchers Program Fellowship. Conclusions drawn here reflect those of the authors and do not necessarily reflect the opinions of the Office of Naval Research or the National Science Foundation. We acknowledge Dean Hegg for providing the cloud water collector and Joseph Ensberg for helpful discussion. Please contact corresponding author for data requests. AMS mass spectra will be uploaded to the spectral database (http://cires.colorado.edu/jimenez-group/AMSsd/).

Attached Files

Published - jgrd51453.pdf

Supplemental Material - CloudMovie_RF10.m4v

Supplemental Material - ReadMeFileCoggon.pdf

Supplemental Material - SI_BelowCloudBackTrajectories.pdf

Supplemental Material - SI_ExternalData.pdf

Supplemental Material - SI_FPEAKCorrelations.pdf

Supplemental Material - SI_FPEAKUncertainty.pdf

Supplemental Material - SI_Factor1And2Comparisons.pdf

Supplemental Material - SI_FactorSolnSpace.pdf

Supplemental Material - SI_PMFDiagnostics.pdf

Supplemental Material - SI_ScaledResiduals.pdf

Supplemental Material - SI_TrianglePlot.pdf

Supplemental Material - SupplementalInformation_Coggon_2013_JGR_Draft3.pdf

Supplemental Material - SupplementalInformation_Coggon_2013_JGR_Draft3.tex


Files (13.5 MB)
Name Size Download all
5.2 MB Download
74.1 kB Preview Download
211.3 kB Preview Download
460.1 kB Preview Download
27.9 kB Preview Download
109.1 kB Preview Download
5.1 MB Preview Download
42.3 kB Preview Download
29.1 kB Download
32.7 kB Preview Download
22.1 kB Preview Download
478.2 kB Preview Download
50.3 kB Preview Download
1.6 MB Preview Download

Additional details

August 22, 2023
October 26, 2023