Observational evidence for the convective transport of dust over the central United States

Authors

C. A. Corr, University of New Hampshire, Durham
L. D. Ziemba, National Aeronautics and Space Administration Langley Research Center
Eric M. Scheuer, University of New Hampshire, DurhamFollow
B. E. Anderson, National Aeronautics and Space Administration Langley Research CenterFollow
A. J. Beyersdorf, National Aeronautics and Space Administration Langley Research Center
G. Chen, National Aeronautics and Space Administration Langley Research Center
E. Crosbie, National Aeronautics and Space Administration Langley Research Center
R. H. Moore, National Aeronautics and Space Administration Langley Research Center
M. Shook, National Aeronautics and Space Administration Langley Research Center
K. L. Thornhill, National Aeronautics and Space Administration Langley Research Center
E. Winstead, National Aeronautics and Space Administration Langley Research Center
R. P. Lawson, SPEC Inc.
M. C. Barth, National Center for Atmospheric Research
J. R. Schroeder, National Aeronautics and Space Administration Langley Research Center
D. R. Blake, University of California, Irvine
Jack E. Dibb, University of New Hampshire, DurhamFollow

Abstract

Bulk aerosol composition and aerosol size distributions measured aboard the DC-8 aircraft during the Deep Convective Clouds and Chemistry Experiment mission in May/June 2012 were used to investigate the transport of mineral dust through nine storms encountered over Colorado and Oklahoma. Measurements made at low altitudes (<5 km mean sea level (MSL)) in the storm inflow region were compared to those made in cirrus anvils (altitude > 9 km MSL). Storm mean outflow Ca2+ mass concentrations and total coarse (1 µm < diameter < 5 µm) aerosol volume (Vc) were comparable to mean inflow values as demonstrated by average outflow/inflow ratios greater than 0.5. A positive relationship between Ca2+, Vc, ice water content, and large (diameter > 50 µm) ice particle number concentrations was not evident; thus, the influence of ice shatter on these measurements was assumed small. Mean inflow aerosol number concentrations calculated over a diameter range (0.5 µm < diameter < 5.0 µm) relevant for proxy ice nuclei (NPIN) were ~15–300 times higher than ice particle concentrations for all storms. Ratios of predicted interstitial NPIN (calculated as the difference between inflow NPIN and ice particle concentrations) and inflow NPIN were consistent with those calculated for Ca2+ and Vc and indicated that on average less than 10% of the ingested NPIN were activated as ice nuclei during anvil formation. Deep convection may therefore represent an efficient transport mechanism for dust to the upper troposphere where these particles can function as ice nuclei cirrus forming in situ.

Department

Earth Systems Research Center

Publication Date

2-12-2016

Journal Title

Journal of Geophysical Research: Atmospheres

Publisher

American Geophysical Union (AGU)

Digital Object Identifier (DOI)

https://dx.doi.org/10.1002/2015JD023789

Document Type

Article

Recommended Citation

Corr, C. A., L. D. Ziemba, E. Scheuer, B. E. Anderson, A. J. Beyersdorf, G. Chen, E. Crosbie, R. H. Moore, M. Shook, K. L. Thornhill, E. Winstead, R. P. Lawson, M. C. Barth, J. R. Schroeder, D. R. Blake and J. E. Dibb (2016), Observational evidence for the convective transport of dust over the central United States, Journal of Geophysical Research, 121, 1306-1319, https://dx.doi.org/10.1002/2015JD023789

Rights

©2016. American Geophysical Union. All Rights Reserved.

Comments

This is an article published by AGU in Journal of Geophysical Research: Atmospheres in 2016, available online: https://dx.doi.org/10.1002/2015JD023789