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Title: Large Contribution of Coarse Mode to Aerosol Microphysical and Optical Properties: Evidence from Ground-Based Observations of a Transpacific Dust Outbreak at a High-Elevation North American Site

Authors:
 [1];  [1];  [1];  [1];  [1];  [1];  [1];  [1];  [1];  [1];  [1];  [2];  [3];  [3];  [4];  [5];  [1]
  1. Pacific Northwest National Laboratory, Richland, Washington
  2. University of Nevada, Reno, Nevada
  3. Storm Peak Laboratory, Desert Research Institute, Steamboat Springs, Colorado
  4. University of Wisconsin–Madison, Madison, Wisconsin
  5. National Oceanic and Atmospheric Administration, Boulder, Colorado
Publication Date:
Sponsoring Org.:
USDOE
OSTI Identifier:
1351708
Resource Type:
Journal Article: Published Article
Journal Name:
Journal of the Atmospheric Sciences
Additional Journal Information:
Journal Volume: 74; Journal Issue: 5; Related Information: CHORUS Timestamp: 2017-04-17 15:26:23; Journal ID: ISSN 0022-4928
Publisher:
American Meteorological Society
Country of Publication:
United States
Language:
English

Citation Formats

Kassianov, E., Pekour, M., Flynn, C., Berg, L. K., Beranek, J., Zelenyuk, A., Zhao, C., Leung, L. R., Ma, P. L., Riihimaki, L., Fast, J. D., Barnard, J., Hallar, A. G., McCubbin, I. B., Eloranta, E. W., McComiskey, A., and Rasch, P. J.. Large Contribution of Coarse Mode to Aerosol Microphysical and Optical Properties: Evidence from Ground-Based Observations of a Transpacific Dust Outbreak at a High-Elevation North American Site. United States: N. p., 2017. Web. doi:10.1175/JAS-D-16-0256.1.
Kassianov, E., Pekour, M., Flynn, C., Berg, L. K., Beranek, J., Zelenyuk, A., Zhao, C., Leung, L. R., Ma, P. L., Riihimaki, L., Fast, J. D., Barnard, J., Hallar, A. G., McCubbin, I. B., Eloranta, E. W., McComiskey, A., & Rasch, P. J.. Large Contribution of Coarse Mode to Aerosol Microphysical and Optical Properties: Evidence from Ground-Based Observations of a Transpacific Dust Outbreak at a High-Elevation North American Site. United States. doi:10.1175/JAS-D-16-0256.1.
Kassianov, E., Pekour, M., Flynn, C., Berg, L. K., Beranek, J., Zelenyuk, A., Zhao, C., Leung, L. R., Ma, P. L., Riihimaki, L., Fast, J. D., Barnard, J., Hallar, A. G., McCubbin, I. B., Eloranta, E. W., McComiskey, A., and Rasch, P. J.. 2017. "Large Contribution of Coarse Mode to Aerosol Microphysical and Optical Properties: Evidence from Ground-Based Observations of a Transpacific Dust Outbreak at a High-Elevation North American Site". United States. doi:10.1175/JAS-D-16-0256.1.
@article{osti_1351708,
title = {Large Contribution of Coarse Mode to Aerosol Microphysical and Optical Properties: Evidence from Ground-Based Observations of a Transpacific Dust Outbreak at a High-Elevation North American Site},
author = {Kassianov, E. and Pekour, M. and Flynn, C. and Berg, L. K. and Beranek, J. and Zelenyuk, A. and Zhao, C. and Leung, L. R. and Ma, P. L. and Riihimaki, L. and Fast, J. D. and Barnard, J. and Hallar, A. G. and McCubbin, I. B. and Eloranta, E. W. and McComiskey, A. and Rasch, P. J.},
abstractNote = {},
doi = {10.1175/JAS-D-16-0256.1},
journal = {Journal of the Atmospheric Sciences},
number = 5,
volume = 74,
place = {United States},
year = 2017,
month = 5
}

Journal Article:
Free Publicly Available Full Text
This content will become publicly available on April 17, 2018
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  • Our work is motivated by previous studies of the long-range trans-Atlantic transport of Saharan dust and the observed quasi-static nature of coarse mode aerosol with a volume median diameter (VMD) of approximately 3.5 µm. We examine coarse mode contributions from the trans-Pacific transport of Asian dust to North American aerosol microphysical and optical properties using a dataset collected at the high-elevation, mountain-top Storm Peak Laboratory (SPL, 3.22 km above sea level [ASL]) and the nearby Atmospheric Radiation Measurement (ARM) Mobile Facility (AMF, 2.76 km ASL). Data collected during the SPL Cloud Property Validation Experiment (STORMVEX, March 2011) are complemented bymore » quasi-global high-resolution model simulations coupled with aerosol chemistry. We identify dust event associated mostly with Asian plume (about 70% of dust mass) where the coarse mode with moderate (~4 µm) VMD is distinct and contributes substantially to aerosol microphysical (up to 70% for total volume) and optical (up to 45% for total scattering and aerosol optical depth) properties. Our results, when compared with previous Saharan dust studies, suggest a fairly invariant behavior of coarse mode dust aerosols. If confirmed in additional studies, this invariant behavior may simplify considerably model parameterizations for complex and size-dependent processes associated with dust transport and removal.« less
  • Comprehensive surface - based retrievals of cloud optical and microphysical properties were made at Taihu, a highly polluted site in central Yangtze Delta region, during a research campaign from May 2008 to December 2009. C loud optical depth (COD) , effective radius (R e ) and liquid water path (LWP) were retrieved from measurements made with a suite of ground - based and space - borne instruments, including an Analytical Spectral Devices (ASD) spectroradiometer , a Multi - Filter Rotating Shadowband R adiometer (MFRSR) , a Multichannel Microwave Radiometer Profiler (MWRP), and the Moderate Resolution Imaging Spectroradiometer ( MODIS) onmore » Terra and Aqua satellites . Retrievals from zenith radiance measurements capture better the temporal variation of cloud properties than do retrievals from hemispherical fluxes . Annual mean LWP, COD and R e are 115.8 ± 90.8 g/m 2 , 28.5 ± 19.2, and 6.9 ± 4.2 μ m . Over 90% of LWP is less than 250 g/m 2 . Most of COD (>90%) fall s between 5 and 60 and ~ 80% of R e is less than 10 μ m . Maximum ( minimum ) values of LWP and R e occur in summer ( winter ); COD is highest in winter and spring. R aining and non - raining clouds have significant difference s in LWP, COD and R e . R ainfall frequency i s best correlated with LWP, followed by COD and R e . Cloud properties retrieved from multiple ground - based instruments are also compared with those from satellite retrievals. On average, relative to surface retrievals, mean differences of satellite retrievals in cloud LWP, COD and R e were - 33.6 g/m 2 ( - 26.4%), - 5.8 ( - 31.4%), and 2.9 μ m (29.3% ) for 11 MODIS - Terra overpasses , and - 43.3 g/m 2 ( - 2 2.3 %), - 3.0 ( - 10.0 %) and - 1.3 μ m ( - 12.0 %) for 8 MODIS - Aqua 40 overpasses, respectively. These discrep ancies indicate that MODIS cloud products still suffer 41 from large uncertainties in this region« less
  • The majority of previous studies dealing with effect of coarse-mode aerosols on the radiation budget have focused primary on polluted regions with substantial aerosol loadings. We reexamine this effect for a relatively "pristine" area using a unique 1-month dataset collected during recent Carbonaceous Aerosol and Radiative Effects Study (CARES). We demonstrate that the coarse-mode (supermicron) particles can contribute substantially (more than 50%) and frequently (up to 85% of time) to the total volume. In contrast to the conventional expectations that the radiative impact of coarse-mode aerosols should be small for "pristine" regions, we find that the neglecting of the largemore » particles may lead to significant overestimation (up to 45%) of direct aerosol radiative forcing at the top-of atmosphere despite of very small aerosol optical depth (about 0.05 at 0.5 ). Our findings highlight the potential for widespread impacts of the coarse-mode aerosols on the pristine radiative properties over land and the need for more explicit inclusion of the coarse-mode aerosols in climate-related observational and model studies.« less
  • Measurements of aerosol properties from aircraft, satellite and ground-based remote sensing: A case study from the Dust and Biomass burning Experiment (DABEX)
  • In this paper aerosol size distributions retrieved from aerosol layer optical thickness spectra, derived from the 14-channel NASA Ames Airborne Tracking Sunphotometer (AATS-14) measurements during the ACE-Asia campaign, are presented. Focusing on distinct aerosol layers (with different particle characteristics) observed in four vertical profiles, we compare the results of two different retrieval methods: constrained linear inversion and a non-linear least squares method. While the former does not use any assumption about the analytical form of the size distribution, the latter was used to retrieve parameters of a bimodal lognormal size distribution. Furthermore, comparison of the retrieved size distributions with thosemore » measured in-situ, aboard the same aircraft on which the sunphotometer was flown, was carried out. Results of the two retrieval methods showed good agreement in the radius ranges from ~0.1μm to ~1.2-2.0μm, close to the range of retrievable size distributions from the AATS-14 measurements. In this radius interval, shapes of retrieved and measured size distributions were similar, in accord with close wavelength dependencies of the corresponding optical thicknesses. Additionally, the effect of a size-resolved refractive index on the retrieved size spectra was investigated in selected cases. Retrieval using a constant refractive index pertaining to particle sizes within the range of retrievable size distributions resulted in a size distribution very close to the one retrieved using a size-resolved refractive index.« less