Determination of size-dependent dry particle deposition velocities with multiple intrinsic elemental tracers. Caffrey, P., F., Ondov, J., M., Zufall, M., J., & Davidson, C., I. Environ. Sci. Technol., 32:1615-1622, 1998.
abstract   bibtex   
Dry deposition flux and aerosol size distribution measurements were made concurrently aboard the RV Lake Guardian 19 km east of the Chicago shoreline during summer 1994 to assess atmospheric inputs of minor and trace elements to southern Lake Michigan. Size-segregated aerosol measurements were made over consecutive 12-h periods with Micro-Orifice and Noll Rotary impacters (MOI and NRI), and depositing-particulate collections to aerodynamically smooth airfoils were made over periods of 3-4 days. The combination of the MOI and NRI provided size-segregated particulate samples in 12 discrete intervals between 0.059 and, nominally, 100 mu m. The samples were analyzed for As, Ca, Mg, Se, Sb, V, and Zn by instrumental neutron activation analysis and for S by X-ray-fluorescence. Aerosol and deposition data for individual elemental constituents were fit with a chemical mass balance deposition (CMBD) model in which a set of particle-size-specific deposition velocities (V-d), best reconciling the deposition data, were determined by iterative (constrained) solution of a series of six linear equations using the Levenberg-Marquardt method. Under stable conditions and mean wind speed of 4.0 m s(-1), minimum V-d values for particles with physical diameters between 0.09 and 0.53 mu m averaged 0.006 +/- 0.005 cm s(-1), wherein uncertainties were determined by Monte Carlo analysis. This agrees favorably with Values determined by microscopy for which uncertainties were much larger and with those predicted by the Williams model for the same period. The results suggest that physically significant V-d values are obtainable from a constrained CMBD model. C1 Univ Maryland, Dept Chem & Biochem, College Pk, MD 20742 USA. Carnegie Mellon Univ, Dept Civil & Environm Engn, Pittsburgh, PA 15213 USA.
@article{
 title = {Determination of size-dependent dry particle deposition velocities with multiple intrinsic elemental tracers},
 type = {article},
 year = {1998},
 pages = {1615-1622},
 volume = {32},
 id = {8d04e31c-c0be-3055-9171-4000fade2fcd},
 created = {2014-10-08T16:28:18.000Z},
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 profile_id = {363623ef-1990-38f1-b354-f5cdaa6548b2},
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 last_modified = {2017-03-14T17:32:24.802Z},
 read = {false},
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 authored = {false},
 confirmed = {true},
 hidden = {false},
 citation_key = {Caffrey:EST:1998a},
 source_type = {article},
 private_publication = {false},
 abstract = {Dry deposition flux and aerosol size distribution
measurements were made concurrently aboard the RV Lake Guardian 19
km east of the Chicago shoreline during summer 1994 to assess
atmospheric inputs of minor and trace elements to southern Lake
Michigan. Size-segregated aerosol measurements were made over
consecutive 12-h periods with Micro-Orifice and Noll Rotary
impacters (MOI and NRI), and depositing-particulate collections to
aerodynamically smooth airfoils were made over periods of 3-4 days.
The combination of the MOI and NRI provided size-segregated
particulate samples in 12 discrete intervals between 0.059 and,
nominally, 100 mu m. The samples were analyzed for As, Ca, Mg, Se,
Sb, V, and Zn by instrumental neutron activation analysis and for S
by X-ray-fluorescence. Aerosol and deposition data for individual
elemental constituents were fit with a chemical mass balance
deposition (CMBD) model in which a set of particle-size-specific
deposition velocities (V-d), best reconciling the deposition data,
were determined by iterative (constrained) solution of a series of
six linear equations using the Levenberg-Marquardt method. Under
stable conditions and mean wind speed of 4.0 m s(-1), minimum V-d
values for particles with physical diameters between 0.09 and 0.53
mu m averaged 0.006 +/- 0.005 cm s(-1), wherein uncertainties were
determined by Monte Carlo analysis. This agrees favorably with
Values determined by microscopy for which uncertainties were much
larger and with those predicted by the Williams model for the same
period. The results suggest that physically significant V-d values
are obtainable from a constrained CMBD model.
C1 Univ Maryland, Dept Chem & Biochem, College Pk, MD 20742 USA.
Carnegie Mellon Univ, Dept Civil & Environm Engn, Pittsburgh, PA
15213 USA.},
 bibtype = {article},
 author = {Caffrey, P F and Ondov, J M and Zufall, M J and Davidson, C I},
 journal = {Environ. Sci. Technol.}
}
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