Publication:
Comparison of in situ aerosol extinction and scattering coefficient measurements made during the Aerosol Intensive Operating Period

Loading...
Thumbnail Image
Authors
Strawa, A. W.
Elleman, R.
Hallar, A. G.
Covert, D.
Ricci, K.
Provencal, R.
Owano, T. W.
Jonsson, H.H.
Schmid, B.
Luu, A. P.
Subjects
Advisors
Date of Issue
2006
Date
2006
Publisher
Language
Abstract
In May 2003, the Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Program sponsored the Aerosol Intensive Operating Period (AIOP) which was conducted over the ARM Climate Research Facility (ACRF) in central Oklahoma. One new instrument that flew in the AIOP, called Cadenza, employed a cavity ring-down technique to measure extinction coefficient and a reciprocal nephelometer technique to simultaneously measure scattering coefficient. This instrument is described in this paper, and measurements are compared to those of conventional instrumentation. Agreement between Cadenza extinction coefficient and that derived from combining nephelometer scattering and PSAP absorption (Neph + PSAP) was excellent, about 2%. Agreement between Cadenza scattering coefficient and TSI nephelometer scattering was also excellent, about 2%, well within the uncertainty of the nephelometer and Cadenza scattering measurements. Comparisons between these instruments, made for the special case of plumes, showed that Cadenza measured extinction and scattering several percent higher on average than the Neph + PSAP and nephelometer alone. This difference is likely due to differences in the instrument response time: The response time for Cadenza is 1 s while that for the nephelometer is a minimum of 8 s. Plumes, identified as originating from Siberian biomass burning, are characterized. Composite size distributions from wing-mounted probes showed that two of the plumes had significant large particle modes that resulted in high values of the effective radius. The effect of the large particle mode was not seen in the A ° ngstro¨m coefficient calculated from the in-cabin scattering measurements because of the characteristics of the aircraft inlet.
Type
Description
Journal of Geophysical Research, Vol. 111, No. D5, D05S03
The article of record as published may be located at http://dx.doi.org/10.1029/2005JD006056.
Series/Report No
Department
Center for Interdisciplinary Remotely Piloted Aircraft Studies (CIRPAS)
Organization
Identifiers
NPS Report Number
Sponsors
Funder
Format
Citation
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.
Collections