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- Author or Editor: Philip A. Leighton x
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Abstract
This paper describes the current status and discuss the validity of the fluorescent particle (FP) tracer technique. Properties of the material itself, the blower generator, membrane filter, drum impactor, and Rotorod samplers, and of counting techniques, are described. The inherent and operational errors involved are evaluated, and evidence on the atmospheric diffusion, fallout and impaction, and fluorescent stability of the particles is presents. It is concluded that in the present state of development of the technique the errors, in terms of 90% confidence Intervals, are approximately ±5–10% for source strength determination, ±10–12% (if 300 particles are counted) for dosages determined by the Rotorod, and ±17–20% for dosages determined by the membrane filter sampler. The effects of atypical diffusion on the validity of the method appear to be insignificant, and fluorescence losses may be controlled by proper selection of materials. For ground releases the losses by fallout and impaction may amount to from 1% to 10% during the first few miles of travel, depending on the rate of rise of the cloud and the nature of the ground cover. For larger travel distances, if the cloud height exceeds 100 meters the fallout loss should he below 2% per hour.
Abstract
This paper describes the current status and discuss the validity of the fluorescent particle (FP) tracer technique. Properties of the material itself, the blower generator, membrane filter, drum impactor, and Rotorod samplers, and of counting techniques, are described. The inherent and operational errors involved are evaluated, and evidence on the atmospheric diffusion, fallout and impaction, and fluorescent stability of the particles is presents. It is concluded that in the present state of development of the technique the errors, in terms of 90% confidence Intervals, are approximately ±5–10% for source strength determination, ±10–12% (if 300 particles are counted) for dosages determined by the Rotorod, and ±17–20% for dosages determined by the membrane filter sampler. The effects of atypical diffusion on the validity of the method appear to be insignificant, and fluorescence losses may be controlled by proper selection of materials. For ground releases the losses by fallout and impaction may amount to from 1% to 10% during the first few miles of travel, depending on the rate of rise of the cloud and the nature of the ground cover. For larger travel distances, if the cloud height exceeds 100 meters the fallout loss should he below 2% per hour.
As part of the U.K. contribution to the international Surface Ocean-Lower Atmosphere Study, a series of three related projects—DOGEE, SEASAW, and HiWASE—undertook experimental studies of the processes controlling the physical exchange of gases and sea spray aerosol at the sea surface. The studies share a common goal: to reduce the high degree of uncertainty in current parameterization schemes. The wide variety of measurements made during the studies, which incorporated tracer and surfactant release experiments, included direct eddy correlation fluxes, detailed wave spectra, wind history, photographic retrievals of whitecap fraction, aerosolsize spectra and composition, surfactant concentration, and bubble populations in the ocean mixed layer. Measurements were made during three cruises in the northeast Atlantic on the RRS Discovery during 2006 and 2007; a fourth campaign has been making continuous measurements on the Norwegian weather ship Polarfront since September 2006. This paper provides an overview of the three projects and some of the highlights of the measurement campaigns.
As part of the U.K. contribution to the international Surface Ocean-Lower Atmosphere Study, a series of three related projects—DOGEE, SEASAW, and HiWASE—undertook experimental studies of the processes controlling the physical exchange of gases and sea spray aerosol at the sea surface. The studies share a common goal: to reduce the high degree of uncertainty in current parameterization schemes. The wide variety of measurements made during the studies, which incorporated tracer and surfactant release experiments, included direct eddy correlation fluxes, detailed wave spectra, wind history, photographic retrievals of whitecap fraction, aerosolsize spectra and composition, surfactant concentration, and bubble populations in the ocean mixed layer. Measurements were made during three cruises in the northeast Atlantic on the RRS Discovery during 2006 and 2007; a fourth campaign has been making continuous measurements on the Norwegian weather ship Polarfront since September 2006. This paper provides an overview of the three projects and some of the highlights of the measurement campaigns.
Abstract
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