Performance of a Focused Cavity Aerosol Spectrometer for Measurements in the Stratosphere of Particle Size in the 0.06–2.0-µm-Diameter Range

Jonsson, Haflidi H.; Wilson, J. C.; Brock, C. A.; Knollenberg, Robert G.; Newton, T.R.; Dye, J. E.; Baumgardner, Darrel; Borrmann, Stephan; Ferry, G. V.; Pueschel, R. F.; Woods, David C.; Pitts, M. C.

doi:10.1175/1520-0426(1995)012<0115:poafca>2.0.co;2

Cited by 95 publications

(80 citation statements)

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“…In practice, the linear range of the chosen sensor must also cover the entire peak of the smallest signal, which is about a factor of 10 (see the next section). With this consideration, the linear range of a PMT (or a combination of two detectors, see Jonsson et al 1995) must be about 4.5 × 10 5 . Stratospheric aerosol is a mixture of sulfuric acid and water, with an index of refraction of 1.44-1.45 (Rosen and Hofmann 1986).…”

Section: Figmentioning

confidence: 99%

“…The flow rate of the air jet was 2-4 cm . A significant disadvantage of this setup is that the scattering signals show much greater variability for a given particle size (Jonsson et al 1995) than would occur with a narrow air jet transecting only the center portion of the laser beam. The variability is due to fact that the radial intensity distribution in a laser beam is close to a Gaussian.…”

Section: Laboratory Prototype Testsmentioning

confidence: 99%

“…Although simple in construction, the current configuration requires significant effort of characterization and calibration (Jonsson et al 1995). Figure 8 shows a proposed design that eliminates this shortfall.…”

Section: High-sensitivity Low-cost Particle Counter Design 143mentioning

confidence: 99%

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A High-Sensitivity Low-Cost Optical Particle Counter Design

Gao

Perring

Thornberry

et al. 2013

Aerosol Science and Technology

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We report the design of a small optical particle counter with high sensitivity and low construction cost for atmospheric aerosol measurements. Particle sensing is based on the detection of the forward scattering of laser light. The separation of the laser beam and scattered light is achieved with a novel yet simple optical system. A laboratory prototype system with a 405-nm laser and photomultiplier tube detector has successfully detected polystyrene latex particles as small as 125 nm in diameter with unit efficiency. Theoretical calculations suggest that a lower detectable size limit of 100 nm can be achieved with reduction of background scattered light. The new counter will be useful in a variety of ground-based as well as small balloon-borne applications such as vertical profiling and in situ measurement of particles from explosive volcanic eruptions.

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Section: Figmentioning

confidence: 99%

Section: Laboratory Prototype Testsmentioning

confidence: 99%

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A High-Sensitivity Low-Cost Optical Particle Counter Design

Gao

Perring

Thornberry

et al. 2013

Aerosol Science and Technology

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“…An isokinetic particle inlet (Jonsson et al, 1995) was used on the Twin Otter to sample fine particles with a diameter cut-off of a few microns. Both the measured and previously published particle size distributions show that particles of diameter below 1 micron account for nearly all the fineparticle (PM 2.5 ) mass emitted by biomass fires (Radke et al, 1991).…”

Section: Nephelometrymentioning

confidence: 99%

Emissions from forest fires near Mexico City

et al. 2007

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Abstract. The emissions of NO x (defined as NO (nitric oxide) + NO 2 (nitrogen dioxide)) and hydrogen cyanide (HCN), per unit amount of fuel burned, from fires in the pine forests that dominate the mountains surrounding Mexico City (MC) are about 2 times higher than normally observed for forest burning. The ammonia (NH 3 ) emissions are about average for forest burning. The upper limit for the mass ratio of NO x to volatile organic compounds (VOC) for these MC-area mountain fires was ∼0.38, which is similar to the NO x /VOC ratio in the MC urban area emissions inventory of 0.34, but much larger than the NO x /VOC ratio for tropical forest fires in Brazil (∼0.068). The nitrogen enrichment in the fire emissions may be due to deposition of nitrogencontaining pollutants in the outflow from the MC urban area. This effect may occur worldwide wherever biomass burning coexists with large urban areas (e.g. the tropics, southeastern US, Los Angeles Basin). The molar emission ratio of HCN to carbon monoxide (CO) for the mountain fires was 0.012±0.007, which is 2-9 times higher than widely used literature values for biomass burning. The ambient molar ratio HCN/CO in the MC-area outflow is about 0.003±0.0003.

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“…Aerosol sizes and concentrations were measured with the University of Denver nuclei mode aerosol size spectrometer (NMASS) and focused cavity aerosol spectrometer (FCAS). These instruments are described in detail elsewhere (Jonsson et al, 1995;Brock et al, 2000;Lee et al, 2003Lee et al, , 2004Young et al, 2007) and have been used for NPF studies in the upper troposphere and lower stratosphere previously (Lee et al, 2003(Lee et al, , 2004Young et al, 2007). Briefly, NMASS has five condensation nucleus counters that measure cumulative number concentrations of aerosols larger than 4, 8, 15, 30 and 60 nm, respectively.…”

Section: Nsf/ncar Gv Progressive Science Missionsmentioning

confidence: 99%

The effects of airmass history on new particle formation in the free troposphere: case studies

et al. 2008

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Abstract. Recent aircraft studies showed that new particle formation (NPF) is very active in the free troposphere. And, these observations lead to a new question: when does NPF not occur? Here, we provide case studies to show how different meteorological parameters affect NPF in the upper troposphere, using the aerosol size distributions measured at latitudes from 18 • N-52 • N and altitudes up to 14 km during the NSF/NCAR GV Progressive Science Missions. About 95% of the total samples showed the NPF feature with median number concentrations of particles with diameters from 4 to 9 nm (N 4−9 ), 288±199 cm −3 , and the total particle number concentrations with diameters from 4 to 2000 nm (N 4−2000 ), 500±259 cm −3 . Surface areas were in general very low in the free troposphere, 1.58±0.87 µm 2 cm −3 , which in part explains the high frequency of NPF measured in this region, but there was no distinctive difference in surface area for the NPF and non-NPF cases. Our case studies show that rather airmass history is more important for nucleation in this region. Weak-or non-events did not display uplifting of airmasses. On the other hand, strong NPF events were usually associated with uplifting of airmasses, although there were also NPF cases in which uplift did not occur, consistent with the previous observations (Young et al., 2007). NPF tends to easily occur in the free troposphere because of low surface areas and low temperatures (Carslaw and Kärcher, 2006), but because of the low aerosol precursors in this region, vertical motion (that can bring higher concentrations of aerosol precursors from low altitude source regions to higher altitudes) can play a critical role. Latitude dependence of new particles also shows higher particle concentrations in the midlatitude and subtropics tropopause region than in the tropics, consistent with Hermann et al. (2003).

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Performance of a Focused Cavity Aerosol Spectrometer for Measurements in the Stratosphere of Particle Size in the 0.06–2.0-µm-Diameter Range

Cited by 95 publications

References 0 publications

A High-Sensitivity Low-Cost Optical Particle Counter Design

A High-Sensitivity Low-Cost Optical Particle Counter Design

Emissions from forest fires near Mexico City

The effects of airmass history on new particle formation in the free troposphere: case studies

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