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Temperature sensitivity of differential absorption lidar measurements of water vapor in the 720-nm region

Applied Optics (Impact Factor: 1.78). 04/1991; 30(12):1517-24. DOI: 10.1364/AO.30.001517
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ABSTRACT Recently measured properties of water vapor (H(2)O) absorption lines have been used in calculations to evaluate the temperature sensitivity of differential absorption lidar (DIAL) H(2)O measurements. This paper estimates the temperature sensitivity of H(2)O lines in the 717-733-nm region for both H(2)O mixing ratio and number density measurements, and discusses the influence of the H(2)O line ground state energies E'', the H(2)O absorption linewidths, the linewidth temperature dependence parameter, and the atmospheric temperature and pressure variations with altitude and location on the temperature sensitivity calculations. Line parameters and temperature sensitivity calculations for sixty-seven H(2)O lines in the 720-nm band are given which can be directly used in field experiments. Water vapor lines with E'' values in the 100-300-cm(-1) range were found to be optimum for DIAL measurements of H(2)O number densities, while E'' values in the 250-500-cm(-1) range were found to be optimum for H(2)O mixing ratio measurements.

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Available from: Edward V. Browell, Aug 20, 2015
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    • "The evaluation of the temperature sensitivities of water vapor absorption lines in the 820–840-nm spectral region were studied using the methods presented by Browell et al. (1991), leading to the selection of this water vapor absorption line for number density profiles at 828.187 nm (vacuum) (the online wavelength). A summary of the water vapor DIAL transmitter and the receiver specifications are shown in Table 2, where the laser transmitter requirements for accurate water vapor profiling are also shown for comparison. "
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    ABSTRACT: Coordinated observational data of atmospheric aerosols were collected over a 24-h period between 2300 mountain daylight time (MDT) on 27 August 2009 and 2300 MDT on 28 August 2009 at Bozeman, Montana (45.66 degrees N, 111.04 degrees W, elevation 1530 m) using a collocated two-color lidar, a diode-laser-based water vapor differential absorption lidar (DIAL), a solar radiometer, and a ground-based nephelometer. The optical properties and spatial distribution of the atmospheric aerosols were inferred from the observational data collected using the collocated instruments as part of a closure experiment under dry conditions with a relative humidity below 60%. The aerosol lidar ratio and aerosol optical depth retrieved at 532 and 1064 nm using the two-color lidar and solar radiometer agreed with one another to within their individual uncertainties while the scattering component of the aerosol extinction measured using the nephelometer matched the scattering component of the aerosol extinction retrieved using the 532-nm channel of the two-color lidar and the single-scatter albedo retrieved using the solar radiometer. Using existing aerosol models developed with Aerosol Robotic Network (AERONET) data, a thin aerosol layer observed over Bozeman was most likely identified as smoke from forest fires burning in California; Washington; British Columbia, Canada; and northwestern Montana. The intrusion of the thin aerosol layer caused a change in the atmospheric radiative forcing by a factor of 1.8 +/- 0.5 due to the aerosol direct effect.
    Journal of Atmospheric and Oceanic Technology 03/2011; 28(3):320-336. DOI:10.1175/2010JTECHA1463.1 · 1.82 Impact Factor
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    • "Our procedure for selecting a water vapor absorption line closely followed the methods of Browell et al., 1991 [41]. Temperature sensitivity analysis involves calculating the error in the absorption cross section with temperature, dσ/dT [cm 2 /K], where σ = KV [cm 2 ], across a range of temperatures, pressures, and ground-state transitional energies, E " [cm -1 ]. "
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    • "). The temperature sensitivity for the number density measurement is calculated using the expression (Browell et al. 1991) "
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