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Douglas N. Yarger

Abstract

Three methods for estimating the vertical distribution of ozone below 10 mb, by inverting the equation of radiative transfer, are presented. The methods are discussed in terms of spectral measurements of back-scattered ultraviolet radiation and allow for all orders of scattering, as well as polarization of the diffusely reflected sunlight. These methods are compared with a statistical method for both 0% and 5% random measurement errors. There were no significant improvements using methods based on the inversion of the radiative transfer equation compared with the statistical method.

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Benjamin M. Herman and Douglas N. Yarger

Abstract

A method of estimating the vertical distribution of ozone by inverting the equation of radiative transfer is presented. The method allows for all orders of scattering as well as polarization of the diffusely reflected sunlight. The information content of the reflected sunlight as a function of observation angle is examined for the case where perfect measurements are assumed, and also for the case where a 1% random error is introduced into the measurements. Inversion results utilizing simulated satellite measurements are presented for several different ozone soundings.

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Daniel J. Hancock and Douglas N. Yarger

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William D. Sellers and Douglas N. Yarger

Abstract

Total ozone amounts and spectral measurements of backscattered ultraviolet radiation received by a satellite are used as statistical predictors of the vertical ozone distribution at Boulder, Colo. The distribution is represented 1) by the actual partial pressures at 42 atmospheric levels and 2) by eigenvectors. Both approaches yield essentially identical results, explaining 45% of the total variance of 72 dependent ozone soundings and 30% of the variance of 11 independent soundings. For the independent data, little improvement is achieved by adding the spectral measurements to total ozone as the single predictor.

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Daniel J. Hancock and Douglas N. Yarger

Abstract

The finite Fourier transform method of cross-spectral analysis is used to investigate the relationship between the Zurich annual sunspot number and state monthly mean temperature and precipitation derived from the Climatological Observation Network data for most of the continuous United States. Both the single (∼11 year) and the double (∼21 year) sunspot cycles are investigated. Our analyses show statistically significant relationships between the double sunspot cycle and the “January thaw” phenomenon along the East Coast and between the double sunspot cycle and “drought” (June temperature and precipitation) in the Midwest.

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Benjamin M. Herman and Douglas N. Yarger

Abstract

The effects of multiple scattering on the heating rates in the ozone layer are investigated. Computations are performed for two wavelengths, one rather highly absorbing, λ=3112 Å, and one rather weakly absorbing, λ=3323 Å, and for three solar elevation angles. These results are compared with heating rates computed on the basis of a Beer's law type of exponential absorption, neglecting all scattering. It is shown that, at the weakly absorbing wavelength, and for small zenith angles, the effect of scattering is such as to increase the heating rate by about 40 per cent. At the more highly absorbing wavelength, scattering effects are small and may safely be neglected.

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William A. Gallus Jr., Douglas N. Yarger, and Daryl E. Herzmann

An interactive Web-based severe weather activity has been developed at Iowa State University with broad applications to motivate student learning. The exercise uses an extensive archive of weather data emphasizing warm-season severe convective events and cold-season winter storms. Several variations of the activity have been developed based upon the meteorological background of students. The flexible design of the activity may allow for its use in K–12 settings, or as a significant training tool for weather forecasters outside the classroom.

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Douglas N. Yarger, William A. Gallus Jr., Michael Taber, J. Peter Boysen, and Paul Castleberry

A large lecture introductory course at Iowa State University has used a forecasting activity since 1993 to actively engage students in doing science. This automatically scored Web-based activity requires students to evaluate selected weather parameters and to also select appropriate physical reasons for their values. Participants can select from more than 1000 cities in the United States for their forecast city. This activity engages students in doing what practicing meteorologists do. Further, forecast scores demonstrate increased understanding throughout the course. Design considerations were based on constructivist learning theory in order to address goals articulated by national panels; to promote problem solving, collaboration, and communication skills by being involved in scientific inquiry.

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