Response to comment on Rayleigh-Scattering Calculations for the Terrestrial Atmosphere.

Rayleigh optical depths that were calculated by Bucholtz represent an improvement over previous calculations (from 1.4% to 20%) because an updated depolarization factor that varied with the wavelength was used. These optical depths were obtained by integrating standard atmospheric model temperature and pressure profiles over height. This integration is a valid method for obtaining an estimate of the column density and therefore the Rayleigh optical depth, given that small errors (less than 0.7%) will be introduced because of quadrature and inaccuracies in any given model.

Direct Radiometric Observations of the Water Vapor Greenhouse Effect Over the Equatorial Pacific Ocean

Airborne radiometric measurements were used to determine tropospheric profiles of the clear sky greenhouse effect. At sea surface temperatures (SSTs) larger than 300 kelvin, the clear sky water vapor greenhouse effect was found to increase with SST at a rate of 13 to 15 watts per square meter per kelvin. Satellite measurements of infrared radiances and SSTs indicate that almost 52 percent of the tropical oceans between 20°N and 20°S are affected during all seasons. Current general circulation models suggest that the increase in the clear sky water vapor greenhouse effect with SST may have climatic effects on a planetary scale.

Rayleigh-scattering calculations for the terrestrial atmosphere.

Rayleigh-scattering cross sections and volume-scattering coefficients are computed for standard air; they incorporate the variation of the depolarization factor with wavelength. Rayleigh optical depths are then calculated for the 1962 U.S. Standard Atmosphere and for five supplementary models. Analytic formulas are derived for each of the parameters listed. The new optical depths can be 1.3% lower to 3% higher at midvisible wavelengths and up to 10% higher in the UV region compared with previous calculations, in which a constant or incorrect depolarization factor was used. The dispersion of the depolarization factor is also shown to affect the Rayleigh phase function slightly, by approximately 1% in the forward, backscattered, and 90° scattering-angle directions.

Cat-transmitted fatal pneumonic plague in a person who traveled from Colorado to Arizona.

Plague, primarily a disease of rodents and their infected fleas, is fatal in 50% of infected humans if untreated. In the United States, human cases have been concentrated in the southwest. The most common modes of plague transmission are through flea bites or through contact with infected blood or tissues; however, primary pneumonic plague acquired from cats has become increasingly recognized. We report on the case investigation of a patient, presumably exposed to a plague-infected cat in Colorado, who presented with gastrointestinal symptoms, and subsequently died of primary pneumonic plague. Public health officials should be vigilant for plague activity in rodent populations, veterinarians should suspect feline plague in ill or deceased cats, and physicians should have a high index of suspicion for plague in any person who has traveled to plague enzootic areas.

Absorption and emission line shapes in the O(2) atmospheric bands: Theoretical model and limb viewing simulations.

A multiple scattering radiative transfer model has been developed to carry out a line by line calculation of the absorption and emission limb measurements that will be made by the High Resolution Doppler Imager to be flown on the Upper Atmosphere Research Satellite. The multiple scattering model uses the doubling and adding methods to solve the radiative transfer equation, modified to take into account a spherical inhomogeneous atmosphere. Representative absorption and emission line shapes in the O(2)((1)Sigma(+)(g)-(3)Sigma(-)(g)) atmospheric bands (A, B, and gamma) and their variation with altitude are presented. The effects of solar zenith angle, aerosol loading, surface albedo, and cloud height on the line shapes are also discussed.