4,477 research outputs found

    Description of SAFIRE for ISES

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    The SAFIRE (Spectroscopy of the Atmosphere using Far Infrared Emission) is a limb emission experiment using a far-IR Fourier transform spectrometer (FTS) and a mid-IR broadband multispectral radiometer covering the range 80 to 1600/cm. The purpose of this experiment is to obtain vertical distributions of temperature and key constituents of O(y), HO(y), NO(y), ClO(y), and BrO(y) families in the stratosphere, mesosphere, and thermosphere. The spectral channels and gases within each channel are summarized. The instrument includes a 48 element (6 x 8) Ge:GA detector array operating at 4 K in the far-IR and a 105 element (7 x 15) HgCdTe array operating at 80 K in the mid-IR. The SAFIRE uses four different scan modes for vertical coverage and resolution to address various scientific requirements. The SAFIRE data reduction will start with the retrieval of temperature profile as a function of pressure using two CO2 channel data. Constituent distributions then are obtained from other channel data using the retrieved temperature profile. The SAFIRE measurements are limited to the region above the tropopause because of radiance saturation by H2O and clouds. The computational capability necessary to process at the instrument data rate is estimated to be 19 MFLOPS for FTS data and 0.02 MFLOPS for radiometer data. It seems, therefore, that the real-time applications of SAFIRE data using an onboard processing device is not feasible. Although a temperature anomaly may be detected from the two CO2 radiometer channels using an onboard processor for the stratosphere, it is not possible to distinguish between CO2 outflux and temperature anomaly. Temperature anomaly does not, therefore, offer tropospheric information useful for real-time application

    Superfluid transitions in bosonic atom-molecule mixtures near Feshbach resonance

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    We study bosonic atoms near a Feshbach resonance, and predict that in addition to a standard normal and atomic superfluid phases, this system generically exhibits a distinct phase of matter: a molecular superfluid, where molecules are superfluid while atoms are not. We explore zero- and finite-temperature properties of the molecular superfluid (a bosonic, strong-coupling analog of a BCS superconductor), and study quantum and classical phase transitions between the normal, molecular superfluid and atomic superfluid states.Comment: 4 revtex pages, 3 eps figures; submitted to PR

    Stratospheric measurements of continuous absorption near 2400 cm^-1

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    Solar occultation spectra obtained with a balloon-borne interferometer have been used to study continuous absorption by N2 and CO2 near 2400 cm^-1 in the lower stratosphere. Synthetic continuum transmittances, calculated from published coefficients for far-wing absorption by CO2 lines and for pressure-induced absorption by the fundamental band of N2, are in fair agreement with the observed stratospheric values. The continuum close to the ν3 R-branch band head of CO2 is sensitive to the CO2 far-wing line shape. Therefore, given highly accurate knowledge of the N2 continuum from laboratory data, high-resolution stratospheric spectra provide a sensitive means for in situ testing of various air-broadened CO2 line shapes at low temperatures
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