23 research outputs found
Rapid computation of the Voigt profile
A computational procedure is described to evaluate the Voigt function with a maximum relative error of about one part in 104, for use in line-by-line transmittance calculations and other applications. An efficient Fortran IV subprogram is given in the Appendix.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/21744/1/0000137.pd
The significance of detailed structure in the boundary layer to thermal radiation at the surface in climate models
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95310/1/grl7683.pd
Wavelet analysis and visualization of the formation and evolution of low total ozone events over northern Sweden
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95037/1/grl9462.pd
Remote sounding of tropospheric minor constituents
The etalon interferometer, or Fabry-Perot interferometer (FPI), with its high throughput and high spectral resolution was widely used in the remote-sensing measurements of the earth's atmospheric composition, winds, and temperatures. The most recent satellite instruments include the Fabry-Perot interferometer flown on the Dynamics Explorer-2 (DE-2) and the High Resolution Doppler Imager (HRDI) to be flown on the Upper Atmosphere Research Satellite (UARS). These instruments measure the Doppler line profiles of the emission and absorption of certain atmospheric species (such as atomic oxygen) in the visible spectral region. The successful space flight of DE-FPI and the test and delivery of UARS-HRDI demonstrated the extremely high spectral resolution and ruggedness of the etalon system for the remote sensing of earth and planetary atmospheres. Recently, an innovative FPI focal plane detection technique called the Circle-to-Line Interferometer Optical (CLIO) system was invented at the Space Physics Research Laboratory (SPRL). The CLIO simplifies the FPI focal plane detection process by converting the circular rings or fringes into a linear pattern similar to that produced by a conventional spectrometer, while retaining the throughput advantage of the etalon interferometer. CLIO makes the use of linear array detectors more practical and efficient with FPI, the combination of FPI and CLIO represents a very promising new technique for the remote sensing of the lower atmospheres of Earth, Mars, Venus, Neptune, and other planets. The Multiorder Etalon Spectrometer (MOES), as a combination of the rugged etalon and the CLIO, compares very favorably to other spaceborne optical instruments in terms of performance versus complexity. The feasibility of an advanced etalon spectrometer for the remote sensing of tropospheric trace species, particularly carbon monoxide (CO), nitrous oxide (N2O), and methane (CH4) was discussed. The etalon atmospheric spectroscopy techniques are described, instrument design and related technical issues are discussed. The primary objective is to establish the concept of atmospheric spectroscopy with the CLIO and etalon system and its applications for the measurements of tropospheric trace species analyze system requirements and performance, determine the feasibility of components and subsystem implementation with available technology, and develop inversion algorithm for retrieval simulation and data analysis
Rapid computation of the radiative absorption rate in the v3 mode of mesospheric and lower thermospheric ozone
We have developed an algorithm to calculate rapidly and accurately the rate (photons-molecule-1-sec-1) at which the ozone v3 fundamental band absorbs i.r. radiation in the terrestrial upper mesosphere and lower thermosphere. Accurate knowledge of this rate is essential for studies of non-LTE processes in ozone and for estimating ozone concentrations from measurements of non-LTE i.r. emission from the middle atmosphere. In our algorithm, the 1252 ozone v3 fundamental lines that govern radiative absorption are divided into 13 groups according to line strength. The absorption rate due to a single line representative of the mean line strength of each group is then calculated. The total absorption rate is obtained by multiplying the absorption rate for each mean line by the total number of lines within each group and adding the resultant products for all 13 groups. We also incorporate several other approximations, such as assuming that each mean line has the same Voigt line shape, which significantly reduces the number of Voigt function evaluations. The algorithm preserves the accuracy of detailed, time-consuming line-by-line approaches while requiring only a fraction of the CPU time of such techniques.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/29065/1/0000098.pd
Observations of aerosol by the HALOE Experiment onboard UARS: A preliminary validation
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/94744/1/grl6692.pd
Haloe Antarctic observations in the spring of 1991
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95167/1/grl6630.pd
Polynomial approximations of exponential integrals
A method is described to calculate polynomial approximations for exponential integrals. Tables of coefficients are presented for exponential integrals of the second, third and fourth order, which allow their rapid evaluation to an absolute accuracy of about 1 x 10-7.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/33109/1/0000495.pd
Investigation of atmospheric absorption for remote sensing applications : final report
http://deepblue.lib.umich.edu/bitstream/2027.42/4656/5/bab4394.0001.001.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/4656/4/bab4394.0001.001.tx
Errors in atmospheric temperature structure solutions from remote radiometric measurements : technical report
http://deepblue.lib.umich.edu/bitstream/2027.42/4652/5/bab8961.0001.001.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/4652/4/bab8961.0001.001.tx