For Further Reading

Finding appropriate spectroscopic data appropriate to a novel planetary atmosphere can be a real challenge. A wealth of specialized spectroscopic data can be found in the Journal of Quantitatitive Spectroscopy and Radiative Transfer. The reader is directed especially to their 2008 special issue on planetary atmospheres (see (Rothman L 2008, JQSRT doi:10.1016/j.jqsrt.2008.02.002). In addition, laboratory and theoretical spectroscopy related to planetary problems can often be found in the journal Icarus.

The HITRAN spectroscopic database is described in

• Rothman LS, et al. 2005: The HITRAN 2004 molecular spectroscopic database, J. Quant. Spectroscopy and Radiative Transfer, 96, pp 139-204.

In a book that one hopes will stick around for a while, there is always some risk in referring to specific means of obtaining digital data. The HITRAN database is so valuable, however, that it is sure to be available in some form more or less indefinitely. At the time of writing, the HITRAN data can be obtained over the Internet at the URL http://cfa-www.harvard.edu/hitran. The 1970's era Goody and Yung book on atmospheric radiation refers to obtaining the data on "AFGL tapes," an no doubt earlier books made reference to things like "punch cards" or "paper tapes." No doubt, our reference to the "Internet" will seem similarly quaint within a few years.

The HITRAN database does not include the very weak CO2 absorption lines that become important for extremely massive atmospheres such as that of Venus, and moreover, the temperature dependence data of the lines that are included becomes somewhat inaccurate at Venusian temperatures. There are two databases that extend the CO2 absorption database to cover the Venusian regime, both of which use the same data format as HITRAN. The first is the HITEMP database. At the time of writing, there is neither a convenient published document describing the database nor a generally accessible download site, but an updated version of the HITEMP database and expanded documentation are expected to be made available through the HITRAN site in the near future. In the meantime, information about the existing database can be found in

• Rothman LS, et al. 1995: HITRAN, HAWKS, and HITEMP High-Temperature Molecular Database, Proc.Soc.Photo-Optical Instrumentation Engineers 2471 105-111.

and the original version of the database can be downloaded by contacting the managers of the HITRAN site. A similar high-temperature,high-pressure database is described in

• Tashkun SA, et al. 2003: CDSD-1000, the high-temperature carbon dioxide spectroscopic databank, J. Quantitative Spectroscopy and Radiative Transfer, 82, pp 165-196.

It is available online via ftp at ftp.iao.ru/pub/CDSD-1000.

Information on the CO2 collision-induced continuum is very sparse. The modeling of the CO2 continuum used throughout this book (and incorporated in the software supplement) is based on a polynomial fit to absorption coefficients described in

• Kasting JF, Pollack JB and Crisp D 1984: Effects of high C02 levels on the surface temperature and atmospheric oxidation state of the early Earth, J. Atmos. Chem, 1, pp 403-428.

References to the laboratory measurements upon which the parameterization is based amount to one published paper, one NASA technical report, and one unpublished personal communication; these may be found in the above referenced article. Some theoretical developments, which have been incorporated in a few of the more recent representations of the far-infrared continuum, are described in

• Gruszka M and Borysow A 1997: Far Infrared Collision-Induced Absorption of CO2 for the Atmosphere of Venus at Temperatures from 200K to 800K, Icarus, 129, pp 172-177.

but there seem to have been no new laboratory measurements since those discussed in the former paper.

The collision induced continua of H2, CH4 and N2 relevant to the atmosphere of Titan are given in

• Courtin R 1988: Pressure-Induced Absorption Coefficients for Radiative Transfer Calculations in Titan's Atmosphere, Icarus, 75, pp 245-254.

Radiative transfer on gas giants is discussed in

• Guillemot T, et al 1994: Are the Giant Planets Fully Convective?, Icarus, 112, pp 337-353.

The water vapor continuum is described in the following two papers:

• Clough SA, Kneizys FX and Davies RW ,1989: Line shape and the water vapor continuum, Atmospheric Research, 23, pp 229-241.

• Grant WB,1990: Water vapor absorption coefficients in the 8-12 pm spectral region: A critical review, Applied Optics, 29, pp 451-462.

The first of these is considered the standard reference at time of writing, but one must take care in reading it, as there are a certain number of typographical errors and mislabeled figures.

The full-featured ccm radiation code is described in complete and somewhat intimidating detail as part of the general description of the NCAR Community Atmospheric Model (CAM) in NCAR Technical Note TN-464+STR, available at the time of writing at

http://www.ccsm.ucar.edu/models/atm-cam/docs/description/.

An accessible overview of an earlier version of the radiation model can be found in

• Kiehl J and Briegleb B 1992: Comparison of the Observed and Calculated Clear Sky Greenhouse-Effect - Implications for Climate Studies, J. Geophys. Res, 97 (D9), 10037-10049.

A version of this radiation code with a simple Python user interface is distributed as part of the software supplement to this book. The Python interface makes it easy to use the code to compute OLR and heating rates within a Python script, and eliminates the need for any familiarity with the FORTRAN language in which the underlying computation is written.

The correlated-k refinement of the exponential-sums approximation to the transmission function is described in

• Lacis A and Oinas V, 1991: A description of the correlated k-distribution method for modeling non-grey gaseous absorption, thermal emission and multiple scattering in vertically inhomogeneous atmospheres. J. Geophys. Res, 96, 90279063.

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