This paper describes the contents of the 2016 edition of the HITRAN molecular spectroscopic compilation. The new edition replaces the previous HITRAN edition of 2012 and its updates during the intervening years. The HITRAN molecular absorption compilation is composed of five major components: the traditional line-by-line spectroscopic parameters required for high-resolution radiative-transfer codes, infrared absorption cross-sections for molecules not yet amenable to representation in a line-by-line form, collision-induced absorption data, aerosol indices of refraction, and general tables such as partition sums that apply globally to the data. The new HITRAN is greatly extended in terms of accuracy, spectral coverage, additional absorption phenomena, added line-shape formalisms, and validity. Moreover, molecules, isotopologues, and perturbing gases have been added that address the issues of atmospheres beyond the Earth. Of considerable note, experimental IR cross-sections for almost 300 additional molecules important in different areas of atmospheric science have been added to the database. The compilation can be accessed through www.hitran.org. Most of the HITRAN data have now been cast into an underlying relational database structure that offers many advantages over the long-standing sequential text-based structure. The new structure empowers the user in many ways. It enables the incorporation of an extended set of fundamental parameters per transition, sophisticated line-shape formalisms, easy user-defined output formats, and very convenient searching, filtering, and plotting of data. A powerful application programming interface making use of structured query language (SQL) features for higher-level applications of HITRAN is also provided.

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The HITRAN 2008 molecular spectroscopic database

A rapid and accurate radiative transfer model (RRTM) for climate applications has been developed and the results extensively evaluated. The current version of RRTM calculates fluxes and cooling rates for the longwave spectral region (10–3000 cm−1) for an arbitrary clear atmosphere. The molecular species treated in the model are water vapor, carbon dioxide, ozone, methane, nitrous oxide, and the common halocarbons. The radiative transfer in RRTM is performed using the correlated-k method: the k distributions are attained directly from the LBLRTM line-by-line model, which connects the absorption coefficients used by RRTM to high-resolution radiance validations done with observations. Refined methods have been developed for treating bands containing gases with overlapping absorption, for the determination of values of the Planck function appropriate for use in the correlated-k approach, and for the inclusion of minor absorbing species in a band. The flux and cooling rate results of RRTM are linked to measurement through the use of LBLRTM, which has been substantially validated with observations. Validations of RRTM using LBLRTM have been performed for the midlatitude summer, tropical, midlatitude winter, subarctic winter, and four atmospheres from the Spectral Radiance Experiment campaign. On the basis of these validations the longwave accuracy of RRTM for any atmosphere is as follows: 0.6 W m−2 (relative to LBLRTM) for net flux in each band at all altitudes, with a total (10–3000 cm−1) error of less than 1.0 W m−2 at any altitude; 0.07 K d−1 for total cooling rate error in the troposphere and lower stratosphere, and 0.75 K d−1 in the upper stratosphere and above. Other comparisons have been performed on RRTM using LBLRTM to gauge its sensitivity to changes in the abundance of specific species, including the halocarbons and carbon dioxide. The radiative forcing due to doubling the concentration of carbon dioxide is attained with an accuracy of 0.24 W m−2, an error of less than 5%. The speed of execution of RRTM compares favorably with that of other rapid radiation models, indicating that the model is suitable for use in general circulation models.

https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/97JD00237

Radiative transfer for inhomogeneous atmospheres: RRTM, a validated correlated-k model for the longwave

The fourth version of the Community Climate System Model (CCSM4) was recently completed and released to the climate community. This paper describes developments to all CCSM components, and documents fully coupled preindustrial control runs compared to the previous version, CCSM3. Using the standard atmosphere and land resolution of 1° results in the sea surface temperature biases in the major upwelling regions being comparable to the 1.4°-resolution CCSM3. Two changes to the deep convection scheme in the atmosphere component result in CCSM4 producing El Nino–Southern Oscillation variability with a much more realistic frequency distribution than in CCSM3, although the amplitude is too large compared to observations. These changes also improve the Madden–Julian oscillation and the frequency distribution of tropical precipitation. A new overflow parameterization in the ocean component leads to an improved simulation of the Gulf Stream path and the North Atlantic Ocean meridional overturning circulati...

/pdf/the-community-climate-system-model-version-4-30sj6n6rru.pdf

The Community Climate System Model Version 4

Description of the NCAR Community Atmosphere Model (CAM 3.0)

SCIAMACHY (Scanning Imaging Absorption Spectrometer for Atmospheric Chartography) is a spectrometer designed to measure sunlight transmitted, reflected, and scattered by the earth’s atmosphere or surface in the ultraviolet, visible, and near-infrared wavelength region (240–2380 nm) at moderate spectral resolution (0.2–1.5 nm, λ/Δλ ≈ 1000–10 000). SCIAMACHY will measure the earthshine radiance in limb and nadir viewing geometries and solar or lunar light transmitted through the atmosphere observed in occultation. The extraterrestrial solar irradiance and lunar radiance will be determined from observations of the sun and the moon above the atmosphere. The absorption, reflection, and scattering behavior of the atmosphere and the earth’s surface is determined from comparison of earthshine radiance and solar irradiance. Inversion of the ratio of earthshine radiance and solar irradiance yields information about the amounts and distribution of important atmospheric constituents and the spectral reflecta...

/pdf/sciamachy-mission-objectives-and-measurement-modes-3hyob1r0ns.pdf

SCIAMACHY: Mission Objectives and Measurement Modes

Line shape and the water vapor continuum

A model and computer code, FASCODE1 (Fast Atmospheric Signature Code) has been developed for the line-by-line calculation of radiance and transmittance with particular applicability to the earth's atmosphere. An algorithm for the accelerated convolution of line shape functions (Lorentz, Voigt and Doppler) with spectral line data is used. The contribution from continuum absorption is included in the model. The method is described and applications of the present code, FASCOD1B, are presented.© (1981) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Atmospheric Spectral Transmittance And Radiance: FASCOD1 B

Atmospheric radiance and transmittance - FASCOD2

: Calculations of atmospheric transmittance and radiance require the knowledge of the integrated amounts of the absorbing gases along the path. This report describes the calculation of the integrated amounts ('air mass' or 'column density') for various infrared absorbing gases for an arbitrary slant path through the atmosphere, including the effects of both curvature and refraction, and presents a Fortran program. FSCATM, to perform the calculation. Among the features of FSCATM are: 1. It calculates the layer-by-layer integrated absorber amounts and density-weighted pressure and temperature for an arbitrary slant path through the atmosphere. 2. It assumes a spherically symmetric atmospheric with exponential profiles of density and refractivity between layer boundaries. 3. It allows a variety of options for specifying the slant path. 4. It includes six representative atmospheric profiles of pressure and temperature, and of density for the gases H2O, CO2, O3, N2O, CO, CH3, and O2 and has provision for user-supplied profiles of up to 20 gases. 5. The output layering may either be generated internally or supplied by the user. 6. It portable to 32 bit word computers in single precision and compatible with both ANSI Standard FORTRAN 66 and 77. 7. It is modular and easily modified to suit the users' particular needs. A discussion of atmospheric profile data and a survey of the literature are included in appendices.

F. X. Kneizys

Papers

Line shape and the water vapor continuum

Atmospheric Spectral Transmittance And Radiance: FASCOD1 B

Atmospheric radiance and transmittance - FASCOD2

Air Mass Computer Program for Atmospheric Transmittance/Radiance Calculation: FSCATM