MODTRAN3: Suitability as a flux-divergence code
- Phillips Lab., Hanscom Air Force Base, MA (United States)
- and others
The Moderate Resolution Atmospheric Radiance and Transmittance Model (MODTRAN3) is the developmental version of MODTRAN and MODTRAN2. The Geophysics Directorate, Phillips Laboratory, released a beta version of this model in October 1994. It encompasses all the capabilities of LOWTRAN7, the historic 20 cm{sup -1} resolution (full width at half maximum, FWHM) radiance code, but incorporates a much more sensitive molecular band model with 2 cm{sup -1} resolution. The band model is based directly upon the HITRAN spectral parameters, including both temperature and pressure (line shape) dependencies. Validation against full Voigt line-by-line calculations (e.g., FASCODE) has shown excellent agreement. In addition, simple timing runs demonstrate potential improvement of more than a factor of 100 for a typical 500 cm{sup -1} spectral interval and comparable vertical layering. Not only is MODTRAN an excellent band model for {open_quotes}full path{close_quotes} calculations (that is, radiance and/or transmittance from point A to point B), but it replicates layer-specific quantities to a very high degree of accuracy. Such layer quantities, derived from ratios and differences of longer path MODTRAN calculations from point A to adjacent layer boundaries, can be used to provide inversion algorithm weighting functions or similarly formulated quantities. One of the most exciting new applications is the rapid calculation of reliable IR cooling rates, including species, altitude, and spectral distinctions, as well as the standard spectrally integrated quantities. Comparisons with prior line-by-line cooling rate calculations are excellent, and the techniques can be extended to incorporate global climatologies of both standard and trace atmospheric species.
- Research Organization:
- USDOE Office of Energy Research, Washington, DC (United States). Environmental Sciences Div.
- OSTI ID:
- 83157
- Report Number(s):
- CONF-940277-; ON: DE95009951; TRN: 95:003626-0016
- Resource Relation:
- Conference: Atmospheric radiation measurement science team meeting, Charleston, SC (United States), 28 Feb - 3 Mar 1994; Other Information: PBD: Apr 1995; Related Information: Is Part Of Proceedings of the Fourth Atmospheric Radiation Measurement (ARM) Science Team Meeting; PB: 373 p.
- Country of Publication:
- United States
- Language:
- English
Similar Records
Very narrow band model calculations of atmospheric fluxes and cooling rates
Line-by-line calculations of atmospheric fluxes and cooling rates: Application to water vapor