Models for Infrared Atmospheric Radiation

Tiwari, S. N.

doi:10.1016/s0065-2687(08)60321-0

Cited by 37 publications

(2 citation statements)

References 93 publications

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“…A fuller discussion of atmospheric radiative transfer is given elsewhere [e.g., Kondratyev, 1969;Tiwari, 1978].…”

Section: Radiative Transfer In the Atmospherementioning

confidence: 99%

The regional optimization of infrared measurements of sea surface temperature from space

Minnett

1990

J. Geophys. Res.

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The accuracy with which well-calibrated satellite infrared radiometers can measure sea surface temperature is limited by the validity of the correction applied for the modification of the electromagnetic radiation before it reaches the radiometer. An accurate numerical line-by-line model of the radiative transfer through the atmosphere is used to simulate measurements of the advanced very high resolution radiometer (AVHRR/2) on the NOAA series of near-polar-orbiting satellites for conditions of the region of the Greenland, Iceland, and Norwegian Sea. A set of regionally optimized zenith-angle dependent coefficients for the "split-window" algorithm is derived and its error characteristics are discussed. While the benefit of using such coefficients is demonstrated, the errors resulting from failing to account properly for seasonal changes in this particular region are shown to be relatively Slllal•. 1. 13,498 I•INNETT:OPTIMIZED SEA SURFACE TEMPERATURE MEASUREMENTS FROM SPACE SEA SURFACE TEMPERATURE RETRIEVALSIn the "thermal infrared" part of the electromagnetic spectrum, where these satellite measurements are made, the atmospheric effect is wavelength dependent (Figure 1). In practice, the algorithm for correcting for attoospheric effects in the measurement of SST takes the form of a simple linear combination of the temperatures measured in the different channels, T/: where T., is the SST measurement, ai are dimensionless coefficients, n is the number of channels, and a0 is a constant temperature [e.g., Prabhakara et al., 1974;McMillin, 1975;McMillin and Crosby, 1984].

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“…A fuller discussion of atmospheric radiative transfer is given elsewhere [e.g., Kondratyev, 1969;Tiwari, 1978].…”

Section: Radiative Transfer In the Atmospherementioning

confidence: 99%

The regional optimization of infrared measurements of sea surface temperature from space

Minnett

1990

J. Geophys. Res.

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“…Approximations must be made to simplify the calculations if •;he radiative solution is to be obtained efficiently and repeatedly for changing conditions, as it must be in atmospheric circulation and climate models. The reader is referred to Tiwari [1978] for an excellent critical review of the different line and band models for infrared absorption. The RTE calculation procedure described here was developed for use in the three-dimensional global climate model at the Goddard Institute for Space Studies [Hansen et al, 1983].…”

Section: Radiative Transfer Calculationsmentioning

confidence: 99%

On the variability of the net longwave radiation at the ocean surface

Fung¹,

Harrison²,

Lacis³

1984

Reviews of Geophysics

135

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The bulk formulae (BF) commonly used to estimate the net longwave radiation at the ocean surface (LW⇅) often give dissimilar results for given surface parameters. Because the differences are climatologically significant amounts of energy, it is important to understand the sources of these differences. We present an evaluation of the most widely used BF, in terms of the assumptions made in each, the climatic conditions on which each is based, and on the results of each compared with results computed from the full radiative transfer equation (RTE) with zonally averaged atmospheric data. The differences can best be understood through examination, using the RTE as the basic tool, of the variability of LW⇅ to variations in temperature, humidity, and cloud properties in the atmospheric column as well as at the surface. These calculations reveal that under clear sky conditions, two standard deviation perturbations of either temperature or specific humidity in the atmospheric column above the surface layer can introduce LW⇅, variations of 30–40 W/m². These variations, which would be typical of the synoptic variations of LW⇅ resulting from typical atmospheric variability, are generally greater than the differences produced by using different BF for the same surface conditions. Although the differences between BF LW⇅ and RTE LW⇅ can be large, the results from the Berliand and Anderson formulae duplicate the RTE clear sky LW⇅ to ±15 W/m² under a wide range of mean and perturbed conditions. The RTE studies also reveal that LW⇅ variations due to cloudiness effects can be very large. Low clouds can reduce LW⇅ from clear sky values by as much as 70 W/m². There is strong dependence of LW⇅ on the vertical distribution of cloud properties which renders useless, for estimating instantaneous LW⇅ under cloudy skies, the BF which do not carefully distinguish between cloud types. The accuracy of BF for climatological applications cannot be assessed without information about the geographic and temporal distributions of cloud properties. The computed sensitivity of LW⇅ to variations in the atmospheric column illustrates the type of information and the level of accuracy necessary to attain a particular level of accuracy in LW⇅. Improved remote sensing techniques and improved information about the cloud distribution statistics will lead to better estimates of LW⇅ at the ocean surface and a more realistic parameterization of cloud effects in BF.

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Radiation

Aeronomy of the Middle Atmosphere

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Models for Infrared Atmospheric Radiation

Cited by 37 publications

References 93 publications

The regional optimization of infrared measurements of sea surface temperature from space

The regional optimization of infrared measurements of sea surface temperature from space

On the variability of the net longwave radiation at the ocean surface

Radiation

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