An image product that is easily generated from the GOES split-window bands can be used to monitor surface skin temperature. This product is a variant of GOES thermal infrared images, corrected for low-level atmospheric absorption. The small transmittance difference between the split-window bands (band 4, 10.7 um; and band 5, 12.0 um, on the GOES Imager) can be used to correct one of them for the effects of atmospheric absorption, arriving at a skin temperature product.

Atmospheric transmittance calculations for the standard mid-latitude atmosphere show that for the GOES Imager the transmittance at 10.7 um is about 0.68 and at 12.0 um it is about 0.53. This translates into a correction factor to be applied to the more transparent 10.7 um band of approximately two times the differential absorption between the two bands. The resulting product is closer to the actual skin temperature than either of the input bands.

Examples of this product generated from the split window bands of both the GOES Imager and GOES Sounder will be shown. For the Sounder a change in the atmospheric correction factor is needed due to differences in the closeness of the split-window bands. Also, the split-window difference temporarily disappears from the GOES Imager with GOES-12 and beyond, due to a change of the 12.0 um band to a more opaque 13.3 um band. A skin temperature product is not as easily generated from this larger spectral separation.

The chief use of the surface temperature product is to determine changes or boundaries in the low-level temperature. Color enhancement tables can be used to quickly quantify the surface temperature and help track changes. Variations in surface heating are inversely related to low-level moisture. Also, when compared to shelter temperatures, the skin temperature can be used to indicate the temperature lapse rate near the surface, at times indicating the presence of low-level temperature inversions.