GOES Skin Temperature

The GOES skin temperature product represents the radiative skin temperature of the earth's land or water surface. This product is generated by correcting the GOES IR window channel for atmospheric absorption effects, those mainly due to water vapor absorption. By using both the IR window channel (channel-4, 10.7 µm) and the "dirty" window (channel-5, 12.0 µm), atmospheric absorption can be estimated. The absorption is effectively determined as the temperature difference between the two window channels. This temperature difference is doubled to reflect the amount of atmospheric absorption in the window channel (based on theoretical calculations) and added back into the GOES window channel to determine a temperature without atmospheric effects. The amount of temperature correction is typically small, even when doubled, and is usually only a few degrees Celsius at most. The temperature correction can also be negative. In those cases the surface is colder than the air above the surface, as occurs in temperature inversions. The areas of negative temperature differences are the color-enhanced areas in the longwave IR difference product.