Hold the left mouse button down as you drag the slider above the image (or use the arrow buttons) to fade between the GOES-8 Sounder water vapor channel weighting functions calculated using the Minneapolis MN rawinsonde profile from 12:00 UTC on 29 March 1999. Due to the very low concentrations of water vapor within the tropospheric column on this day, the weighting function curves for Sounder channels 10 (7.5um), 11 (7.0 um), and 12 (6.5 um) were shifted to much lower pressure levels than would be found in a more moist "standard atmosphere".