Water vapor channel imagery from NOAA GOES-12 (above, left) and GOES-08 (above, right) revealed a distinct pattern of mountain waves over the mid-Atlantic states on 04 February 2003. Mountain waves are often a signature of atmospheric turbulence, and in this case there were several pilot reports of moderate to severe turbulence over that particular region.
A 3-panel comparison of re-mapped water vapor channel data from GOES-08, GOES-12, and Terra MODIS (below, left) shows that the mountain wave signature is better resolved using GOES-12 and MODIS. The 6.5 micrometer GOES-12 water vapor channel has improved spatial resolution (4 km) and is a spectrally wider channel, which contributes to better mountain wave detection compared to the 6.7 micrometer GOES-08 water vapor channel (8 km resolution). The superior spatial resolution (1 km) of the MODIS data offers an additional advantage in detecting the full areal coverage of the mountain waves in this case. Water vapor channel weighting functions calculated for GOES-08 and GOES-12 (below, right) using the morning rawinsonde data from Nashville, TN show that the GOES-12 water vapor channel should sense a brightness temperature about 1.4 K warmer than GOES-08. This is in agreement with the observed satellite brightness temperatures averaged over a 30x30 pixel region along the Virginia/North Carolina border (the red squares on the 3-panel water vapor comparison). GOES-12 will be replacing GOES-08 as the operational GOES-East satellite in April 2003.