Kelvin-Helmholtz billows: a satellite signature of turbulence potentital?

February 10th, 2013

MODIS 0.65 µm visible, 11.0 µm IR, and 6.7 µm water vapor channel images

A comparison of AWIPS images of 1-km resolution MODIS 0.65 µm visible channel, 11.0 µm IR channel, and 6.7 µm water channel data (above) revealed subtle Kelvin-Helmholtz (K-H) billow features across parts of eastern Iowa on 10 February 2013 that were only apparent in the water vapor imagery. In the vicinity of these elongated mesoscale wave signatures, there were a few pilot reports of light to moderate turbulence (primarily within the 14,000-21,000 foot altitude range).

An animation of 4-km resolution GOES-13 6.5 µm water vapor images (below) did not show any evidence of these K-H billow features within the dry slot that was wrapping around the center of a large and intense winter storm that was producing blizzard conditions from Nebraska to North Dakota.

GOES-13 6.5 µm water vapor channel images (click image to play animation)

GOES-13 6.5 µm water vapor channel images (click image to play animation)

A comparison of the 1-km resolution MODIS water vapor image with the corresponding 4-km resolution GOES-13 water vapor image (below) demonstrated the advantage of improved spatial resolution for the detection of such potentially-important mesoscale features. The slight northwestward shift of features seen on the GOES-13 water vapor image is due to parallax.

MODIS 6.7 µm and GOES-13 6.5 µm water vapor channel images

MODIS 6.7 µm and GOES-13 6.5 µm water vapor channel images