![\"GOES-15](\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-content\/uploads\/sites\/5\/2017\/05\/170523_goes15_water_vapor_pireps_anim.gif\")
<\/a>GOES-15 Water Vapor (6.5 \u00b5m) images, with pilot reports of turbulence [click to play animation]<\/p><\/div>An interesting linear feature appeared over the East Pacific Ocean on GOES-15 (GOES-West)<\/em> Water Vapor (6.5 \u00b5m) images (above)<\/strong><\/em> on 23 May 2017, which at first glance immediately nominated it for the “What the heck is this?” blog category. A contrail was ruled out, since it was not oriented along a common or busy flight route — so potential large-scale dynamic processes were briefly investigated. Since the linear feature was perpendicular to the busy California\/Hawaii flight route, pilot reports of turbulence are plotted on the water vapor images; two reports of light turbulence at altitudes of 33,000-34,000 feet (at 0918<\/strong><\/a> and 1109 UTC<\/strong><\/a>) appeared to be close enough to have possibly been related to the linear feature.<\/p>\n GOES-15 Water Vapor (6.5 \u00b5m) images, with contours of satellite wind derived Upper-Level Divergence [click to enlarge]<\/p><\/div>Satellite atmospheric motion vector (AMV) derived products such as Upper-Level Divergence (above)<\/strong><\/em> calculated at 3-hour intervals (source<\/strong><\/a>) revealed an area of divergence focused near the area of the linear satellite image feature — around 30\u00ba N, 140\u00ba W, at the center of the images — which reached its peak intensity at 12 UTC<\/strong><\/a>; this suggested that the feature may have formed along the axis of the sharp deformation zone between two upper-level lows over the East Pacific Ocean (mid\/upper level winds<\/strong><\/a> | 200 hPa Vorticity product<\/strong><\/a>).<\/p>\n GOES-15 sounder Water Vapor (6.5 \u00b5m, top; 7.0 \u00b5m, middle; 7.5 \u00b5m, bottom) images [click to enlarge]<\/p><\/div>Unfortunately, this region was not within the view of Himawari-8 or GOES-16 (each of which provide 2-km resolution water vapor imagery at 3 atmospheric levels). However, the GOES-15 sounder<\/strong><\/a> instrument has 3 similar water vapor bands (above)<\/strong><\/em> — albeit at a more coarse 10-km spatial resolution at satellite sub-point — which showed the linear “deformation axis cloud signature” at all 3 levels of the atmosphere. The GOES-15 sounder water vapor weighting functions<\/strong><\/a> for a “typical” US Standard Atmosphere are shown below.<\/p>\n<\/a><\/a>