![Himawari-8 Water Vapor images: 6.2 µm (top), 6.9 µm (middle), and 7.3 µm (bottom) - [click to play MP4 animation]](http://cimss.ssec.wisc.edu/goes/blog/wp-content/uploads/2016/03/320x1280_AHIM08_B8910_HIM08_WV_3PANEL_PACIFIC_CYCLONE_1719FEB_2016078_120000_0003PANELS.GIF)
Himawari-8 Water Vapor images: 6.2 µm (top), 6.9 µm (middle), and 7.3 µm (bottom) – [click to play MP4 animation]
The Himawari-8
AHI instrument has 3 water vapor bands, centered at 6.2 µm, 6.9 µm, and 7.3 µm. Images of these 3 water vapor bands
(above; also available as a large 126 Mbyte animated GIF) showed the intensification of a mid-latitude cyclone as it moved east of Japan during the 17-19 March 2016 period. Surface analyses of this storm produced by the
Ocean Prediction Center are shown below.
![West Pacific surface analyses [click to play animation]](http://cimss.ssec.wisc.edu/goes/blog/wp-content/uploads/2016/03/160318_18z_wpac_sfc.gif)
West Pacific surface analyses [click to play animation]
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![Himawari-8 Water Wapor images: 7.3 µm (left), 6.9 µm (center), and 6.2 µm (right) - [click to play MP4 animation]](http://cimss.ssec.wisc.edu/goes/blog/wp-content/uploads/2016/03/960x427_AHIM08_B1098_HIM08_WV_3PANEL_PACIFIC_CYCLONE_1416FEB_2016075_120000_0003PANELS.GIF)
Himawari-8 Water Wapor images: 7.3 µm (left), 6.9 µm (center), and 6.2 µm (right) – [click to play MP4 animation]
Several days earlier (during 14-16 March), another storm just off the coast of Japan rapidly intensified to hurricane force as it moved north-northeastward toward the southern tip of the Kamchatka Peninsula. A comparison of the three Himawari-8 AHI water vapor bands
(above; also available as a large 109 Mbyte animated GIF) depicted varying aspects of the storm evolution. The corresponding Ocean Prediction Center surface analyses are shown below.
![West Pacific surface analyses [click to play animation]West Pacific surface analyses [click to play animation]](http://cimss.ssec.wisc.edu/goes/blog/wp-content/uploads/2016/03/160315_18z_wpac_sfc.gif)
West Pacific surface analyses [click to play animation]
The
GOES-R ABI instrument will have nearly identical water vapor bands; plots of their weighting functions
(below, from this site) show that each of these 3 spectral bands senses radiation from different layers of the atmosphere. This example assumes a typical cold mid-latitude winter temperature/moisture vertical profile, with a satellite view angle (or “zenith angle”) of 45 degrees.

GOES-R ABI water vapor band weighting function plots