2 West Pacific storms, as seen using 3 Himawari-8 water vapor bands

March 19th, 2016 |

Himawari-8 Water Vapor images: 6.2 µm (top), 6.9 µm (middle), and 7.3 µm (bottom) - [click to play MP4 animation]

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]

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]

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]

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

GOES-R ABI water vapor band weighting function plots