CIMSS Satellite Blog

Himawari-8 Infrared Imagery (6.2 µm, top; 6.9 µm, middle; 7.3 µm, bottom), 1700-1900 UTC on 27 December 2016 [click to enlarge]

Turbulence over the Pacific Ocean affected at least one flight on Tuesday 27 December, near 24º N, 162º E.

PGUA UUA /OV 24N 162E/TM 1745/FL340/TP B777/TB MOD-SEV/RM ZOA

The animation above of the three Himawari-8 Water Vapor Channels (sensing energy emitted at 6.2 µm, 6.9 µm and 7.3 µm) shows a characteristic herringbone structure and a pilot report of turbulence. In contrast to the event earlier this month, also documented on this blog (here), this event was distinct with 8-bit data, and in all three water vapor channels. Satellite data were used in the issuance of the SIGMET, below.

WSPA06 PHFO 271824
SIGPAS

KZAK SIGMET SIERRA 1 VALID 271825/272225 PHFO-
OAKLAND OCEANIC FIR MOD OCNL SEV TURB FCST BTN FL280 AND FL360.
WI N2640 E16810 – N2120 E16810 – N2120 E16240 – N2640 E16250
– N2640 E16810. MOV E 25KT. BASED ON ACFT AND SAT.

The full 11-bit imagery from the 6.2 µm channel on Himawari-8, below, shows multiple ephemeral regions of turbulence. In contrast to the event on 14 December, turbulence in this event perturbed clouds enough that it was apparent in the window channel as well, as shown in this toggle between the 10.3 and 6.2 channels.

Himawari-8 Infrared Imagery (6.2 µm), 1600-1900 UTC on 27 December 2016 [click to animate]

The superior spatial resolution of Himawari-8 (2-km at the sub-satellite point) was vital in detecting the gravity wave features causing the turbulence. Water Vapor imagery from COMS-1, with a nominal resolution of 4 km, does not show features associated with turbulence.

COMS-1 Infrared Imagery (6.75 µm), 1630-1800 UTC on 27 December 2016 [click to animate]

Similarly, Himawaricast data that is broadcast at reduced resolution was insufficient to monitor this event. See the toggle below from 1740 UTC.

Himawari-8 Infrared Imagery (6.2 µm) at 1740 UTC on 27 December 2016, native resolution and as distributed via Himawaricast [click to enlarge]

from CIMSS Satellite Blog http://ift.tt/2ifT2b5