The Solar Ultraviolet Imager (SUVI) on GOES satellites revealed an equatorial coronal hole directed towards Earth on the 11th and 12th of December.  Coronal holes appear as dark areas in the extreme ultraviolet, or the 195 Angstroms band on SUVI. They appear dark because they are cooler and less dense regions... Read More

Target Sector (2.5-minute interval) JMA Himawari-9 AHI Red Visible (0.64 µm) images (above) and Clean Infrared Window (10.4 µm) mages (below) showed Super Typhoon Bolaven as it reached Category 5 intensity west of the Northern Mariana Islands at 0000 UTC (SATCON) on 11 October 2023. Bolaven was an annular tropical cyclone, exhibiting a symmetric eye surrounded by a... Read More

Tropical Storm Bolaven formed southeast of the Mariana Islands at 1200 UTC on 07 October 2023 (about 540 miles southeast of Guam, according to the initial advisory issued by JTWC). With sufficient illumination from the Moon (which was in the Waning Crescent phase, at 41% of Full), a nighttime Suomi-NPP VIIRS... Read More

Target Sector (2.5-minute interval) JMA Himawari-9 AHI Clean Infrared Window (10.4 µm) images (above) showed Typhoon Koinu after it reached Category 4 intensity at 0600 UTC (SATCON) on 04 October 2023. The coldest cloud-top infrared brightness temperatures (-80 to -89C, shades of violet to purple) were generally confined to the southern semicircle of the storm.... Read More